Meta-analysis on the effectiveness of powered toothbrushes for orthodontic patients.

INTRODUCTION: Although powered toothbrushes have been recommended for gingivitis prevention in orthodontic patients, a relevant meta-analysis has been lacking. The aim of this meta-analysis was to compare the effectiveness of powered and manual toothbrushes in reducing gingival inflammation in patients having fixed orthodontic appliance therapy. METHODS: Citations of potentially relevant trials published in journals, dissertations, and conference proceedings were located by searching the appropriate databases. In addition, efforts to identify potentially relevant unpublished or ongoing trials were made by searching the databases of research registers. Trials appropriate for inclusion had to be randomized controlled trials fulfilling certain criteria concerning study design, participants' characteristics, intervention characteristics, and principal outcome measures. The weighted mean difference with the 95% confidence interval was used to express the comparative treatment effect. The random effects method for meta-analysis was used to combine treatment effects across studies in each category. Trial quality was evaluated by assessing randomization, allocation concealment, blinding, and handling losses. RESULTS: Five trials were considered appropriate for the meta-analysis. Based on quality assessment and the short experimental period of these trials, current evidence is insufficient to support the comparative efficacy of powered toothbrushes in reducing gingivitis in patients undergoing fixed orthodontic appliance therapy. CONCLUSIONS: Any inferences about clinical practice are precluded. Greater standardization of the methodology used is desirable in future trials.

Taxonomic characterization of Mogibacterium diversum sp. nov. and Mogibacterium neglectum sp. nov., isolated from human oral cavities.

Novel isolates, strains HM-7, HM-6, HH-31, P9a-hT and UJB13-d, which were isolated from tongue plaque and necrotic dental pulp, were studied taxonomically and phylogenetically. These organisms were anaerobic, non-spore-forming, gram-positive, rod-shaped bacteria that were inert in most of the conventional biochemical tests and phenotypically resemble Mogibacterium species or asaccharolytic Eubacterium species. The G+C contents of the DNAs from the novel isolates ranged from 41 to 42 mol %. DNA-DNA hybridization studies demonstrated that these strains might be assigned to the genus Mogibacterium but not to the previously described species. It was also apparent that strain HM-7 belonged to the same species as strains HM-6 and HH-31, and that strains P9a-hT and UJB13-d belonged to a second species. The levels of DNA-DNA relatedness to asaccharolytic Eubacterium species, including Eubacterium brachy, Eubacterium nodatum, Eubacterium saphenum and the more recently proposed Eubacterium minutum and Eubacterium exiguum (reclassified as Slackia exigua), are less than 2%. The results of 16S rDNA sequence comparisons revealed that these organisms represent novel lineages distinct from all previously described species of gram-positive, rod-shaped bacteria. On the basis of phenotypic characteristics, DNA-DNA hybridization data and phylogenetic analysis with 16S rRNA gene sequence data, new species are proposed, namely Mogibacterium diversum (for strains HM-7, HM-6 and HH-31) and Mogibacterium neglectum (for strains P9a-hT and UJB13-d). HM-7T (= ATCC 700923T = JCM 11205T) is the type strain of the former and P9a-hT (= ATCC 700924T = JCM 11204T) is the type strain for the latter.

Effect of xylitol on mutans streptococci and lactic acid formation in saliva and plaque from adolescents and young adults with fixed orthodontic appliances.

This study aimed to investigate two dose regimens of xylitol-containing tablets on the ecology of dental plaque and saliva during treatment with fixed orthodontic appliances. The study group comprised 56 healthy patients (mean age 15.8 yr) randomly assigned into the following groups: A, (n = 23) two xylitol tablets two times a day (1.7 g xylitol d(-1)) for 18 wk; B, (n = 23) two tablets four times per day (3.4 g xylitol d(-1)) for 18 wk; and C, (n = 10) no tablets. The levels of mutans streptococci (ms) were enumerated in plaque and saliva and the proportion of xylitol-sensitive (X(S)) strains in saliva was determined by autoradiography with [(14)C]-xylitol at baseline and at 6, 12, and 18 wk. The lactic acid formation rate was assessed enzymatically in sucrose-challenged plaque suspensions. A drop in salivary ms levels was found in Group A after 6 wk but not after 12 or 18 wk. The proportion of X(S) ms was decreased after 6 wk in groups A and B and remained so during the experimental period. The lactic acid formation rates decreased slightly ( approximately 10%) in the two xylitol groups compared with baseline. In conclusion, our results showed that although an alteration of ms strains was demonstrated following a regular daily low-dose intake of xylitol, the long-term total ms counts in plaque and saliva as well as plaque acidogenicity remained unchanged.