Faculty Bibliography

Prevalence of mutans streptococci (MS) and the effect of selected variables, including the early childhood use of antibiotics on the oral colonization of MS, were studied among 353, 5- to 12-year-old African-American children using a cross-sectional study. MS prevalence was estimated using pooled plaque and stimulated saliva samples (spatula). Data on antibiotic use and other potential determinants of oral colonization of MS were obtained using a self-administered questionnaire. Antibiotic data were validated using health records of subjects. MS prevalence (92%, 95% Confidence Interval [CI] = 89-95%) was associated with dental caries (Odds Ratio [OR] = 2.5, 95% CI = 1.3-6.2), age (Chi for trend = 4.3, P = 0.04), increased frequency of sweet consumption (Chi for trend = 5.1, P = 0.02), and increased number of teeth in the mouth (unit OR = 1.3, 95% CI = 1.1-1.6). Higher MS levels were associated with higher number of decayed teeth (P < 0.0001), and also, with having the mother as the primary caregiver during the second year of life (P = 0.02). Furthermore, children who took antibiotics during early childhood and those who lived in the same household with many others during the second year of life had a higher MS prevalence than those who did not (OR = 8.3, 95% CI = 2.0-35.0; unit OR = 1.5, 95% CI = 1.03-2.2, respectively). It is unclear why those exposed to antibiotics during the "window of infectivity" of MS exhibit a higher MS prevalence. Antibiotic-related oral ecological changes (i.e, lower levels of S. sanguis) and environmental changes (i.e., frequent exposure to sugar through most pediatric antibiotic preparations) may make the oral cavity more favorable for initial MS colonization.

Different methods reported for assessing mutans streptococci (MS) make the direct comparisons of results across studies difficult. To quantitate the variations of MS estimates attributable to differences in method, stimulated and unstimulated saliva samples and oral swab samples were compared with pooled dental-plaque samples. Detection of MS in stimulated saliva samples was in excellent agreement with the presence of MS in pooled plaque samples. MS detection in unstimulated saliva samples, however, was significantly discordant with that in either pooled plaque or oral swab samples. When caries status was used as the criterion of validity of MS estimates, stimulated saliva samples demonstrated a sensitivity (94%) similar to that of pooled plaque samples, but exhibited a lower specificity (11%) than that of pooled plaque samples (17%). As a result, the measure of association between MS and caries was biased (towards null) when MS status was based on stimulated saliva samples. Interestingly though, in enumerating MS, stimulated saliva samples yielded significantly higher levels of MS (about 1.5 log10 increase) with a lower variability compared to unstimulated saliva samples. The use of different culture media for detection of MS gave different results as well. MS detection was poor (kappa = 0.31) and MS levels were lower (p = 0.0001) when samples were grown on glucose-sucrose-potassium tellurite-bacitracin agar compared to mitis-salivarius-bacitracin agar. Together with the relative ease of sampling and processing, these findings collectively justify the use of plaque samples for the qualitative assessment of MS and stimulated saliva samples for the quantitative assessment of MS, while providing a basis for adjustment of estimates when comparing results across studies.

We compared the mother's recall of her child's antibiotic use with the information obtained from the child's health records, while studying the association between antibiotic use and prevalence of mutans streptococci among 102 (5-12 years) inner-city black children. Poor recall of the mother (concordance ratio = 62 percent; kappa = 0.18, p = 0.06) and the lower frequency reported by her (p = 0.02) biased the positive association between child's antibiotic use during the second year of life and oral presence of mutans streptococci toward the null value (Odds Ratio [OR] based on health records = 3.1, 95 percent Confidence Interval [CI] = 1.03-9.3; OR based on mother's recall = 1.6, 95 percent CI = 0.44-5.8). Multiple logistic regression analysis failed to identify any significant determinant of the accuracy of the mother's recall. Since mothers considerably underestimate child's use of antibiotics, at least among inner-city low income blacks, this method of data collection should be limited to circumstances where no other options are available, and such results should be interpreted with caution.

In a randomized clinical trial, six applications of an I2-NaF or a placebo solution were administered to the mothers' dentition at the time of tooth emergence of her infant, to evaluate its effect on transmission of mutans streptococci (MS) to the infant. MS and other bacterial levels were periodically monitored in 48 mother-infant pairs until the child's third birthday. There were significant reductions in maternal salivary MS (P = 0.04), lactobacilli (P = 0.04), total streptococci (P = 0.002), and total cultivable organisms (P = 0.004) immediately following treatment. In children, 3-yr incidence of MS colonization and the time of acquisition of MS or the caries experience did not differ significantly between the two groups. We conclude that short-term application of I2-NaF to the maternal dentition of predentate infants significantly lowers MS, lactobacilli, total streptococci, and total cultivable bacteria in mothers' saliva, but does not influence the incidence and the time of acquisition of MS or the caries experience in children.

Oral bacterial levels of 46 mother-child pairs were monitored from infant birth up to five years of age so that the acquisition of mutans streptococci (MS) by children could be studied. The initial acquisition of MS occurred in 38 children at the median age of 26 months during a discrete period we designated as the "window of infectivity". MS remained undetected in eight children (17%) until the end of the study period (median age of 56 mo). The levels of both MS and lactobacilli in saliva of mothers of children with and without MS were not significantly different. Comparisons between a caries-active cohort colonized by MS (nine of 38) and children without detectable MS revealed similar histories in terms of antibiotic usage, gestational age, and birth weight. Interestingly, half of the children between the ages of one and two years who were not colonized by MS were attended by caretakers other than the mother, while all of the caries-active children during this same time period were cared for by their mothers; the difference was statistically significant. Here we report for the first time that MS is acquired by infants during a defined period in the ontogeny of a child. Support for the notion of a discrete window of infectivity comes from other sources, including animal models.

Oral complications during cancer therapy are a common source of discomfort and a potential source of systemic infection. We report the results of a 2 1/2-year prospective follow-up study on the incidence of oral complications in 214 pediatric patients with cancer. Overall, the incidence of ulcers in these patients ranked highest followed by gingivitis. Children with sarcomas had more ulcers (p = 0.03) and Candida infections (p = 0.03) than those with leukemia. The rate of gingivitis among patients with leukemia was five times higher than in patients with sarcoma (p = 0.02). Candida infections in children with solid tumors occurred four times more often than in patients with leukemia (p = 0.02). This study shows that oral complications are a frequent cause of morbidity in children with cancers and are more common in some cancers than in others. Oral complications may be prevented or diminished in severity by identifying the risk groups and developing preventive and treatment strategies

The objective of the study was to document the existence of localized deficiency of folate in a tissue exposed to cigarette smoke, by analysis of oral and circulatory levels of this vitamin in smokers and non-smokers. Buccal mucosal cells and blood samples were collected from 25 smokers and 34 non-smokers. The Health Habits and History Questionnaire was completed by each subject. A 96-well plate L. casei assay, along with preincubation with a folate-free chick pancreas pteroyl-gamma-glutamyl hydrolase, was used to quantitate total buccal mucosal cell folates. The reproducibility (CV 5 to 7%) and recovery (95 to 106%) of the folate assay were satisfactory. Smokers had significantly lower buccal mucosal cell folate levels than did non-smokers. The mean plasma folate level of smokers although within normal limits, was also significantly lower than that of non-smokers. There were no significant differences in mean dietary folate intake or in alcohol consumption between the 2 groups. The strength of the positive association between smoking and plasma and buccal mucosal cell folate deficiency (by any definition) was moderate to strong and statistically significant. Our results indicate that cigarette smoking may result in a localized folate deficiency in buccal mucosal cells, independent of the plasma folate levels

Dental caries results from the dissolution of mineralized dental tissues by the metabolic by-products of oral bacteria colonizing the surface of teeth. The principal modality for dealing with this infectious process is through restorative treatment which removes the pathologic tissue and replaces it with a variety of inert materials. The purpose of this study was to evaluate the effect of traditional restorative treatment on select oral bacterial populations. Fifty-two females demonstrating high levels of mutans streptococci (greater than or equal to 2.5 x 10(4) colony forming units (cfu) per ml saliva) with no more than four missing posterior teeth were recruited for this study. Salivary levels of mutans streptococci, lactobacilli, total streptococci, and total cultivable bacteria were evaluated before, during, and after restorative treatment. Initial DMFS scores were established by two standardized examiners using bitewing radiographs and clinical examination, which was conducted under optimal conditions. All restorative treatment was completed by faculty members of the University of Alabama School of Dentistry using treatment plans developed by the DMFS examiners. The participants received a mean of 16.4 restored surfaces, which resulted in significant reductions of all the bacterial populations tested. All microbial populations monitored were predicted to return to their baseline levels within 151 days after restorative treatment in 50% of the participants. This study shows that conventional restorative treatment results in a significant reduction of bacterial populations including those associated with the dental caries process, i.e., mutans streptococci and lactobacilli.(ABSTRACT TRUNCATED AT 250 WORDS)