Povidone-iodine as a periodontal pocket disinfectant.

OBJECTIVES AND BACKGROUND: Povidone-iodine [polyvinylpyrrolidone-iodine complex (PVP-iodine)] might constitute a valuable adjunct to current periodontal therapy because of its broad-spectrum antimicrobial activity, low potential for developing resistance and adverse reactions, wide availability, ease of use, and low financial cost. This investigation employed a randomized, split-mouth study design to determine the microbiological and clinical effects of 10% PVP-iodine subgingival irrigation in periodontitis lesions showing radiographic evidence of subgingival calculus. METHODS: Sixteen adults having at least one periodontal pocket of 6 mm or more in each quadrant of the dentition and harboring one or more periodontopathic bacteria participated in the study. In each subject, a study site in each quadrant was randomly chosen to receive either subgingival irrigation with 10% PVP-iodine together with scaling and root planing, scaling and root planing alone, subgingival irrigation with 10% PVP-iodine, or subgingival irrigation with sterile saline. Prior to therapy and at 5 weeks post-treatment, microbiological culture was carried out without knowledge of the clinical status or the type of treatment rendered. A blinded clinical examiner determined presence of dental plaque, probing pocket depth, and gingival bleeding on probing. Microbiological and clinical data were analyzed using a repeated measures analysis of variance and Kruskal-Wallis rank test with the Tukey and Mann-Whitney post hoc tests. RESULTS: At 5 weeks post-treatment, subgingival irrigation with PVP-iodine together with scaling and root planing caused a 95% or greater reduction in total pathogen counts in 44% of pockets having >/= 6 mm depth whereas scaling and root planing alone, povidone-iodine irrigation alone and water irrigation alone caused 95% reduction of total pathogens only in 6-13% of similar study sites (P = 0.02). Reduction in mean pocket depth was 1.8 mm for the PVP-iodine/scaling and root planing group, 1.6 mm for the scaling and root planing group, and 0.9 mm for the PVP-iodine and the saline monotherapy groups, with statistical significance reached for the scaling and root planing group vs. the PVP-iodine group (P = 0.04) and for the scaling and root planing group vs. the saline group (P = 0.02). Reduction in visible dental plaque, which ranged from 38% to 62%, showed no significant differences among treatment groups. CONCLUSIONS: The addition of subgingival PVP-iodine irrigation to conventional mechanical therapy may be a cost-effective means of reducing total counts of periodontal pathogens and helping control periodontal disease. However, subgingival irrigation with PVP-iodine without concomitant mechanical debridement might not improve microbiological and clinical variables in comparison with saline irrigation, at least not in sites with radiographic evidence of subgingival calculus.

Genetic influence on dental arch form in orthodontic patients.

Human arch form varies considerably. This study analyzed the size and shape of the maxillary and mandibular dental arches of 320 adolescents from 155 sibships. A broad battery of measurements (k = 48) was computer-generated from Cartesian coordinates of cusp tips and line angles of the permanent teeth, and heritability estimates were generated from intraclass correlations, controlling for sex and age where indicated. Arch size has a modest genetic component, on the order of 50%, although this estimate may contain shared environmental influences. Tooth rotations have low h2 estimates, most of them indistinguishable from zero. Arch shape, assessed as length-width ratios, also has a modest transmissible component, suggesting that arch length and width growth factors are largely independent. Highest heritability estimates, as a group, were for transverse arch widths, which averaged about 60%. Several measures of left-right asymmetry also were analyzed (k = 31), and, while the arches are systematically asymmetric (generally with left > right), there is only weak evidence of a transmissible component for directional asymmetry and essentially none for fluctuating asymmetry. In all, arch size and shape are seen to be more subject to environmental influences than to heredity. These findings direct attention toward the need to better understand what extrinsic factors modulate arch size and shape during development.

Education, research, and personnel needs in orthodontics.

Because of changing patterns of dental care delivery, the nature of orthodontic education, research, and personnel needs has changed markedly in recent times. Changes have occurred in the university environment, dental education, and undergraduate and graduate orthodontic education. Orthodontic research is shifting to more clinically oriented topics. Orthodontic personnel needs are being addressed by changing levels of specialist and general practitioner involvement.