Effect of surface corrosion of ceramo-metallic porcelain finished by different methods on their surface roughness and bacterial accumulation

ABSTRACT

The effect of surface corrosion of ceramo-metallic dental porcelain finished by autoglazing, overgIazing and polishing on their surface roughness and bacterial accumulation was studied. Thirty samples were constructed from one type of commercial available ceramo-metallic porcelain [VMK 95, Vita, Germany]. These samples were divided into 3 groups [10 samples each]. Each group represented one type of finishing method. Then each group was subdivided into 2 subgroups 5 samples each]; the first subgroup [control], this subgroup was not subjected to corrosion test, while the second subgroup was subjected to corrosion test. The two subgroups were then subjected to surface roughness test, followed by a bacterial accumulation test. The results showed that there wasn't a statistical significant difference between the surface roughness of the tested ceramic for the autoglazed and the overglazed groups before and after corrosion. While there was a statistical difference between these two groups and the polished group before and after corrosion test. At the same time there was a significant difference between the two subgroups of the polished group. Overglazed recorded the least surface roughness, while the polished ceramic recorded the highest surface roughness. Polished ceramic showed bacterial accumulation and it had increased due to corrosion test. While Overglazed and autoglazed ceramic didn't record any bacterial accumulation. The microscopic examination of the accumulated bacteria revealed two species of bacteria gram positive bacilli anthrocoid and gram positive diplococci pneumococci