Distalization rate of maxillary canines in an alveolus filled with leukocyte-platelet-rich fibrin in adults: A randomized controlled clinical split-mouth trial.

Introduction: The objective of this study was to evaluate the distalization rate and changes in inclination of the maxillary canines in alveoli preserved with leukocyte-platelet-rich fibrin (L-PRF) membranes in adult patients. The null hypothesis was that there are no differences in the canine distalization movement rate between the treated and the control sides.

Methods: A total of 21 healthy adult patients with a minimum age of 20 years (mean age, 33 ± 5.9 years) and Angle Class I or Class II Division 1 malocclusion, who had an indication of extraction of the maxillary first premolars and orthodontic distalization of the maxillary canines were included in this study. A randomized controlled clinical split-mouth trial was conducted; the experimental maxillary side was treated with L-PRF membranes, and the other side served as the control. A randomization sequence of the experimental sides among patients was generated using the random number generation function of Microsoft Excel. Neither the patients nor the operators were blinded. Fifteen days after the extractions, distalization was initiated using an elastic chain applying 150 g of force to the canines on a 0.020-in stainless steel archwire. The distalization rate was the main outcome of the study, and it was assessed monthly for 5 months through the intraoral use of a flexible ruler. The degree of inclination of the canines was the secondary outcome, and it was evaluated through cone-beam computed tomography. A Shapiro-Wilk test was performed, and a Wilcoxon signed rank test was subsequently used to compare the experimental and the control group. Spearman rank correlation coefficient was calculated to evaluate the correlation between distalization and inclination for each side.

Results: Four of the subjects dropped out of the study, leaving a total of 17 patients (n = 17). The distalization rate and inclination of the canines were greater on the control side than on the side treated with L-PRF (P <0.05). A weak correlation was found between the distalization rate and inclination of the canines for both sides (control side, ρ = 0.17; experimental, ρ = 0.11). No harm was observed during the study.

Conclusions: The null hypothesis was rejected. The use of L-PRF in young adult patients decreased the rate of distalization and changes in inclination of the maxillary canines compared with the control group.

Registration: This trial was not registered.

Protocol: The protocol was not published before trial commencement.