Surface Roughness of Tooth Coloured Materials after Streptococcus Mutans Culture

Abstract

Surface texture of a dental material may cause non-aesthetic appearance, secondary caries and periodontal problem. Factors influencing surface roughness include the type of the material, its filler, and exposure to bacterial accumulation. The aim of this study was to investigate surface roughness of glass ionomer cement (GIC) and resin composite (CR). A total of 112 specimens consisting of Fuji II LC (microfilled GIC), Ketac N100 (nanofilled GIC), Z250 (microfilled composite) and Z350 (nanofilled composite) were used. All specimens were packed in acrylic mould, light cured for 40 s and polished with Sof-Lex discs. The samples were divided into two groups of 7 and 24 hrs (n=7). Ra values were assessed at baseline and after bacterial colonization using Atomic Force Microscope (AFM, Ambios, USA). The data was analyzed using SPSS version 20 and the level of significance had been set at p < 0.05. After 7 hrs of Streptococcus Mutans culture, only Fuji II LC showed a significant change in the Ra with p value of 0.031. Furthermore, Ra value of Fuji II LC was significantly different from the other test materials with P=0.000. There was also a significant difference in Z250 when compared to Ketac Nano.(Fuji II>Ketac Nano>Filtek Z250). After 24-hrs culture with Streptococcus Mutans, all materials were significantly different P=0.000 from each other, except between Z350 and Z250. (Fuji II>Ketac Nano>Filtek Z250=Filtek Z350). There was no significant difference between 7 and 24 hrs in all tested materials. In conclusion, in the early stages of bacterial growth; after 7 and 24 hrs culture with Streptococcus Mutans. the microfilled GIC shows the highest surface roughness, followed by nanofilled GIC and the resin composites.