Evaluation of Clinical Performance of Class IV Restoration Using Organically Modified Ceramic (OMNOCER) in Comparison to a Methacrylate Based Composite Resin a Randomized Clinical Trial

Statement of the problem:

Resin composites have been the most popular material in esthetic dentistry since 1960's. Esthetic restorative material should resemble the natural tooth; in both color match and stability, and should have adequate strength, wear and sealing characteristics

. Longevity of anterior restorations varied in earlier studies depending on the restorative material and cavity class. Involvement of the incisal angle in anterior teeth resulted in accompanied reduction in average survival time. In contrast to class I, II, III and V cavity configurations, class IV restorations are stressed at the incisal angle, posing a challenge to the tooth restoration interface. Because the majority of class IV restorations lack mechanical retention; the tooth-bonded interface faces additional obstacles. In addition, color is one of the most important factors of esthetic restorations, since color change may be due to intrinsic factors as; changes in the filler, matrix and silane coating as well as extrinsic staining; as absorption of stains, chemical reactivity, diet and oral hygiene. But the recent advances in the resin composite restoration in their monomer chemistry, filler type and structure have been continuously developed to improve their mechanical and physical properties.

Rationale:

In order to optimize the properties of the material and facilitate deeper light transmission, manufacturers incorporated an advanced composite filler technology and resin matrix modifications by introducing Organically Modified Ceramics with pure silicate technology showing superior material properties, which was claimed to be better than Methacrylate Based Composite Resin. Moreover, polymerization shrinkage stresses depend on many factors, like composition of resin matrix, quantity of filler and degree of conversion. Ormocer induces polymerization as a result of a matrix of long inorganic silica chains with organic lateral chains. This type of Ormocer enhances aesthetics, color stability, abrasion resistance, and reduces polymerization shrinkage and surface roughness due to the presence of ceramic polysiloxane, which has low degree of polymerization shrinkage (1.25%)