The impact of platelet-rich fibrin (PRF) on delayed tooth replantation: A preliminary animal study.

The aim of this study was to evaluate the effect of platelet-rich fibrin (PRF) placed in delayed replantation of mature extracted teeth. Sixteen intentionally extracted teeth in two mature beagle dogs were selected. In one quadrant of each jaw, the extraction sockets were filled with PRF prior to replantation, and the other quadrant served as control without PRF. All extracted teeth underwent endodontic treatment and dried for 60 min. Thereafter, they were replanted with a flexible splint. After 8 weeks, the animals were euthanised, and the histological sections examined. Less inflammatory root resorption was noted in the PRF group compared to the control (P = 0.031). However, there was no significant difference between the two groups with regard to new bone formation, inflammatory status, connective tissue healing and replacement resorption (P > 0.05). Using PRF in the extracted socket before delayed replantation did not provide any significant benefit other than reduced inflammatory root resorption.

Effects of flapless bur decortications on movement velocity of dogs' teeth.

BACKGROUND: Different surgical procedures that reduce orthodontic treatment time have been recommended. The aim of this study was to evaluate the effectiveness of a new less invasive surgical technique (called flapless bur decortications) for accelerating orthodontic tooth movement. MATERIALS AND METHODS: This study was designed as a split-mouth study. The left and right maxillary first premolars of five dogs were extracted. An A-NiTi closed coil spring and an absolute anchorage was used for premolar protraction in both sides. In each dog, decortications were performed for one side and the other side was used as the control group. The distance between canine and second premolar was measured and the sites of decortication were evaluated histologically. The data was analyzed by paired samples t-test and multivariate analysis of two-way repeated measures ANOVA. RESULTS: The study teeth moved more than their controls in the first month and less than their controls in the third month (P < 0.05). The total difference between study and control movements was not significant (P < 0.05). CONCLUSION: (1) Corticotomy facilitated orthodontic tooth movement is achievable with flapless bur decortication technique. (2) Velocity of tooth movement decreases in later stages of treatment due to maturation of newly formed bone at decortication sites.