%0 Journal Article
%T Surface degradation of glass ceramics after exposure to acidulated phosphate fluoride
%A Ccahuana
%A Vanessa Z.S.
%A £¿zcan
%A Mutlu
%A Mesquita
%A Alfredo M. M.
%A Nishioka
%A Renato S.
%A Kimpara
%A Estev£¿o T.
%A Bottino
%A Marco A.
%J Journal of Applied Oral Science
%D 2010
%I University of S?o Paulo
%R 10.1590/S1678-77572010000200010
%X objective: this study evaluated the surface degradation effect of acidulated phosphate fluoride (apf) gel exposure on the glassy matrix ceramics as a function of time. material and methods: disc-shaped ceramic specimens (n = 120, 10/per ceramic material) were prepared in stainless steel molds (inner diameter: 5 mm, height: 2 mm) using 6 dental ceramics: 3 indicated for ceramic-fused-to-metal (vita omega 900, carmen and vita titankeramik), 2 for all-ceramic (vitadur alpha and finesse£¿ low fusing) and 1 for both types of restorations (ips d.sign). the specimens were wet ground finished, ultrasonically cleaned and auto-glazed. all specimens were subjected to calculation of percentage of mass loss, surface roughness analysis and topographical description by scanning electron microscopy (sem) before (0 min) and after exposure to 1.23 % apf gel for 4 min and 60 min representing short- and long-term etching effect, respectively. the data were analyzed using two-way anova with repeated measures and tukey's test (a=0.05). results: significant effect of the type of the ceramics (p=0.0000, p=0.0031) and exposure time (p=0.0000) was observed in both surface roughness and percentage of mass loss values, respectively. the interaction factor between both parameters was also significant for both parameters (p=0.0904, p=0.0258). both 4 min (0.44¡À0.1 - 0.81¡À0.2 mm) and 60 min (0.66¡À0.1 - 1.04¡À0.3 mm) apf gel exposure created significantly more surface roughness for all groups when compared to the control groups (0.33¡À0.2 - 0.68¡À0.2 mm) (p<0.05). there were no significant differences in percentage of mass loss between the ceramics at 4 min (p>0.05) but at 60 min exposure, ips d.sign showed the highest percentage of mass loss (0.1151¡À0.11). the mean surface roughness for vita titankeramik (0.84¡À0.2 mm) and finesse£¿ low fusing (0.74.¡À0.2 mm) was significantly higher than those of the other ceramics (0.59¡À0.1 mm - 0.49¡À0.1 mm) and vita titankeramik (p<0.05) regardless of the exposure tim
%K acidulated phosphate fluoride
%K dental ceramics
%K dental materials
%K loss mass analysis
%K microscopy [electron]
%K microscopy [scanning]
%K surface roughness.
%U http://www.scielo.br/scielo.php?script=sci_abstract&pid=S1678-77572010000200010&lng=en&nrm=iso&tlng=en