ABSTRACT
PURPOSE: To investigate and compare the surface roughness (SR), weight and height of monolithic zirconia (MZ), ceramometal (CM), lithium disilicate glass ceramic (LD), composite resin (CR), and their antagonistic human teeth enamel. MATERIALS AND METHODS: 32 disc shaped specimens for the four test materials (n=8) and 32 premolars were prepared and randomly divided. SR, weight and height of the materials and the antagonist enamel were recorded before and after subjecting the specimens to 240,000 wear-cycles (49 N/0.8 Hz/5℃/50℃). SR, height, weight, and digital microscopic qualitative evaluation were measured. RESULTS: CM (0.23 + 0.08 µm) and LD (0.68 + 0.16 µm) exhibited the least and highest mean difference in the SR, respectively. ANOVA revealed significance (P=.001) between the materials for the SR. Paired T-Test showed significance (P < .05) for the pre- and post-SR for all the materials. For the antagonistic enamel, no significance (P=.987) was found between the groups. However, the pre- and post-SR values of all the enamel groups were significant (P < .05). Wear cycles had significant effect on enamel weight loss against all the materials (P < .05). CR and MZ showed the lowest and highest height loss of 0.14 mm and 0.46 mm, respectively. CONCLUSION: MZ and CM are more resistant to SR against the enamel than LD and CR. Enamel worn against test materials showed similar SR. Significant variations in SR values for the tested materials (MZ, LD, CM, and CR) against the enamel were found. Wear simulation significantly affected the enamel weight loss against all the materials, and enamel antagonist against MZ and CM showed more height loss.
Subject(s)
Humans , Bicuspid , Ceramics , Dental Enamel , Evaluation Studies as Topic , Glass , Lithium , Tooth , Tooth Wear , Weight LossABSTRACT
Objective:To evaluate the wear resistance of four types of composite resin when they were opposed by human enamel antagonist. The relationship between pH value and wear resistance was also evaluated. Methods:Mutual wear between four types of composite resins(3 mm?20 mm?1 mm),Beautifit(B),SureFilTM(S),TE-Econom(T),Charisma (C),with same rough surface and opposing enamel was evaluated using a wear simulator of UMT-2 (n=10).Wear resistance was assessed as weight loss(g).The worn surfaces were observed with scanning electron microscope(SEM).All data were statistically analyzed with SPSS14.0.Results:SEM observation showed that the fillers particles of resin B,S were bigger than that of the others. Fillers of resin C was the smallest and the most well-distributed. Many filler particles were lost. In the acid environment,the enamel surface had the special appearance. The S,C,T composite resins were less worn. The weight loss of the T,B,S composite resins increased when pH value fell down to 4.0 (P0.05).Conclusion:The wear resistance among the different brands of composite resins are discrepant. The weight loss might be accelerated with the decreased pH value.