Biomedical subjects

R L Gregory

Publications and source records attributed to R L Gregory.

183 records · Page 11Linked to original sources

PubMedDate not supplied

Distribution of three cariogenic bacteria in secondary carious lesions around amalgam restorations.

Secondary dental caries remains an unresolved problem in dentistry and little is known of its microbial etiology. The purpose of this study was to compare the distribution of the three most suspected cariogenic groups of bacteria, mutans streptococci. Actinomyces naeslundii genospecies 2 and lactobacilli, in natural secondary caries around amalgam restorations. Extracted teeth with secondary caries were sectioned to obtain three samples that were randomly distributed to three different groups. Each group was immunolabeled with antibodies to either Streptococcus mutans, A. naeslundii genospecies 2 or Lactobacillus casei and subsequently labeled with secondary fluorescent antibodies. All samples were analyzed three-dimensionally using confocal microscopy. The results indicated that the three different bacteria were widely present and could have an important role in the development of secondary caries around amalgam restorations.

Actinomyces↗

PubMedDate not supplied

IgA antibodies to Streptococcus mutans in caries-resistant and -susceptible children.

Previous studies have shown a positive correlation between salivary IgA antibody levels to Streptococcus mutans and caries resistance in adults. In this study, enzyme-linked immunosorbent assay (ELISA) was used to compare IgA antibody levels with S. mutans in whole and parotid saliva from 20 caries-susceptible (CS; DMFS > 5) and 20 caries-resistant (CR; DMFS < or = 1) children (aged 7-11 years). Whole salivary S. mutans numbers were significantly greater (P < or = 0.05) in the CS group (mean of 31.2% of total oral streptococci) than in the CR group (mean of 1.6% of total oral streptococci). Whole saliva, but not parotid saliva, from CR children had significantly higher (P < or = 0.05) levels of IgA antibodies to S. mutans than saliva from CS children. These results suggest that salivary IgA antibodies to S. mutans may play a role in natural protection from dental caries in children and that the source of increased salivary IgA antibody in CR children may be either the minor, submandibular, or sublingual salivary glands.

Antibodies, Bacterial↗

PubMedDate not supplied

Effect of restorative treatment on mutans streptococci and IgA antibodies.

PURPOSE: Streptococcus mutans has been implicated as the major causative agent of dental caries. Although restorative treatment for caries is thought to temporarily eliminate the carious challenge, there are few reports of alterations in salivary mutans streptococci (MS) numbers and no reports of changes in salivary IgA antibody to S. mutans following restorative treatment. METHODS: This study investigated the effects of treatment in 12 caries-active children. RESULTS: Numbers of MS decreased slightly from pre- to postrestoration levels in six subjects and increased in five subjects. However, there were no significant differences in pre-to postrestoration numbers of total oral streptococci, MS, the percentage of MS/total oral streptococci, salivary IgA antibody levels to S. mutans, or correlations between bacterial counts and IgA antibody levels. CONCLUSIONS: These results indicate that successful restorative treatment does not alter mutans streptococcal numbers and suggest the need for more effective methods for reducing the cariogenic challenge.

Antibodies, Bacterial↗