The effect of filler content and storage conditions such as drying, storing in water and thermal cycling on linear dimensional changes were investigated and evaluated. The dimensional accuracy studies were performed using a specific designed mould and a coordinate measuring machine. The findings gave support to the view that tiller content is an important factor influencing the physical and mechanical properties of the composite inlay material. The higher tiller content gave less polymerization shrinkage. The greatest linear shrinkage recorded was 0.79 %. The average linear shrinkage (in air, water and thermal cycling) for 79 % filler Prisma AP.H was 0.33 %, for 65 % tiller Prisma AP.H was 0.35 % and for 50 % filler Prisma AP.H was 0.42 %. Generally, dimensional changes was greatest when stored dry. This was followed by materials which were thermal cycled. The least dimensional change recorded was when the materials were stored in water.
The widespread use of aesthetic fillings has highlighted their advantages and disadvantages. One
of the most troublesome features of earlier aesthetic materials was the difficulty of finishing the restoration surface to decrease adherence of food debris. The rougher the finished surface, the greater the possibility of bacterial accumulation and discolouration of restoration along the restoration margin with secondary caries formation. Aside from these clinical implications, patients are highly discerning and could detect roughness of 0.30 μm with their tongue. The aesthetic restoration should mimic the appearance of natural dentition and should have an enamel-like appearance. An increased demand for superior aesthetics from composite resin has increased the
demand for more eff icient and simple polishing techniques. The development of nanocomposites has given a new perspective to the polishing of composite resins. Nanocomposites claim the advantage of improved gloss, optical characteristics and reduced wear. To date, results of in vitro studies have been equivocal regarding the most efficient and effective polishing system. There is variation in the effects of different finishing and polishing instruments on the surface roughness due to great diversity in size, shape, composition and distribution of the filler particles of composite resins, type of resin and a wide variety of finishing and polishing instruments. This paper will
review the different factors that affect polishing techniques used in achieving the desired polish on
composite resin restorations.