Six-month comparison of powered versus manual toothbrushing for safety and efficacy in the absence of professional instruction in mechanical plaque control.

BACKGROUND: Reports suggest powered toothbrushing may provide some clinical benefit over manual tooth-brushing, but most studies have been of short duration with subjects trained in toothbrush use. The aim was to determine if the oscillating-rotating powered brush (PB) could safely provide clinical benefits over and above a manual brush (M) in subjects with no formal instruction or experience in powered brush use. METHODS: This 6-month, single-masked, parallel design, randomized clinical trial compared the PB with an American Dental Association (ADA)-accepted soft-bristle manual brush in a non-flossing gingivitis population (n = 157). Subjects were given written instructions but no demonstration on toothbrush use at baseline. Efficacy was assessed by changes in gingival inflammation, plaque, calculus, and stain, while changes in clinical attachment levels and recession measurements provided safety data. A prophylaxis was provided after baseline assessment. The 6-month plaque index (PI) was recorded immediately post-brushing after covert timing of the subjects, and correlation analyses were run to assess the relationship of brushing time to PI. Paired t tests, analysis of variance (ANOVA), and analysis of covariance (ANCOVA) were used to assess within and between treatment group differences for PB (n = 76) versus M groups (n = 81). RESULTS: Measures of inflammation showed a statistically significant drop for both brushes at 3 and 6 months. Mean overnight full-mouth PI scores were significantly lower at 3 months for the PB (1.57) compared to the M group (1.80), P = 0.0013. Immediate post-brushing PI at 6 months was also significantly lower for the PB (1.10) versus M (1.39) (P= 0.0025). There was an overall negative correlation for PI and brushing time (r = -0.377, P= 0.0001). Mean calculus index (CI) scores were lower for the PB at 3 (P= 0.0304) and 6 months (P = 0.0078), while no significant differences in stain were observable. Clinical attachment level and recession measurements showed no significant between-group changes from baseline for either brush on canine teeth or on teeth with recession at baseline. CONCLUSION: The oscillating-rotating toothbrush safely provides clinical benefits in plaque and calculus reduction over a manual brush even in subjects with no formal oral hygiene instruction.

Cervical enamel projections and associated pouch-like opening in mandibular furcations.

BACKGROUND: Cervical enamel projections (CEPs) have been listed among the tooth-associated risk factors that could lead to isolated furcation defects around molar teeth. This is more likely when Grade III CEPs are present. However, the histologic aspects of the CEP interface with regard to the presence or absence of cementum over the enamel projection within the furcation have not been well described. This study was initially undertaken to evaluate this relationship. METHODS: Thirty-five mandibular molars with Grade III CEPs were selected from a collection of extracted teeth and evaluated for the presence of cementum covering these areas by stereomicroscopy, light microscopy, and scanning electron microscopy (SEM). RESULTS: Sixteen of the 35 teeth (45.7%) with Grade III CEPs appeared completely covered by cementum. SEM evaluation showed the presence of a narrow pouch-like opening between cementum and enamel in 15 of 16 teeth (93.8%). Light microscopy evaluation confirmed the presence of the pouch along with some indication of residual degenerated mesenchymal tissue within the defects. SEM evaluation showed the presence of globular bodies in this pouch. CONCLUSIONS: This study reports on the presence of a pouch-like opening between the enamel and cementum in mandibular molars with Grade III CEPs. The clinical significance of these cementum pouches has yet to be determined but bacterial contamination of these pouch-like structures in areas of furcation periodontal breakdown may serve as a nidus for recolonization and disease recurrence or for the development of furcation caries if exposed to the oral cavity after surgical procedures.