Subgingival debridement of root surfaces with a micro-brush: macroscopic and ultrastructural assessment

Aim: The aim of this study was to assess the use of a micro-brush to remove plaque deposits from subgingival, periodontally involved root surfaces in vivo. Methods: 30 periodontally involved teeth requiring extraction for periodontal or prosthetic reasons in 26 adult patients were utilised. For inclusion, teeth had to display at least 30% bone loss radiographically. Following the establishment of local anaesthesia, grooves were cut on the proximal root surface adjacent to the gingival margin at the line angles. For each tooth, I proximal root surface was rubbed with the micro-brush for 2 min to the depth of the pocket whilst the other root surface acted as an undebrided control. The teeth were then extracted, rinsed in 0.85% NaCl, stained with 2% erythrosine solution and photographed. The amount of erythrosine staining on each subgingival, periodontally involved root surface was assessed by tracing the areas of stain on a colour photograph and scanning the tracings into a computerised image tracing program. Results: Results were expressed as the % of the periodontally involved root-surface area that exhibited staining. Stained areas were further examined with the scanning electron microscope (SEM). The undebrided root surfaces each displayed 100% staining. The debrided surfaces (with probing pocket depths of 4-10 mm) displayed mean staining of 16.1% (SD +/-7.1%) of the proximal surface area. SEM assessment showed that undebrided root surfaces were covered with thick deposits of bacteria. On debrided surfaces, stain-free areas were free of plaque whilst areas of faint staining exhibited either no plaque, calculus deposits or scanty, isolated islands of bacteria. Bacteria had been partially removed from the surface of calculus in some areas. Conclusions: The findings indicate that subgingival debridement with a micro-brush is effective in removing plaque deposits from periodontally involved root surfaces.