OBJECTIVES: To investigate the impact of feeding habits and daytime sugar intake on the prevalence of early childhood caries in a population where prolonged breastfeeding is a norm.

METHODS: A cross-sectional study was carried out at 18 of 102 public health centers in Tehran. During a 4-day period at each center, between 20 and 35 children aged 1-3 years were enrolled, resulting in a sample of 504 children. In structured interviews, mothers were asked to give information about their child's feeding habits, daytime sugar intake, and their family's background. Sugar intake during the night was operationalized as separately calculated burdens of nighttime breastfeeding and bottle-feeding. Clinical dental examinations followed the World Health Organization criteria. Data analysis included chi-square test, t-test, ANOVA, and logistic regression modeling.

RESULTS: Of the children, 56% were solely breastfed (mean duration 16.6 months; 95% CI 16.0-17.2), 42% were both breastfed and bottle-fed, and 2% were solely bottle-fed. Mean duration of breastfeeding for the solely breastfed 24- to 36-month olds was 22.8 months (95% CI 21.8-23.9). At bedtime, 69% were breastfed, 11% bottle-fed, and 20% were not fed at all. With respect to feeding during the night, 72% of children were breastfed, 12% were bottle-fed with milk, 1% received a bottle with water, while 15% were not fed. Early childhood caries (ECC) occurred in 3-26% of the children, depending on age group (P<0.001). The burden of milk-bottle feeding at night was a clear determinant for ECC (OR = 5.5) whereas breastfeeding per se, its duration, the burden of breastfeeding at night, and daytime sugar intake were not.

CONCLUSION: On account of its association with ECC, milk-bottle feeding at night should be limited, whereas prolonged breastfeeding appears to have no such negative dental consequences.

BACKGROUND: One strategy for treating dental caries is to suppress oral mutans streptococci, or MS, with chlorhexidine, or CHX, mouthrinse. Oral MS levels, however, tend to quickly return to baseline values without further intervention. In this clinical study, the authors evaluated the effect of xylitol chewing gum on MS regrowth. METHODS: The authors selected 151 subjects with elevated oral MS levels (>or = 105 colony-forming units per milliliter, or CFU/mL, of paraffin-stimulated saliva). Subjects rinsed with 0.12 percent CHX gluconate mouthrinse twice daily for 14 days. The authors then randomly assigned the subjects to one of three groups. Those in the test group (n = 51) chewed a commercial xylitol gum three times daily for a minimum of five minutes each time for three months. The placebo group subjects (n = 50) used a commercial sorbitol gum, and the control group subjects (n = 50) did not chew gum. The authors estimated MS load on the dentition using paraffin-stimulated saliva samples. The authors serially diluted the samples, plated them on selective media and incubated them anaerobically; they then enumerated the colonies under a stereomicroscope. RESULTS: MS levels were not significantly different between the three groups at baseline (mean log CFU/mL +/- standard deviation: 5.4 +/- 0.7, 5.4 +/- 0.8, 5.2 +/- 0.7, respectively) nor after CHX therapy (2.7 +/- 0.8, 3.1 +/- 1.1, 3.0 +/- 1.1, respectively). After three months of gum chewing, the test group subjects had significantly lower salivary MS levels (3.6 +/- 1.2) than did the placebo (4.7 +/- 1.2) or control (4.4 +/- 1.3) group subjects. CONCLUSIONS: Xylitol chewing gum appears to have the ability to prolong the effect of CHX therapy on oral MS. CLINICAL IMPLICATIONS: Maintaining long-term caries-pathogen suppression is feasible with currently available commercial products and can be expected to result in significant caries inhibition.

Among various preventive approaches, non-invasive phototherapy/photodynamic therapy is one of the methods used to control oral biofilm. Studies indicate that light at specific wavelengths has a potent antibacterial effect. The objective of this study was to determine the effectiveness of violet-blue light at 380-440 nm to inhibit biofilm formation of Streptococcus mutans or kill S. mutans. S. mutans UA159 biofilm cells were grown for 12-16 h in 96-well flat-bottom microtiter plates using tryptic soy broth (TSB) or TSB with 1 % sucrose (TSBS). Biofilm was irradiated with violet-blue light for 5 min. After exposure, plates were re-incubated at 37 °C for either 2 or 6 h to allow the bacteria to recover. A crystal violet biofilm assay was used to determine relative densities of the biofilm cells grown in TSB, but not in TSBS, exposed to violet-blue light. The results indicated a statistically significant (P < 0.05) decrease compared to the non-treated groups after the 2 or 6 h recovery period. Growth rates of planktonic and biofilm cells indicated a significant reduction in the growth rate of the violet-blue light-treated groups grown in TSB and TSBS. Biofilm viability assays confirmed a statisticallysignificant difference between violet-blue light-treated and non-treated groups in TSB and TSBS. Visible violet-blue light of the electromagnetic spectrum has the ability to inhibit S. mutans growth and reduce the formation of S. mutans biofilm. This in vitro study demonstrated that violet-blue light has the capacity to inhibit S. mutans biofilm formation. Potential clinical applications of light therapy in the future remain bright in preventing the development and progression of dental caries.

An important caries prevention strategy for children includes measures to interfere with transmission of mutans streptococci (MS). This study confirmed the effectiveness of maternal early exposure to xylitol chewing gum on mother-child transmission of MS. After screening, 107 pregnant women with high salivary MS were randomized into two groups: xylitol gum (Xylitol; n = 56) and no gum (Control; n = 51) groups. Maternal chewing started at the sixth month of pregnancy and terminated 13 months later in the Xylitol group. Outcome measures were the presence of MS in saliva or plaque of the children until age 24 months. The Xylitol-group children were significantly less likely to show MS colonization than Control-group children aged 9-24 months. The Control-group children acquired MS 8.8 months earlier than those in the Xylitol group, suggesting that maternal xylitol gum chewing in Japan shows beneficial effects similar to those demonstrated in Nordic countries.