ABSTRACT
Statement of the Problem: Alveolar ridge resorption after tooth extraction may interfere with optimal dental implant placement. Purpose: This study aimed to compare the marginal bone loss (MBL) and thickness of the buccal aspect of the augmented site in simultaneous versus delayed implant placement following lateral ramus horizontal ridge augmentation in the posterior mandible. Materials and Method: This prospective cohort study was conducted on patients who required horizontal bone augmentation of the posterior mandible using lateral ramus autogenous bone graft. Patients were divided into two groups of simultaneous implant placement (group 1) and delayed implant placement (group 2). Cone-beam computed tomography (CBCT) images were obtained before augmentation, at the time of implant placement, and 10 months later (6 months after implant loading). MBL and thickness of the buccal aspect were evaluated over time. Results: There were 18 patients in the group 1 and 16 patients in the group 2. Analysis of the CBCT scans demonstrated that the mean MBL was 1.21±0.35mm in the group 1 and 1.08±0.19mm in the group 2, with no significant difference between the two groups (p= 0.19). Thickness of the buccal aspect of the augmented site at the time of implant placement was 1.85±0.20mm in the group 1 and 2.16±0.29 mm in the group 2, with a significant difference (p< 0.001). However, data analysis regarding changes in the buccal plate thickness showed no significant difference between the two groups (p= 0.36). Conclusion: According to the results of this study, there was no significant difference in M-BL and post-operative changes in the thickness of the buccal aspect of the augmented sites with onlay lateral ramus bone blocks between simultaneous and delayed implant placement.
ABSTRACT
Purpose: Early postoperative infection can lead to dental implant failure. This study aimed to evaluate the frequency of failed and survived implants after acute postoperative infection and the related factors. Materials and Methods: This cross-sectional cohort evaluated early infection after dental implant surgery. The study variables included the site of implant placement, age and gender of patients, bone augmentation, postoperative antibiotic therapy, smoking, and time of infection occurrence or diagnosis. Failed and survived implants were the outcome of the study. The patients were studied in 2 groups of survived implants (group 1) and failed implants (group 2). Results: Thirty-four (3.46%) out of 980 patients developed a postoperative infection following implant placement, which included 25 males and 9 females. Ten implants (29.4%) survived (group 1), and 24 implants (70.6%) failed (group 2). There were significant differences between the 2 groups regarding the number of smoker patients, fresh socket or delayed implant placement, patients who received bone graft, and the meantime of diagnosis (P < 0.05). Regarding the covariates, the Kaplan-Meier analysis showed that the risk of implant failure in patients who did not receive postoperative antibiotic therapy increased by 1.1 times (hazard ratio) when infection occurred four days after surgery. In patients who received postoperative antibiotics, the risk of failure increased when infection occurred after 6 days in smokers and after 9 days in non-smokers. Conclusion: Considering the study results, it seems that smoking, early infection, fresh socket placement, and placement of implants along with bone substitutes may increase the failure rate after acute infection in dental implant placement.
