Effect of fluoride and 10% carbamide peroxide on the surface roughness of low-fusing and ultra low-fusing porcelain.
BACKGROUND
The effect of repeated applications of fluoride solutions and 10% carbamide peroxide on the surface roughness of newer dental porcelains is not completely known.


OBJECTIVE
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.


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.


CONCLUSIONS
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.
Butler
Craig J
CJ
Department of Restorative Dentistry, Baltimore College of Dental Surgery, University of Maryland, 21201 USA.
Masri
Radi
R
Driscoll
Carl F
CF
Thompson
Geoffrey A
GA
Runyan
Dennis A
DA
Anthony von Fraunhofer
Joseph
J
D000149:Acidulated Phosphate Fluoride / Q000737:chemistry; D000537:Aluminum Oxide / Q000737:chemistry; D000538:Aluminum Silicates / Q000737:chemistry; D000704:Analysis of Variance; D000077463:Carbamide Peroxide; D002327:Cariostatic Agents / Q000737:chemistry*; D003775:Dental Polishing; D003776:Dental Porcelain / Q000737:chemistry*; D018130:Diamond / Q000737:chemistry; D004338:Drug Combinations; D005459:Fluorides / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D016877:Oxidants / Q000737:chemistry*; D010545:Peroxides / Q000737:chemistry*; D017680:Potassium Compounds / Q000737:chemistry; D013499:Surface Properties; D014002:Tin Fluorides / Q000737:chemistry; D014508:Urea / Q000031:analogs & derivatives* / Q000737:chemistry*; D014867:Water / Q000737:chemistry
C105314:AllCeram; D000538:Aluminum Silicates; D002327:Cariostatic Agents; D004338:Drug Combinations; D016877:Oxidants; D010545:Peroxides; D017680:Potassium Compounds; D014002:Tin Fluorides; D014867:Water; D003776:Dental Porcelain; C016447:feldspar; D000077463:Carbamide Peroxide; D000149:Acidulated Phosphate Fluoride; C037884:finesse; D018130:Diamond; C058233:Ceramco; D014508:Urea; D000537:Aluminum Oxide; D005459:Fluorides