Differences of direct and indirect resin composite and its effect on esthetic restoration

Abstract

As a result of the increasing needs among the public to enhance esthetics, many approaches have been made and the results included different approaches as non-metallic tooth-colored restorations, including the direct and indirect resin composites. In addition, another approach is the ceramic onlays or inlays. In this study, we aim to formulate strong evidence regarding the differences between direct and indirect resin composite the clinical outcomes, and related effects on esthetic restorations, based on evidence obtained from the current and previous studies in the literature. Many differences were discussed within the study manuscript between the direct and indirect resin groups. Furthermore, evidence shows that esthetic outcomes are in favor of the latter. We also discussed the color stability outcomes for the two groups and evidence in this area was controversial. Finally, many studies have reported that the clinical efficacy of the indirect resin composites is superior to the direct ones, while many others reported that they are similar, and only a few reported that direct resin composites are superior. Accordingly, further studies are encouraged to unify these contradicting results.

Indirect Restorative Polymeric Dental Materials

“…Modern veneering materials, regardless of their nature, based on poly-methylmethacrylate (PMMA) or composite resins, obtain superior physiognomic effects, especially due to the possibilities of layering different types of masses (opaque layer for masking the metallic core, dentine, enamel and shades for individualization). The polymerization can take place at temperature and pressure or by introducing it into a photo-polymerization device [16].…”

“…The higher it is, the lower the fracture susceptibility of a material. CAD/CAM composites have a Weibul modulus (10)(11)(12)(13)(14)(15)(16)(17) lower than hybrid ceramics.…”

“…Methacrylatebased monomers are widely used for dental composites because of the double bonds of the polymerization mechanism. Highly cross-linked methacrylate-based monomer mixture displayed satisfying mechanical and aesthetical properties but their high viscosity imposed some limitation on conversion degree and incorporation of filler phase [16][17][18][19]. Research from the recent years introduces new multi-functional monomers; the use of vinyl, diallyl monomers instead of TEGDMA offers higher degree of conversion (DC), lower volume shrinkage (VS), optimal mechanical resistance and cytocompatibility [20,21].…”

“…The initial gloss of hybrid composites (micro-hybrid and nanohybrid) is fading because of the difference in size of filler content. The nano-filled composited have similar matrix abrasion and the polish surface is kept on long term [16,31].…”

“…The cost of indirect composite restoration includes the laboratory work and additionally, there is a needed to increase tooth reduction to assure the insertion path of the restauration. Also, the luting layer of the resin cement may be subjected to shrinkage [16][17][18].…”