Novel methods reveal that parallelism contributes to the functional vertical slot dimension in ceramic and metal brackets.

OBJECTIVES:: To validate a novel method for measuring the clinically relevant bracket slot and use these methods to test the hypothesis that various metal injection molded (MIM) and esthetic ceramic injection molded (CIM) brackets have a bracket slot accuracy within 1 mil (0.001") of their reported slot dimension. MATERIALS AND METHODS:: A Nikon iNEXIV-VMA-2520 laser microscope was used to measure slots of six series of CIM brackets and two series of MIM brackets via a vision measuring system of 256 gray levels to capture each edge of the slot, largely taking out human subjectivity. This system had a maximum permissible error of 2 + 8 L/1000 µm with a point resolution of 0.1 µm and was estimated to be more accurate than previous methods by a factor of 10. The video image for each bracket was autofocused by a blinded operator, and 40 point-to-line measurements were calculated along the clinical slot and averaged. RESULTS:: Vertical slot dimension varied from series to series and within the series of brackets. Three of six CIM and two of three MIM brackets had a statistically significant mean slot size 0.001 inches larger than reported. The reported precision of these CIM brackets, as determined from standard deviation, varied from series to series. CONCLUSIONS:: A novel system that incorporates parallelism into analysis of vertical bracket slot dimension was described. When the entire clinically relevant slot was considered, MIM and CIM brackets had similar precision but were significantly oversized, with contribution from a nonparallel, likely diverging, vertical slot dimension.

Impact of maternal xylitol consumption on mutans streptococci, plaque and caries levels in children.

AIM: The present study was designed to determine whether maternal xylitol consumption through regular chewing of xylitol gums can affect the salivary mutans streptococci (MS), dental caries, and dental plaque levels of their children. METHOD: Study sample included 60 mother and child pairs with high salivary mutans streptococcus (MS) levels. Samples were randomly divided into experimental group (30 pairs) and control group (30 pairs). Mothers in the experimental group received xylitol chewing gum treatment three times/day for three months, whereas the controls received fluoride varnish. Both groups received oral hygiene instructions, dietary counseling and restorative treatment. All children were examined after 6, 12 and 18 months from the initiation of the study to assess caries, plaque and salivary mutans streptococcus (MS) levels. RESULTS: Showed that at 18 month the percent of children with high streptococcus levels in the control significantly increased when compared to the increase in the experimental group. Throughout the study, dmft scores of experimental children showed marginal non significant increase compared to controls that showed higher scores. Plaque scores revealed statistically non significant decrease among both groups. CONCLUSIONS: Maternal xylitol consumption provided better preventive outcomes on salivary (MS) levels compared to fluoride varnish treatments.

Effect of xylitol on dental caries and salivary Streptococcus mutans levels among a group of mother-child pairs.

UNLABELLED: Recent researches have focused on xylitol as convenient and effective method to inhibit cariogenic bacteria. The purpose of the present study is to assess the effect of xylitol on plaque accumulation, caries activity and salivary Streptococcus Mutans in a group of Saudi mother-child pairs. MATERIALS AND METHODS: The study sample included 60 mother and child pairs selected on the basis of having high salivary streptococcus mutans levels. The study sample was randomly divided into experimental group (30 pairs) and control group (30 pairs). The experimental group was given xylitol treatment and the controls received fluoride varnish. Both groups were examined to assess caries, plaque and salivary streptococcus mutans levels. Xylitol treatment in the form of chewing gum for mothers and tablets for children was consumed three times/day for three months. All subjects received oral hygiene instructions, dietary counseling and restorative treatment. The results showed that the number of mothers and children with high streptococcus levels in the experimental group decreased to a statistically significant level at the end of the three month period, similarly, the control mothers showed the same trend. A statistically significant decrease in plaque scores was evident only among the children S experimental group. The caries level of children and mothers showed no statistically significant differences between the experimental and control groups. The factors which significantly affected the streptococcus mutans count in children after three months were the child' dmft at baseline the preventive method used and the mother'salivary streptococcus mutans level.