Efficacy of manual and powered toothbrushes (II). Effect on microbiological parameters.

BACKGROUND/AIM The purpose of the present investigation was to determine the effect of self-performed supragingival plaque removal using either manual (Crest Complete) or power (Braun 3D Plaque Remover) toothbrushing on supra and subgingival plaque composition. METHODS 47 periodontal maintenance subjects completed this single-blind 6 month longitudinal study. At baseline, samples of supra and separately subgingival plaque were taken from the mesial aspect of each tooth in each subject using sterile curettes and individually analyzed for their content of 18 bacterial taxa using checkerboard DNA-DNA hybridization. After random assignment to groups receiving either a manual (n=25) or power toothbrush (n=22), subjects received instruction in oral hygiene and used their assigned toothbrush 2x daily for 6 months. Clinical monitoring and microbiological sampling were repeated at 3 and 6 months. Significant differences in microbiological measures over time were sought using the Quade test and between brushing groups at each time point using the Mann-Whitney test. RESULTS Mean total counts were significantly reduced for supra- and subgingival plaque samples in the manual group and subgingival samples in the powered brushing group. Actinomyces naeslundii and Actinomyces israelii/gerencseriae were the most numerous organisms detected at baseline and showed the greatest reductions in counts in both brushing groups. Streptococcus constellatus/intermedius was significantly reduced in both groups, while Streptococcus mitis/oralis/sanguis was significantly reduced in the manual toothbrushing group. Mean counts of species were more markedly altered in subgingival plaque. Major reductions occurred in both groups for A. naeslundii, A. israelii/gerencseriae, Peptostreptococcus micros, Veillonella parvula, Prevotella intermedia/nigrescens, S. mitis/oralis/sanguis and S. constellatus/intermedius. All taxa examined were reduced in prevalence (% of sites colonized) in the subgingival plaque samples for both brushing groups. The reductions in prevalence were greater for A. naeslundii, S. constellatus/intermedius, V. parvula, A. israelii/gerencseriae, S. mitis/oralis/sanguis, P. micros, Streptococcus mutans and P. intermedia/nigrescens. Mean prevalence was decreased more for Porphyromonas gingivalis, Campylobacter rectus/showae, Treponema denticola and Bacteroides forsythus in supragingival plaque than subgingival plaque. CONCLUSIONS The major finding was the effect of supragingival plaque removal on the composition of the subgingival microbiota. Counts and prevalence of most taxa examined were markedly decreased in both toothbrushing groups. This reduction should translate to a decreased risk of periodontal disease initiation or recurrence. Further, the decreased prevalence of periodontal pathogens in supragingival plaque lowers potential reservoirs of these species.