Effects of pH on the surface texture of glass ionomer based/containing restorative materials.
This study determined the effect of pH on the surface texture of commonly used posterior glass-ionomer based/containing restorative materials. The materials evaluated included a compomer (Dyract AP), a giomer (Beautifil) and two highly viscous glass ionomer cements (Fuji IX and Ketac Molar). A resin composite (Esthet-X) was used for comparison. Forty-two specimens (3-mm wide x 3-mm long x 2-mm deep) were made for each material. The specimens were divided into six groups and conditioned in the following solutions at 37 degrees C for one week: Citric acid (pH 2, 3, 4, 5 and 6) and distilled water (pH 7). After conditioning, the surface roughness (Ra, microm) of each specimen was measured using a surface profilometer (Surftest, Mitutoyo Corp, Tokyo, Japan). Data was analyzed using one-way ANOVA and Scheffe's test at a significance level of 0.05. The effects of pH on the surface texture of glass-ionomer based/containing restoratives were material dependent. Ra values ranged from 0.02 microm to 0.15 microm and 0.03 microm to 4.40 microm for pH 7 and 2, respectively. With the exception of the composite, the surface roughness of all materials evaluated was significantly affected by acids of low pH. The surface texture of highly viscous glass ionomer cements deteriorated significantly when conditioned in solutions of low pH, which makes them more susceptible to clinical failure.
Mohamed-Tahir
M A
MA
Department of Preventive Dentistry, Faculty of Dentistry, National University of Singapore, Republic of Singapore. rashid@nus.edu.sg
Yap
A U J
AU
D000704:Analysis of Variance; D017438:Bisphenol A-Glycidyl Methacrylate; D019343:Citric Acid / Q000737:chemistry; D020770:Compomers / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D003764:Dental Materials / Q000737:chemistry*; D003793:Dental Restoration, Permanent; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D013499:Surface Properties; D014783:Viscosity; D014867:Water / Q000737:chemistry
C470433:Beautifil composite resin; D020770:Compomers; D003188:Composite Resins; D003764:Dental Materials; C088486:Dyract; C466112:Esthet-X; D005899:Glass Ionomer Cements; C110713:fuji IX; C110712:ketac-molar; D014867:Water; D019343:Citric Acid; D017438:Bisphenol A-Glycidyl Methacrylate