A cemented or fixed dental bridge is a way to replace one or more missing teeth to help restore function and/or esthetics. A fixed dental bridge requires at least one tooth on either side of the missing tooth or teeth to provide the attachment and support.
Saturday, October 15, 2011
Bridge (dentistry)
A bridge, also known as a fixed partial denture, is a dental restoration used to replace a missing tooth by joining permanently to adjacent teeth or dental implants.
Types of bridges may vary, depending upon how they are fabricated and the way they anchor to the adjacent teeth. Conventionally, bridges are made using the indirect method of restoration. However, bridges can be fabricated directly in the mouth using such materials as composite resin.
A bridge is fabricated by reducing the teeth on either side of the missing tooth or teeth by a preparation pattern determined by the location of the teeth and by the material from which the bridge is fabricated. In other words, the abutment teeth are reduced in size to accommodate the material to be used to restore the size and shape of the original teeth in a correct alignment and contact with the opposing teeth. The dimensions of the bridge are defined by Ante's Law: "The root surface area of the abutment teeth has to equal or surpass that of the teeth being replaced with pontics".[1]
The materials used for the bridges include gold, porcelain fused to metal, or in the correct situation porcelain alone. The amount and type of reduction done to the abutment teeth varies slightly with the different materials used. The recipient of such a bridge must be careful to clean well under this prosthesis.
When restoring an edentulous space with a fixed partial denture that will crown the teeth adjacent to the space and bridge the gap with a pontic, or "dummy tooth", the restoration is referred to as a bridge. Besides all of the preceding information that concerns single-unit crowns, bridges possess a few additional considerations when it comes to case selection and treatment planning, tooth preparation and restoration fabrication.
When a posterior tooth intended for an abutment tooth already possesses an intracoronal restoration, it might be better to make that bridge abutment into an inlay or an onlay, instead of a crown. However, this may concentrate the torque of the masticatory forces onto a less enveloping restoration, thus making the bridge more prone to failure.
In some situations, a cantilever bridge may be constructed to restore an edentulous area that only has adequate teeth for abutments either mesially or distally. This must also conform to Ante's rule but, because there are only abutments on one side, a modification to the rule must be applied, and these bridges possess double abutments in the majority of cases, and the occlusal surface area of the pontic is generally decreased by making the pontic smaller than the original tooth.
When this is not possible, due to severe tipping of one of more of the abutments, for example, an attachment may be useful, as in the photo at right, so that one of the abutments may be cemented first, and the other abutment, attached to the pontic, can then be inserted, with an arm on the pontic slipping into a groove on the cemented crown to achieve a span across the edentulous area.
As with single-unit crowns, bridges may be fabricated using the lost-wax technique if the restoration is to be either a multiple-unit FGC or PFM. Another fabrication technique is to use CAD/CAM software to machine the bridge.[2] As mentioned above, there are special considerations when preparing for a multiple-unit restoration in that the relationship between the two or more abutments must be maintained in the restoration. That is, there must be proper parallelism for the bridge to seat properly on the margins. Sometimes, the bridge does not seat, but the dentist is unsure whether or not it is only because the spatial relationship of the two or more abutments is incorrect, or whether the abutments do not actually fit the preparations. The only way to determine this is to section the bridge and try in each abutment by itself. If they all fit individually, it must have simply been that the spatial relationship was incorrect, and the abutment that was sectioned from the pontic must now be reattached to the pontic according to the newly confirmed spatial relationship. This is accomplished with a solder index.
The proximal surfaces of the sectioned units (that is, the adjacent surfaces of the metal at the cut) are roughened and the relationship is preserved with a material that will hold on to both sides, such as GC pattern resin. With the two bridge abutments individually seated on their prepared abutment teeth, the resin is applied to the location of the sectioning to reestablish a proper spatial relationship between the two pieces. This can then be sent to the lab where the two pieces will be soldered and returned for another try-in or final cementation.
Types of bridges may vary, depending upon how they are fabricated and the way they anchor to the adjacent teeth. Conventionally, bridges are made using the indirect method of restoration. However, bridges can be fabricated directly in the mouth using such materials as composite resin.
A bridge is fabricated by reducing the teeth on either side of the missing tooth or teeth by a preparation pattern determined by the location of the teeth and by the material from which the bridge is fabricated. In other words, the abutment teeth are reduced in size to accommodate the material to be used to restore the size and shape of the original teeth in a correct alignment and contact with the opposing teeth. The dimensions of the bridge are defined by Ante's Law: "The root surface area of the abutment teeth has to equal or surpass that of the teeth being replaced with pontics".[1]
The materials used for the bridges include gold, porcelain fused to metal, or in the correct situation porcelain alone. The amount and type of reduction done to the abutment teeth varies slightly with the different materials used. The recipient of such a bridge must be careful to clean well under this prosthesis.
When restoring an edentulous space with a fixed partial denture that will crown the teeth adjacent to the space and bridge the gap with a pontic, or "dummy tooth", the restoration is referred to as a bridge. Besides all of the preceding information that concerns single-unit crowns, bridges possess a few additional considerations when it comes to case selection and treatment planning, tooth preparation and restoration fabrication.
Case selection and treatment planning
When a single tooth requires a crown, the prosthetic crown will in most instances rest upon whatever tooth structure was originally supporting the crown of the natural tooth. However, when restoring an edentulous area with a bridge, the bridge is almost always restoring more teeth than there are root structures to support. For instance, in the photo at right, the 5-unit bridge will only be supported on three abutment teeth. To determine whether or not the abutment teeth can support a bridge without failure from lack of support from remaining root structures, the dentist employs Ante's rule—which states that the roots of abutment teeth must have a combined surface area in three dimensions that is more than that of the missing root structures of the teeth replaced with a bridge. When the situation yields a poor prognosis for proper support, double abutments may be required to properly conform to Ante's rule.When a posterior tooth intended for an abutment tooth already possesses an intracoronal restoration, it might be better to make that bridge abutment into an inlay or an onlay, instead of a crown. However, this may concentrate the torque of the masticatory forces onto a less enveloping restoration, thus making the bridge more prone to failure.
In some situations, a cantilever bridge may be constructed to restore an edentulous area that only has adequate teeth for abutments either mesially or distally. This must also conform to Ante's rule but, because there are only abutments on one side, a modification to the rule must be applied, and these bridges possess double abutments in the majority of cases, and the occlusal surface area of the pontic is generally decreased by making the pontic smaller than the original tooth.
Tooth preparation
As with preparations for single-unit crowns, the preparations for multiple-unit bridges must also possess proper taper to facilitate the insertion of the prosthesis onto the teeth. However, there is an added dimension when it comes to bridges, because the bridge must be able to fit onto the abutment teeth simultaneously. Thus, the taper of the abutment teeth must match, to properly seat the bridge. This is known as requiring parallelism among the abutments.When this is not possible, due to severe tipping of one of more of the abutments, for example, an attachment may be useful, as in the photo at right, so that one of the abutments may be cemented first, and the other abutment, attached to the pontic, can then be inserted, with an arm on the pontic slipping into a groove on the cemented crown to achieve a span across the edentulous area.
Restoration fabrication
The proximal surfaces of the sectioned units (that is, the adjacent surfaces of the metal at the cut) are roughened and the relationship is preserved with a material that will hold on to both sides, such as GC pattern resin. With the two bridge abutments individually seated on their prepared abutment teeth, the resin is applied to the location of the sectioning to reestablish a proper spatial relationship between the two pieces. This can then be sent to the lab where the two pieces will be soldered and returned for another try-in or final cementation.
CHAPTER 9 MISCELLANEOUS OPERATIVE DENTISTRY FACTS AND TRIVIA
Forces created by mastication
molars 125 lbs
bicuspids 50 lbs
incisors 25 lbs
Caridex
NaOH, NaCl, Aminobutyric acid (NMAB N-monochloro DL-2 aminobutyrate); must have access to lesion
Pulpal effects of Operative Dentistry
Permeability characteristics of dentin
Exposure of 1mm2 dentin exposes 30,000 dentinal tubules
Thick dentin is less permeable than thin dentin
Elevation of more than 10 degrees causes destructive changes in the pulp
Coronal dentin much more permeable than radicular dentin
In class 2 preps, axial wall dentin is 2x more permeable than is pulpal floor dentin
Two main theories of dental material toxicity
Material toxicity - Stanley
Bacterial inflammation - Brannstrom
Most current literature supports Brannstrom. For example, Cox did a study on monkeys where different restorative materials were placed at the pulp dentin interface, and histology showed that dental materials do not inherently cause pulpal inflammation, but rather microleakage of bacterial infiltrates).
CEJ
60% cementum covers enamel
30% butt joint
10% do not meet
Bibliography
Baratz RS: Journal of Biomaterials Applications 1(3):318-322, Jan 1987.
Baum, Phillips, Lund: Textbook of Operative Dentistry, 1995
Burke FJ, McCaughey AD: The Four Generations of Dentin Bonding. Am J Dent 8:88-92, 1995.
Caughman WF, Rueggeberg FA, Curtis JW: Clinical Guidelines for Photocuring Restorative Resins. JADA 126:1280-1286, Sept. 1995.Craig: Restorative Dental Materials, 1997.
CRA. 1997, 1998, 1999.
Internet
Kunzelmann KH*, A. Mehl, R. Hickel (Dept. of Operative Dentistry and Periodontology, University of Munich, GER) Sliding-wear of an Experimental Ormocer and 15 Commercial Composites.
Leinfelder KF, Osborne JW: Clinical Behaviors of Composite Resins. J of Biomat Appl 1:327-335, Jan 1987.
Leinfelder KF: Posterior Composite Resins: The Materials and Their Clinical Performance. JADA 126:663-676, May 1995.
Reality. Vol 12, 1998.
Schwartz, Summit, Robbins: Fundamentals of Operative Dentistry, 1996.
Sturdevant: Operative Dentistry, 1994.
CHAPTER 8 DIRECT GOLD/GOLD FOILS
Indications for direct gold restorations
Conservative class 1,2,3,5,6 areas
Also incipient lesions, cervical erosions and small carious defects
Good gingival tissue health
Low caries index.
Able to obtain good isolation
Area is not an esthetic concern to the patient
Direct gold filling materials
Gold Foil: sheets, ropes, pellets, platinized
Electrolytic gold: mat, electraloy RV
Powdered gold: precipitated gold in wax matrix
OPER DENT 19: 16-19, 1994. A new direct gold material that is considerably different from other direct golds
has been available since 1989. The advantages of this material are that the final restoration exhibits greater
density than other forms of granular gold and has a 50% increase in shear strength when compared to gold
foil. This new direct filling gold, STOPFGOLD, has had encouraging clinical results.
DIRECT GOLD ANNEALING (DEGASSING) PROCESS
A heating process in which surface contaminants (oxygen, sulfur, moisture, wax) heated to 800-11000 F
are removed to enhance cohesiveness
Methanol or ethanol should be used in the alcohol lamp
CHAPTER 7 ESTHETICS: VENEERS, BLEACHING, & MICROABRASION
Veneer Restoration Types
Feldspathic porcelain
Cast or pressed ceramic
Heat/pressure/light processed composite
Hydrofluoric acid (9%) etching for 4 minutes on internal aspect of veneer is the most important aspect for
Bonding; silanation enhances bond
Maryland bridges
Indications
Young permanent teeth, minimal restorations, short span
Temp to let ridge heal after O.S.; minimal overbite
Contraindications
Insufficient enamel on abutments
Anterior procedures
Clear occlusion
Remove fluoride rich layer
Cingulum rest positive vertical seat
Proximal wrap, 180 degrees, grooves
Posterior procedure
Single path of insertion
Proximal resistance form, parallel proximal planes
Cover as much F and L as possible, 180 degrees
Include L cusp if occlusal permits
Vital Bleaching
Tooth discolorations
intrinsic stains- congenital, systemic, metabolic, pharmacologic, traumatic or iatrogenic
erythroblastosis fetalis, porphyria, jaundice, amelogenesis imperfecta, dentinogenesis imperfecta,
tetracycline, enamel dysplasia (hypoplasia and fluorosis), amalgam pigment, trauma/pulpal injury
extrinsic- superficial enamel
pitting, plaque and calculus, metals, food stains, tobacco, orange stain, green stain
extrinsic stain can be removed with prophy cups and other cleaning devices or with disks
The chemistry of bleaching natural teeth
Unstable peroxides break down into unstable free radicals; free radicals oxidize organic pigmented
molecules which change ring structures to unsaturated chains and further to hydroxy groups; pigments
become lighter with each step of the reaction; end product of complete oxidation produces water
and carbon dioxide
The basic process almost always involves oxidation, at which time the molecules causing the discoloration
are released; consequently, the technique's success depends on the ability of the bleach to permeate
to the source of the discoloration and remain there long enough (or frequently enough) to overcome
the stain
Clinical steps to consider when treatment plan includes re-shaping the natural dentition
Photos and study models
Line drawing
Use fine diamonds (micron), carbide finishing burs and a sequential series of abrasive disks
Evaluate protrusive function.
Apply post-op 2% NaF
Modified McInnes Technique
Effective for mild to moderate fluorosis staining and superficial hypoplasia
Place McInnes solution on tooth for 5 minutes
one part diethyl ether
five parts 36% HCL acid
five parts 30% H2O2 solution
Use a fine cuttle paper disk to remove the surface layer of the enamel (approximately 15 seconds)
Repeat step #2 PRN (3-5X)
Using a cotton applicator, neutralize the teeth with a 5.25% NaOCl solution and wash with water before
rubber dam removal
Polish enamel and use fluoride (2% NaF) treatment
Acid pumice microabrasion
Indications
Superficial hypoplasia and mild to moderate fluorosis stains
Procedure
Pumice teeth and isolate with rubber dam
Use PREMA system or mix a thick paste of 18% HCl and apply to stained teeth with tongue blade
or PREMA cups mounted on gear reduction handpiece supplied with system -apply for 5 seconds
and rinse for 10 seconds
Repeat for up to 15 applications
5 applications results in an average enamel loss of 46 microns
Apply 2% NaF and remove rubber dam
Thermocatalytic technique
Effective for mild to moderate fluorosis and tetracycline-type stains
Acid etch for 5-10 seconds and rinse for 30 seconds
Bleach tooth (teeth) with 35% H2O2; place one thickness of gauze over teeth, and keep teeth wet
throughout the procedure with H2O2 by reapplying every 5 minutes
Heat can be supplied in two different ways depending on the number of teeth being bleached
position light 12 " from patient
no anesthesia- stop if patient is uncomfortable***
keep lips moist with water
flush teeth with warm water and remove rubber dam
repolish teeth and provide F treatment
Home bleaching
Fabricate nightguard (vacu-form type .020", .030", .035 optimal, .060 for bruxers)
If done, the gel will be expressed out the tray from the occlusal force
Debatable whether to include gingival coverage
Place 2-3 drops of 10% carbamide peroxide (or a hydrogen peroxide solution: carbamide peroxide solutions
containing carbopol
Have higher viscosity and are slow oxygen releasing agents-so it releases oxygen over a longer period of
time into the tray area of each tooth to be bleached
Patient wears the trays for 4-20 hours per day for 3-4 weeks
Following bleaching, you must wait 6 weeks for enamel crystal structure to remineralize for an optimal
bond to composite
CHAPTER 6 COMPOSITE RESINS
DEFINITIONS
composite - matrix, filler, coupling agent
BIS-GMA, UDMA, EGDMA, TEGDMA
diacrylate - a salt or ester of acrylic acid
oligomer [Greek oligo: few, little] - a polymer consisting of 2,3, or 4 monomers
polymer [Greek polus: much, many] - poly: many; mers: parts
aliphatic - of or relating to fat
aromatic - presence of one benzene ring
adhesion [Latin adhaerere: ad, to; haerere to stick] - bond
peritubular - around the tubules
intertubular - between the tubules
ceromer – ceramic optimized polymer
ormocer – organic modified ceramic
GLUMA – glutaraldehyde hydroxyethyl methacrylate
EPIC-TMPT – Trimethylol Propane Trimethacrylate
PRIMM – Polymeric Rigid Inorganic Matrix Material
FRC – Fiber Reinforced Composite
pHc – pH control
ART – atraumatic restorative treatment
Alert - Amalgam-like esthetic restorative treatment
PRFC – Polyethylene Reinforced Fiber Composite
HISTORY
silicates – 1871; alumina silica glass and phosphoric acid
disadvantages - high solubility in oral environment, poor biocompatibility, loss of translucency,
surface crazing, decreased mechanical properties
advantage - fluoride release
acrylic resins – 1937; powder: poly (methyl methacrylate) & liquid: methyl methacrylate
disadvantages - unfilled, lacked strength, dimensional instability, high polymerization shrinkage:
5-8% thermal dimensional changes, i.e. microleakage, CTE: 7-8 X of a tooth
advantages - better than silicates, less susceptible to fracture, less solubility in oral fluids, more
color stability
acid etching, first generation DBA - 1956, Buonocore
composite resins - 1962, Ray Bowen
second generation DBA - 1978, Kuraray (Clearfil Bond System)
third generation DBA - 1987, Kuraray (Clearfil New Bond), GLUMA
composite resin luting agents - 1986
fourth generation DBA – 1990 (Scotchbond MP)
fifth generation DBA - 1995 (One-Step)
COMPONENTS | ||
| Matrix | -continuous or matrix phase -organic polymer either an aromatic or urethane diacrylate (a salt or ester of acrylic -acid) oligomer which are viscous and therefore require the addition of a diluent monomer such as triethylene glycol dimethacrylate (TEGDMA) a difunctional monomer of low molecular weight BIS-GMA – bisphenol A glycidyl methacrylate 1 molecule bisphenol A + 2 molecules glycidyl methacrylate = an oligomer viscosity UDMA – urethane dimethacrylate | |
| Filler | -inorganic dispersed phase - quartz, borosilicate glass, lithium aluminum silicate, barium aluminum silicate, strontium glass, zinc glass, colloidal silica -Quartz: ¯ polished surface; wear on opposing enamel -Size Conventional: 8-12um but can be up to 100um -traditional or macrofilled -ground quartz Microfine: .04-.2um -colloidal silica - surface area \only 25 vol% or 38 wt% (manufacturer gives wt%) -to [filler], prepolymerization (pre-cured or heterogenous) process occurs: microfine fillers in polymerized oligomers are prepared and ground into particles 10-20um in diameter and these reinforced fillers are added to the oligomer to inorganic content to 32-50 vol% or 50-60 wt% -better for Class V abrasion/erosion due to ¯ MOE ( elasticity) -only microfillers < 0.1mm can be colloidally dispersed Fine: .5-3um -irregularly shaped glass or quartz -60-70 vol% or 77-88 wt% -try for surface smoothness of microfine and retain or improve the physical and mechanical properties of conventional -simply by virtue of its ¯ particle size (by a factor of 10), and its filler loading, the composite proved to be 2x as wear resistant as conventional hybrid: mostly fine w/ some microfine; generally .1-1um -colloidal silica and ground glass particles -70 vol% or 75-80 wt% and still have workable clinical consistency -surface smoothness and esthetics are competitive w/ microfine -physical and mechanical properties range between conventional and fine and generally superior to microfine -Radiopacity: barium, zinc, boron, zirconium, yttrium added -Improves: translucency, ¯ CTE, ¯ polymerization shrinkage, makes material harder, denser and more wear resistant | |
| Coupling Agent | -Organosilane w/ functional groups: methoxy - hydrolyze and react w/ inorganic filler; unsaturated organic groups - react w/ oligomer during polymerization -Work best w/ silica filler particles -Aids in transferring stress from one strong filler particle to another through the matrix | |
| POLYMERIZATION METHODS | ||
| Auto-cure (self-cure) | Benzoyl peroxide initiator + tertiary amine accelerator ® free radicals ® attack C=C bonds ® polymerization; 60-75% degree of conversion Amine accelerators tend to discolor after 3-5 yrs. | |
| Light-cure | 460 nm light absorbed by camphoroquinone (photoinitiator) and accelerated by aliphatic amine (activator) w/ C=C; 65-80% degree of conversion wear resistant due to < air or oxygen trapped in the auto-cure (oxygen inhibition and voids created) color stability | |
| Dual-cure | Combination of auto-cure and self-cure; 80% degree of conversion | |
LIGHT-CURING REQUIREMENTS
< 2 mm thickness of composite resin ( light to medium shades); » 1 mm for dark shades
Wavelength: 450-490 nm
Intensity of power outage: ³ 280 mw/cm2
Exposure time = 60 sec.
Light curing tip < 6 mm from composite resin
800 mw/cm2 @ 80 sec. ineffective @ 3mm depth
PARTICLE SIZE
Properties are proportional to vol% of phases but it is much easier to both measure and formulate wt%
AS OVERALL FILLER CONTENT , THE PHYSICAL, CHEMICAL AND MECHANICAL PROPERTIES GENERALLY IMPROVE
The largest particle size is used to describe the hybrid
Large filler particles have relatively small amount of particle surface area per unit of filler particle volume
As an equivalent volume of smaller filler particles is used to replace larger ones ® surface area rapidly
The smaller the filler particle size ® smoother surface
As filler surface area ® ¯ fluidity
COMPROMISE: FLUIDITY « SMOOTHNESS
SETTING AND WORKING TIME
For photoinitiated resins, 75% of polymerization occurs during first 10 min. but continues for 24 hrs.
25% of available unsaturated C=C bonds remain unreacted in bulk of restoration
Air-inhibited layer - 75% unreacted C=C surface bonds w/o matrix; 30um
POLYMERIZATION SHRINKAGE
Direct function of the amount of oligomer and diluent
¯ amt. of oligomer and diluent in fine w/ subsequent [filler] ® ¯ shrinkage
Can generate contraction forces as high as 4-7 MPa
Polymerization shrinkage ® stresses as high as 130 kg/cm2 ® microleakage gap
polymer vol% in microfine w/ subsequent ¯ [filler] ® polymerization shrinkage
Auto-cure composites polymerize toward the center of the mass while VLC polymerizes toward the light
Greatest source of postoperative sensitivity: polymerization ® physical properties, but polymerization shrinkage; ¯ filler content ® ¯ viscosity ® diffusion of reactive groups ® cure ® polymerization shrinkage; Best degree of polymerization is » 73-74%
THERMAL PROPERTIES
[polymer] in microfine or ¯ [filler]® CTE
WATER SORPTION
[polymer] of microfine ® water sorption in resin matrix component ®¯ filler-resin bond; if the
stress is > the bond strength, the resulting debond is referred to as hydrolytic breakdown
Does not compensate for polymerization shrinkage
SOLUBILITY
Leaching of inorganic ions ® breakdown of interfacial bonding ® ¯ resistance to wear & abrasion
MECHANICAL PROPERTIES
Brittle: fine > unfilled; microfine < fine
[filler] of fine ® hardness of fine
Microfine may have ¯ vol. fraction, but there are more filler particles per vol. \wear crack can only
propagate a short distance before hitting another filler particle
Microfine particles scatter light ® longer exposure time requirement
Indirect restorations have a degree of polymerization due to higher-energy light sources, vacuum
chambers and heat
Clinical wear acceptability - 50 um/yr.
Flexible restorations (¯ MOE) would be clinically more retentive in facial cervical restorations where flexural stresses produce large Deformations; the opposite would be true for MOD restorations where rigid ( MOE) materials are required
MICROFILL COMPOSITES ARE THE MOST WEAR-RESISTANT FORMULATION – filler particles are much harder than the polymer matrix and thus resist wear very well; if filler particles are closely spaced, then they shelter the intervening matrix; but because of their ¯ filler content, microfills are more susceptible to attrition (loss of material that occurs as a direct contact with opposing tooth surfaces) and more resistant to abrasion (generalized wear across the entire occlusal surface caused by the abrasive action of particles during mastication) due to their smoother surface, decreased interparticle spacing and decreased friction to food particles. Hybrids are just the opposite: more resistant to attrition because they are more heavily filled but because of their larger mean particle size they tend to have significantly higher abrasion wear which is due to the loss of the larger filler particles leading to three body wear and increased stress transfer from the filler particles to the resin matrix resulting in crack formation.
The > the mean particle size, the faster the wear initially
¯ tensile strength compared to compressive strength ® ¯ fracture toughness
BOND STRENGTHS FROM IN VITRO STUDIES (Dental Advisor Sep 1991)
Enamel – 20-22MPa
Bonds w/ smear layer – 4-11MPa
Bonds w/o smear layer – 6-18MPa
Polymerization stresses – 2-7MPa
1MPa = 1MN/m2 = 10kg/cm2 = 150psi
ENAMEL BONDING
etching = conditioning
standard etchant: 35-50% phosphoric acid
15-20 seconds application
rinsing for 15 sec. removes dissolved calcium phosphates
mechanical retention of polymer matrix or bonding agent into the demineralized porous rod ends
¯ bond w/ salivary mucoprotein contamination
retentive mechanical tags 15-50 um
air-inhibited layer of polymerized material bonds to the next layer of the composite chemically
unfilled acrylic monomer
Enamel etching patterns
Type I: predominant dissolution of prism cores
Type II: predominant dissolution of prism peripheries
Type III: no prism structures are evident
DENTIN BONDING
BIGGEST FACTOR AFFECTING BONDING IS THE PRESENCE OF WATER IN THE TUBULES AND THE CONSTANT POTENTIAL FOR HYDROLYSIS
DBA system = acid conditioning + primer + unfilled liquid acrylic monomer
The Dental Advisor, March 1997: Etching opens microspaces in enamel and dentin and increases the
surface area, resulting in a better bond. it also cleans the surface of debris and oily substances. Etched
enamel appears chalky; etched dentin does not. Etched dentin exposes a layer of collagen, allowing the
primer and adhesive components contained in the bonding agent to penetrate and adhere to the dentin.
The primer serves to raise collagen, and the adhesive resin flows in between the collagen and interlocks
with it to form a sandwich or hybrid layer. This layer is also sometimes referred to as the resin-reinforced
layer. Think of etched collagen as cooked spaghetti settled on the bottom of the pot. If you overdrain it, it
sticks together. By rinsing and adding olive oil, the noodles stay fluffing - that is what primer does to the
collage. Non-sticky noodles allow the sauce to flow between them, just like the adhesive resin flows
between the collagen fibers.
DBA’s - bifunctional monomer w/ hydrophilic group for dentinal wetting and hydrophobic group for
bonding to composite
Conditioner - removes the smear layer and demineralizes the dentinal surface exposing a microporous
scaffold of collagen fibrils ® microporosity of intertubular dentin
After conditioning, a moist dentinal surface is essential for optimal bonding to occur as desiccation of
the dentin at this stage will cause a collapse of the unsupported collagen web due to the
demineralization of the inorganic portion of the dentin
Although primer and/or bonding agent may flow into the tubules, the bond strength is derived from the
micro-mechanical bonding to the intertubular dentin; 90% of strengths are due to mechanical
bonding not chemical bonding
Smear layer: 1-5 um; leaving the smear layer only gives a shear bond strength of < 6Mpa
Most potent to least potent conditioners for removing the smear layer: EDTA, phosphoric acid, lactic
acid, polyacrylic acid, citric acid, H2O2 and cavity cleaners
1st and second generation DBA a decade ago were designed to bond to the smear layer. This limited their bond strengths to the cohesive forces holding smear layer particles to each other and the underlying dentin. The next generation of dentin bonding agents avoided the intrinsic weakness of the smear layer by removing it using EDTA or nitric acid. While improving the bond strengths for some materials, bonding was inconsistent.
Currently, a micromechanical interlocking principle is proposed as the prime mechanism of adhesion. The development of bonding systems that not only demineralize the dentin surface to a depth of 5-10 microns, but also infiltrate hydrophilic monomers into that surface to form a resin-dentin hybrid layer provide high quality, uniform bonds that are close to those of acid-etched enamel-resin bonds (20 MPa). Management of the smear layer remains a topic of controversy, but the general consensus is that the smear layer should be modified or completely removed.
Various bonding agents interact with the smear layer in different ways: leaving the smear layer (such as original Scotchbond), modifying the smear layer (such as Prisma Universal Bond 3), removing the smear layer (such as All-Bond 2), or replacing the smear layer (such as Tenure). Sodium hypochlorite dissolves organic material and EDTA is a chelation agent which dissolves inorganic materials.
What is the smear layer?
An amorphous, relatively smooth layer of microcrystalline debris whose featureless surface cannot be
seen with the naked eye bacteria, dentinal debris, mineralized collagen matrix, inorganic tooth
particles, saliva, blood, and other debris
The precise mechanism for formation of the smear layer is not completely understood
Removal ( in order of greatest effect on dentin)
EDTA 10%-15% - solubilizes protein
nitric acid
citric acid
polyacrylic acid
lactic acid
phosphoric acid - degrades collagen
tubulicid - removes smear layer but not plugs
hydrogen peroxide - no effect
Primer: hydrophobic and hydrophilic monomer, i.e. HEMA, 4-META, NTG-GMA, PMDM, BPDM and
PENTA, dissolved in organic solvent such as acetone or ethanol; can also be used for sensitivity
The water is removed during the priming stage by evaporation and replaced by monomer
Effective primers contain monomers that have an affinity for exposed collagen fibrils with its
hydrophilic properties and its hydrophobic properties allow copolymerization with adhesive resins
The adhesive resin’s primary role is the stabilization of the hybrid layer and the formation of resin
extensions into the dentinal tubules called resin tags
The adhesive resin (bonding agent) consists of hydrophobic monomers , i.e. Bis-GMA and UDMA, and
more hydrophilic monomers such as TEGDMA as a viscosity regulator and HEMA as a wetting agent
Because oxygen always inhibits polymerization, an oxygen-inhibitor layer of 15-30um will form on top
of the adhesive resin; this layer allows sufficient double MMA bonds for copolymerization of the
adhesive resin with the restorative resin
Hybrid layer: 1-5um; zone of adhesive system micromechanically interlocking with dentinal collagen
FIRST GENERATION
Objective was to promote chemical adhesion as bifunctional organic monomers w/ specific reactive
groups that reacted w/ either the inorganic calcium-hydroxyapatite and or the organic
collagen component
In 1956, Buonocore reported GPDM (glycerophosphoric acid dimethacrylate) bonds to HCl-
etched dentinal surfaces (2-3MPa); hydrolysis occurred at the link between the phosphate and
monomer ® ¯ bond strength
In 1962, Masuhara utilized tri-n-buty-borane as a co-catalyst to facilitate chemical adhesion to
dentinal collagen; commercially named Palakav
In 1965, Bowen used NPG-GMA [first DBA (Cervident)] to theoretically bond to enamel and dentin by
chelating w/ calcium on the tooth surface and it possessed improved water resistance BIS-GMA, NTG-GMA = unfilled resin
Hydrophobic contraction gap; hydrolyzed quickly; clinically unsuccessful
Products - Adaptic, Enamel Bond Resin, Durafill Bond
SECOND GENERATION
Further advancement of the hydroxyapatite-phosphate concept
In 1974, Anbar and Farley suggested polyphosphonates to overcome hydrolysis
Based on phosphorous esters of methacrylate derivatives
Adhesive mechanism was enhanced surface wetting and ionic interaction of phosphate groups w/
calcium ions
In early 80’s, Bis-GMA was substituted for methacrylate; predominately halophosphorous esters of Bis-GMA
Bond strengths of 5-6 MPa because it was merely bonded to the smear layer
In 1982, Nakabayashi developed the 4-META system: 10% citric acid and 3% ferric chloride
followed by 35% HEMA and a self-curing adhesive resin containing 4-META, MMA and
TBB (an initiator)
Scotchbond, Bondlite, Prisma Universal Bond, Dentin Adhesit, Clearfil, C&B Superbond/ Me-
tabond
Phosphonated esters
Ionic bonds to calcium in smear layer; limited by the strength of the smear layer (2-4 MPa)
Hydrophobic; rapid hydrolysis of the bonds
Products examples; Prisma Universal Bond (Original) , original Scotchbond, Bondlite, Clearfil, etc.
THIRD GENERATION
Removed/ modified smear layer
Bifunctional primer molecule- HEMA, 4-META, PMDM, PMGDM, BPDM, PENTA
Unfilled bonding resin placed after primer (BIS-GMA, or UDMA)
Bond to collagen
Hydrophilic and hydrophobic groups penetrate the collagen and polymerize creating a hybrid layer
Differ from predecessor by the use of a solution, or series of solutions, which were applied to the
dentin to modify it prior to application of the resin
Removal of the smear layer w/ acids or chelating agents ® ¯ availability of Ca++ for interaction
w/ chelating surface-active comonomers (NPG-GMA); utilized hydrophilic and hydrophobic
groups
In 1985, Bowen used 6.8% ferric oxalate (changed to aluminum oxalate because the ferric caused
blackening) as dentin conditioner then an acetone solution of PMDM (pyromellitic acid
dianhydride and 2-hydroxyethyl methacrylate) mixed w/ NTG-GMA (n-tolyl-glycine and
glycidyl methacrylate); the dentinal etching contributed more to the bond and in fact the
oxalate precipitate may have interfered w/ the interaction of adhesive and dentin
All-Bond is a variation: 10% phosphoric acid as dentinal etchant prior to the application of an NTG-
GMA/BPDM/acetone primer
In 1985, Asmussen and Munksgaard developed the Gluma system: EDTA as chelating agent,
then glutaraldehyde + hydroxyethyl methacrylate (HEMA)
Scotchbond 2 system: 2.5% maleic acid and 55% HEMA followed by unfilled Bis-GMA/HEMA/ photoinitiator adhesive resin
Tenure, Mirage Bond, Prisma Universal Bond 3, Scotchbond 2, GLUMA, XR Bond, etc.
FOURTH GENERATION
Now considered adhesive systems vs. bonding agents
Pretreatment of dentin w/ conditioners and/or primers that make the heterogeneous and
hydrophilic dentin substrate more receptive to bonding
Minimal technique sensitivity, similar bond strengths to enamel and dentin, no reduction in bond
strength when applied to a moist surface marginal integrity
Aqueous solutions with acetone or ethanol
Exposed collagen fibers after conditioning , increased permeability an wettability for penetration of the
priming resins, forming a Hybridized denin/ resin interdiffusion zone (Nakabayashi)
With acetone based Primers (Eg. All Bond 2), moist surface preferred, improved bond strengths.
Scotchbond Multi-Purpose: 10% maleic acid (can substitute phosphoric acid) as etchant; HEMA/
polyalkenoic acid copolymer as primer; Bis-GMA/HEMA/photoinitiator as adhesive resin
Gluma 2000, Pertac Universal Bond, All-Bond 2, Imperva Bond, Optibond, Probond
FIFTH GENERATION
One step but with multiple applications + the conditioning
OptiBond Solo - ethanol solvent which has been found to be more forgiving if the dentin is dried
(compared to acetone-containing products [more sensitive to the level of dentin dampness,
which means overdrying of the dentin hampers its performance; but it seeks out moisture in
the dentinal tubules more aggressively and is more volatile making it easier to evaporate once
it carries the monomer into the dentin]); hydrophilic priming/bonding solution lightly filled
(25%) with fluoride-releasing particles of fumed silica and barium glass
DOES NOT BOND TO CHEMICAL-CURE COMPOSITES
Prime & Bond 2.1 - DOES NOT BOND TO CHEMICAL-CURE COMPOSITES
Single Bond, One-Step, Bond 1
MICROFILLS
Resist wear due to abrasion very well
Conventional - Renamel, Durafill VS, Amelogen, Silux Plus
Reinforced - Heliomolar RO, Helio Progress
Renamel is the standard: best combination of handling, colors and commitment from company
Heliomolar RO: excellent wear resistance, stood the test of time, releases fluoride from filler (ytterbium
fluoride)
Others: Crystalline L3, Epic - TMPT, Perfection, Visio-Dispers
HYBRIDS
Contain more than one type of filler particle; typically consist of a glass in the 1-3mm range plus 0.04mm
silica ® best combination of strength and esthetics
XRV Herculite
The standard against which all other hybrids are compared
4yr. posterior study showed 87% success rate
Tetric®Ceram
Light-curing , tooth-colored microhybrid restorative material featuring 'Advanced CompositeTechnology
Ceromer – ceramic optimized polymer
Available in 15 shades; 5 coordinated, finely ground fillers; 3 ceramic fillers provide excellent esthetics
2 sources of fluoride; reduced plaque retention; addition of a rheological modifier
3M™ Z100™ Restorative
Single filler - 100% zirconia/ silica
Unique filler allows more particles per gram of paste, resulting in excellent strength and wear resistance Available in 15 shades in either capsules or syringes
Dental Advisor 5 yr. clinical performance: all-purpose VLC; inorganic filler is zirconia/silica (71% vol., 84.5% wt.) with average particle size of 0.6mm; 2% of posterior restorations needed replacement
Others: Prodigy, Charisma, TPH Spectrum, Amelogen Universal, Brilliant
INDIRECT RESIN SYSTEMS
ADVANTAGES
Better fit; easier to adjust and polish; not as hard or abrasive on opposing teeth; can be repaired in the
mouth
CONCEPT
Concept is an indirect resin restorative system for esthetic inlay and
onlays. Concept is a highly filled microfill composite which is heat and
pressure polymerized extraorally under 85 psi pressure and at
temperatures of 250°F (121°C) for 10 min. The result is a homogeneous
inlay/onlay with superior esthetics and excellent resistance to wear.
Due to its unique heat and pressure polymerization, Concept undergoes
maximum polymerization and eliminates inherent porosity. Concept
will not abrade opposing dentition, is highly radiopaque and releases
fluoride. Concept is available in a variety of dentin and enamel shades
to meet all esthetic demands and is bonded to tooth structure utilizing
the latest generation of recommended luting systems.
ARTGLASS (Heraeus/Kulzer)
Combines the benefits of porcelain and composites, but avoids the downsides:
No fractures caused by brittleness
No wear of opposing dentition
Intraoral occlusal adjustments are easy; intraoral repair or repolish easy if necessary
Fracture toughness, MOE, wear resistance and esthetics comes so close to natural teeth
Highly polished Artglass surfaces color stable and extremely resistant to staining
Ultra-dense surface makes Artglass plaque resistant gives restorations esthetics with longevity
Part of the Artglass System is a new metal bonding process called Kevloc; very high bond strength
achieved with all types of dental alloys
Shock absorbing function of tough elastic Artglass advantage with implant supported restorations
Artglass restorations can be added on to or repaired intraorally with the use of Kulzer’s Charisma
JADA MAY, 1997: since 1995; with or without metal substrate; metal can range from nickel-chromium to gold-based and the polymer is bonded by applying an acrylonitrile copolymer (Kevloc); annual wear rate of 4-5mm; multifunctional monomers and a narrow range of filler particles (barium silicate); photo-cured in a special unit using xenon stroboscopic light: 20 milliseconds high intensity, 80 milliseconds of darkness ® polymerization potential by allowing the already cured resin molecules to relax ® more of the non-reactive C=C are made available for reaction
Reaity, 1998: multifunctional highly crosslinked resin cured under intense strobe light creating an amorphous organic polymer known as a vitroid or organic glass which is combined with silica and the same glass filler present in Charisma to make a polymer glass. Filled 75% wt. with average particle size of 0.7mm.
CRA Report Oct. 98 (one year study): 37% sensitivity; separation from metal substructure frequently occurs; 77mm wear and across entire surface of crown, not just restricted to occlusal contacts; surface degeneration similar to early resin formulations; 30% of crowns debonded from dentin; 70% developed pitting at areas of heavy occlusal contact; start with high gloss finish but most developed matte surface in 2 years; good color match, breakage is minimal, good interproximal contacts, no caries detected, good gingival health. At 2 years, Artglass opposing itself caused substantial wear on both crowns.
THE TARGIS SYSTEM (Ivoclar-Vivadent)
The Targis Indirect Ceromer System is a light and heat cured, esthetic, high strength, wear compatible, excellent fitting, bondable posterior crown & bridge system without metal. Its unique highly filled Ceromer (ceramic optimized polymer) composition provides the esthetics of ceramics with the flexural strength and shade control of a resin. The Targis Ceromer material combined with the fiber reinforced Vectris material is indicated for bridges, crowns, inlays and onlays. Used with Targis Link, a covalent metal bonding agent, and Targis Opaquer, Targis provides an esthetic, wear compatible, high strength material that can be used with metal in crown, bridge, inlays/onlays, partial dentures and implant cases or combination cases.
VECTRIS
A prefabricated, light activated, translucent, tooth colored shapeable material made from fiber reinforced composite (FRC). Vectris is composed of a number of layers of fiber wafers as well as uniaxially positioned fiber bundles. The material is reinforced with the same type of organic polymer matrix contained in Targis (Ceromer). This matrix assures a strong bond and homogeneously distributes the masticatory force exerted on the Targis material throughout the framework and the entire tooth.
The revolutionary FRC (fiber-reinforced composite) has
High flexural strength
Breaking load of Targis and Vectris similar to PFM
Flexural strength of Vectris Pontic approx. 1000 MPa
Polymerized fiber/matrix
Optimum bond of Targis and Vectris material
Modulus of elasticity similar to dentin
Reality, 1998: Filled 78% wt. with 0.7mm particle size and the composition is optimized for both light-curing and heat tempering. Vectris is the fiber-reinforced substructure. Glass fibers are silanated and impregnated into a resin matrix, followed by cutting into specific forms for the different types of restorations. Then, when pressed against a die, the fibers are further driven together to form a very strong network. Vectris is pressed over the die using pressure and vacuum and then cured with light. Targis is light-cured then heat tempered.
CRA Report Oct. 98 (one year study): 16% sensitivity; 28% separation from metal substructure frequently occurs; 106mm wear and across entire surface of crown, not just restricted to occlusal contacts; surface degeneration similar to early resin formulations; 1/60 crowns debonded from dentin using Syntac; 62% developed pitting at areas of heavy occlusal contact; start with matte/high gloss finish but most developed matte surface; good color match, breakage is minimal, good interproximal contacts, no caries detected, good gingival health.
belleGlass HP (Kerr)
belleGlass HP is a heat and pressure processed polymer-ceramic designed for the fabrication of inlays, onlays, veneers, full coverage crowns, reinforced bridges, long term provisionals, lingual splints and other appliances. The polymer-ceramic is processed at high temperature and pressure in a nitrogen gas environment which produces enhanced physical properties as a significantly lower clinical wear rate.
Light cured foundation in 16 Vita shades for strength and shading
Maintains anatomy and surface polish after 5 years
Less than 3 microns per year wear after 5 years
Blend of urethane dimethacrylate and aliphatic dimethacrylate resins; heat/pressure cured by high
temperature initiator @ 135°C and 80 psi Nitrogen pressure
GUARANTEE - 5 years workmanship
JADA May 1997: since 1996; atmospheric pressure (29 psi) ® ¯ vaporization potential of the monomers at elevated temperatures; N2 atmosphere during polymerization process ® wear resistance; annual wear exceeded that of enamel by only 1.3mm
Reality, 1998: Combines 2 different types of materials with 2 different curing systems to produce a polymer-glass restorative. The enamel uses a filler of Pyrex glass combined with a blended resin of aliphatic and urethane dimethacrylates. The Pyrex glass is the same filler used in incisal shades of XRV Herculite. The enamel is 74% wt.; the dentin uses barium glass combined with Bis-GMA and filled 78.7% wt. with average particle size of 0.6mm. The dentin is cured by light to preserve unreacted sites to enhance bonding. The enamel is cured under heat and pressure in nitrogen atmosphere to achieve 98% conversion and to eliminate voids and the oxygen inhibition layer. Therefore, it is supposed to be extremely wear resistant.
CRA Report Oct. 98 (one year study): 37% sensitivity; 7% separation from metal substructure frequently occurs; 62mm wear and across entire surface of crown, not just restricted to occlusal contacts; surface degeneration similar to early resin formulations; no crowns debonded from dentin using Nexus; 54% developed pitting at areas of heavy occlusal contact; start with matte/high gloss finish but most developed matte surface; good color match, breakage is minimal, good interproximal contacts, no caries detected, good gingival health.
COMPARE ARTGLASS, TARGIS, AND BELLEGLASS WITH INDIRECT RESINS, i.e. CONCEPT & BRILLIANT DI, AND CERAMICS, i.e. CELAY VITA, CERINATE, DICOR & MIRAGE
SENSITIVITY: Targis < indirect; Artglass & belleGlass > ceramics
WEAR: Artglass & Targis > indirect; all > ceramics
OCCLUSAL CONTACT PITTING: all > indirect and ceramics
SURFACE SMOOTHNESS COMPARED TO ENAMEL: Targis rougher than indirect; all were smoother than ceramics
COLOR MATCH: all matched surrounding dentition better than indirect; all matched surrounding dentition better
BREAKAGE: Artglass & belleGlass had less than ceramics
FLOWABLE COMPOSITES
Basically resin cements that have had their handling and/or setting mechanisms modified so they can perform different functions; more elastic than the sculptable hybrids
Similar to sealant and resin cements
INDICATIONS
Class V defects
Minimal Class I
Gingival wall of Class II
Blocking out small undercuts
AELITEFLO
Rated #1: excellent polishability, non-slumping consistency, superior strength; flows when you decide
due to its thixotrophic character
TETRIC FLOW
Light-curing, tooth-colored flowable Ceromer™ material suitable for small restorations and the
cementation of composite and ceramic restorations
Tetric® Flow is based on the same chemical formula as Tetric® Ceram™ and is also distinguished for
the revolutionary "Advanced Composite Technology" (1996)
COMPOSITION
Fine particle hybrid composite for restorative and for cementation of ceramic and composite
restorations
Monomer matrix: Bis-GMA, UDMA, TEGDMA (31.5%wt.)
Inorganic filler particles: barium glass, ytterbium fluoride, Ba-Al-fluorosilicate glass, highly dispersed
SiO2 and spheroid mixed oxide (43.8%vol., 68.1%wt.)
Other components: catalysts, stabilizers and pigments (0.4%wt.)
PROPERTIES
Outstanding flow properties, excellent wetting of all areas of the cavity, adapts to cavity walls
'by itself’, miniature cavities completely filled without air bubbles
Reduced sensitivity to ambient light, provides longer working time
High radiopacity, distinguishes caries and restorative material on X-rays, 8 shades available, including translucent, continuous fluoride release from two sources of fluoride
SEALANTS
IDEAL PROPERTIES
Preventive modality
Adequate flow
Excellent delivery system
Fluoride releasing
Radiopaque
Filled: 8-60%
UltraSeal XT® plus™
Composition: filled 60% wt.; fluoride; PrimaDry is 99% ethyl alcohol
Thixotropic - thins when delivered into fissure with Inspiral®, brush tip, doesn't run after placement
Available in Opaque White, Universal (A2), and new Clear shades
The light cure 60% filled resin makes UltraSeal XT plus a stronger, more wear-resistant composite/
sealant; because it is significantly filled, the UltraSeal XT plus has less polymerization shrinkage
The use of PrimaDry to fissures just prior to resin placement virtually eliminates microleakage
Indications
"Rated excellent"5 UltraSeal XT plus is a quality, predictable, easy to use, fissure sealant
UltraSeal XT plus additionally performs as a micro restorative
Fills small, conservative preparations from bottom up with a super-adaptive, flowable material
UltraSeal XT plus offers exciting possibilities when applied through the Inspiral Brush tip
as the first layer of larger posterior bonded composite restorations
Use thin diamond bur or air abrasion device to clean fissures
Shelf life: 24 Months
CONDENSABLE COMPOSITES (PACKABLE)
Differ from traditional anterior/posterior composites in the increased amount of filler loading. This is accomplished with fibers (Alert), porous filler particles (Solitaire) or irregular filler particles (SureFil). The contact among these particles causes the packable behavior. A bulk fill technique may be possible due to the high depth of cure and low polymerization shrinkage.
PROPERTIES
Yield average strength
stiffness, radiopacity
Wear rates are low (3.5mm/yr) and comparable to amalgam
Benefit over traditional composites of ¯ polymerization shrinkage (1% v 2-3%)) resulting from filler
load (>80% wt.) ® viscosity
Depth of cure > 5mm
SOLITAIRE
The Easy Amalgam Alternative
Outstanding Physical Characteristics - Excellent marginal adaptation; "Superior marginal integrity, the
best I’ve ever seen," according to Dr. Ray Bertolotti
Very low wear rates, comparable to natural dentition, due, in part, to a high filler content (90% vol.)
Filler particle is porous to allow penetration by resin matrix to produce a more uniform mass
Non-brittle for tough-elastic behavior under load
Radiopaque for easier diagnostics
Fluoride release
Available in six shades for aesthetic flexibility
Amalgam-like condensability, firm consistency will not slump
No stickiness-use conventional amalgam placement instruments, accessories
Easy establishment of interproximal contact points using metal matrix bands
Shape and hold occlusal anatomy
Simple horizontal layering and curing
Solid Bond - primer and sealant
Dental Advisor clinical tip: use flowable composite to line proximal box
PRIMM – Polymeric Rigid Inorganic Matrix Material
Rather than ground filler, the inorganic phase consists of a scaffold of ceramic fibers; fibers composed
of Al2O3 and SiO2 with a diameter of £ 2mm and the chambers surrounding the fibers are »
25mm; the fibers are silanated and then the spaces infiltrated with Bis-GMA or UDMA; % of
scaffolding material ® ¯ polymerization shrinkage, flexural modulus ( wear resistance);
curing depths of 6mm possibly relates to light-conducting properties of the ceramic fibers
RESIN CEMENTS
Modified composites
Composite resin, adhesive resin and esthetic resin
Can be self-cure, light-cure or dual-cure
VARIOLINK II
Dual-cure luting system for cementing ceramics, Ceromer/FRC and composite restorations
Light-cure only when just the Variolink II Base is used
Based on the Advanced Composite Technology of Tetric Ceram special filler composition
COMPOSITION
Monomer: Bis-GMA, UDMA and TEGDMA (26.3%wt.)
Inorganic filler particles: barium glass, ytterbium trifluoride, Ba-Al-fluorosilicate glass and sphe-
roid mixed oxide (46.7%vol., 73.4%wt.)
Other components: catalysts, stabilizers and pigments (0.3%wt.)
The particle size is 0.04-3.0mm. The mean particle size is 0.7mm.
Variolink II is nearly identical to Tetric Flow; the only difference is ytterbium trifluoride in Vario-
link II and highly dispersed SiO2 in the Tetric Flow; The %wt. difference between the 2 is:
Variolink II Tetric Flow
Monomer 26.3 31.5
Inorganic filler 73.4 68.1
Other 0.3 0.4
A two component, micro-hybrid Ceromer™ dual curing luting system for the adhesive luting of various dental materials, resin Ceromers™ and all-ceramic restorations. Variolink® II is available in five shades with three levels of translucency and two viscosities (thick and thin).
Variolink® II Base can be used without the catalyst and is light-cured to be used with applications that allow adequate light penetration (e.g. veneers).
• # 1 recommended cement for all Targis™, IPS Empress® and Concept® restorations
• Fluoride release • High abrasion resistance• Radiopaque • High translucency
• Veneers, Crowns, Inlay/Onlay, Bridges • Resin lined amalgams • Metal restorations
• 18 month shelf life
C&B Metabond
4-META resin cement analog of Amalgambond
Unlike all the other cements, it does not contain any inorganic glass filler
Instead, its filler is organic (PMMA) with a submicron particle size.
COMPONENTS
Etchant: Phosphoric acid
Dentin activator: 10% citric acid, 3% ferric chloride, polyvinyl alcohol
Base: 4-META
Catalyst: Tri-N-butyl borane oxide
Powder: PMMA
Sliding-wear of an Experimental Ormocer and 15 Commercial Composites.
K.-H. Kunzelmann*, A. Mehl, R. Hickel (Dept. of Operative Dentistry and Periodontology, University of Munich, GER)
The wear rate of an experimental composite with a novel matrix system (interpenetrating network of inorganic and organic polymer = organically modified ceramic = ormocer) was compared with commercial composites. Occlusal contact wear was simulated in a sliding-wear test (Munich Artificial Mouth). The materials were: Estilux Hybrid (EH), Pertac II (PII), Tetric (Te), Tetric Ceram (TeC), Tetric flow (Tef), Z100 (Z), TPH Spectrum (TPH), Degufill Ultra (DU), Degufill mineral (DM), Degufill SC micro hybrid (DS), Charisma (Cha), Solitaire (Sol), Heliomolar RO (HM), Metafill CX (MF), Durafill VS (DF) and ormocer (Orm). Eight specimen of each material were tested in a pin-on-block-design with oscillating sliding of a Degusit antagonist (5 mm diameter) at a vertical load of 50 N. The horizontal excursion of the antagonist was 8 mm. The materials were applied to an aluminum sample holder (7.5 diameter, 2 mm depth) in one layer and polymerized in a Dentacolor XS light curing unit for 180 s. The surface was ground with abrasive paper (P1000) to remove any matrix rich surface layer. The samples were stored in Ringer-solution for 24 h at 37 °C. Wear was quantified by a replica technique (Permadyne Garant / ESPE, New Fuji Rock White / GC) using a 3D-laser scanner (Laser Scan 3D, Willytec). Replica were made after 4,000 6,000, 10,000, 30,000 and 50,000 periods. The mean wear rate (MWR [µm³/cycle]) was obtained by a linear regression analysis in the steady-state of the time-wear-curve (SPSS). ANOVA and Duncans multiple comparison test were used to identify homogeneous subsets (homog. SS) at an alpha level of 0.05.
The microfilled composites had the lowest wear rate. Tetric Flow was not significantly different to Tetric Ceram which has the same matrix system but about 10 wt% more fillers. The experimental ormocer had a low wear rate compared to the hybrid composites with the same filler level. However, it was in the same subset as the other materials of the same company. The filler system has a very high influence on the wear properties. Especially the proportion and size of the largest fillers dominate the wear behavior. The mean particle size does not adequately describe the filler system.
DEFINITIONS
composite - matrix, filler, coupling agent
BIS-GMA, UDMA, EGDMA, TEGDMA
diacrylate - a salt or ester of acrylic acid
oligomer [Greek oligo: few, little] - a polymer consisting of 2,3, or 4 monomers
polymer [Greek polus: much, many] - poly: many; mers: parts
aliphatic - of or relating to fat
aromatic - presence of one benzene ring
adhesion [Latin adhaerere: ad, to; haerere to stick] - bond
peritubular - around the tubules
intertubular - between the tubules
ceromer – ceramic optimized polymer
ormocer – organic modified ceramic
GLUMA – glutaraldehyde hydroxyethyl methacrylate
EPIC-TMPT – Trimethylol Propane Trimethacrylate
PRIMM – Polymeric Rigid Inorganic Matrix Material
FRC – Fiber Reinforced Composite
pHc – pH control
ART – atraumatic restorative treatment
Alert - Amalgam-like esthetic restorative treatment
PRFC – Polyethylene Reinforced Fiber Composite
HISTORY
silicates – 1871; alumina silica glass and phosphoric acid
disadvantages - high solubility in oral environment, poor biocompatibility, loss of translucency,
surface crazing, decreased mechanical properties
advantage - fluoride release
acrylic resins – 1937; powder: poly (methyl methacrylate) & liquid: methyl methacrylate
disadvantages - unfilled, lacked strength, dimensional instability, high polymerization shrinkage:
5-8% thermal dimensional changes, i.e. microleakage, CTE: 7-8 X of a tooth
advantages - better than silicates, less susceptible to fracture, less solubility in oral fluids, more
color stability
acid etching, first generation DBA - 1956, Buonocore
composite resins - 1962, Ray Bowen
second generation DBA - 1978, Kuraray (Clearfil Bond System)
third generation DBA - 1987, Kuraray (Clearfil New Bond), GLUMA
composite resin luting agents - 1986
fourth generation DBA – 1990 (Scotchbond MP)
fifth generation DBA - 1995 (One-Step)
COMPONENTS | ||
| Matrix | -continuous or matrix phase -organic polymer either an aromatic or urethane diacrylate (a salt or ester of acrylic -acid) oligomer which are viscous and therefore require the addition of a diluent monomer such as triethylene glycol dimethacrylate (TEGDMA) a difunctional monomer of low molecular weight BIS-GMA – bisphenol A glycidyl methacrylate 1 molecule bisphenol A + 2 molecules glycidyl methacrylate = an oligomer viscosity UDMA – urethane dimethacrylate | |
| Filler | -inorganic dispersed phase - quartz, borosilicate glass, lithium aluminum silicate, barium aluminum silicate, strontium glass, zinc glass, colloidal silica -Quartz: ¯ polished surface; wear on opposing enamel -Size Conventional: 8-12um but can be up to 100um -traditional or macrofilled -ground quartz Microfine: .04-.2um -colloidal silica - surface area \only 25 vol% or 38 wt% (manufacturer gives wt%) -to [filler], prepolymerization (pre-cured or heterogenous) process occurs: microfine fillers in polymerized oligomers are prepared and ground into particles 10-20um in diameter and these reinforced fillers are added to the oligomer to inorganic content to 32-50 vol% or 50-60 wt% -better for Class V abrasion/erosion due to ¯ MOE ( elasticity) -only microfillers < 0.1mm can be colloidally dispersed Fine: .5-3um -irregularly shaped glass or quartz -60-70 vol% or 77-88 wt% -try for surface smoothness of microfine and retain or improve the physical and mechanical properties of conventional -simply by virtue of its ¯ particle size (by a factor of 10), and its filler loading, the composite proved to be 2x as wear resistant as conventional hybrid: mostly fine w/ some microfine; generally .1-1um -colloidal silica and ground glass particles -70 vol% or 75-80 wt% and still have workable clinical consistency -surface smoothness and esthetics are competitive w/ microfine -physical and mechanical properties range between conventional and fine and generally superior to microfine -Radiopacity: barium, zinc, boron, zirconium, yttrium added -Improves: translucency, ¯ CTE, ¯ polymerization shrinkage, makes material harder, denser and more wear resistant | |
| Coupling Agent | -Organosilane w/ functional groups: methoxy - hydrolyze and react w/ inorganic filler; unsaturated organic groups - react w/ oligomer during polymerization -Work best w/ silica filler particles -Aids in transferring stress from one strong filler particle to another through the matrix | |
| POLYMERIZATION METHODS | ||
| Auto-cure (self-cure) | Benzoyl peroxide initiator + tertiary amine accelerator ® free radicals ® attack C=C bonds ® polymerization; 60-75% degree of conversion Amine accelerators tend to discolor after 3-5 yrs. | |
| Light-cure | 460 nm light absorbed by camphoroquinone (photoinitiator) and accelerated by aliphatic amine (activator) w/ C=C; 65-80% degree of conversion wear resistant due to < air or oxygen trapped in the auto-cure (oxygen inhibition and voids created) color stability | |
| Dual-cure | Combination of auto-cure and self-cure; 80% degree of conversion | |
LIGHT-CURING REQUIREMENTS
< 2 mm thickness of composite resin ( light to medium shades); » 1 mm for dark shades
Wavelength: 450-490 nm
Intensity of power outage: ³ 280 mw/cm2
Exposure time = 60 sec.
Light curing tip < 6 mm from composite resin
800 mw/cm2 @ 80 sec. ineffective @ 3mm depth
PARTICLE SIZE
Properties are proportional to vol% of phases but it is much easier to both measure and formulate wt%
AS OVERALL FILLER CONTENT , THE PHYSICAL, CHEMICAL AND MECHANICAL PROPERTIES GENERALLY IMPROVE
The largest particle size is used to describe the hybrid
Large filler particles have relatively small amount of particle surface area per unit of filler particle volume
As an equivalent volume of smaller filler particles is used to replace larger ones ® surface area rapidly
The smaller the filler particle size ® smoother surface
As filler surface area ® ¯ fluidity
COMPROMISE: FLUIDITY « SMOOTHNESS
SETTING AND WORKING TIME
For photoinitiated resins, 75% of polymerization occurs during first 10 min. but continues for 24 hrs.
25% of available unsaturated C=C bonds remain unreacted in bulk of restoration
Air-inhibited layer - 75% unreacted C=C surface bonds w/o matrix; 30um
POLYMERIZATION SHRINKAGE
Direct function of the amount of oligomer and diluent
¯ amt. of oligomer and diluent in fine w/ subsequent [filler] ® ¯ shrinkage
Can generate contraction forces as high as 4-7 MPa
Polymerization shrinkage ® stresses as high as 130 kg/cm2 ® microleakage gap
polymer vol% in microfine w/ subsequent ¯ [filler] ® polymerization shrinkage
Auto-cure composites polymerize toward the center of the mass while VLC polymerizes toward the light
Greatest source of postoperative sensitivity: polymerization ® physical properties, but polymerization shrinkage; ¯ filler content ® ¯ viscosity ® diffusion of reactive groups ® cure ® polymerization shrinkage; Best degree of polymerization is » 73-74%
THERMAL PROPERTIES
[polymer] in microfine or ¯ [filler]® CTE
WATER SORPTION
[polymer] of microfine ® water sorption in resin matrix component ®¯ filler-resin bond; if the
stress is > the bond strength, the resulting debond is referred to as hydrolytic breakdown
Does not compensate for polymerization shrinkage
SOLUBILITY
Leaching of inorganic ions ® breakdown of interfacial bonding ® ¯ resistance to wear & abrasion
MECHANICAL PROPERTIES
Brittle: fine > unfilled; microfine < fine
[filler] of fine ® hardness of fine
Microfine may have ¯ vol. fraction, but there are more filler particles per vol. \wear crack can only
propagate a short distance before hitting another filler particle
Microfine particles scatter light ® longer exposure time requirement
Indirect restorations have a degree of polymerization due to higher-energy light sources, vacuum
chambers and heat
Clinical wear acceptability - 50 um/yr.
Flexible restorations (¯ MOE) would be clinically more retentive in facial cervical restorations where flexural stresses produce large Deformations; the opposite would be true for MOD restorations where rigid ( MOE) materials are required
MICROFILL COMPOSITES ARE THE MOST WEAR-RESISTANT FORMULATION – filler particles are much harder than the polymer matrix and thus resist wear very well; if filler particles are closely spaced, then they shelter the intervening matrix; but because of their ¯ filler content, microfills are more susceptible to attrition (loss of material that occurs as a direct contact with opposing tooth surfaces) and more resistant to abrasion (generalized wear across the entire occlusal surface caused by the abrasive action of particles during mastication) due to their smoother surface, decreased interparticle spacing and decreased friction to food particles. Hybrids are just the opposite: more resistant to attrition because they are more heavily filled but because of their larger mean particle size they tend to have significantly higher abrasion wear which is due to the loss of the larger filler particles leading to three body wear and increased stress transfer from the filler particles to the resin matrix resulting in crack formation.
The > the mean particle size, the faster the wear initially
¯ tensile strength compared to compressive strength ® ¯ fracture toughness
BOND STRENGTHS FROM IN VITRO STUDIES (Dental Advisor Sep 1991)
Enamel – 20-22MPa
Bonds w/ smear layer – 4-11MPa
Bonds w/o smear layer – 6-18MPa
Polymerization stresses – 2-7MPa
1MPa = 1MN/m2 = 10kg/cm2 = 150psi
ENAMEL BONDING
etching = conditioning
standard etchant: 35-50% phosphoric acid
15-20 seconds application
rinsing for 15 sec. removes dissolved calcium phosphates
mechanical retention of polymer matrix or bonding agent into the demineralized porous rod ends
¯ bond w/ salivary mucoprotein contamination
retentive mechanical tags 15-50 um
air-inhibited layer of polymerized material bonds to the next layer of the composite chemically
unfilled acrylic monomer
Enamel etching patterns
Type I: predominant dissolution of prism cores
Type II: predominant dissolution of prism peripheries
Type III: no prism structures are evident
DENTIN BONDING
BIGGEST FACTOR AFFECTING BONDING IS THE PRESENCE OF WATER IN THE TUBULES AND THE CONSTANT POTENTIAL FOR HYDROLYSIS
DBA system = acid conditioning + primer + unfilled liquid acrylic monomer
The Dental Advisor, March 1997: Etching opens microspaces in enamel and dentin and increases the
surface area, resulting in a better bond. it also cleans the surface of debris and oily substances. Etched
enamel appears chalky; etched dentin does not. Etched dentin exposes a layer of collagen, allowing the
primer and adhesive components contained in the bonding agent to penetrate and adhere to the dentin.
The primer serves to raise collagen, and the adhesive resin flows in between the collagen and interlocks
with it to form a sandwich or hybrid layer. This layer is also sometimes referred to as the resin-reinforced
layer. Think of etched collagen as cooked spaghetti settled on the bottom of the pot. If you overdrain it, it
sticks together. By rinsing and adding olive oil, the noodles stay fluffing - that is what primer does to the
collage. Non-sticky noodles allow the sauce to flow between them, just like the adhesive resin flows
between the collagen fibers.
DBA’s - bifunctional monomer w/ hydrophilic group for dentinal wetting and hydrophobic group for
bonding to composite
Conditioner - removes the smear layer and demineralizes the dentinal surface exposing a microporous
scaffold of collagen fibrils ® microporosity of intertubular dentin
After conditioning, a moist dentinal surface is essential for optimal bonding to occur as desiccation of
the dentin at this stage will cause a collapse of the unsupported collagen web due to the
demineralization of the inorganic portion of the dentin
Although primer and/or bonding agent may flow into the tubules, the bond strength is derived from the
micro-mechanical bonding to the intertubular dentin; 90% of strengths are due to mechanical
bonding not chemical bonding
Smear layer: 1-5 um; leaving the smear layer only gives a shear bond strength of < 6Mpa
Most potent to least potent conditioners for removing the smear layer: EDTA, phosphoric acid, lactic
acid, polyacrylic acid, citric acid, H2O2 and cavity cleaners
1st and second generation DBA a decade ago were designed to bond to the smear layer. This limited their bond strengths to the cohesive forces holding smear layer particles to each other and the underlying dentin. The next generation of dentin bonding agents avoided the intrinsic weakness of the smear layer by removing it using EDTA or nitric acid. While improving the bond strengths for some materials, bonding was inconsistent.
Currently, a micromechanical interlocking principle is proposed as the prime mechanism of adhesion. The development of bonding systems that not only demineralize the dentin surface to a depth of 5-10 microns, but also infiltrate hydrophilic monomers into that surface to form a resin-dentin hybrid layer provide high quality, uniform bonds that are close to those of acid-etched enamel-resin bonds (20 MPa). Management of the smear layer remains a topic of controversy, but the general consensus is that the smear layer should be modified or completely removed.
Various bonding agents interact with the smear layer in different ways: leaving the smear layer (such as original Scotchbond), modifying the smear layer (such as Prisma Universal Bond 3), removing the smear layer (such as All-Bond 2), or replacing the smear layer (such as Tenure). Sodium hypochlorite dissolves organic material and EDTA is a chelation agent which dissolves inorganic materials.
What is the smear layer?
An amorphous, relatively smooth layer of microcrystalline debris whose featureless surface cannot be
seen with the naked eye bacteria, dentinal debris, mineralized collagen matrix, inorganic tooth
particles, saliva, blood, and other debris
The precise mechanism for formation of the smear layer is not completely understood
Removal ( in order of greatest effect on dentin)
EDTA 10%-15% - solubilizes protein
nitric acid
citric acid
polyacrylic acid
lactic acid
phosphoric acid - degrades collagen
tubulicid - removes smear layer but not plugs
hydrogen peroxide - no effect
Primer: hydrophobic and hydrophilic monomer, i.e. HEMA, 4-META, NTG-GMA, PMDM, BPDM and
PENTA, dissolved in organic solvent such as acetone or ethanol; can also be used for sensitivity
The water is removed during the priming stage by evaporation and replaced by monomer
Effective primers contain monomers that have an affinity for exposed collagen fibrils with its
hydrophilic properties and its hydrophobic properties allow copolymerization with adhesive resins
The adhesive resin’s primary role is the stabilization of the hybrid layer and the formation of resin
extensions into the dentinal tubules called resin tags
The adhesive resin (bonding agent) consists of hydrophobic monomers , i.e. Bis-GMA and UDMA, and
more hydrophilic monomers such as TEGDMA as a viscosity regulator and HEMA as a wetting agent
Because oxygen always inhibits polymerization, an oxygen-inhibitor layer of 15-30um will form on top
of the adhesive resin; this layer allows sufficient double MMA bonds for copolymerization of the
adhesive resin with the restorative resin
Hybrid layer: 1-5um; zone of adhesive system micromechanically interlocking with dentinal collagen
FIRST GENERATION
Objective was to promote chemical adhesion as bifunctional organic monomers w/ specific reactive
groups that reacted w/ either the inorganic calcium-hydroxyapatite and or the organic
collagen component
In 1956, Buonocore reported GPDM (glycerophosphoric acid dimethacrylate) bonds to HCl-
etched dentinal surfaces (2-3MPa); hydrolysis occurred at the link between the phosphate and
monomer ® ¯ bond strength
In 1962, Masuhara utilized tri-n-buty-borane as a co-catalyst to facilitate chemical adhesion to
dentinal collagen; commercially named Palakav
In 1965, Bowen used NPG-GMA [first DBA (Cervident)] to theoretically bond to enamel and dentin by
chelating w/ calcium on the tooth surface and it possessed improved water resistance BIS-GMA, NTG-GMA = unfilled resin
Hydrophobic contraction gap; hydrolyzed quickly; clinically unsuccessful
Products - Adaptic, Enamel Bond Resin, Durafill Bond
SECOND GENERATION
Further advancement of the hydroxyapatite-phosphate concept
In 1974, Anbar and Farley suggested polyphosphonates to overcome hydrolysis
Based on phosphorous esters of methacrylate derivatives
Adhesive mechanism was enhanced surface wetting and ionic interaction of phosphate groups w/
calcium ions
In early 80’s, Bis-GMA was substituted for methacrylate; predominately halophosphorous esters of Bis-GMA
Bond strengths of 5-6 MPa because it was merely bonded to the smear layer
In 1982, Nakabayashi developed the 4-META system: 10% citric acid and 3% ferric chloride
followed by 35% HEMA and a self-curing adhesive resin containing 4-META, MMA and
TBB (an initiator)
Scotchbond, Bondlite, Prisma Universal Bond, Dentin Adhesit, Clearfil, C&B Superbond/ Me-
tabond
Phosphonated esters
Ionic bonds to calcium in smear layer; limited by the strength of the smear layer (2-4 MPa)
Hydrophobic; rapid hydrolysis of the bonds
Products examples; Prisma Universal Bond (Original) , original Scotchbond, Bondlite, Clearfil, etc.
THIRD GENERATION
Removed/ modified smear layer
Bifunctional primer molecule- HEMA, 4-META, PMDM, PMGDM, BPDM, PENTA
Unfilled bonding resin placed after primer (BIS-GMA, or UDMA)
Bond to collagen
Hydrophilic and hydrophobic groups penetrate the collagen and polymerize creating a hybrid layer
Differ from predecessor by the use of a solution, or series of solutions, which were applied to the
dentin to modify it prior to application of the resin
Removal of the smear layer w/ acids or chelating agents ® ¯ availability of Ca++ for interaction
w/ chelating surface-active comonomers (NPG-GMA); utilized hydrophilic and hydrophobic
groups
In 1985, Bowen used 6.8% ferric oxalate (changed to aluminum oxalate because the ferric caused
blackening) as dentin conditioner then an acetone solution of PMDM (pyromellitic acid
dianhydride and 2-hydroxyethyl methacrylate) mixed w/ NTG-GMA (n-tolyl-glycine and
glycidyl methacrylate); the dentinal etching contributed more to the bond and in fact the
oxalate precipitate may have interfered w/ the interaction of adhesive and dentin
All-Bond is a variation: 10% phosphoric acid as dentinal etchant prior to the application of an NTG-
GMA/BPDM/acetone primer
In 1985, Asmussen and Munksgaard developed the Gluma system: EDTA as chelating agent,
then glutaraldehyde + hydroxyethyl methacrylate (HEMA)
Scotchbond 2 system: 2.5% maleic acid and 55% HEMA followed by unfilled Bis-GMA/HEMA/ photoinitiator adhesive resin
Tenure, Mirage Bond, Prisma Universal Bond 3, Scotchbond 2, GLUMA, XR Bond, etc.
FOURTH GENERATION
Now considered adhesive systems vs. bonding agents
Pretreatment of dentin w/ conditioners and/or primers that make the heterogeneous and
hydrophilic dentin substrate more receptive to bonding
Minimal technique sensitivity, similar bond strengths to enamel and dentin, no reduction in bond
strength when applied to a moist surface marginal integrity
Aqueous solutions with acetone or ethanol
Exposed collagen fibers after conditioning , increased permeability an wettability for penetration of the
priming resins, forming a Hybridized denin/ resin interdiffusion zone (Nakabayashi)
With acetone based Primers (Eg. All Bond 2), moist surface preferred, improved bond strengths.
Scotchbond Multi-Purpose: 10% maleic acid (can substitute phosphoric acid) as etchant; HEMA/
polyalkenoic acid copolymer as primer; Bis-GMA/HEMA/photoinitiator as adhesive resin
Gluma 2000, Pertac Universal Bond, All-Bond 2, Imperva Bond, Optibond, Probond
FIFTH GENERATION
One step but with multiple applications + the conditioning
OptiBond Solo - ethanol solvent which has been found to be more forgiving if the dentin is dried
(compared to acetone-containing products [more sensitive to the level of dentin dampness,
which means overdrying of the dentin hampers its performance; but it seeks out moisture in
the dentinal tubules more aggressively and is more volatile making it easier to evaporate once
it carries the monomer into the dentin]); hydrophilic priming/bonding solution lightly filled
(25%) with fluoride-releasing particles of fumed silica and barium glass
DOES NOT BOND TO CHEMICAL-CURE COMPOSITES
Prime & Bond 2.1 - DOES NOT BOND TO CHEMICAL-CURE COMPOSITES
Single Bond, One-Step, Bond 1
MICROFILLS
Resist wear due to abrasion very well
Conventional - Renamel, Durafill VS, Amelogen, Silux Plus
Reinforced - Heliomolar RO, Helio Progress
Renamel is the standard: best combination of handling, colors and commitment from company
Heliomolar RO: excellent wear resistance, stood the test of time, releases fluoride from filler (ytterbium
fluoride)
Others: Crystalline L3, Epic - TMPT, Perfection, Visio-Dispers
HYBRIDS
Contain more than one type of filler particle; typically consist of a glass in the 1-3mm range plus 0.04mm
silica ® best combination of strength and esthetics
XRV Herculite
The standard against which all other hybrids are compared
4yr. posterior study showed 87% success rate
Tetric®Ceram
Light-curing , tooth-colored microhybrid restorative material featuring 'Advanced CompositeTechnology
Ceromer – ceramic optimized polymer
Available in 15 shades; 5 coordinated, finely ground fillers; 3 ceramic fillers provide excellent esthetics
2 sources of fluoride; reduced plaque retention; addition of a rheological modifier
3M™ Z100™ Restorative
Single filler - 100% zirconia/ silica
Unique filler allows more particles per gram of paste, resulting in excellent strength and wear resistance Available in 15 shades in either capsules or syringes
Dental Advisor 5 yr. clinical performance: all-purpose VLC; inorganic filler is zirconia/silica (71% vol., 84.5% wt.) with average particle size of 0.6mm; 2% of posterior restorations needed replacement
Others: Prodigy, Charisma, TPH Spectrum, Amelogen Universal, Brilliant
INDIRECT RESIN SYSTEMS
ADVANTAGES
Better fit; easier to adjust and polish; not as hard or abrasive on opposing teeth; can be repaired in the
mouth
CONCEPT
Concept is an indirect resin restorative system for esthetic inlay and
onlays. Concept is a highly filled microfill composite which is heat and
pressure polymerized extraorally under 85 psi pressure and at
temperatures of 250°F (121°C) for 10 min. The result is a homogeneous
inlay/onlay with superior esthetics and excellent resistance to wear.
Due to its unique heat and pressure polymerization, Concept undergoes
maximum polymerization and eliminates inherent porosity. Concept
will not abrade opposing dentition, is highly radiopaque and releases
fluoride. Concept is available in a variety of dentin and enamel shades
to meet all esthetic demands and is bonded to tooth structure utilizing
the latest generation of recommended luting systems.
ARTGLASS (Heraeus/Kulzer)
Combines the benefits of porcelain and composites, but avoids the downsides:
No fractures caused by brittleness
No wear of opposing dentition
Intraoral occlusal adjustments are easy; intraoral repair or repolish easy if necessary
Fracture toughness, MOE, wear resistance and esthetics comes so close to natural teeth
Highly polished Artglass surfaces color stable and extremely resistant to staining
Ultra-dense surface makes Artglass plaque resistant gives restorations esthetics with longevity
Part of the Artglass System is a new metal bonding process called Kevloc; very high bond strength
achieved with all types of dental alloys
Shock absorbing function of tough elastic Artglass advantage with implant supported restorations
Artglass restorations can be added on to or repaired intraorally with the use of Kulzer’s Charisma
JADA MAY, 1997: since 1995; with or without metal substrate; metal can range from nickel-chromium to gold-based and the polymer is bonded by applying an acrylonitrile copolymer (Kevloc); annual wear rate of 4-5mm; multifunctional monomers and a narrow range of filler particles (barium silicate); photo-cured in a special unit using xenon stroboscopic light: 20 milliseconds high intensity, 80 milliseconds of darkness ® polymerization potential by allowing the already cured resin molecules to relax ® more of the non-reactive C=C are made available for reaction
Reaity, 1998: multifunctional highly crosslinked resin cured under intense strobe light creating an amorphous organic polymer known as a vitroid or organic glass which is combined with silica and the same glass filler present in Charisma to make a polymer glass. Filled 75% wt. with average particle size of 0.7mm.
CRA Report Oct. 98 (one year study): 37% sensitivity; separation from metal substructure frequently occurs; 77mm wear and across entire surface of crown, not just restricted to occlusal contacts; surface degeneration similar to early resin formulations; 30% of crowns debonded from dentin; 70% developed pitting at areas of heavy occlusal contact; start with high gloss finish but most developed matte surface in 2 years; good color match, breakage is minimal, good interproximal contacts, no caries detected, good gingival health. At 2 years, Artglass opposing itself caused substantial wear on both crowns.
THE TARGIS SYSTEM (Ivoclar-Vivadent)
The Targis Indirect Ceromer System is a light and heat cured, esthetic, high strength, wear compatible, excellent fitting, bondable posterior crown & bridge system without metal. Its unique highly filled Ceromer (ceramic optimized polymer) composition provides the esthetics of ceramics with the flexural strength and shade control of a resin. The Targis Ceromer material combined with the fiber reinforced Vectris material is indicated for bridges, crowns, inlays and onlays. Used with Targis Link, a covalent metal bonding agent, and Targis Opaquer, Targis provides an esthetic, wear compatible, high strength material that can be used with metal in crown, bridge, inlays/onlays, partial dentures and implant cases or combination cases.
VECTRIS
A prefabricated, light activated, translucent, tooth colored shapeable material made from fiber reinforced composite (FRC). Vectris is composed of a number of layers of fiber wafers as well as uniaxially positioned fiber bundles. The material is reinforced with the same type of organic polymer matrix contained in Targis (Ceromer). This matrix assures a strong bond and homogeneously distributes the masticatory force exerted on the Targis material throughout the framework and the entire tooth.
The revolutionary FRC (fiber-reinforced composite) has
High flexural strength
Breaking load of Targis and Vectris similar to PFM
Flexural strength of Vectris Pontic approx. 1000 MPa
Polymerized fiber/matrix
Optimum bond of Targis and Vectris material
Modulus of elasticity similar to dentin
Reality, 1998: Filled 78% wt. with 0.7mm particle size and the composition is optimized for both light-curing and heat tempering. Vectris is the fiber-reinforced substructure. Glass fibers are silanated and impregnated into a resin matrix, followed by cutting into specific forms for the different types of restorations. Then, when pressed against a die, the fibers are further driven together to form a very strong network. Vectris is pressed over the die using pressure and vacuum and then cured with light. Targis is light-cured then heat tempered.
CRA Report Oct. 98 (one year study): 16% sensitivity; 28% separation from metal substructure frequently occurs; 106mm wear and across entire surface of crown, not just restricted to occlusal contacts; surface degeneration similar to early resin formulations; 1/60 crowns debonded from dentin using Syntac; 62% developed pitting at areas of heavy occlusal contact; start with matte/high gloss finish but most developed matte surface; good color match, breakage is minimal, good interproximal contacts, no caries detected, good gingival health.
belleGlass HP (Kerr)
belleGlass HP is a heat and pressure processed polymer-ceramic designed for the fabrication of inlays, onlays, veneers, full coverage crowns, reinforced bridges, long term provisionals, lingual splints and other appliances. The polymer-ceramic is processed at high temperature and pressure in a nitrogen gas environment which produces enhanced physical properties as a significantly lower clinical wear rate.
Light cured foundation in 16 Vita shades for strength and shading
Maintains anatomy and surface polish after 5 years
Less than 3 microns per year wear after 5 years
Blend of urethane dimethacrylate and aliphatic dimethacrylate resins; heat/pressure cured by high
temperature initiator @ 135°C and 80 psi Nitrogen pressure
GUARANTEE - 5 years workmanship
JADA May 1997: since 1996; atmospheric pressure (29 psi) ® ¯ vaporization potential of the monomers at elevated temperatures; N2 atmosphere during polymerization process ® wear resistance; annual wear exceeded that of enamel by only 1.3mm
Reality, 1998: Combines 2 different types of materials with 2 different curing systems to produce a polymer-glass restorative. The enamel uses a filler of Pyrex glass combined with a blended resin of aliphatic and urethane dimethacrylates. The Pyrex glass is the same filler used in incisal shades of XRV Herculite. The enamel is 74% wt.; the dentin uses barium glass combined with Bis-GMA and filled 78.7% wt. with average particle size of 0.6mm. The dentin is cured by light to preserve unreacted sites to enhance bonding. The enamel is cured under heat and pressure in nitrogen atmosphere to achieve 98% conversion and to eliminate voids and the oxygen inhibition layer. Therefore, it is supposed to be extremely wear resistant.
CRA Report Oct. 98 (one year study): 37% sensitivity; 7% separation from metal substructure frequently occurs; 62mm wear and across entire surface of crown, not just restricted to occlusal contacts; surface degeneration similar to early resin formulations; no crowns debonded from dentin using Nexus; 54% developed pitting at areas of heavy occlusal contact; start with matte/high gloss finish but most developed matte surface; good color match, breakage is minimal, good interproximal contacts, no caries detected, good gingival health.
COMPARE ARTGLASS, TARGIS, AND BELLEGLASS WITH INDIRECT RESINS, i.e. CONCEPT & BRILLIANT DI, AND CERAMICS, i.e. CELAY VITA, CERINATE, DICOR & MIRAGE
SENSITIVITY: Targis < indirect; Artglass & belleGlass > ceramics
WEAR: Artglass & Targis > indirect; all > ceramics
OCCLUSAL CONTACT PITTING: all > indirect and ceramics
SURFACE SMOOTHNESS COMPARED TO ENAMEL: Targis rougher than indirect; all were smoother than ceramics
COLOR MATCH: all matched surrounding dentition better than indirect; all matched surrounding dentition better
BREAKAGE: Artglass & belleGlass had less than ceramics
FLOWABLE COMPOSITES
Basically resin cements that have had their handling and/or setting mechanisms modified so they can perform different functions; more elastic than the sculptable hybrids
Similar to sealant and resin cements
INDICATIONS
Class V defects
Minimal Class I
Gingival wall of Class II
Blocking out small undercuts
AELITEFLO
Rated #1: excellent polishability, non-slumping consistency, superior strength; flows when you decide
due to its thixotrophic character
TETRIC FLOW
Light-curing, tooth-colored flowable Ceromer™ material suitable for small restorations and the
cementation of composite and ceramic restorations
Tetric® Flow is based on the same chemical formula as Tetric® Ceram™ and is also distinguished for
the revolutionary "Advanced Composite Technology" (1996)
COMPOSITION
Fine particle hybrid composite for restorative and for cementation of ceramic and composite
restorations
Monomer matrix: Bis-GMA, UDMA, TEGDMA (31.5%wt.)
Inorganic filler particles: barium glass, ytterbium fluoride, Ba-Al-fluorosilicate glass, highly dispersed
SiO2 and spheroid mixed oxide (43.8%vol., 68.1%wt.)
Other components: catalysts, stabilizers and pigments (0.4%wt.)
PROPERTIES
Outstanding flow properties, excellent wetting of all areas of the cavity, adapts to cavity walls
'by itself’, miniature cavities completely filled without air bubbles
Reduced sensitivity to ambient light, provides longer working time
High radiopacity, distinguishes caries and restorative material on X-rays, 8 shades available, including translucent, continuous fluoride release from two sources of fluoride
SEALANTS
IDEAL PROPERTIES
Preventive modality
Adequate flow
Excellent delivery system
Fluoride releasing
Radiopaque
Filled: 8-60%
UltraSeal XT® plus™
Composition: filled 60% wt.; fluoride; PrimaDry is 99% ethyl alcohol
Thixotropic - thins when delivered into fissure with Inspiral®, brush tip, doesn't run after placement
Available in Opaque White, Universal (A2), and new Clear shades
The light cure 60% filled resin makes UltraSeal XT plus a stronger, more wear-resistant composite/
sealant; because it is significantly filled, the UltraSeal XT plus has less polymerization shrinkage
The use of PrimaDry to fissures just prior to resin placement virtually eliminates microleakage
Indications
"Rated excellent"5 UltraSeal XT plus is a quality, predictable, easy to use, fissure sealant
UltraSeal XT plus additionally performs as a micro restorative
Fills small, conservative preparations from bottom up with a super-adaptive, flowable material
UltraSeal XT plus offers exciting possibilities when applied through the Inspiral Brush tip
as the first layer of larger posterior bonded composite restorations
Use thin diamond bur or air abrasion device to clean fissures
Shelf life: 24 Months
CONDENSABLE COMPOSITES (PACKABLE)
Differ from traditional anterior/posterior composites in the increased amount of filler loading. This is accomplished with fibers (Alert), porous filler particles (Solitaire) or irregular filler particles (SureFil). The contact among these particles causes the packable behavior. A bulk fill technique may be possible due to the high depth of cure and low polymerization shrinkage.
PROPERTIES
Yield average strength
stiffness, radiopacity
Wear rates are low (3.5mm/yr) and comparable to amalgam
Benefit over traditional composites of ¯ polymerization shrinkage (1% v 2-3%)) resulting from filler
load (>80% wt.) ® viscosity
Depth of cure > 5mm
SOLITAIRE
The Easy Amalgam Alternative
Outstanding Physical Characteristics - Excellent marginal adaptation; "Superior marginal integrity, the
best I’ve ever seen," according to Dr. Ray Bertolotti
Very low wear rates, comparable to natural dentition, due, in part, to a high filler content (90% vol.)
Filler particle is porous to allow penetration by resin matrix to produce a more uniform mass
Non-brittle for tough-elastic behavior under load
Radiopaque for easier diagnostics
Fluoride release
Available in six shades for aesthetic flexibility
Amalgam-like condensability, firm consistency will not slump
No stickiness-use conventional amalgam placement instruments, accessories
Easy establishment of interproximal contact points using metal matrix bands
Shape and hold occlusal anatomy
Simple horizontal layering and curing
Solid Bond - primer and sealant
Dental Advisor clinical tip: use flowable composite to line proximal box
PRIMM – Polymeric Rigid Inorganic Matrix Material
Rather than ground filler, the inorganic phase consists of a scaffold of ceramic fibers; fibers composed
of Al2O3 and SiO2 with a diameter of £ 2mm and the chambers surrounding the fibers are »
25mm; the fibers are silanated and then the spaces infiltrated with Bis-GMA or UDMA; % of
scaffolding material ® ¯ polymerization shrinkage, flexural modulus ( wear resistance);
curing depths of 6mm possibly relates to light-conducting properties of the ceramic fibers
RESIN CEMENTS
Modified composites
Composite resin, adhesive resin and esthetic resin
Can be self-cure, light-cure or dual-cure
VARIOLINK II
Dual-cure luting system for cementing ceramics, Ceromer/FRC and composite restorations
Light-cure only when just the Variolink II Base is used
Based on the Advanced Composite Technology of Tetric Ceram special filler composition
COMPOSITION
Monomer: Bis-GMA, UDMA and TEGDMA (26.3%wt.)
Inorganic filler particles: barium glass, ytterbium trifluoride, Ba-Al-fluorosilicate glass and sphe-
roid mixed oxide (46.7%vol., 73.4%wt.)
Other components: catalysts, stabilizers and pigments (0.3%wt.)
The particle size is 0.04-3.0mm. The mean particle size is 0.7mm.
Variolink II is nearly identical to Tetric Flow; the only difference is ytterbium trifluoride in Vario-
link II and highly dispersed SiO2 in the Tetric Flow; The %wt. difference between the 2 is:
Variolink II Tetric Flow
Monomer 26.3 31.5
Inorganic filler 73.4 68.1
Other 0.3 0.4
A two component, micro-hybrid Ceromer™ dual curing luting system for the adhesive luting of various dental materials, resin Ceromers™ and all-ceramic restorations. Variolink® II is available in five shades with three levels of translucency and two viscosities (thick and thin).
Variolink® II Base can be used without the catalyst and is light-cured to be used with applications that allow adequate light penetration (e.g. veneers).
• # 1 recommended cement for all Targis™, IPS Empress® and Concept® restorations
• Fluoride release • High abrasion resistance• Radiopaque • High translucency
• Veneers, Crowns, Inlay/Onlay, Bridges • Resin lined amalgams • Metal restorations
• 18 month shelf life
C&B Metabond
4-META resin cement analog of Amalgambond
Unlike all the other cements, it does not contain any inorganic glass filler
Instead, its filler is organic (PMMA) with a submicron particle size.
COMPONENTS
Etchant: Phosphoric acid
Dentin activator: 10% citric acid, 3% ferric chloride, polyvinyl alcohol
Base: 4-META
Catalyst: Tri-N-butyl borane oxide
Powder: PMMA
Sliding-wear of an Experimental Ormocer and 15 Commercial Composites.
K.-H. Kunzelmann*, A. Mehl, R. Hickel (Dept. of Operative Dentistry and Periodontology, University of Munich, GER)
The wear rate of an experimental composite with a novel matrix system (interpenetrating network of inorganic and organic polymer = organically modified ceramic = ormocer) was compared with commercial composites. Occlusal contact wear was simulated in a sliding-wear test (Munich Artificial Mouth). The materials were: Estilux Hybrid (EH), Pertac II (PII), Tetric (Te), Tetric Ceram (TeC), Tetric flow (Tef), Z100 (Z), TPH Spectrum (TPH), Degufill Ultra (DU), Degufill mineral (DM), Degufill SC micro hybrid (DS), Charisma (Cha), Solitaire (Sol), Heliomolar RO (HM), Metafill CX (MF), Durafill VS (DF) and ormocer (Orm). Eight specimen of each material were tested in a pin-on-block-design with oscillating sliding of a Degusit antagonist (5 mm diameter) at a vertical load of 50 N. The horizontal excursion of the antagonist was 8 mm. The materials were applied to an aluminum sample holder (7.5 diameter, 2 mm depth) in one layer and polymerized in a Dentacolor XS light curing unit for 180 s. The surface was ground with abrasive paper (P1000) to remove any matrix rich surface layer. The samples were stored in Ringer-solution for 24 h at 37 °C. Wear was quantified by a replica technique (Permadyne Garant / ESPE, New Fuji Rock White / GC) using a 3D-laser scanner (Laser Scan 3D, Willytec). Replica were made after 4,000 6,000, 10,000, 30,000 and 50,000 periods. The mean wear rate (MWR [µm³/cycle]) was obtained by a linear regression analysis in the steady-state of the time-wear-curve (SPSS). ANOVA and Duncans multiple comparison test were used to identify homogeneous subsets (homog. SS) at an alpha level of 0.05.
The microfilled composites had the lowest wear rate. Tetric Flow was not significantly different to Tetric Ceram which has the same matrix system but about 10 wt% more fillers. The experimental ormocer had a low wear rate compared to the hybrid composites with the same filler level. However, it was in the same subset as the other materials of the same company. The filler system has a very high influence on the wear properties. Especially the proportion and size of the largest fillers dominate the wear behavior. The mean particle size does not adequately describe the filler system.
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