![ PHYSICAL PROPERTIES
WORKING & SETTING TIME
Light cure: surface hardens in 60-90 sec
Chemical cure: 3-5 min
Polymerization shrinkage –
Microfill composite – 2 to 3%
Packable composite – 0.6 to 0.9%
Macrofilled composite – 1.2 to 1.3%
Small particle filled composite – 2 to 3%
Thermal properties –
The thermal conductivity of composites with fine particles (25 to 30 ×10-4
cal/sec/cm2[0C/cm]) is greater than that of composites with microfine
particles (12 to 15 ×10-4 cal/sec/cm2[0C/cm]).](https://image.slidesharecdn.com/renjithcompositeppt-191115052137/85/Renjith-composite-ppt-58-320.jpg)
Renjith composite ppt..
- 1. DR.RENJITH RAJ C V
- 2. Introduction History Definition Indication and contraindication Advantages and disadvantages Classification Composition Mode of supply Polymerization of composite Properties of composite journal review Conclusion
- 3. The search of beauty can be traced to earliest civilization. Dental art has long been a part of the quest to enhance the esthetics of teeth and mouth. The constant desire of dental profession to achieve a natural appearance has led to development of various tooth colored materials, one among them being dental composites
- 4. In the past, teeth were most commonly repaired with amalgam (silver) fillings or gold restorations. Teeth can be restored with a more aesthetic and natural appearance Tooth colored restorative materials have increasingly been used to replace missing tooth structure and to modify tooth color and contour, thus enhancing facial esthetics. The simplest form of 'white filling' is technically called a Composite.
- 5. 1855-vulcanite/ebonite 1868-John Wesley Hyatt- “celluloid” 1878-Thomas Fletcher – Silicate cement 1937-Dr Walter Wright-methyl methacrylate resin (acrylic resins) 1955 Michael Buonocore 1962 Dr Rafael Bowen – BisGMA 1972- Light Curing 1976 - Microfilled Composites
- 6. 1981 Hybrid composites 1991 – Beta quartz inserts 1995 – Compomer was introduced to improve the handling and fluoride release. 1996 – Flowable composite; ceromer 1997 – Packable composite 1998 – Ormocers; ion-releasing composites; fiber –reinforced composites 1999 – Single crystal-modified composites 2000-nanofill composites
- 7. By Anusavice Composite – in material science, a solid formed from two or more distinct phases that have been combined to produce properties superior to or intermediate to those of the individual constituents. Dental composite is defined as a highly cross-linked polymeric material reinforced by a dispersion of amorphous silica, glass, crystalline, or organic resin filler particles and/or short fibers bonded to the matrix by a coupling agent .
- 8. Class III, IV, V, VI Core buildups Esthetic enhancement procedures Luting Cements Temporary restorations Periodontal splinting Non-carious lesions Enamel hypoplasia Repair of old composite /ceramic restorations Patients allergic to metals
- 9. Isolation Occlusion Subgingival area/root surface Poor oral hygiene High caries index Habits (bruxism) Limited Operator abilities
- 10. Esthetics Conservation of tooth structure Less complex when preparing the tooth Insulation to pulp Used almost universally Bonded to tooth structure Repairable No corrosion
- 11. Polymerization shrinkage Technique sensitive Higher coefficient of thermal expansion time consuming Increased occlusal wear Low modulus of elasticity Staining Costly
- 12. 1. Skinner’s classification (10th edition) (mean particle size of major filler) Traditional composites (Macrofilled) 8-12m Small particle filled composite – 1-5m Microfilled composite – 0.04 – 0.4 m Hybrid composite – 0.6 – 1 m
- 13. Based on range of filler particle size Megafill-β quartz , large size Macrofill – 10-100 m Midifill – 1-10 m Minifill – 0.1-1 m Microfill – 0.01-0.1 m Nanofill – 0.005-0.01 m
- 14. Based on method of curing Chemical curing Light curing UV light Visible light Dual cure
- 15. Based on consistency Light body – Flowable composite Medium body – Homogeneous microfills, macrofills and midifills Heavy body – Packable hybrid minifills
- 17. PRINCIPAL MONOMERS ◦ BIS-GMA-aromatic-1962-”BOWEN’S RESIN” ◦ Modified BIS-GMA ◦ UDMA(urethane dimethacrylate)- 1974 (Foster and Walker) DILUENT MONOMERS ◦ TEGDMA(Triethylene glycol dimethacrylate)-aliphatic ◦ UDMA NEW MONOMERS
- 18. Bis-GMA structure – The bis-phenol A nucleus: Terminal methacrylate groups – Hydroxyl groups –
- 19. To overcome the high viscosity of Bis-GMA; diluent was added Diluent is any fluid methacrylate – TEGDMA Ratio of Bis-GMA to TEGDMA – 3:1 Functions of the diluent – Reduce the viscosity Results in higher filler loading. Results in higher degree of conversion. Increase the number of cross-linking reactions.
- 20. Benefits Reinforcement of matrix resin resulting in increased hardness, strength and decreased wear. Reduction in polymerization shrinkage. Reduction in thermal contraction and expansion. Improved workability by increasing the viscosity. Reduction in water sorption. Increased radiopacity and diagnostic sensitivity through the incorporation of strontium (Sr) and barium (Ba) glass and other heavy metal compounds that absorb X-rays. Contribute to esthetics.
- 21. Materials used for fillers:- Type of glass Quartz, silica, barium glass
- 22. Filler loading Between 30 and 70 volume% or 50 to 85 wt% of a composite. Filler surface area 50-400 m2/gm
- 23. Essential for bonding of fillers to the resin matrix. Functions:- Bind filler particles to resin. Allow more flexible polymer matrix to transfer stresses to the higher modulus (more stiffer & stronger) filler particles Impart improved physical & mechanical properties Inhibit leaching by preventing water from penetrating along the resin- filler interface. Types :- Organosilanes – γ-methacryloxypropyl trimethoxysilane (MPS).(most commonly used) Titanates. Zirconates
- 24. Chemically activated supplied as two pastes Benzoyl peroxide initiator (universal paste) Aromatic tertiary amine activator (N,N, dimethyl-p-toluidine)(catalyst paste) p-toluidine sulfinic acid Light activated supplied as single paste contained in a light proof syringe. Camphorquinone -0.2%-1%( photosensitizer)-Absorbs blue light with wavelength between 400 and 500 nm Organic aliphatic amine –dimetylaminoethyl methacrylate (DMAEMA)-0.15%, ethyl-4-dimethylaminobenzoate (EDMAB), or N,N-cyanoethyl- methylaniline (CEMA)
- 25. “Butylated hydroxytoluine” (BHT), which is used in concentration of 0.01 wt%. inhibitors have two functions – They extend the storage life time for all resins They ensure sufficient working time Optical modifiers To match the appearance of teeth commonly titanium dioxide and aluminum oxides are added as opacifiers in minute amounts – 0.001 to 0.007 wt%.
- 26. Chemical activation Light curing (external energy – light) Both ( dual curing)
- 27. Also called cold curing or self curing. Initiated by mixing two pastes just before use. Advantages – ◦ Even polymerization throughout the restoration to maximum 75% Disadvantages – Impossible to avoid incorporation of air into the mix forms pores and weakens the structure. Oxygen inhibition of polymerization during curing No control over the working time Both insertion and contouring must be completed quickly once the resin components are mixed and placed into the cavity Often discolors after 3-5 yrs of intraoral service.
- 28. Developed to overcome the problems of chemical activation. Light curable composites are supplied as a single paste system. Camphorquinone (CQ) is photosensitizer - absorbs blue light with wavelengths between 400 and 500nm Amine activator is Dimethylaminoethylmathacrylate (DMAEMA) in case of visible light and Benzoylmethylether in case of UV light polymerization
- 29. Advantages – Easy to use, single paste system Less porosity Color stability Command polymerization Allow operator to complete insertion and contouring before curing is initiated They are not as sensitive to oxygen inhibition as the chemical cured systems Better mechanical properties Setting time – faster cure; an exposure of 40 seconds or less is required to light cure a 2mm thick layer.
- 30. Disadvantages – They must be applied incrementally when the bulk exceeds approx. 2 – 3mm Limited depth of light penetration Time consuming Relatively poor accessibility in certain posterior and interproximal locations Variable exposure times because of shade differences, resulting in longer exposure times for darker shades and/or increased opacity Sensitivity to room illumination – leads to formation of a skin or crust when an opened tube is exposed too long to room light. light curing unit is expensive Shrinkage towards light source Ocular damage – can cause retinal damage if one looks directly at the beam.
- 31. Chemical Light cure Polymerization is central Peripheral Curing is one phase Is in increments Sets within 45 seconds Sets only after light activation No control over working time Working time under control Shrinkage towards centre of bulk Shrinkage towards light source Air may get incorporated Less chance of air entrapment More wastage of material Less wastage Not properly finished Better finish
- 32. Consists of two light curable pastes, one containing benzoyl peroxide and the other paste containing the aromatic tertiary amine. When these two pastes are mixed and then exposed to light, light curing is promoted by the amine/CQ combination and the chemical curing is promoted by the amine/BP interaction
- 33. INDICATIONS Any situation that doesn’t allow sufficient light penetration to produce adequate monomer conversion. DISADVANTAGES Air inhibition and porosity.
- 34. Table-top devices Hand-held/gun type devices Fiber-optic handpiece attachment
- 35. Quartz-Tungsten halogen light units (QTH) Plasma-arc (PAC) light unit Argon laser Light-emitting diode (LED)
- 36. Quartz-tungsten halogen lamps:- Have a quartz bulb with a tungsten filament that irradiates both UV and white light that must be filtered to remove heat and all wavelengths except those in the violet-blue range (~400 to 500 nm) Typically, the intensity ranges from 400 to 800 Mw/ cm2 Wavelength varies among the units from 450 to 490nm A typical resin composite requires an energy density of 16J/cm2 (400 mW/cm2 X 40 seconds =16,000mWs/ cm2) for polymerization.
- 37. Advantages of the QTH:- ◦ Cost is less than the other light systems ◦ They generate little or no heat ◦ They are time proven Disadvantages of the QTH They have a slower cure time (about 15 sec) than PAC lights (about 3 sec) or some LED lights (a range of 10 to 20 sec) Most devices must be plugged into the house electricity The units are relatively large and cumbersome The bulbs decrease in output over a period of time
- 38. Contain two tungsten electrodes seperated by a small gap in which a large voltage potential is generated. This ionize a gas (Xenon gas) to produce a conductive gas(plasma) The PAC light produces a high intensity limited spectrum light that is filtered to blue light in the range of 460 – 490 nm Able to cure composites with photo- initiators other than Camphorquinone. Typically an exposure of 10 seconds from a PAC light is equivalent to 40 seconds from a QTH light. Use of 2 mm increments is still required.
- 39. Advantages - Shorter polymerization time (6-10 seconds) Shorter curing times makes overall procedures shorter and more integrated Disadvantages – increased heat production . Expensive. Most of the devices are large, heavy and bulky. Rapid polymerization can increase the polymerizatin shrinkage.
- 40. Argon laser emit a monochromatic coherent light in wavelength (488nm) that cover the blue light region of the visible light spectrum. Does not employ filters. Five seconds argon laser exposure results in a resin composite cure at 2mm depth laser curing light
- 41. Advantages Increased degree of polymerization compared to standard QTH units. Greater depth of cure. Polymerization is uniform even if light guide is at a distance from the material. Disadvantages Adjacent restorations may be affected by lasers. Rise in temperature may damage the pulp. Rapid polymerization can increase polymerization shrinkage.
- 42. Solid state LEDs use junctions of doped semiconductors based on gallium nitride to emit blue light. Spectral output of blue LEDs falls between 450 and 490 nm, which is in the absorbance range of camphoroquinone.
- 43. Generations of LED’S – First generation - relatively low-powered chips offering a comparative low output and poor curing performance compared with conventional QTH lights Second generation - have a single high-powered diode with multiple emission areas E.g. Elipar Freelight 2 Third generation - they have two or more diode frequencies and emit light in different ranges to activate CQ and alternative photo-initiators. E.g. – UltraLume 5 Elipar Freelight 2 Jetlite 5000
- 44. Advantages - Consistent output, with no bulbs to change No need for filter systems Low power consumption (battery-operation is possible) Long service life of LEDs(10,000 hrs) Quiet Cordless, light weight Disadvantages - Due to the narrow emission spectrum LEDs can only polymerize materials with an absorption maximum between 430 and 480 nm (camphorquinone as photoinitiator) Slower than PAC Batteries must be recharged Cost more than halogen lamps
- 45. 1.Uniform continuous – 2.Soft start technique – ◦ Stepped curing ◦ Ramped curing ◦ Delayed curing
- 46. 4 types Conventional /traditional composite Small particle filled composite Microfilled composite Hybrid composite
- 47. Developed during the 1970s filler used - finely ground amorphous silica and quartz. The average particle size is 8 - 12µm, Filler loading generally is 70 – 80 wt% or 60 – 70 vol% Indication – used in class II and class IV
- 48. Clinical considerations Produce rough surface Restorations tend towards discolouration. Poor resistance to occlusal wear Can be used for stress bearing class 4 cavities. Advantages Disadvantages Compressive, tensile strength Stiffness Hardness Polymerization shrinkage Water sorption, thermal expansion Polishability Surface roughness Staining, plaque Occlusal wear Poor esthetics
- 49. Introduced to overcome the disadvantages of traditional composite Inorganic fillers are ground to a size range of approximately 0.5 to 3µm, but with a fairly broad size range distribution Contain more inorganic filler (80 wt% to 90 wt% and 65 to 77 vol%) than traditional composites Use amorphous silica as filler, but most incorporate glasses that contain heavy metals for radiopacity. Colloidal silica added in amounts of approximately 5 wt% to adjust the viscosity of paste. Silane-coated silica or glass (1-5 u) Polymer matrix
- 50. Clinical application – Indicated for application in which large stresses and abrasion might be encountered Attain a reasonably smooth surface for anterior application but not as good as hybrid or microfilled composites. Advantages Disadvantages Good mechanical properties Good smoothness Less polymerization Shrinkage Radiopacity Prone to wear and deterioration.
- 51. Introduced in late1970s Individual particles are approximately 0.04 µm (40nm) in size - Colloidal silica particles Inorganic filler content - 35 to 60% by wt. The greater surface area per unit volume of these microfine particles, the microfill composites cannot be heavily filled Approaches to increase the filler loading Sintering the colloidal silica Organic filler –prepolymerized particles. Final inorganic filler - 50 wt%; if composite particles counted as filler particles, the filler content is closer to 80 wt% (approx 60 vol %) Ground polymer with colloidal silica (50 u) Polymer matrix with colloidal silica
- 52. Clinical consideration – In stress-bearing situation, the potential for fracture is greater Diamond burs rather than fluted tungsten-carbide burs are recommended for trimming Low modulus of elasticity – suitable for restoring class V cervical lesions or defects where cervical flexure can be significant Smoothest surface finish among all composite resins. Indications Esthetic anterior restorations. Restoring sub-gingival areas. Carious lesion on smooth surface (Class 3 and 5)
- 53. Advantages Disadvantages Best surface finish Excellent wear resistance Decreased tensile strength Higher Water sorption and CTE fracture resistance is les
- 54. Developed to combine properties of conventional and microfilled composites Contain two kinds of filler particles - colloidal silica and ground particles of glasses containing heavy metals Content of approximately 75 to 80 wt%. Average particle size of about 0.4 to 1.0 µm Colloidal silica represents 10 – 20 wt% of total filler content. Silane-coated silica or glass Polymer matrix with colloidal silica
- 55. Clinical considerations – Surface smoothness and reasonably good strength – used in anteriors including Class IV Provides a smooth “Patina-like” surface texture in finished restoration. Currently are the predominant direct esthetic restorative material used. Have almost universal clinical applicability Advantages Disadvantages Good physical properties Improve wear resistance Superior surface morphology Good esthetics Increased surface roughness with time
- 56. Chemically cured composite – Syringes Tubes Light-cured composite – Syringes Compules
- 58. PHYSICAL PROPERTIES WORKING & SETTING TIME Light cure: surface hardens in 60-90 sec Chemical cure: 3-5 min Polymerization shrinkage – Microfill composite – 2 to 3% Packable composite – 0.6 to 0.9% Macrofilled composite – 1.2 to 1.3% Small particle filled composite – 2 to 3% Thermal properties – The thermal conductivity of composites with fine particles (25 to 30 ×10-4 cal/sec/cm2[0C/cm]) is greater than that of composites with microfine particles (12 to 15 ×10-4 cal/sec/cm2[0C/cm]).
- 59. Water sorption – (in mg/cm2) Traditional composite – 0.5 to 0.7 Small particle composite – 0.5 to 0.6 Hybrid composite – 0.5 to 0.7 Microfilled composite – 1.4 to 1.7 Color stability:- Stress cracks within the polymer matrix and partial debonding of the filler to the resin as a result of hydrolysis- increase opacity and alter the appearance. Discolouration can also occur by oxidation. Chemical cure less than light cure.
- 60. Flexural(mpa) Compressive Diametral tensile strength Nanocomposite 180 460 81 Multipurpose composite 80 - 160 240 – 300 30 – 55 Microfilled 60 – 120 220 – 300 25 – 40 Packable 85 – 110 210 – 280 33 – 48 Flowable 70 – 120 210 – 280 33 – 48 Compomer 65 – 125 180 – 250 25 – 40
- 61. Wear – Ability to resist surface loss Wear resistance of composite are of at least five types – Wear by food (CFA wear) Impact by tooth contact in centric contacts (occlusal contact area wear) (two-body concept) Sliding by tooth contact in function (functional contact area wear) Rubbing by tooth contact interproximally (proximal contact area wear) Wear from oral prophylaxis methods (toothbrush or dentifrice abrasion)
- 62. Marginal integrity exhibit good marginal adaptation when the margins are on enamel and dentin. Poor adaptation to root surfaces. To enhance the marginal adaptation, reducing the microleakage of composite restorations - 5 ways (Cheung, J prosth Dent,1990) Acid etch technique Dentin bonding Cavity design Incremental technique Sealing the margins-unfilled resin
- 63. Radiopacity important requirement for composite resins. imparted by certain glass filler particles containing heavy metal atoms . Even at highest volume fraction of filler, the amount of radiopacity is less than amalgam.
- 64. Biocompatibility Direct biological risk Post-placement tooth sensitivity Local immunological effects Long-term pulpal inflammation. estrogenic in in vitro studies. May elicit allergic reactions, or may possibly Even act as carcinogens Indirect biological risk – ◦ Post-operative sensitivity, pulpitis, and secondary caries resulting from microleakage/nanoleakage.
- 65. FLOWABLE COMPOSITES Introduced in 1996 Resin matrix- TEGDMA( Triethylene glycodimethacrylate) Fillers - silica(0.02- 0.05µm) - 60% by weight Indicated in low stress bearing areas where increased flow of composite resins is desirable. Clinical consideration: Pit& fissure sealants Preventive resin restorations Small class III & v restorations Liners in class I & II cavities(especially in proximal box) Repair of ceramic crown bridge
- 66. Matrix consists of ceramic polysiloxane(silicon- oxygen chains) instead of bis-GMA Low shrinkage on polymerization(only 1.8%) Versatile in application in both anterior and posterior regions of the mouth. Has high abrasion resistance. Also releases fluoride, calcium & phosphate ions
- 67. Have nanofillers(Size: 0.005-0.01µm) These particles are extremely small & virtually invisible. Incorporation of 90-95 % fillers by weight-high filler levels result in good physical properties and esthetics. Commercially available: Filtek™ Supreme Plus
- 68. Chlorhexidine- toxic effects of the released material Antibacterial activity is short lived Deterioration of the properties of the material Imazato et al(1994)- MDPB (methacryloxydecyl pyridinium bromide)= hydroxydodecyl pyridinium bromide+ meth acryloyl group - Antibacterial effect even after long term immersion in water - Also no adverse effects on properties of resin matrix. - Effective against streptococci Silver “Oligodynamic action” on bacteria's.
- 69. Calcium phosphate and its modified varieties are being used as fillers in recent composites. serve as bioactive liners and bases to enhance remineralization. When ph of saliva drops, ca and po4 ions are released. Amorphous calcium phosphate hybridized with glass forming agents are also used as filler.( Ariston pH control) ‘smart composite’
- 70. Developed in 1998. Fibers of glass or polyethylene & resin matrix being coupled during manufacture. end result is fibres uniformly impregnated with the matrix.
- 71. Properties Very high compressive strength and tensile strength. High flexural strength Uses Inlays, onlays, full veneer crowns. Restoration of endodontically treated teeth. Metal free composite crowns. 3-unit bridges. Splinting .
- 72. Composites have provided clinicians with wide range of restorative options. Since last two decades these materials have risen exponentially and have enabled the dentist to implement preventive & minimally invasive techniques. Today, aesthetics and restorative dentistry are unthinkable without composite resins. The most important aspect , is that patients retain their teeth longer with better esthetics. Interest in the scientific background, development and performance of these restorative materials is a must to avoid being snared by advertising promises.
Editor's Notes
- #24: Mps-most commonly used.
- #25: Light activated-initially uv light..today visible blue light activated systems.-greatly improved depth of cure, controllable working time.
- #69: Studies hav shown that greater amount of bacteria & plaque accumulates on the surface of the resins composites/ enamel surface. The more the plaque, greater is the incidence of secondary caries.
- #70: Wen ph of saliva drops