Cleansing efficacy of an auto-cleaning toothbrushing device with nylon bristles: a randomized-controlled pilot study.

OBJECTIVES: To compare the cleansing efficacy of an auto-cleaning device with nylon bristles (Y-brush®) to that of manual toothbrushing. MATERIALS AND METHODS: Twenty probands refrained from oral hygiene for 3 days. Rustogi Modified Navy Plaque Index was assessed before and after (randomized) toothbrushing either with the auto-cleaning device for 5 s per jaw or with a manual toothbrush for a freely chosen time up to 4 min. The clinical investigation was repeated in a cross-over design. In a third trial period, the brushing time for auto-cleaning was increased to 15 s per jaw. The study was supplemented by plaster cast analyses. RESULTS: Full-mouth plaque reduction was higher with manual toothbrushing than with auto-cleaning for 5 s per jaw (p < 0.001). There was no statistically significant difference on smooth tooth surfaces but on marginal and interdental sites. Increasing the brushing time of auto-cleaning to 15 s per jaw resulted in a comparable full-mouth plaque reduction as with manual toothbrushing (p = 0.177). In 95% of individuals, the device was too short not completely covering second molars. In 30.67% of teeth, the gingival margin was not covered by bristles. CONCLUSIONS: Auto-cleaning devices with nylon bristles have a future potential to reach plaque reduction levels comparable to manual toothbrushing, although manufacturers must focus on improving an accurate fit. CLINICAL RELEVANCE: Under the premise of an ameliorated fit, the auto-cleaning device might be recommendable for people with low brushing efficacy. Interdental sites remain a failure point if adjunct interdental cleaning is not viable.

Diversity of Sinorhizobium meliloti from the Central Asian Alfalfa Gene Center.

Sinorhizobium meliloti was isolated from nodules and soil from western Tajikistan, a center of diversity of the host plants (Medicago, Melilotus, and Trigonella species). There was evidence of recombination, but significant disequilibrium, between and within the chromosome and megaplasmids. The most frequent alleles matched those in the published genome sequence.