Immediate Implantation with Autologous Mineralized Dentin Graft versus Deproteinized Bovine Bone as Space-Filling Substitute in Maxillary Anterior Zone: Retrospective Radiological and Clinical Study.

Background/Objectives: Various bone substitutes have been recommended to augment the horizontal gap following immediate implantation. The purpose of this study was to compare the effectiveness of an autogenous mineralized dentin graft or a deproteinized bovine bone in horizontal gap augmentation following immediate implant placement in the maxillary anterior region. Methods: A total of 110 patients underwent tooth extraction followed by immediate implant placement. The patients were divided into two groups. The first group received an autogenous mineralized dentin graft (the test group) while the second group received a deproteinized bovine bone (the control group) to augment the horizontal gap. Preoperative (T0), immediate postoperative (T1), and 1-year postoperative (T2) cone beam computed tomography scans were taken from all the patients. Linear measurements were recorded 1 mm (R1) and 5 mm (R2) points apical to the implant platform at both T1 and T2 time intervals. Pink Esthetic Scores and prosthetic complications were evaluated as well. Results: There were 57 patients with a mean age of 45.42 ± 9.86 (range 24-63 years) selected as the test group and 53 patients with a mean age of 40.28 ± 11.69 (range 20-63 years) as the control group. The mean reduction in the buccal bone plate at R1 was 6.39 ± 3.78% in the test group and 6.99 ± 5.01% in the control group (p > 0.05). The mean reduction in the buccal bone plate at R2 was 5.46 ± 4.98% in the test group and 6.77 ± 7.60% in the control group (p < 0.05). The PES and prosthetic-related complications were shown to be negligible between the groups (p > 0.05). Conclusions: The efficiency of using an autogenous mineralized dentin graft for horizontal gap augmentation showed similar results in comparison to using a deproteinized bovine bone in relation to buccolingual socket reduction following immediate implantation.

Maxillary Sinus Floor Elevation and Simultaneous Implant Installation via Osseodensification Drills: A Retrospective Analysis of Bone Gain in 72 Patients Followed for 6 Months.

Background/Objectives: The aim of this retrospective study was to radiographically evaluate the endo-sinus bone gain (ESBG) following osseodensification procedures using CBCT and compare the results to more conventional sinus lifting techniques. Methods: A total of 72 patients underwent crestal sinus floor elevation procedures and were provided with 102 implants with a sand-blasted and acid-etched surface with microthreads (Medentika® Microcone Implants, Hugelsheim, Germany). Patients were divided into two groups; the osseodensification group (OD; n = 36) and the osseodensified augmentation group (ODA; n = 36). Results: The mean residual bone height (RBH) was 5.71 (1.77) and 4.30 (0.94) mm in the OD and ODA groups, respectively. An ESBG of 3.45 (1.18) and 5.74 (1.31) mm was observed in the OD and ODA groups, respectively, and as compared to the baseline RBH, the ESBG was statistically significant in both groups after 6 months (p < 0.001). Conclusions: Within the limits of this retrospective study, crestal sinus lifting with the osseodensification technique seems to be a fast, effective, and safe method. Longer follow-up studies with full intrasinus bone topography and structure analyses are needed to prove the success rate of endo-sinus bone gain.

Retrospective analysis of three different xenografts in maxillary sinus augmentation: histologic and three-dimensional radiologic study.

OBJECTIVES: Low bone density and lack of adequate vertical bone dimension as a result of maxillary sinus pneumatization present some of the most problematic cases for endosseous implant applications in posterior maxillary regions that hinder prosthetic rehabilitation. The overall objectives of the study were to assess the histologic, histomorphometric, and radiologic evaluation of biopsies gathered from maxillary sinuses that were grafted with three different bovine bone particles (Bio-Oss, Cerabone, and Ti-Oss) and analyze the volume of the bone graft and the quantity of new bone formation. METHOD AND MATERIALS: Thirty-six patients with < 4 mm of residual ridge height unilaterally in the posterior maxilla were equally divided into three groups, each of which received different bovine bone particles for maxillary sinus augmentation. Six months later, biopsies were harvested for histologic and histomorphometric evaluations. Volumetric changes in maxillary sinus augmentation were analyzed at 1-week and 6-month time-points following maxillary sinus augmentation surgery. RESULTS: Histomorphometric and histologic analysis revealed a significant difference between the Ti-Oss group compared with the Bio-Oss and Cerabone groups (P = .011). In terms of residual graft particles and soft tissue, there were no significant differences between groups. 3D volumetric reductions between 1-week (baseline) and 6-month time-points recorded significant graft volume reduction in all groups (P < .05). Significantly greater bone resorption and lower new-bone formation were manifested in the Ti-Oss group in comparison to the other groups. CONCLUSIONS: Within the limits of this study, histologic and radiologic results indicated that Bio-Oss and Cerabone could be used efficiently in sinus augmentation procedures, while further prospective studies are needed to evaluate the Ti-Oss material in maxillary sinus augmentation.

Effect of soft tissue thickness on crestal bone loss of early loaded implants with platform switching: 1- and 5-year data.

Objectives: The aim of this retrospective study was to evaluate the effect of vertical soft tissue thickness (STT) on crestal bone loss (CBL) of early loaded implants after 1 and 5 years. Method and materials: Forty-four tapered implants with platform switching and conical connection were placed in the posterior mandible and maxilla to rehabilitate edentulous sites. STT at implant sites was divided into two groups: thin (n = 21, mean STT = 2.0 ±â€¯0.3 mm) and thick (n = 23, mean STT = 3.0 ±â€¯0.8 mm). The implants were loaded after 6 to 8 weeks. Survival and success rates and CBL were measured after 1 and 5 years. Results: The survival and success rates at 1 and 5 years were 100% and 97.8%, respectively. At the 1-year follow-up, the CBL of the thin and thick gingival groups was 0.96 ±â€¯0.49 and 0.55 ±â€¯0.41 mm, respectively; the difference was statistically significant (P = .004). At 5 years, the CBL of the thin and thick gingiva groups increased to 1.12 ±â€¯0.84 and 0.65 ±â€¯0.69 mm, respectively; the difference was not statistically significant (P = .052). Conclusion: At 1 year, the CBL was more pronounced at sites with a thin gingiva; at 5 years the difference between the groups was not statisically significantly different. Within the limitations of this study, early loading of implants with platform switched and conical connection was safe.

Histologic, Histomorphometric, and Clinical Analysis of the Effects of Growth Factors in a Fibrin Network Used in Maxillary Sinus Augmentation.

This randomized controlled clinical trial evaluated the effect of mineralized plasmatic matrix (MPM), comprised of synthetic graft and platelet concentrates, on new bone formation and volume stability over time in maxillary sinus lifting (MSL). Unilateral MSL was performed in 20 patients with either beta-tricalcium phosphate (ß-TCP) or MPM grafts (10 sinuses each). Six months postsurgery, specimens were obtained with a trephine bur prior to implant placement in 39 cases. Volumetric changes in sinus augmentation were analyzed between 1 week (T-I) and 6 months (T-II) postsurgery. Histomorphometric and histological analyses of biopsy samples revealed mean new bone percentages of 35.40% ± 9.09% and 26.92% ± 7.26% and residual graft particle areas of 23.13% ± 6.16% and 32.25% ± 8.48% in the MPM and ß-TCP groups, respectively (p < 0.05). The mean soft-tissue areas in the MPM and ß-TCP groups were 41.48% ± 8.41% and 40.83% ± 8.86%, respectively (p > 0.05). Graft reductions between baseline and 6-months postprocedure in the ß-TCP and MPM groups were 17.12% ± 13.55% and 14.41% ± 12.87%, respectively, with significant graft volume reduction observed in both groups (p < 0.05) while there is no significant difference between MPM and ß-TCP groups (p > 0.05). Thus, MPM, representing growth factors in a fibrin network, increases new bone formation and has acceptable volume stability in MSL procedures.

Presence of ROS in Inflammatory Environment of Peri-Implantitis Tissue: In Vitro and In Vivo Human Evidence.

Analyses of composition, distribution of cellular and extracellular matrix components, and molecular analysis of mitochondria related genes of bone loss in the presence of inflammatory environment in humans was the aim of the present project. As a human model we chose peri-implantitis. Morphological analyses were performed by means classical histological, immunohistochemical, and SEM (scanning electron miscroscopy) test. Gene expression analysis was performed to evaluate epithelium maturation, collagen fiber production, and genes related to mitochondrial activity. It was found that a well-defined keratinocyte epithelium was present on the top of all specimens; a distinct basal lamina was present, as well as desmosomes and autophagic processes related to the maturation of keratinocytes. Under this epithelium, a full inflammatory cell infiltrate was present for about 60% of the represented by plasma cells. Collagen type I fibers were present mainly in the form of fragmented cord tissue without cells. A different distribution of blood vessels was also present from the apical to the most coronal portion of the specimens. High levels of genes related to oxidative stress were present, as well as the activation of genes related to the loss of ability of osteogenic commitment of Mesenchymal stem cells into osteoblasts. Our study suggests that peri-implantitis lesions exhibit a well defined biological organization not only in terms of inflammatory cells but also on vessel and extracellular matrix components even if no difference in the epithelium is evident, and that the presence of reactive oxygen species (ROS) related to the inflammatory environment influences the correct commitment of Mesenchymal stem cells.