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Biomedical subjects

S A Mundorff-Shrestha

Publications and source records attributed to S A Mundorff-Shrestha.

7 recordsLinked to original sources
PubMed2004

Clinical outcomes for Early Childhood Caries (ECC): the influence of salivary mutans streptococci levels.

AIM: To assess the relationship between clinical outcomes for children treated for Early Childhood Caries (ECC) and salivary mutans streptococci (MS) levels. STUDY DESIGN AND METHODS: The study cohort consisted of 79 children (42 males, 37 females) treated for ECC, aged from 2.3 to 7.3 years at time of entry. Whole non-stimulated saliva samples were obtained from each subject prior to dental surgery and at 6 mths post dental surgery, by saturating a cotton swab in the saliva pooled in the floor of the mouth. Samples were placed into PBS on ice and processed within 2 hours. Samples were sonicated, serially diluted and plated onto MSB and SBA agar plates, then incubated 48 hours anaerobically; SBA plates were incubated an additional 24 hours aerobically. The MS level in each sample was expressed as a percentage of the total cultivable flora. The cohort was evaluated for new caries lesions at 6 months post dental surgery. Relapse was defined as the presence of new smooth surface caries lesions. STATISTICS: Comparisons between Relapse (R) and Non-Relapse (NR) groups with respect to mutans streptococci levels were performed using Wilcoxon tests. Within group comparisons were performed using Wilcoxon signed-rank tests. RESULTS: 57 children (72%) returned for the 6 months examination and 21 of these subjects (37%) relapsed. No statistically significant difference in median salivary MS levels existed between the R (0.20%) and NR (0.033%) groups at baseline (p=0.647) or at 6 months post dental surgery (R=0.03%; NR=0.01%; p=0.273). A statistically significant difference between baseline and 6 months post dental surgery was noted in the median salivary MS level within the R group (p=0.0007) and within the NR group (P<0.0001). CONCLUSIONS: The relapse rate (37%) was high and rapid for children treated for ECC. Dental surgery resulted in a statistically significant reduction in salivary MS reservoirs for children treated for ECC. However, this did not translate into acceptable clinical outcomes.

Child↗
PubMed1999

Cariostatic effect of a two-part fluoride dentifrice in rats.

This study compared the cariostatic effect of a two-part, fluoride-calcium-phosphate-containing prototype dentifrice (containing 1100 ppm F) to a conventional, clinically proven effective "gold standard" (1100 ppm F, USP Standard) and an Enamelon placebo dentifrice (0 ppm F) using a rat model. Three groups of 18 Crl:CDR(SD)BR rats were inoculated with S. sobrinus 27352 and fed MIT-200 for 35 days in a programmed feeder. Double-deionized water (DDW) was given ad libitum. The rats were treated twice daily with one two-part dentifrice. Just prior to treatment, each of the two parts of dentifrice were mixed 1:1 and applied undiluted. The rats were euthanized and their mandibular molars scored for caries using the Keyes quantification method. Shrestha SNP caries scores were then calculated. Non-parametric comparisons were done among treatments at the 0.05 level of significance using analyses based on ranks. The mean Shrestha SNP Caries Scores +/- standard deviations for the prototype dentifrice, USP standard and Enamelon placebo were 84.9 +/- 62.8, 101.3 +/- 66.3, and 181.2 +/- 100.1, respectively. Scores for the 1100 ppm F prototype treatment were significantly lower than the USP Standard and the Enamelon placebo. These results indicate that the new prototype dentifrice, containing fluoride-calcium-phosphate, increased the anti-caries efficacy in a rat model when compared with a fluoride-containing USP Standard dentifrice.

Administration, Topical↗
PubMed1995

Effects of sodium bicarbonate dentifrices on the levels of cariogenic bacteria in human saliva.

This investigation evaluated the efficacy of two bicarbonate-containing dentifrices (one with fluoride and one without) against one placebo dentifrice (containing neither fluoride nor bicarbonate) in vivo in a panel of human volunteers to determine whether or not sodium bicarbonate would affect salivary mutans streptococci and lactobacilli. Ten caries-inactive adults were divided randomly into three groups, each of which was exposed to all three dentifrices, in a crossover manner, during three 4-week test periods. Saliva samples were taken at 1-week intervals. Samples were stored on ice, and microbiological analyses were conducted. The statistical analyses showed that, over a 4-week period, there was a statistically significant (p < 0.05) reduction in numbers of mutans streptococci with the two bicarbonate dentifrices as compared with the placebo dentifrice. Although not statistically significant, a similar trend was observed with lactobacilli. Longer-term, large-scale studies need to be conducted to investigate the possible mechanisms of action of sodium bicarbonate on these organisms and to relate the results to possible cariostatic effects in humans.

Adult↗
PubMed1994

Cariogenic potential of foods. II. Relationship of food composition, plaque microbial counts, and salivary parameters to caries in the rat model.

A series of rat caries experiments was carried out to test the relative cariogenic potential and to identify the major carcinogenic elements of 22 popular snack foods. Parameters that were measured included rat caries, number of cariogenic bacteria in plaque, salivary parameters including flow rate, buffering capacity, total protein, lysozyme and amylase content, and composition of test foods including protein, fat, phosphorus, calcium, fluoride, galactose, glucose, total reducing sugar, sucrose, and starch. Many interesting relationships were observed between food components, numbers of plaque bacteria, salivary components, and specific types of carious lesions. Protein, fat, and phosphorus in foods were all associated with inhibition of both sulcal and buccolingual (smooth-surface) caries. Food fluoride was associated with inhibition of buccolingual caries, whereas calcium was related to inhibition of sulcal caries. Glucose, reducing sugar, and sucrose in foods were all related to promotion of both sulcal and smooth-surface caries. The numbers of Streptococcus sobrinus in plaque were associated with promotion of smooth-surface caries only, whereas lactobacilli, non-mutans bacteria, and total viable flora were related to promotion of both smooth-surface and sulcal caries. The salivary flow rate was associated with inhibition of both buccolingual and sulcal caries. Salivary buffering capacity (at pH 7) and salivary lysozyme delivery were associated with inhibition of number and severity of sulcal caries, while the salivary amylase content was related to the promotion of the number of sulcal lesions.

Amylases↗
PubMed1993

Caries risk assessment by a cross-sectional discrimination model.

Although the prevalence of dental caries is continuing to decline, it still affects a majority of the US population and can be a serious problem for those afflicted. The objective of this project was to develop and perfect a model for assessment of risk of dental caries onset in children. In the first study, reported herein, a set of clinical, microbiological, biochemical, and socio-demographic variables was identified that distinguished, with an acceptable level of sensitivity and specificity, between children who had no previous caries experience and children who had high caries levels. A total of 313 children--age 12-15 years, 140 from a fluoridated community and 173 from a fluoride-deficient community--was selected on the basis of previous caries experience, either zero DMFS or high DMFS (> or = 6 in the fluoridated or > or = 8 in the fluoride-deficient community). Clinical exams for DMFS, dental fluorosis, and plaque were conducted. Stimulated whole saliva was collected for analysis of mutans streptococci, lactobacilli, total viable flora, and fluoride concentration. A questionnaire was used for collection of demographic data as well as information on prior fluoride exposure, dietary habits, and oral hygiene practices. By means of discriminant analyses, with use of seven key clinical and laboratory variables, it was possible for zero-DMFS subjects to e classified correctly (specificity) in 77.6% of cases in the fluoridated community and in 86.1% of cases in the fluoride-deficient community. High-caries subjects were classified as such (sensitivity) in 79.3% and 88.1% of cases, respectively.

Adolescent↗
PubMed1993

Caries risk assessment in a longitudinal discrimination study.

Our objective was to develop and perfect a model for the assessment of risk of dental caries onset in children. Even though dental caries prevalence in children is continuing to decline, there is still a significant minority for whom it is a problem. In this study, we sought to ascertain whether a set of variables selected in a previous cross-sectional study could be used to differentiate between caries-free six-year-olds who would or would not subsequently present with clinically-detectable caries. A total of 472 caries-free six-year-olds--286 from a fluoridated community and 186 from a fluoride-deficient community--was selected. Clinical examinations for DMFS, dental fluorosis, and plaque were conducted. Stimulated whole saliva was collected for analysis of mutants streptococci, lactobacilli, total viable flora, and fluoride, calcium, and phosphate concentrations. A questionnaire was used for collection of demographic data as well as information on prior fluoride exposure, dietary habits, and oral hygiene practices. By means of linear discriminant analyses, it was possible to predict correctly which children would develop caries within six to 12 months (sensitivity) in 82.8% of cases and which children would not develop caries during that period (specificity) in 82.4% of cases.

Apatites↗