Background Currently, insufficient bone volume always occurs in the posterior maxilla which makes implantation difficult. Short implants combined with transcrestal sinus floor elevation (TSFE) may be an option to address insufficient bone volume. Purpose The clinical performance of short implants combined with TSFE was compared with that of conventional implants combined with TSFE according to the survival rate. Method In this systematic review and meta-analysis, we followed the Meta-Analysis of Observational Studies in Epidemiology (MOOSE) guidelines. Articles were identified through PubMed, Embase, the Cochrane Library, and manual searching. Eligibility criteria included clinical human studies. The quality assessment was performed according to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines. The odds ratio (OR) with its confidence interval (CI) was considered the essential outcome for estimating the effect of short implants combined with TSFE. Results The registration number is INPLASY202050092. Eleven studies met the inclusion criteria, including 1 cohort study and 10 cross-sectional studies. With respect to the 1-year survival rate, no significant effect was observed between short implants (length ≤ 8 mm) and conventional implants combined with TSFE (I2=0%, OR=1.04, 95% CI: 0.55-1.96). Similarly, no difference was seen between the two groups regarding the survival rate during the healing period (I2=10%, OR=0.74, 95% CI: 0.28-1.97) and 3-year loading (OR=1.76, 95% CI: 0.65-4.74). Conclusion There was no evidence that the survival rate of short implants combined with TSFE was lower or higher than that of conventional implants combined with TSFE when the residual bone height was poor and the implant protrusion length of short implants was less than or similar to conventional implants. Nevertheless, the results should be interpreted cautiously due to the lack of random controlled trials in our meta-analysis.

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Objectives This study aimed to evaluate factors related to new bone formation (NBF) following simultaneous implant placement with transcrestal sinus floor elevation (TSFE). Materials and methods Between 2008 and 2020, 357 implants (276 patients) were placed with TSFE. Clinical and radiographic examinations were performed at the preoperative, postoperative, restoration, and follow-up stages. Marginal bone loss, during healing, and the survival rate were retrospectively analyzed. Results Implant protrusion lengths (IPL: 3–5 mm) significantly influenced NBF during the healing period (P-value = 0.026, Odds Ratio = 1.15, 95% confidence interval = 1.02- 1.30). Bone grafting was correlated with NBF (P-value = 0.001). The distance between the implant and lateral wall of the sinus (mesial: P-value = 0.041, distal: P-value = 0.019, buccal: P-value = 0.032, lingual: P-value = 0.043) and angle between the implant and sinus floor significantly influenced NBF in four directions (mesial: P-value = 0.041, distal: P-value = 0.02, buccal: P-value = 0.047, lingual: P-value = 0.005). Implant shape (cylindrical or conical), perforations, smoking, and diabetes did not significantly affect NBF during the healing period (P > 0.05). Conclusion Increasing the distance and angle between the implant and lateral wall of the sinus floor corresponded with reduced NBF. IPL may be an important factor that should be considered. Clinical relevance Our study analyzed new bone formation following transcrestal sinus floor elevation among patients who underwent this procedure with simultaneous implant placement, several factors (including angle and distance between sinus and lateral wall and implant protrusion length) were included in our study.

Objective This study investigated the factors associated with early implant failure. Material and methods This retrospective study was conducted on 3,247 implants in 2,061 patients. Patient-related and surgery-related factors, including smoking, sex, diabetes, bone grafting, implant length, implant width, implant design, adjacent teeth, and insertion torque, were manually retrieved and analyzed. Using univariate and multivariate analyses, a generalized estimating equation (GEE) model was employed to evaluate factors related to early implant failure. Results The mean age of the patients was 49.2 ± 15.0 (18–91) years. Ninety-nine implants failed during the healing period. Three factors were statistically significant regarding early implant failure: smoking (odds ratio [OR] = 7.060, P = 0.008), implant design (OR = 6.983, P = 0.008), and implant length (OR = 7.500, P = 0.006). Factors including diabetes, bone grafting, location, adjacent teeth (root canal therapy in the adjacent teeth and the distance between the implant and adjacent teeth), healing method, and insertion torque did not exhibit a significantly higher early implant failure rate. Ninety-three sites with failed implants received replantation, and six implants failed during the healing period. Conclusions This retrospective study identified three factors associated with early implant failure: smoking, implant design, and implant length. A prospective study with larger sample size is needed in the future. Clinical relevance: There is fierce debate on the factors influencing early implant failure (failure during the healing period) in the rehabilitation and restoration of oral function in partially edentulous patients.

ObjectivesThis study aimed to evaluate factors related to NBF following simultaneous implant placement with transcrestal sinus floor elevation (TSFE).Materials and methodsBetween 2008 and 2020, 357 implants (276 patients) were placed with TSFE. Clinical and radiographic examinations were performed at the preoperative, postoperative, restoration, and follow-up stages. Marginal bone loss, new bone formation (NBF) during healing, and the survival rate were retrospectively analyzed.ResultsImplant protrusion lengths (3–5 mm) significantly influenced NBF during the healing period (P-value = 0.026, Odds Ratio = 1.15, 95% confidence interval = 1.02–1.30). Bone grafting was correlated with NBF (P-value = 0.001). The distance between the implant and lateral wall of the sinus (mesial: P-value = 0.041, distal: P-value = 0.019, buccal: P-value = 0.032, lingual: P-value = 0.043) and angle between the implant and sinus floor significantly influenced NBF in four directions (mesial: P-value = 0.041, distal: P-value = 0.02, buccal: P-value = 0.047, lingual: P-value = 0.005). Implant shape (cylindrical or conical), perforations, smoking, and diabetes did not significantly affect NBF during the healing period (P > 0.05).ConclusionIncreasing the distance and angle between the implant and lateral wall of the sinus floor corresponded with lesser NBF. Implant protrusion length (IPL) may be an important factor that should be considered.Clinical Relevance: Our study analyzed new bone formation following transcrestal sinus floor elevation among patients who underwent this procedure with simultaneous implant placement, several factors (including angle and distance between sinus and lateral wall and implant protrusion length) were included in our study.