[In-vivo corrosion tests of dental alloys in relationship to saliva pH].

: The corrosion of four dental alloys and titanium was studied in relationship to saliva pH and plaque accumulation in vivo. Test specimens were scanned for porosities with an image analysis system before and after exposure to the oral milieu. The saliva pH was monitored during the study period. After four days of exposure in the mouth the plaque accumulation and the vitality of the plaque on the alloy surfaces was evaluated. Plaque accumulation and mean saliva-pH were not correlated with the observed surface corrosion. The least surface effects were observed on titanium, which showed the highest plaque accumulation. Different alloys showed different bacteriostatic effects. The least amount of living bacteria was found on titanium. Plaque accumulation and bacteria vitality depended on material and test person.