Evaluation and comparison for the mechanical and biomimetic properties of selected composite veneer systems / Amar M. Thiyab

The composite resin veneer systems have been considered one of the most affordable restorations in the cosmetic dentistry nowadays. The aim of the present study was to evaluate two of the mechanical and one of the biomimetic features of the prefabricated veneer systems and compare them with a laboratory-made veneer system. The physical features were represented by surface roughness and shear bond strength, while the biomimetic features were represented by colour stability. Three veneer systems were been evaluated; two of them considered prefabricated veneers (Edelweiss and Componeer) and last one considered as laboratory-made veneer (Nexco). Thirty-six veneer samples were been selected randomly for each veneer system then subdivided into three groups, each group represent one of the evaluated features. The surface roughness samples were prepared with three different surface treatments, two mechanical and one chemical treatment. After that, AMBIOS XP-1 profilometer was been used to evaluate the surface roughness and the Stereo Electron Microscope (SEM) was used to evaluate the changes in the surface textures. For the shear bond strength evaluation, the veneer samples were divided and prepared with three different adhesive agents related to the three different veneer systems. The universal testing machine (SHIMADZU) was used to evaluate the shear bond strength. For the colour stability evaluation, the veneer samples were immersed in the staining solution (Instant coffee) and regularly evaluated them colour changes by the Minolta spectrophotometer CM–(C 3500) for duration of 27 days by three days intervals. All research data were collected and evaluated statistically with One-way ANOVA, Two-way ANOVA, Student’s t-test and Liner regression analysis. The results showed that the laboratory-made veneer system (Nexco) was significantly showed higher surface roughness enhancement, higher shear bond strength and more colour stable than the prefabricated veneer systems. The present study concluded that both of the prefabricated veneer systems and the laboratory-made veneer systems were showed clinically accepted features. However, the laboratory-made veneer system was showed higher mechanical and biomimetic features than prefabricated veneer systems.