[Application of β-TCP for bone defect restore after the mandibular third molars extraction: A splitmouth clinical trial].

To evaluate the effect of bone defect regeneration and the periodontal status of the second molars after mandibular third molars extraction using β-tertiary calcium phosphate (β-TCP) in the test side compared with the spontaneously healed side. To the bone defect of mandibular second molars as a result of surgical removal of impacted mandibular third molars is a common phenomenon, many research shows that the mandibular second molars alveolar bone regeneration was about 1.5 mm and the periodontal pocket >7 mm was greater than 43.3% after mandibular third molars extraction. There has been significant progress researches in the repair of bone defect after the third molar removal, and bone graft filling was one of the effective methods. The bone graft substitutes include autogenous bone, allograft bone, xenograft bone and synthetic bone.A split mouth, randomized clinical study was designed. Fifteen patients with mandibular third molars in the same jaw planned to be extracted were enrolled in the study. One of the sockets of each patient was randomly selected and filled with easy-graftTMCLASSIC (test group). The contralateral socket was left to heal spontaneously (control group). cone beam computed tomography (CBCT) scans were performed the day after the extraction and after 6 months. The horizontal dimensional changes of the sockets were recorded. The newly formed bone volume in the bone was analyzed by CBCT, and the probing depth (PD) was recorded. Student's t test was used to evaluate the difference between the two groups for each parameter, and the P value lower than 0.05 was considered to be statistically significant.Fifteen patients (30 sockets) completed the flow-up, and all the 30 sockets healed uneventfully. After 6 months' healing, the new bone volume fraction of the test group was 63.3%±2.2%, while the new bone volume fraction of the control group was 50.1%±1.9%. The vertical dimensional increment of the test group was (5.53±0.39) mm, while the vertical change of the control group was (1.53±0.27) mm. The distal buccal site PD of the second molar was (3.0±0.7) mm in the test group, and (6.5±0.8) mm in the control group. Statistically significant differences were detected between the two groups.The randomized controlled clinical trial showed that the application of β-TCP for bone defect repair after the mandibular third molars extraction resulted in more vertical bone regeneration and less probing depth when compared with what was spontaneously healed.