The Effect of Inter-Radicular Brushing on Class II Furcation of Lower Molars: A Randomized, Single-Blinded, Prospective Trial

Purpose: A randomized, single-blind, prospective clinical trial was performed to evaluate the effects of plaque control by inter-radicular brushing on class II furcation of lower molars. Methods: Twenty-two patients presenting with at least one class II furcation with horizontal probing depth (PD) ≥ 4 mm on the buccal aspect of lower molars were recruited. Each patient was randomly assigned to do either inter-radicular brushing with an inter dental brush (test: 12 subjects, 12 sites) or not (control: 10 subjects, 12 sites). After 4 weeks, the clinical parameters of furcated molars were evaluated and microbial analysis of the sub gingival plaque collected from furcation entrances was performed using quantitative real-time polymerase chain reaction. Results: Two test group patients did not show up at the appointment, and thus, a total of 20 patients completed the study. No statistically significant differences in mean vertical PD, horizontal PD, gingival recession, or plaque index at furcation sites were observed between the control and test groups. However, the mean gingival index of the control and test sites were 2.3, and 1.2, respectively, and the mean modified sulcus bleeding index was 2.3 and 0.6, respectively; differences in both sets of parameters were statistically significant between groups. Among total and 6 specific pathogenic bacterial species, the copy numbers of total bacteria, Fusobacterium nucleatum, Parvimonas micra and Tannerella forsythia were significantly lower in test than control sites. Conclusion: Preventing the accumulation of pathogenic bacteria by inter-radicular brushing can inhibit gingival inflammation and improve the long-term stability of molars with class II furcation defects.