Composites

INTRODUCTION ?Composite resins are a class of mature and well established restorative materials that have their own indication in anterior and posterior teeth. ?Dental composites have continued to evolve with the development of smaller particle sizes, better bonding systems, curing refinements and sealing systems. Although composites are now well accepted in general practice, the complex steps involved have hindered their full success.

HISTORICAL DEVELOPMENT ? During the first half of the 20th century, silicates were the only tooth coloured esthetic material available for cavity restoration. ? Acrylic resins similar to those used for custom impression trays and dentures replaced silicates during the late 1940s and the early 1950s because of their tooth like appearance , insolubility in oral fluids, ease of manipulation and low cost.

INDICATIONS Class I, II, III, IV, V, VI core buildups Sealants and preventive resin restorations Esthetic enhancement procedures Cements Veneering metal crowns/bridges Temporary restorations Periodontal splinting Non carious lesions Enamel hypoplasia Composite inlays Repair of old composite restoration Patients allergic to metals

CONTRAINDICATIONS Isolation Occlusion Subgingival area/root surface Poor oral hygiene High caries index Habits (bruxism) Operator abilities

ADVANTAGESEsthetics Conservation Less complex Used almost universally Strengthening Bonded to tooth structure Repairable No corrosion No health hazard Cheaper then porcelain

DISADVANTAGES Polymerization shrinkage Technique sensitive Higher coeff. Of thermal expansion Difficult, time consuming Increased occlusal wear Low modulus of elasticity Lack of anticariogenic property Staining Costly

CLASSIFICATION:
  1. SKINNER’S (10th ed)
  2. Traditional composites (Macrofilled) 8-12µm
  3. Small particle filled composite – 1-5µm
  4. Microfilled composite – 0.04 – 0.4 µm
  5. Hybrid composite – 0.6 – 1 µm