STATEMENT OF PROBLEM: The effect of repeated applications of fluoride solutions and 10% carbamide peroxide on the surface roughness of newer dental porcelains is not completely known. PURPOSE: The purpose of this study was to compare the surface roughness of 3 different porcelains when exposed to 2 fluoride solutions, a 10% solution of carbamide peroxide, and distilled water. MATERIAL AND METHODS: Forty discs (10-mm diameter, 2 mm thick) were made of each of the following porcelains: feldspathic porcelain (Ceramco II), low-fusing porcelain (Finesse), and an aluminous porcelain (All-Ceram). Each disc was abraded with a medium-grit diamond bur and auto-glazed. One side of each disc was abraded with a diamond bur and polished using a porcelain polishing kit to simulate a chairside adjustment and polishing. The discs (10 specimens/group) were immersed in 1.23% APF, 0.4% stannous fluoride, 10% carbamide peroxide, and distilled water for 50 seconds (control). The discs in the 10% carbamide peroxide solution were immersed for 48 hours. The surface of each disc was evaluated with surface profilometry (0.1 mm/s speed, 600-microm range). The data were analyzed by factorial analysis of variance and a Tukey multiple comparison test, (alpha=.05). RESULTS: The data showed that the acidulated phosphate fluoride etched the auto-glazed surface of all 3 porcelains. For Finesse specimens, the mean Ra values for the auto-glazed surface were significantly higher than that of the control after immersion in 1.23% APF (mean Ra 0.3 +/- 0.06 microm, P<.031). All-Ceram auto-glazed surface specimens had a significantly higher mean Ra value when immersed in the 3 solutions than the control (1.23% APF, 0.4% stannous fluoride, and 10% carbamide peroxide, 0.245 +/- 0.115 microm, 0.22 +/- 0.104 microm, 0.22 +/- 0.04 microm, respectively; P<.002). Ceramco II specimens were affected by all 3 solutions, with the auto-glazed surface having higher Ra values (1.23% APF, 0.4% stannous fluoride, and 10% carbamide peroxide, with mean Ra values of 0.35 +/- 0.1 microm, 0.26 +/- 0.08 microm, and 0.24 +/-.0.05 microm, respectively, P=.001). Immersion in the 3 solutions had no effect on the polished surfaces of all-ceramic specimens tested. CONCLUSION: Prior to the use of fluoride and 10% carbamide peroxide, dentists should ascertain the type of porcelain restoration present to prevent a roughened surface from occurring.
STATEMENT OF PROBLEM: The effect of repeated applications of fluoride solutions and 10% carbamide peroxide on the surface roughness of newer dental porcelains is not completely known. PURPOSE: The purpose of this study was to compare the surface roughness of 3 different porcelains when exposed to 2 fluoride solutions, a 10% solution of carbamide peroxide, and distilled water. MATERIAL AND METHODS: Forty discs (10-mm diameter, 2 mm thick) were made of each of the following porcelains: feldspathic porcelain (Ceramco II), low-fusing porcelain (Finesse), and an aluminous porcelain (All-Ceram). Each disc was abraded with a medium-grit diamond bur and auto-glazed. One side of each disc was abraded with a diamond bur and polished using a porcelain polishing kit to simulate a chairside adjustment and polishing. The discs (10 specimens/group) were immersed in 1.23% APF, 0.4% stannous fluoride, 10% carbamide peroxide, and distilled water for 50 seconds (control). The discs in the 10% carbamide peroxide solution were immersed for 48 hours. The surface of each disc was evaluated with surface profilometry (0.1 mm/s speed, 600-microm range). The data were analyzed by factorial analysis of variance and a Tukey multiple comparison test, (alpha=.05). RESULTS: The data showed that the acidulated phosphate fluoride etched the auto-glazed surface of all 3 porcelains. For Finesse specimens, the mean Ra values for the auto-glazed surface were significantly higher than that of the control after immersion in 1.23% APF (mean Ra 0.3 +/- 0.06 microm, P<.031). All-Ceram auto-glazed surface specimens had a significantly higher mean Ra value when immersed in the 3 solutions than the control (1.23% APF, 0.4% stannous fluoride, and 10% carbamide peroxide, 0.245 +/- 0.115 microm, 0.22 +/- 0.104 microm, 0.22 +/- 0.04 microm, respectively; P<.002). Ceramco II specimens were affected by all 3 solutions, with the auto-glazed surface having higher Ra values (1.23% APF, 0.4% stannous fluoride, and 10% carbamide peroxide, with mean Ra values of 0.35 +/- 0.1 microm, 0.26 +/- 0.08 microm, and 0.24 +/-.0.05 microm, respectively, P=.001). Immersion in the 3 solutions had no effect on the polished surfaces of all-ceramic specimens tested. CONCLUSION: Prior to the use of fluoride and 10% carbamide peroxide, dentists should ascertain the type of porcelain restoration present to prevent a roughened surface from occurring.
Authors: R R Moraes; J L M Marimon; L F J Schneider; L Correr Sobrinho; G B Camacho; M Bueno Journal: Clin Oral Investig Date: 2005-11-16 Impact factor: 3.573