Oral colonisation by aerobic and facultatively anaerobic Gram-negative rods and yeast in Tibetans living in Lhasa

Sample groups of children (n=50) and adults (n=38) were selected from pools of 207 children, (11-13-year olds from two primary schools) and 94 adults (25-44-year olds from four governmental agencies) who were the subjects of an oral health survey among Tibetans living in Lhasa, Tibet Autonomous Region. Mean ages of the study groups of children (38% females) and adults (61% females) were 11.6+/-0.9 and 37.1+/-6.1 years, respectively. All had lived in Tibet since birth. Oral rinse samples were selective cultured to isolate, quantify and speciate aerobic and facultatively anaerobic Gram-negative rods (using the API 20E kit) and yeasts (using API 20C AUX and API ZYM kits). For children, the isolation rates for oral coliform bacteria and yeasts were 84 and 14%, respectively, for adults, the respective rates were 26 and 40%. The corresponding quantities of coliforms/yeasts for children and adults were 0.4+/-1.6 x 10(3)c.f.u./15.8+/-72.3 and 0.2+/-0.6 x 10(3)c.f.u./57.2+/-137.5c.f.u. per millilitre oral rinse, respectively. Aerobic and facultatively anaerobic Gram-negative rods and Stenotrophomonas maltophilia, a free-living saprophytic and ubiquitous bacterial species of wide geographic distribution, were significantly more frequently recovered from the children's oral rinses. The isolation rates of facultatively anaerobic Gram-negative rods in adults and yeasts in both groups were similar to those found in similar cohorts from southern China in earlier studies. Randomly amplified polymeric DNA analysis showed that the S. maltophilia spp. isolated from children were of several different clonal types and were school specific. This study shows that the colonisation rate of facultatively anaerobic Gram-negative rods in adults and yeasts in both groups are similar to those in populations living at lower altitudes, the native young, urban Tibetans appear to exhibit a high oral carriage rate of S. maltophilia spp.     

Trends in dental caries in children and adolescents according to poverty status in the United States from 1999 through 2004 and from 2011 through 2014

Background

Except for a small increase in caries prevalence in young children from 1999 through 2004, the prevalence of pediatric caries in the United States has remained consistent for the past 3 decades.

Efficacy of an adenosine triphosphate meter for evaluating caries risk in clinical dental practice

BackgroundAdenosine triphosphate bioluminescence (ATP-B) readings have been proposed as markers of caries risk. ATP readings may indicate bacteria or oral streptococci activity in microbial plaque. The authors of this study aimed to evaluate whether readings using a commercial ATP meter (CariScreen Testing Meter, Oral BioTech) are significantly different for patients with low, moderate, and high caries risk in the Caries Management by Risk Assessment Practice-Based Research Network study.MethodsTwenty practice-based research network dentists enrolled 460 patients; 271 returned for 2 or more semiannual follow-up visits over 2 years. Dentists were trained and calibrated to perform ATP-B testing and caries risk assessment (CRA) using established protocols. ATP-B readings were compared via CRA category (low, moderate, high). Generalized estimating equations were used to compare the risk of experiencing incident clinical outcomes (newly recorded decayed, missing, or restored tooth surfaces and CRA disease indicators) according to ATP-B reading at prior patient visits (≥ 1,500 versus < 1,500 relative light units).ResultsMedian ATP-B readings did not differ statistically significantly by clinician-assessed caries risk level (low, 2,323; moderate, 2,940; high, 3,217; P = .65). Adjusted for patient demographics and trial intervention assignment, higher readings were not associated with newly developed decayed, missing, or restored tooth surface (relative risk, 1.57; 95% confidence interval, 0.55 to 4.45) or disease indicators (relative risk, 1.08; 95% confidence interval, 0.85 to 1.37) at the following visit, whereas clinician-assessed caries risk level was strongly associated.ConclusionsATP-B readings poorly predicted caries risk and future clinical outcomes. CRA incorporating multiple risk, protective, and disease indicators has superior predictive performance.Practical ImplicationsThe findings of this study do not provide evidence supporting the use of ATP-B to predict caries risk.