Composite fillings are now the preferred alternative to alloy-based materials. More and more patients are refusing to have any new metallic fillings; some are even asking for their old amalgam ones to be replaced with more aesthetic materials. Composite materials continue to improve steadily, and bonding techniques even more so; this means we can offer our patients dependable, good-looking restorations which last a considerable time – provided certain conditions are met: the right choice of composite, a layering technique which allows guided shrinkage on curing (polymerization), minimum curing stress, proper rebuilding of the contact point and the correct occlusal anatomy.
The layering must:
- provide a perfect seal at the cervical, proximal and occlusal edges.
- enable a contact point or surface to be rebuilt.
- reproduce the occlusal anatomy without difficulty.
Many layering techniques have been proposed for rebuilding the proximal surface: all aim to reduce composite curing constraints and stress. For horizontal layering successive applications are recommended, none more than 2mm thick. Oblique layering is fairly hard to do, especially in a deep and narrow proximal area. The technique consists of managing the vectors of polymerization by putting the light source against the cusps, so directing polymerization preferentially in the direction of the dental tissues.