Effect of immediate and delayed finishing/polishing on surface roughness and color stability of direct composite resins submitted to staining

• Grant number: 13/19187-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): April 01, 2014
• Effective date (End): March 31, 2015
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Mirela Sanae Shinohara
• Grantee: Iana Rodrigues Briggo
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil

Abstract

Most current direct composite resins have showed physical and mechanical properties to use for both anterior and posterior teeth. To achieve excellence in composite resin (CR) restoration, the final step of finishing/polishing (Fin/Pol) is essential to obtain a well-adapted restoration, smooth surface, color stability, to prevent plaque retention and recurrent caries formation. Thus, the aim of this study will be to evaluate the effect of immediate and delayed (after 24 hours and 7 days) Fin/Pol of a nanoparticle and microhybrid composite resins subjected or not to staining using coffee solution by surface roughness and gloss retention analysis. CR disks (8.0mm diameter x 2.0mm deep) will be prepared and separated according to the surface treatment and time of Fin/Pol (n=5): 1) Sof-lex Pop-on Fin/Pol - immediate, 24h, and 7 days; 2) Laboratory Fin/Pol with silicon carbide sandpaper - immediate, 24h, and 7 days; 3) Without Fin/Pol - immediate, 24h, and 7 days. Half of the samples from each group will be subjected to staining for 15 consecutive days in coffee solution. Then, the surface of specimens will be analyzed using a portable profilometer SJ-401 (Mitutoyo) at a speed of 0.05mm/sec (cut-off 0.25mm) and three measurements in different directions on each sample. For gloss retention analysis, it will be measured on central portion of each sample. The G.U. (gloss units) measures will be made at 60° angle of incidence in order to obtain the measure in the same point on the surface. After analysis of surface roughness and gloss retention, the results will be subjected to statistical analysis with significance level of 5%.