Objectives: Finishing and polishing are essential phases of composite restoration. There is not agreement in literature regarding the gold standard technique to achieve a polished surface under a 0.2 ìm Ra threshold. The present rugosimetric study investigates the effectiveness of each step of a polishing protocol by using a diamond bur, decreasing particle size rubber points and resin coating. Methods: Seventy-two composite discs (Filtek Z250, 3M ESPE, USA) were prepared and randomly divided into 6 groups (n=12); each group represented a step of the following polishing protocol: G1, 40 ìm diamond bur; G2, bur and 70 ìm black rubber point; G3, bur, black and 40 ìm yellow rubber points; G4, bur, black, yellow and 5 ìm grey rubber points; G5 as G4 + felt wheel; G6 as G4 + resin coating and felt wheel. Specimens underwent profilometric analysis by considering a superficial parameter (Sa). Data were statistically analyzed by means of Kruskal-Wallis and Conover tests (p<0.05). Results: The mean Sa values ±DS (ìm) were: G1, 0.50 ±0.21; G2, 0.18 ±0.01; G3, 0.19 ±0.04; G4, 0.11 ±0.04; G5, 0.12 ±0.02; G6, 0.10 ±0.03. Maximum roughness values were found in G1; a significant surface roughness decrease was registered in the groups in which the black (G2) and grey rubber points (G4) were used. Conclusions: The black rubber point step already produced roughness values lower than the established threshold; therefore, it is possible to shorten the polishing sequence by excluding the yellow rubber point. Felt wheel and resin coating did not seem able to further decrease surface roughness.
Rubber point polishing and resin coating of a micro-hybrid composite
ANGERAME, DANIELE;DE BIASI, MATTEO;
2011-01-01
Abstract
Objectives: Finishing and polishing are essential phases of composite restoration. There is not agreement in literature regarding the gold standard technique to achieve a polished surface under a 0.2 ìm Ra threshold. The present rugosimetric study investigates the effectiveness of each step of a polishing protocol by using a diamond bur, decreasing particle size rubber points and resin coating. Methods: Seventy-two composite discs (Filtek Z250, 3M ESPE, USA) were prepared and randomly divided into 6 groups (n=12); each group represented a step of the following polishing protocol: G1, 40 ìm diamond bur; G2, bur and 70 ìm black rubber point; G3, bur, black and 40 ìm yellow rubber points; G4, bur, black, yellow and 5 ìm grey rubber points; G5 as G4 + felt wheel; G6 as G4 + resin coating and felt wheel. Specimens underwent profilometric analysis by considering a superficial parameter (Sa). Data were statistically analyzed by means of Kruskal-Wallis and Conover tests (p<0.05). Results: The mean Sa values ±DS (ìm) were: G1, 0.50 ±0.21; G2, 0.18 ±0.01; G3, 0.19 ±0.04; G4, 0.11 ±0.04; G5, 0.12 ±0.02; G6, 0.10 ±0.03. Maximum roughness values were found in G1; a significant surface roughness decrease was registered in the groups in which the black (G2) and grey rubber points (G4) were used. Conclusions: The black rubber point step already produced roughness values lower than the established threshold; therefore, it is possible to shorten the polishing sequence by excluding the yellow rubber point. Felt wheel and resin coating did not seem able to further decrease surface roughness.Pubblicazioni consigliate
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