5. Application of Resin Composite a. Bulk-Packing This technique involves a single application of the whole bulk of a composite restoration. It is suitable for chemically activated resin composite and small restorations of VLC ones

b. Incremental Packing The incremental condensa- tion technique involves packing of the restoration in successive thin increments. Each is pressed into a predetermined location and polymerized.

Advantages: Drawback: It serves, to compensate for polymerization shrinkage. It increases the degree of polymerization and improves the physical properties of composite restoration. Drawback: This technique may cause air inclusion and development of oxygen-inhibited soft spots with loss in strength.

6. Carving: Gold-plated or Teflon-tipped carving instruments are used to overcome the stickiness of composite. Care must be taken to maintain the carving in a direction towards the margins to avoid disturbing peripheral apposition to substrate enamel surface.

7. Polymerization Polymerization is the transformation of liquid monomer into solid polymer induced by free radical activation of the double bonded monomer molecules. Eye protection requires the use of colored shields and/or special glasses as well as avoid looking at the light.

8. Finishing and Polishing VLC systems do not need much finishing because dentist-controlled working time allows perfection of surface texture at the time of carving. 1. Slight marginal overhangs at critical embrasure areas may carefully be shaved by sharp Black’s gold-foil knife or using the Widelstaedt chisels of suitable size.

2. Gross finishing: Using Soflex discs in descending order of roughness, starting with the coarse grit to remove excess material, followed by successively smoother discs to develop the final satin gloss.

Alternatively, white stones followed by abrasive-incorporated rubber finishing tips, fine flame-shaped diamond points, or 12 bladed carbide burs may be used

Using resin composite as a posterior restorative material Indications: Good standard of oral hygiene. Absence of any traumatic occlusion or damaging occlusal habits. No evidence of tooth wear. There is no interference with field isolation Small to medium sized cavities.

Centric occlusal stops should be located on tooth structure. In case of class II restorations: Presence of a part of contact area proximally. The gingival cavo surface margin should be located on intact enamel No gingival bleeding. As a rule “Composites do best when reserved for smaller restorations”

A resin composite for posterior teeth restoration should be; 1) Light cured: As it is denser and free of any bulk voids created during mixing of auto cured resins. 2) High filler content: Filler content may reach 87 % by weight. This will reduce the stress on the resin matrix during function.

3) Small filler particle size: The ideal filler size should be less than 2 microns. 4) Putty – like: A high viscosity resin will give a chance to create proper marginal adaptation and secured proximal contacts. 5) Radiopaque: Radiopacity is essential to detect any restoration overhangs or recurrent decay.

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