Bone volume and height changes for lateral window sinus floor elevation using two types of deproteinized bovine bone mineral: A retrospective cohort study of 1-4 years.

OBJECTIVE: To compare bone volume and height changes of two types of deproteinized bovine bone mineral (DBBM) for lateral window sinus floor elevation (LSFE) with simultaneous implant placement. MATERIALS AND METHODS: This retrospective cohort study involved 72 patients who underwent LSFE using low-temperature sintered cancellous bone-derived DBBM (C-DBBM) or high-temperature two-step sintered epiphyseal-derived DBBM (E-DBBM). Cone-beam computed tomography (CBCT) was acquired preoperatively, immediately postoperatively, 6 months and 1-4 years post-surgery. Bone volume (BV), apical bone height (ABH), endo-sinus bone gain (ESBG), and crestal bone level (CBL) were evaluated through three-dimensional fitting and superimposition. Linear mixed models (LMM) were employed to analyze factors influencing the reduction of BV (ΔBV) and ESBG (ΔESBG). RESULTS: The E-DBBM group showed no significant change in BV 1-4 years post-surgery, while the C-DBBM group demonstrated a significant reduction (p = .006) with volume stability of 85.86%. Bone height in the E-DBBM group increased at 6 months and subsequently decreased at 1-4 years (p = .003). In the C-DBBM group, it decreased at 6 months (p = .014), then further decreased at 1-4 years (p = .001). ΔESBG was lower in the E-DBBM group than the C-DBBM group from immediate postoperative to 1-4 years (p = .009). LMM showed graft material type was the primary factor influencing ΔBV (p = .026) and ΔESBG (p = .003). CONCLUSIONS: Within the limitations of this study, both types of DBBM could achieve favorable clinical outcomes. E-DBBM demonstrated enhanced stability in maintaining bone volume and height.

Outcomes that may affect implant and prosthesis survival and complications in maxillary fixed prosthesis supported by four or six implants: A systematic review and meta-analysis.

Objective: To investigate whether the clinical and radiographical outcomes are affected when four or six implants support the maxillary fixed complete denture (FCD). Materials and methods: This study was registered on PROSPERO (CRD42021226432) and followed the PRISMA guidelines. The focused PICO question was, "For an edentulous maxillary patient rehabilitated with an implant-supported fixed prosthesis, do the clinical and radiographical outcomes differ when four or six implants support the prosthesis ". A thorough search of the relevant studies was designed and performed electronically. The survival rate of implant and prosthesis, marginal bone loss, and complications (mechanical and biological) were the primary outcomes, whereas implant distribution and using the surgical guide, follow-up, and framework material were evaluated as secondary outcomes. Results: Out of 1099 articles initially retrieved, 53 clearly stated the outcomes of interest and were included in this study. There were no significant differences in implant and prosthesis survival, technical/mechanical complications, and biological complications between the 4-implant group (4-IG) and the 6-implant group (6-IG). However, marginal bone loss (MBL) was significantly higher in the 4-IG (p < 0.01). The surgical guide and follow-up period did not significantly affect implant/prosthesis survival. Additionally, using the CAD/CAM milled framework and anteroposterior implant distribution were associated with significantly higher implant survival in the 6-IG (p < 0.01). Conclusion: The findings of this study indicated that having a greater number of implants, as seen in the 6-implant group, can lead to a decrease in technical and biological complications and reduce marginal bone loss. It is worth noting that factors such as using CAD/CAM frameworks and the anteroposterior distribution of implants were recognized as important in improving implant survival rates when more implants are present.

Three-dimensional relationship between the degree of bilateral impacted mandibular third molars angulation and the mandibular dental arch parameters: a cross-sectional comparative study.

OBJECTIVE: The purpose of this study was to three-dimensionally evaluate the relationship between the degree of bilateral impacted mandibular third molar (IM3M) angulation and the mandibular dental arch parameters in normal skeletal and dental malocclusion patients. MATERIALS AND METHODS: In this retrospective cross-sectional comparative study, 120 adult subjects' cone-beam computed tomography (CBCT) images were three-dimensionally analyzed. The sample included 120 adults aged 20-30 years, with a gender distribution of 51 male and 69 female participants. The sample was divided into 100 adults with bilateral IM3M (study group) and 20 adults with normal bilateral erupted M3M (control group). The study group was sub-divided into three groups according to the degree of IM3M buccolingual angulation (BL°): group A, < 12° on the center of the ridge (N = 30), group B, 12-24° off-center of the ridge (N = 40), group C, > 24° off-center of the ridge (N = 30). The study group was also sub-divided into two groups according to IM3M mesiodistal angulation (MD°): group 1 from 10 to 45° (N = 36), group 2 > 45° (N = 64). Comparison within and between groups was performed using one-way ANOVA followed by Tukey's post hoc test. The correlation between IM3M, BL, and MD angulation and the mandibular arch parameter was calculated using Pearson's correlation coefficient. RESULTS: Statistically significant differences (P < 0.001) were found between the IM3M BL° and anterior teeth inclination, arch length (AL), and inter-second molar width (inter 2nd MW) as well as between the IM3M MD° with anterior crowding and the arch length (P < 0.001). A significant positive correlation was found between IM3M BL° and anterior teeth inclination and between IM3M MD° and anterior teeth crowding and inter 2nd MW. A significant negative correlation was observed between IM3M BL° and inter 1st MW and 2nd MW. CONCLUSION: The degree of buccolingual and mesiodistal angulation of the impacted mandibular third molars was related with mandibular dentoalveolar changes. Increased buccolingual angulation is generally associated with increased anterior teeth inclination and decreased 1st and 2nd inter-molar width. The increase in mesiodistal angulations was generally related with increased anterior teeth crowding and 2nd inter-molar width. CLINICAL RELEVANCE: Assessment of the relationship between the impacted mandibular third molars and the degree of arch discrepancy, and the position of mandibular incisors in the three planes of space might help in the decision-making process for the extraction of the impacted third molars in adult patients.

Clinical and patient-centered outcomes following rehabilitation of atrophic edentulous maxilla using six implants placed simultaneously with bilateral maxillary sinus augmentation: A retrospective case series.

OBJECTIVES: To evaluate treatment success, patient satisfaction, and oral health-related quality of life (OHRQoL) after rehabilitation of atrophic edentulous maxilla (AEM) with six implants placed simultaneously with bilateral maxillary sinus floor augmentation (MSFA). MATERIALS AND METHODS: The selected patients were fully edentulous with atrophic maxillary posterior residual ridges and rehabilitated with six implants placed simultaneously with bilateral MSFA and immediate All-on-4 provisional fixed prosthesis (PFP). After 7-12 months of implant surgery, all patients have received an All-on-6 definitive fixed prosthesis (DFP). After at least one year of function with DFP, clinical and radiographic examinations were performed. Patient satisfaction was assessed through a visual analog scale (VAS). The OHRQoL before treatment (T0), during provisional (T1), and after definitive prosthesis (T2) was evaluated using OHI-14. RESULTS: 20 maxillary edentulous patients were rehabilitated with 120 implants, 20 immediate All-on-4 PFP, and 20 All-on-6 DFP. Of those, 12 patients have passed at least a year follow-up after DFP insertion and were eligible to be included in the assessment of treatment success. After a mean of 20 (12-36) months follow-up, the implant and prosthesis survival rates were 100%. The success rate at the implant level was 98.6%. The mean marginal bone loss (MBL) was 0.09 ± 0.06 mm. No prosthetic or postoperative complications, and the mean general satisfaction was (91.75 ± 7.06). There was a significant improvement in all OHIP-14 domains during the final All-on-6 prosthesis (T2) (P < 0.01). CONCLUSIONS: Rehabilitation of atrophic edentulous maxilla using six implants with simultaneous bilateral MSFA and immediate All-on-4 PFP is a successful treatment approach associated with minimal postoperative complications and significant improvement in OHRQoL.