Plaque retention on elastomeric ligatures. An in vivo study.

UNLABELLED Fixed orthodontic appliances make it difficult to maintain the oral hygiene, resulting in plaque accumulation. Retention of bacterial plaque, represents a risk for white spot lesions and development of periodontal disease. AIM Purpose of this study was to determine in vivo the retention of plaque on three different elastic ligatures, in comparison with stainless steel ligature, to determine a possible association between type of ligatures and accumulation of microorganisms. MATERIAL AND METHODS THREE ELASTIC LIGATION SYSTEMS WERE ANALYZED FOR PLAQUE RETENTION: ring-shape, clear, latex ligatures (Leone® Spa), ring-shape, grey, polyurethane ligatures (Micerium® Spa) and grey, polyurethane, Slide low-friction ligatures (Leone® Spa), compared with stainless steel ligatures (Leone® Spa) used as control. Forthy orthodontic patients undergoing fixed orthodontic therapy were selected. A sample for each type of ligature were applied inside the oral cavity of each subject. Samples were kept in the oral cavity for 28 days, ligating 0.16 X 0.22 stainless steel archwire to stainless steel orthodontic premolars brackets. The presence of bacterical slime was quantified by spectrophotometric method (crystal violet-Bouin's fixative) and morphological observations was evaluated by Scanning Electron Microscopy (SEM). RESULTS From analysis of bacterical slime emerges that all the elastics showed a low plaque retention, especially if compared to the group of steinless steel ligatures, that presented a greater plaque adhesion, statistically significant compared to the Slide group (r<0.0002) and the two elastic groups (r<0.0001). This study reported no significant difference between the Slide ligatures and the traditional elastic ligatures as regards the retention of plaque. SEM images showed presence of cocci, rods and few filamentous organisms and an interbacterial matrix in all observed samples. CONCLUSION Elastomeric ligatures showed a significant lower susceptibility to plaque adhesion, in comparison to the stainless steel of the metallic ligatures. No statistically significant difference was observed among the elastic devices.