– Secretion rate and buffer effect of resting and stimulated whole saliva, and number of lactobacilli and S. mutans in stimulated whole saliva were determined for 182 subjects, of whom 109 were cigarette smokers. For secretion rate, no difference between smokers and non‐smokers was observed. The median buffer effect was significantly lower in smokers. The median numbers of lactobacilli and S. mutans were significantly higher in saliva of smokers. The number of lactobacilli was significantly correlated with number of cigarettes smoked per day. About 40% of the smokers had 106 S. mutans CFU/ml, which was more than twice that of non‐smokers. In a complementary study on 20 smokers, the immediate influence of cigarette smoking on secretion rate and buffer effect of stimulated whole saliva was investigated for 1 h after smoking. No significant effect was found.

– The capacity of the oral bacteria Streptococcus mitior, S. mutans and S. sanguis to methylate mercury was investigated in vitro. Mercuric chloride and pulverized dental amalgam in distilled water, respectively, were used as sources of mercury. Methylmercury was found in the bacterial cells of all three tested strains. The results indicate that organic mercury compounds may be formed in the oral cavity.

The study was undertaken to evaluate differences in development of caries-like lesions (wall lesions) around three principally different amalgams (conventional, fluoride-containing and dispersed) under standardized conditions. Amalgam restorations were made on sound buccal and lingual surfaces of extracted premolars. After 10 weeks in an acidified gelatin gel the teeth were sectioned through the restorations and planoparallel ground sections were produced. The enamel surrounding the restoration was studied by polarized light microscopy after imbibition with quinoline (n = 1.62). It was found that the depth of the wall lesion and the extent of demineralized enamel were significantly less around the fluoride-containing amalgam than around the other two. Although not always statistically significant, the largest extent of demineralization was seen in wall lesions surrounding the dispersed amalgam. The number, depth and extent of wall lesions were significantly smaller in the cervical part of the cavities than in the coronal part. Signs of intermediate remineralization processes (presence of dark zones) were most often seen in relation to the fluoride-containing amalgam. These findings are discussed in relation to other differences between the amalgams, such as sealing property and corrosion proneness.

No abstract

– Forty‐two adults, visiting a Swedish health home, participated in the investigation, which included a 6‐day period of fasting, followed by a 6‐day period with a lactovegetarian diet. The results obtained indicated only a minor and mostly not significant influence on secretion rate, buffer effect, concentration of various electrolytes, and number of lactobacilli and S. mutans of whole saliva.