Periodontal parameters and cervical root resorption during orthodontic tooth movement.

OBJECTIVES To assess the relationship between periodontal parameters and cervical root resorption in orthodontically moved teeth. MATERIAL AND METHODS In a standardized experimental tooth movement in 16 periodontally healthy subjects, 29 pre-molars were tipped buccally for 8 weeks. Eighteen contralateral pre-molars not subjected to orthodontic movement served as controls. Plaque Index (PI), Gingival Index (GI), probing depth and bleeding on probing were assessed three times before and six times during the experimental phase. Teeth were extracted and scanned in a micro-computed tomography scanner. The presence or absence, and the severity of cervical root resorption were evaluated on the three-dimensional reconstruction of the scans by two calibrated examiners. RESULTS Overall, periodontal parameters were not different between the test and the control teeth. Clear signs of buccal cervical resorption were detected on 27 of 29 orthodontically moved teeth and on one control tooth. Ten subjects had perfect oral hygiene and no gingivitis, whereas six subjects showed a moderate level of plaque and gingivitis (>20% occurrences of PI or GI with >0). No relationship could be demonstrated between resorption and periodontal parameters. CONCLUSIONS Nearly all orthodontically moved teeth showed signs of cervical resorption. Periodontal parameters were unrelated to this important side effect of orthodontic treatment.