Dental caries experience in a Connecticut Head Start program in 1991 and 1999.

PURPOSE: Reports from most industrialized countries suggest that dental caries in children has been declining over the last 50 years. However, this trend may be reversing, especially in younger children. The aim of the present study was to compare caries levels and patterns of 3- and 4-year-old Head Start children observed in 1999 with those observed in 1991. METHODS: Clinical dental caries data were collected from 517 children enrolled in the Hartford, Conn, Head Start program in 1999 and compared to similar data from 311 children attending the same Head Start program in 1991. No radiographs were used in either sample. RESULTS: In 1999, a mean dmft score of 1.49 and a caries prevalence of 38% was found compared to 1.68 and 49%, respectively, in 1991. When only those with caries were considered, both the mean dmft and mean dmfs were greater in 1999 than in 1991. In 1999, 57% of carious surfaces were treated compared to only 39% in 1991. Furthermore, this increased treatment was seen predominantly in those with greatest severity of disease. When the patterns of disease were analyzed, children in 1999 had greater levels and severity of maxillary anterior caries compared to 1991. No differences in pit and fissure caries and posterior proximal caries were observed. CONCLUSIONS: The overall prevalence of dental caries in the study population was less in 1999 than 1991, however, those with disease experienced a greater severity.

Salivary mutans streptococci and caries development in the primary and mixed dentitions of children.

OBJECTIVES: For more than 25 years, both cross-sectional and longitudinal studies of dental caries have focused on the role of salivary mutans streptococci (SMS) as a predictor of caries risk. This study examined the relationship between SMS and longitudinal caries development in the primary and mixed dentitions. METHODS: Eighty-five children, initial mean age 3.8 years, were examined for dental caries at baseline and once annually for 6 years. Children's SMS were sampled with a tongue blade, which was impressed onto plates containing a medium selective for SMS. After incubation, colony forming units of SMS were determined semi-quantitatively and categorized as low, moderate or high. RESULTS: Children classified as high caries risk at baseline had significantly greater (P<0.05) dmfs scores for all teeth, and in the primary molars, than children classified as moderate or low caries risk at every age but 9 (P<0.10). Children classified as high risk at age 3 had the greatest DMFS increment through age 8. Based on annual examinations, there was a trend towards increasing mean dmfs/DMFS scores among children classified as high risk in every year. CONCLUSIONS: The current study is among the first to report on the ability of annual measurements of SMS to identify long-term caries risk in both the primary and the mixed dentitions. Despite limitations in predicting caries risk using microbiological methods, this longitudinal study supports the overall benefits of this type of testing.

Peroral famciclovir in the treatment of experimental ultraviolet radiation-induced herpes simplex labialis: A double-blind, dose-ranging, placebo-controlled, multicenter trial.

Three doses of famciclovir were tested for treatment of experimental ultraviolet radiation (UVR)-induced herpes labialis. Patients received 125, 250, or 500 mg of famciclovir or placebo 3 times a day for 5 days beginning 48 h after UVR exposure, a model of early episodic intervention. Of 248 patients irradiated, 102 developed lesions while on treatment. There were no significant differences between groups in the number of lesions. The mean maximal lesion size was reduced in a dose-proportional manner: 139, 105, 77, and 55 mm2 for the placebo and 125-, 250-, and 500-mg famciclovir groups, respectively (P=.040, linear regression). Median time to healing was faster in the 500-mg famciclovir group than in the placebo group, both by investigator (4 vs. 6 days, 33% reduction, P=.010) and patient assessment (3.0 vs. 5.8 days, 48% reduction, P=.008) analyses. These findings suggest that evaluation of higher drug doses for herpes labialis treatment is warranted.

Measurement of lip and skin pigmentation using reflectance spectrophotometry.

Previous methods for evaluating the color of oral epithelial tissues have relied primarily on subjective indices and interpretation. In this study, a narrow-band reflectance spectrophotometer was used to measure melanin and hemoglobin pigmentation in the lips and skin of individuals who self-reported their skin type from a choice of white, olive, or black. Significant differences in melanin pigmentation were observed among skin types and at most anatomical sites evaluated between skin types. Hemoglobin levels were not significantly different among skin types at most anatomical sites, but differences were observed among anatomical sites within each skin color group. Within each skin type, melanin (except in blacks) and hemoglobin were significantly higher for both the upper and lower lips compared with most other anatomical sites. Results suggest that reflectance spectrophotometry is a useful tool for quantifying differences in melanin and hemoglobin pigmentation in oral tissues.

Caries experience and mutans streptococci as indicators of caries incidence.

Studies indicate that previous caries experience can influence future caries development; however, caries-free individuals also may develop caries. The aim of this study was to examine the relationship between baseline caries experience and salivary mutans streptococci (SMS) levels as an indicator for predicting caries incidence in pre-school children. One hundred forty-eight preschool children (mean baseline age, 3-8 years) of low socioeconomic status were examined for dental caries and SMS levels at baseline and annually for 2 years. All children were identified at baseline as either caries free or caries positive. The 2-year delta dmfs scores for both groups were evaluated as 0, 1-2, 3-4, or > 4. The children's baseline SMS levels were categorized as low (0 CFU), moderate (1-50 CFU), or high (> 50 CFU), and were recoded to assigned ranges of 1, 2, and 3, respectively, in each year for longitudinal analysis. Both the caries-free and caries-positive groups had high SMS levels associated with the greatest delta dmfs, and when SMS ranges were added for the three examination years (minimum = 3, maximum = 9), the mean second-year dmfs scores varied directly as the sum of the ranges. Results from this study suggest that SMS levels may be useful in identifying and predicting future caries in preschool children, independent of baseline caries experience.

Salivary mutans streptococci and dental caries patterns in pre-school children.

Recent studies have suggested that the identification of caries as discrete patterns may be valuable in describing and predicting caries experience on an individual basis. The purpose of this study was to assess the association between levels of salivary mutans streptococci and the prevalence, incidence and distribution of caries patterns in the primary dentition. A cohort of pre-school children (n = 146, mean age 3.8 yr) were examined for dental caries and sampled for salivary mutans streptococci (SMS) at baseline and once annually for 2 yr. Children's tooth surfaces were categorized into four patterns: pit/fissure, maxillary anterior, posterior proximal, and buccal/lingual smooth surface. Salivary mutans streptococci were enumerated using a tongue blade technique, and were categorized as low (0 CFU), moderate (1-50 CFU) and high (> 50 CFU). At year 2, children with high baseline SMS had the 1) highest prevalence of caries (87%) and the highest dmfs (9.15); 2) highest prevalence of each pattern, and 3) greatest number of patterns. Among children with the pit/fissure pattern, those with high baseline SMS had the greatest pit/fissure dmfs after 2 yr. Results show that baseline SMS levels were associated with both cross-sectional and longitudinal caries experience, numbers of caries patterns, and the prevalence and severity of those patterns.

Salivary mutans streptococci and incidence of caries in preschool children.

The aim of this study was to assess the relationship between salivary mutans streptococcus (SMS) levels and the prevalence and incidence of dental caries in 148 children (mean baseline age 3.8 years) of low socioeconomic status. Caries data (dmfs) and semiquantitative SMS counts were obtained at baseline and annually for 2 years. The children were classified during each of the 3 years as low (0 colony-forming units; CFU), moderate (1-50 CFU), or high (> 50 CFU) caries risk based on total SMS counts. The results indicated that the prevalence of dental caries increased with SMS levels at baseline and generally in both assessment years. At baseline the mean dmfs of the children classified as low, moderate, or high caries risk was 0.15, 1.44, and 3.36, respectively, while the mean dmfs of the same children at year 2 was 1.18, 3.10, and 7.87, respectively. The mean dmfs of the high-caries-risk group increased by 79% between baseline and year 1 and by 30% between year 1 and year 2. At year 2, 50% of the children in the low- and 47% in the moderate-caries-risk groups were caries free as compared with 11% in the high-caries-risk group. Thirty-three percent of the children examined remained in the same caries risk category from baseline to year 2; the incidence (delta dmfs) of dental caries in those children designated as low, moderate, and high caries risk during this period was 1.44, 3.36, and 10.07, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Mutans streptococci and caries prevalence in preschool children.

Numerous studies have reported a correlation between mutants streptococci levels and dental caries. The aim of this study was to assess the relationship between salivary mutans streptococci levels and caries in preschool children of low socioeconomic status. A total of 462 Head Start children, mean age 3.8 yr (range 2.0-5.3 yr), were examined by the modified method of Radike. Saliva samples from 458 of these children were collected with tongue blades and impressed onto mutants streptococci selective agar. Children's mutants streptococci levels were categorized as low (0 CFU), moderate (1-50 CFU) or high (> 50 CFU), and the mean dmfs was 0.40, 1.92 and 4.88, respectively. All study groups (Black, Hispanic and White) had infection rates of approximately 83%; however, 39.1% of Black children had high mutans streptococci levels compared with 28.4% of White children. Pit/fissure caries was the most prevalent disease type in children with moderate or high mutants streptococci levels, although White children in the high group had significantly less of this pattern than Blacks and Hispanics. Sensitivity, specificity, and positive and negative predictive values for the high mutants streptococci group were 91.3%, 57.5%, 69.3% and 86.3%. Results from this study indicate that differences between Black, Hispanic and White preschool children may influence caries activity within populations that have similar mutants streptococci infection levels and socioeconomic backgrounds.

Survey of the medical history questionnaire.

The purpose of this study was to examine and to compare the type of information requested on representative health history questionnaires commonly used by the dental profession. Samples of medical history questionnaires were obtained from American and Canadian dental schools, commercial vendors, and the American Dental Association. Results indicated that more than 140 questions have been included on questionnaires and more than 92% of these appeared in some type of yes-or-no format. The number of questions per form ranged from 32 to 88, with an average of 58 items. Although there was wide variation in the range of information requested, the 25 most frequently asked questions occurred in 70% of the forms. The majority of questions focused on noninfectious disease conditions that affect the cardiovascular system and major organ functions, allergies, and blood disorders; infectious diseases such as hepatitis, tuberculosis, mumps, and venereal disease; and health care status and special treatment considerations.

Chain formation and de-chaining in Streptococcus sobrinus SL-1.

Regulation of chain length by chain-forming bacteria is believed to depend on wall-associated autolytic activity and environmental conditions. In this study, the chain length of Streptococcus sobrinus SL-1 was determined under various initial culture and pH conditions and NaF concentrations. Crude wall extracts were prepared by dilute alkali treatment of whole cells and were tested for de-chaining activity. The results indicate that S. sobrinus SL-1 grows primarily as short chains under alkaline growth conditions and at high (3.0 mM) medium fluoride levels, and growth as long chains occurs under acidic growth conditions. De-chaining activity was observed following incubation of the longer chain form of the organism with crude wall extracts. The evidence suggests that the chain length of S. sobrinus SL-1 depends on environmental conditions, including pH and fluoride, and that cell wall-associated factors may be active in regulating the chain length of the organism.

pH-dependent fluoride inhibition of catalase activity.

The inhibitory effects of fluoride on several catalases were examined over a range of pH conditions. Preparations of bovine-liver catalase were sensitive to fluoride under acidic conditions. Catalase activity associated with whole-cell preparations of Actinomyces viscosus NP 311A remained relatively constant between pH 3.0 and 8.0 and was inhibited by fluoride in a pH-dependent manner. Fluoride was also observed to enhance hydrogen peroxide killing of A. viscosus NP 311A under acidic pH conditions. Results suggest that some catalase enzymes, including those associated with common plaque bacteria, may be inhibited by fluoride in a pH-dependent manner.

pH-dependent fluoride inhibition of peroxidase activity.

Fluoride was found to be a potent inhibitor of bovine lactoperoxidase and of salivary peroxidase at acid pH values. Inhibition was reversible at neutral pH, and appeared to involve HF binding by the enzyme. Fluoride inhibition of lactoperoxidase occurred with all reductants tested, including thiocyanate, iodide, and guaiacol. Fluoride concentrations for 50% inhibition of enzymatic activity with iodide as reductant were: less than 0.05 mM at a pH value of 4.0, 0.3 mM at 5.0, 4.0 mM at pH 6.0, and more than 10.0 mM at pH 7.0. Salivary peroxidases were found to have lower pH optima but to be approximately as sensitive to acid-dependent fluoride inhibition as was purified bovine lactoperoxidase. The findings suggest that the fluoride in dental plaque may be inhibitory to the antimicrobial peroxidase system.

Reduction of acidurance of streptococcal growth and glycolysis by fluoride and gramicidin.

The acidurance of glycolysis by intact cells of Streptococcus mutans GS-5, Streptococcus salivarius ATCC 25925, and Streptococcus sanguis NCTC 10904 was found to be highly dependent on membrane functions affected by gramicidin, which increases the proton permeability of cell membranes. Plots of % glucose utilized during two hours against suspension pH values for cells suspended in 100 mM phosphate buffer plus 1 mM MgCl2 plus 13.9 mM glucose indicated, for 50% glucose utilization, pH values of 5.0 for S. mutans, 5.7 for S. salivarius, and 6.2 for S. sanguis. Gramicidin treatment shifted these values to 6.0, 6.3, and 6.9, respectively. Growth of S. mutans and S. salivarius in complex media proved to be more acid-sensitive than was glycolysis, and in batch cultures, there was a well-defined, post-growth phase of glycolysis. Minimum pH values for growth and for glycolysis in medium with excess glucose were approximately 4.8 and 4.4, respectively, for S. mutans, and 4.9 and 4.3 for S. salivarius. S. sanguis was less aciduric and showed little differential acid sensitivity, with minimum pH values of about 5.2 for both growth and glycolysis. Fluoride acted to eliminate the differences in acidurance of growth and glycolysis for S. mutans or S. salivarius and to render both processes more acid-sensitive. Thus, glycolysis was more fluoride-sensitive than was growth. Growth was found to be acid-limited in media with initial glucose levels greater than 0.2, 0.3, and 0.5% (weight/volume) for S. sanguis, S. mutans, and S. salivarius, respectively, and to be glucose-limited at lower levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid sensitivity of glycolysis in normal and proton-permeable cells of Streptococcus mutans GS-5.

Gramicidin, an ionophoric antibiotic which enhances proton permeability of cell membranes, was found to increase the acid sensitivity of glycolysis by intact cells of Streptococcus mutans GS-5, to inhibit uptake of 2-deoxyglucose at pH values of 5.5 or less, and to cause a decrease in the intracellular levels of early intermediates of glycolysis. The inhibitory effects of the antibiotic on glycolysis at low pH values were related to inhibition of sugar uptake via the phosphotransferase system.

Inhibition and killing of oral bacteria by silver ions generated with low intensity direct current.

Silver cations generated by passing low intensity direct current through pure silver electrodes were found to be sufficiently antibacterial to cause sterilization of samples of infected dentin. The optimal procedure involved a 5 microA current applied for 20 minutes with the anode then left in contact with the sample. Minimal inhibitory concentrations of electrically generated silver ions for representative oral bacteria were essentially equal to those for silver ions added as nitrate or fluoride salts, and medium constituents, including sodium thioglycolate, antagonized antibacterial action. A major advantage to the use of the electrode method is that it allows for continuous, focal application of antibacterial silver cations.