Effect of oral environmental conditions on surface roughness and fatigue strength of porcelain fused to metal restorations

Author: 
Mohamed T. Hamed, Abdulghani I. Mira, Mohamed Hashem, Saeed Alamoudi, Hisham A. Mously and Ghada H. Naguib

Ceramic restorations are widely used to achieve esthetics but the durability and long-term success of ceramics in oral cavity may be affected by the oral environmental condition. The cola and orange juices may affect the surface quality as well as fatigue strength of ceramics. This research study was done to evaluate the immersion of low fusing ceramic in artificial salvia, cola and orange juice on surface roughness and fatigue strength. A total of 90 ceramic discs were equally distributed into three groups as follows:-Group1: immersed in artificial saliva adjusted at pH 7 for one year.Group2: immersed in cola for 4 hours.Group3: immersed in orange juice for 4 hours. The pH was measured for the three solutions using pH meter. The degradation of porcelain was tested by measuring the surface roughness using the profilometer. The fatigue strength was tested using Llyoid testing machine. Results were analyzed using ANOVA and least significant differences at 95% level of confidence. The results showed that the surface roughness increased when ceramic was immersed in acidic medium. The surface roughness was accompanied by a statistically significant decrease in strength property of low fusing ceramic (p=0.019). It was concluded that low fusing ceramic is not an inert material and the acidic saliva leads to increase in surface roughness and decrease of fatigue strength.

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DOI: 
http://dx.doi.org/10.24327/ijcar.2019.20109.3919
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