RCT on orthodontic timing post-periodontal regeneration: root resorption and tooth movement outcomes

OBJECTIVES: To assess whether timing of orthodontic treatment after periodontal regenerative procedures influences root resorption and orthodontic tooth movement (OTM) in patients with pathologic tooth migration. TRIAL DESIGN: This was a multicenter, randomized, parallel-group clinical trial. PARTICIPANTS: Patients with stage IV periodontitis presenting with pathologic tooth migration and requiring orthodontic treatment were recruited from four centers in Germany, Italy, and Spain. Inclusion criteria involved completed initial periodontal therapy and presence of intrabony defects requiring regeneration. INTERVENTIONS: Forty-seven patients were randomly assigned to early (EOT, 4 weeks post-surgery; n = 24) or late (LOT, 6 months post-surgery; n = 23) orthodontic treatment following regenerative surgery of intrabony defects, treated with one of three biomaterial protocols: deproteinized bovine bone mineral (DBBM), enamel matrix derivative (EMD), or a combination of both. OUTCOMES: Primary outcome was external apical root resorption (EARR), assessed using periapical radiographs. Secondary outcomes included the amount of tooth movement (mm) and the duration of orthodontic treatment (months). RANDOMIZATION METHOD: Participants were randomized using computer-generated permuted blocks. Allocation was concealed in opaque envelopes. BLINDING: Outcome assessors were blinded to group allocation. RESULTS: EARR at the end of treatment was comparable between EOT and LOT groups (1.15 ± 1.09 mm vs. 1.25 ± 0.94 mm). No statistically significant differences were observed in the amount of tooth movement between groups, between grafted (test) and non-grafted (control) teeth within the same patient, or in treatment duration. Group allocation, type of grafting biomaterial, orthodontic movement type, and treatment duration had no significant influence on EARR. HARMS: No adverse events were reported. CONCLUSIONS: OTM initiated 4 weeks after regenerative surgery did not increase the risk of EARR compared with late OTM and showed no significant differences in tooth movement or treatment duration, regardless of graft material used. Trial registration number: NCT02761668.