Effect of different types of polishing systems on the surface roughness and microhardness of different composites

Objectives: The aim of this in –vitro study was to evaluate the effect of different polishing systems on the the surface roughness and microhardness of different composites
Methods: Three different types of composite resins were used in the study. These were: Filtek Z₂₅₀ (microhybrid), Filtek Z₅₅₀ (nanohybrid) and Filtek Ultimate (nanofill) (3M ESPE). A total of 72 discs were prepared with dimensions of 8X3 mm. Eights discs were prepared for each type of composite. The polymerization of all composites were made using Blue Light ( Dentsply,Maillefer, Ballaguies, Switzerland) light curing device. The prepared samples were stored in an incubator at 37⁰ C for 24 hours. The composite samples were divided into 3 groups according to the polishing system. These were: Groups polished with Pogo ( Dentsply,Maillefer, Ballaguies, Switzerland) and Spiral disk (3M ESPE): Eight discs were prepared for each polishing groups ( n:8). Surfqace roughness was measured using Profilometer (Mahr Germany ). Microhardness was measured with 100 gr / 15 sec. (Buchler Japan). Data was analyzed using SPSS 21.0 program. ANOVA and Post Hoc HDS Tukey tests were used for statistical analysis. ( p ˂ 0.05).
Results: Statistically significant differences were found between the spiral and pogo groups according to Anova test in terms of surface roughness. (p ˂ 0,0001). Significant differences were also noted between Z₂₅₀ Ultimate and Z₅₅₀ groups using the HDS Tukey test. (p˂ 0.01). Using the Anova test for microhardness, a highly significant difference was determined between 1200 and pogo groups however no significant difference was found with the spiral group. ( p˃ 0.05). Significant differences were found according to the Ultimate and Z₂₅₀ ANOVA and HDS Tukey tests. ( p˂ 0.01). No statistically significant difference was found according to the Z₅₅₀ ANOVA test.
Conclusions: All composite types and polishing systems had a positive effect on surface roughness. A positive effect was observed in all groups in terms of microhardness except Z₅₅₀ among the composites and spiral polishing system among the polishing systems.