Objective To clarify the related factors of marginal bone loss (MBL) around tissue level implants in the posterior part of the mandible.Methods A total of 116 tissue level implants were implanted in the mandibular posterior region of 76 patients. Patients’ information, including general characteristics, implant characteristics, implant site characteristics, and prosthesis characteristics, was recorded. Their cone beam computed tomography data were measured immediately after implant placement, 3 months later, and 3 and 12 months after prosthesis loading. The measurement of MBL was conducted by One Volume Viewer software. SPSS 20.0 was used for statistic analysis.Results Smoking, cortical bone thickness (CBT), collum angle (CA), and implant local sanitation showed significant differences with body mass loss (PP>0.05).Conclusion The risk factors that caused MBL were smoking, thicker CBT, larger CA, and poor implant local sanitation. Among them, poor implant local sanitation had the highest correlation with MBL.
