Lixin Qiu

Purpose: To compare clinical and histological outcomes of sinus augmentation performed immediately or 3 months after pseudocyst removal through a prospective randomized controlled study.Materials and Methods: In total, 33 sinus augmentation procedures were performed in 31 patients. Augmentation was performed either immediately after pseudocyst removal (one‐stage intervention) or after 3 months (two‐stage intervention). Six months postoperatively, bone specimens were harvested, and histomorphometric analysis was performed as primary outcome. Data were recorded and evaluated for implant survival rates, marginal bone resorption, complication rate, and patient‐centered outcomes (visual analogue scale [VAS]).Results: There were no baseline differences between groups or dropouts. Twelve biopsies obtained for histomorphometric analysis showed that delayed sinus augmentation, when compared to immediated led to a 1.1% increased mineralized bone ratio (95% confidence interval [CI]: −15.9 to 13.7). Graft leakage and acute sinusitis occurred in one patient in the one‐stage group, none in the two‐stage group. No pseudocyst recurrence was observed until the end of 1‐year follow‐up. Median VAS scores for overall acceptance were significantly increase of 1.4 (95% CI: 0.3–2.56) in immediate group. The degree of post‐operative discomfort was not significantly different, although an increase of VAS (0.52, 95% CI: −0.32 to 1.37) was observed in delay group.Conclusions: Both procedures of sinus augmentation immediately and 3 months after pseudocyst removal could obtain comparable histological outcomes and had low complication rates. Patients who underwent the one‐stage procedure had a short treatment course and high satisfaction rates, but this procedure is technically challenging to perform.This clinical trial was not registered prior to participant recruitment and randomization. The clinical trial registration number is ChiCTR2200063121. The hyperlink is as follows: https://www.chictr.org.cn/showproj.html?proj=172755.

Background: The prosthetic emergence profile design might be an important factor in postsurgical mucosal recession etiology. Therefore, a restorative buccal emergence profile designed correctly might reduce gingival margin recession.Purpose: To compare the marginal gingival level and the width/height (W/H) ratio between two profile configurations of single implant‐supported restorations at molar sites.Materials and Methods: Twenty‐one patients requiring a single mandibular molar tooth replacement with supracrestal mucosal thickness ≥2 mm were recruited and randomly assigned to a prosthesis buccal emergence profile design based on the buccal mucosal W/H ratio (Test Group) or maintained the original emergence profile of the healing abutment (Control Group). Assessments were made before delivery of the definitive restoration (T0), at prosthesis placement (T1), one (T2), and 12 (T3) months after loading. The gingival margin level change (△GM), initial emergence angle, buccal mucosal W/H ratio, marginal bone loss (MBL), implant failure, and complications were assessed.Results: The gingival recession in the test group (0.13 ± 0.32 mm) was significantly lower than in the control group (0.63 ± 0.38 mm) at T3 (p = 0.006). The initial emergence angle in the test group (31.4 ± 7.22 degrees) was significantly lower than the control group (40.0 ± 7.60 degrees) (p = 0.025). The W/H ratio in the test group at T2 was significantly higher than at T0 but remained stable thereafter. The W/H ratio presented a continued rising trend in the control group.Conclusions: When the initial supracrestal soft tissue thickness was ≥2 mm, a restorative emergence profile based on the W/H ratio significantly reduced gingival margin recession. An emergence angle of 32.4 degrees showed better behavior in maintaining the gingival margin than 40 degrees.Clinical Trial Registration Number: ChiCTR190002210.

Background Short implants (intra‐bony length ≤ 8 mm) are generally considered as an alternative to bone augmentation in challenging situations; however, clinical evidence from large‐scale studies with long follow‐up regarding the application of short implants remains deficient. Purpose The present study aimed to assess the mid‐term clinical outcomes of short implants supporting fixed prostheses in the posterior region, and to investigate the effects of the crown‐to‐implant ratio (C/I), and other patient‐, implant‐, prosthesis‐relevant factors on the clinical conditions around short implants. Materials and methods 180 Thommen short implants in 130 partially edentulous patients were enrolled in the study after 3 to 7 (mean 4.2) years of follow‐up. Potential risk factors (patient sex and age, implant diameter and location, splinted vs single‐tooth restorations, retention mode, anatomical and clinical C/I ratios) were evaluated according to the following outcomes: Implant survival, marginal bone loss (MBL), and mechanical and biological complications. Results In total, four implants in four patients failed as a result of peri‐implantitis. The cumulative survival rate was 97.8% for implant‐based analysis. The peri‐implant MBL around 180 short implants was 0.90 ± 0.78 mm. The mean clinical C/I ratio was 1.16 ± 0.36. Correlation analysis revealed that the influence of the clinical C/I ratio and patient age were significant for MBL (P < .05), whereas other potential risk factors showed no significant association with the outcome. Among 180 short implants, 24 cases (13.3%) had biological complications and 32 cases (17.8%) had mechanical complications, respectively. Peri‐implant MBL and complication rates around splinted and non‐splinted implants were not statistically different. Conclusion Within the limitations of this study, short implants supporting fixed prostheses in the posterior region achieved predictable clinical outcomes over a 3 to 7 year period. Within the range of 0.47 to 3.01, the higher the C/I ratio, the less the peri‐implant MBL.

Background: Maxillary sinus pathologies are a potential risk for failure of implant and bone augmentation. Management of lateral sinus floor elevation in the presence of a pseudocyst remains controversial, and reports on histological outcomes of endo‐sinus bone augmentation with maxillary cysts are scarce.Purpose: To present a modified surgical technique for removal of maxillary pseudocyst with simultaneous sinus floor elevation, and to evaluate clinical and histological outcomes of the bone grafting.Materials and Methods: Patients with a radiographic dome‐shaped opacity in the posterior maxillary sinus were included to receive lateral sinus floor elevation with simultaneous pseudocyst removal. Bone core specimens harvested from the lateral aspect of the augmentation sites were histomorphometrically analyzed. Data were recorded and evaluated in terms of survival rates and complications.Results: A total of 15 patients were included who underwent 17 maxillary sinus augmentation surgeries. Implant survival rate was 97.0%. Bone biopsy specimens were obtained at 6 months after surgery. Histomorphometric analysis revealed that mean percentages of mineralized bone, bone substitute, and nonmineralized tissue were 24.9% ± 18.1%, 14.4% ± 12.5%, and 60.1% ± 12.44%, respectively. No recurrence of the pseudocyst was detected on radiographic examination.Conclusions: The described technique could be successfully applied in clinical practice to perform sinus augmentation in the presence of pseudocysts.

Background: Maturation of the grafted volume after lateral sinus elevation is crucial for the long‐term survival of dental implants.Purpose: To compare endo‐sinus histomorphometric bone formation between the solo‐ and two‐window maxillary sinus augmentation techniques with or without membrane coverage for the rehabilitation of multiple missing posterior teeth.Materials and Methods: Patients with severely atrophic posterior maxillae were randomized to receive lateral sinus floor elevation via the solo‐window technique with membrane coverage (Control Group) or the two‐window technique without coverage (Test Group). Six months after surgery, bone core specimens harvested from the lateral aspect were histomorphometrically analyzed.Results: Ten patients in each group underwent 21 maxillary sinus augmentations. Histomorphometric analysis revealed mean newly formed bone values of 26.08 ± 16.23% and 27.14 ± 18.11%, mean connective tissue values of 59.34 ± 12.42% and 50.03 ± 17.13%, and mean residual graft material values of 14.6 ± 14.56% and 22.78 ± 10.83% in the Test and Control Groups, respectively, with no significant differences.Conclusions: The two‐window technique obtained comparative maturation of the grafted volume even without membrane coverage, and is a viable alternative for the rehabilitation of severely atrophic posterior maxillae with multiple missing posterior teeth.

Background: Implant failures are more common when multiple missing posterior teeth need lateral sinus floor elevation owing to inadequate tissue maturation after grafting. Effects of lateral window dimensions on vital bone formation have rarely been compared.Purpose: To compare endo‐sinus bone formation between two‐ and solo‐window techniques to rehabilitate multiple missing posterior teeth that need substantial augmentation.Methods and materials: Patients with severely atrophic posterior maxilla were randomized to receive lateral sinus floor elevation via solo or two bony windows. Bone core specimens harvested from lateral aspect of the augmentation sites were histomorphometrically analyzed. Proportions of mineralized bone (MB), bone substitute materials (BS), and nonmineralized tissue (NMT) were quantified.Results: Twenty‐one patients underwent 23 maxillary sinus augmentations. One patient in each group dropped out during the follow‐up period. Lateral window dimensions were 81.65 ± 4.59 and 118.04 ± 19.53 mm² in the test and control groups, respectively. Histomorphometric analysis revealed mean MB of 42.32% ± 13.07% and 26.00% ± 15.23%, BS of 40.34% ± 9.52% and 60.03% ± 10.13%, and NMT of 18.14% ± 14.24% and 14.75% ± 10.38% in test and control groups, respectively, with significant differences.Conclusion: The two‐window technique could facilitate faster maturation and consolidation of the grafted volume and is an effective alternative for rehabilitation of severely atrophic posterior maxilla with multiple missing posterior teeth.