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Purpose: To compare bone substitutes composed of glycated collagen with synthetic micro-sized (1 to 10 µm) hydroxyapatite (OB) vs non-cross-linked collagen matrix with large-particle (250 to 1,000 µm) bovine-derived hydroxyapatite (BOC). Materials and Methods: The P1 to P4 premolars were bilaterally extracted from the mandibles of 19 Beagle dogs. After 21 days, osteotomies were created in each dog that received OB or BOC and were covered with a collagen membrane or were left untreated. The animals were randomly divided into three groups based on sacrifice time (4, 12, or 24 weeks). The right and left hemimandibles were trimmed to facilitate imaging and histology, and all tissues were placed in 10% neutral-buffered formalin. Microcomputed tomography (MicroCT 40 Scanner, Scanco) was used to analyze bone sections. Bone volume, residual material volume, and bone mineral density were determined for each treatment site (OB and BOC) based on a volume of interest that encompassed the original defect. Additionally, blinded histopathologic assessment (based on the ISO 10993-6 scoring system) and histomorphometry were performed on sections ground to < 100 µm thick and stained with Stevenel's blue. Results: No clinical side effects were noted. No statistical differences were observed for OB vs BOC regarding the mineral volume percentage. Compared to OB, BOC had significantly higher mean mineralization densities at 12 weeks (P < .01), but this difference did not extend to 24 weeks. For residual grafting material, bone maturation, alveolar ridge restoration, and inflammatory response, OB showed a residual amount of bone graft and no statistical differences compared to BOC. Conclusion: Both OB and BOC represent valid treatment options for critically sized bone defects. Both bone fillers outperformed the sham-operated, ungrafted (empty) control, demonstrating statistically improved bone growth and ridge restoration. [ABSTRACT FROM AUTHOR]

Purpose: To compare glycated multilayered membranes (OV) to a commercially available thin-layer membrane (OP) in a lateral ridge augmentation model in dogs. Materials and Methods: This was designed as a three-arm study, where one negative control (empty defect) was compared to two test arms: alveolar bone defects grafted with a mixture of 90% deproteinized bovine bone mineral and 10% porcine collagen, then covered with either a thick- (OV) or thin-layered (OP) membrane. Animals were randomly divided into three groups corresponding to the final sacrifice times of 4 weeks, 12 weeks, and 24 weeks. Sections underwent microCT, histology, histopathology, and histomorphometry. Results: No statistical differences were observed for OV compared to OP regarding the percentage of mineral volume and mean mineral density, amount of bone maturation, percentage of bone graft and membrane remaining in the grafted area, alveolar ridge width measurements, membrane mineralization, or ossification. Test groups presented significantly higher values compared to the empty control for all the endpoints. Conclusions: Within its limitations, this in vivo study highlighted that multilayered thick glycated membranes can serve as effective occlusive barriers for up to 6 months. [ABSTRACT FROM AUTHOR]

Among different therapeutic strategies proposed in the case of bone volume deficit, guided bone regeneration (GBR) is a consolidated surgical procedure. The objective of this study is to retrospectively evaluate the behavior of two bone grafts with different consistencies in the GBR procedure by measuring the volumetric tissue changes 1 year after surgery. For this retrospective analysis, 25 cases of GBR with simultaneous implant insertion were selected. A total of 13 were grafted with a porcine cortico-cancellous bone mix (CCBM group), and 12 were grafted with a pre-hydrated granulated cortico-cancellous bone mix of porcine origin blended with 20% TSV gel (Collagenated-CCBM). A collagen membrane was fixed to cover the bone defect. A total of 42 implants were placed with computer-guided surgery. Preoperative and 12-month postoperative digital impressions were used to evaluate dimensional changes. Student's t-test used for independent samples showed no statistically significant differences between the integrated distance (p = 0.995) and mean distance (p = 0.734). The mean integrated distance in the CCBM group was 41.80 (SD. 101.18) compared to a mean of 42.04 (SD. 66.71) in the Collagenated-CCBM group. Given the limitations of this study, in patients with peri-implant bone dehiscence, simple heterologous and collagenated heterologous cortico-cancellous bone grafts are suitable for filling the bone defect to promote bone regeneration, although further studies are needed. [ABSTRACT FROM AUTHOR]

Background: Restorative materials might significantly affect load transmission in peri-implant bone. The aim of the present study is to evaluate the shock absorption capacity of two different polymeric materials to be used for implant-supported prostheses. Methods: A masticatory robot was used to compare the shock absorption capacity of veneered and non-veneered polyetherketoneketone (PEKK), Pekkton®ivory (Cendres+Mètaux), and the glass fiber-reinforced composite (GFRC), TRINIATM (Bicon). Five identical sample crowns for each of the three groups were tested. Forces transmitted at the simulated peri-implant bone were recorded and statistically analyzed. Results: The statistical analysis of forces transmitted at the simulated dental implant revealed significant differences between the materials tested and between these materials and zirconia, glass ceramic, composite resin, and acrylic resin. Only differences between PEKK and veneered PEKK and between PEKK and one of the previously tested composite resins were not statistically significant. PEKK samples demonstrated significantly greater shock absorption capacity compared to GFRC. Conclusions: PEKK revealed optimal shock absorption capacity. Further studies are needed to evaluate its efficacy in the case of long-span prostheses with reduced prosthetic volume. [ABSTRACT FROM AUTHOR]

Purpose: To monitor the early bone reaction in a canine model to a conventional sandblasted and dual acid-etched implant surface (ABT), a nanostructured hydrophilic surface (Nano), a dry salt--bioactivated ultra-hydrophilic surface (Hydro), and a bioactivated nanosurface obtained from the addition of dry salts to the Nano surface (Nano-Active). Materials and Methods: ABT, Nano, Hydro, and Nano-Active implants were placed in 12 dogs. A randomized split-mouth design was adopted. One implant of each type was placed in the mandible 3 months after tooth extraction in healed sites at the first molar region bilaterally. In the same session, the third and fourth premolars were extracted bilaterally and one implant of each type was immediately placed into the extraction socket. The dogs were euthanized at 14 and 28 days following surgery, and the peri-implant bone reaction was assessed histologically using Stevenel's blue and alizarin red in nondecalcified sections. Results: The postoperative healing was uneventful. The 14-day histologic analysis reported nonsignificant results in terms of difference between the groups, while significant results were found 28 days after surgery. In fact, a significantly higher rate of new bone around the implant was reported in the Nano-Active compared to the Nano groups (51.0% ± 10.2% vs 36.0% ± 10.2%) and Hydro compared to the Nano groups (47.3% ± 10.7% vs 36.0% ± 10.2%). Conclusion: The results obtained indicate that new bone formed after 4 weeks demonstrated a tendency for dry salt--treated bioactivated surfaces to improve bone deposition in the interface in the early stages of healing; however, due to the limited number of dogs, the results failed to show a statistical significance. A study with a significantly larger group of animals should be performed in order to challenge the assumption that ultra-hydrophilic--surface implants might show higher bone-implant contact in immediate postextraction replacement. [ABSTRACT FROM AUTHOR]

Purpose: To retrospectively evaluate the survival rate and technical and biologic complications of feather-edge zirconia and metal-ceramic implant restorations cemented on conical titanium abutments.Materials and Methods: Patients rehabilitated with implant-supported single crowns or fixed dental prostheses (FDPs) were divided into four groups: ZR-TL = tissue-level implant with a convergent collar and zirconia restoration; ZR-BL = bone-level implant and zirconia restoration; MC-TL = tissue-level implant with a convergent collar and metal-ceramic restoration; MC-BL = bone-level implant and metal-ceramic restoration. All of the restorations were cemented onto conical titanium abutments and had feather-edge margins, following the biologically oriented preparation technique (BOPT). Crown-level survival rates, technical and biologic complications, and bone resorption were registered. Chi-square test was performed to analyze all evaluated parameters among the groups. Nonparametric Mann-Whitney test was performed to analyze changes in bone level.Results: A total of 85 patients (133 implants, 66 single crowns, and 28 FDPs) were included in the present study with a mean follow-up time of 4.98 years. The overall survival rate was 98.2% for zirconia and 97.5% for metal-ceramic restorations at the crown level. No significant differences were found between the zirconia (ZR-BL and ZR-TL) and the metal-ceramic (MC-BL and MC-TL) groups for technical complications (P > .05). Bone resorption was 0.33 (0.37) mm in MC-TL; 0.61 (0.52) mm in MC-BL; 0.39 (0.51) mm in ZR-TL; and 0.77 (0.64) mm in ZR-BL, showing significantly greater bone loss in bone-level implants (P = .011).Conclusion: Zirconia implant restorations with feather-edge margins seem to be a viable alternative in cases of both tissue-level and bone-level implants. [ABSTRACT FROM AUTHOR]

Objective: To assess the peri‐implant soft tissue profiles between argon plasma treatment (PT) and non‐treated (NPT) healing abutments by comparing clinical and histological parameters 2 months following abutment placement. Materials and Methods: Thirty participants were randomly assigned to argon‐plasma treatment abutments group (PT) or non‐treated abutments (NPT) group. Two months after healing abutment placement, soft peri‐implant tissues and abutment were harvested, and histological and clinical parameters including plaque index, bleeding on probing, and keratinized mucosa diameter (KM) were assessed. Specialized stainings (hematoxylin–eosin and picrocirious red) coupled with immunohistochemistry (vimentin, collagen, and CK10) were performed to assess soft tissue inflammation and healing, and the collagen content keratinization. In addition to standard statistical methods, machine learning algorithms were applied for advanced soft tissue profiling between the test and control groups. Results: PT group showed lower plaque accumulation and inflammation grade (6.71% vs. 13.25%, respectively; p‐value 0.02), and more advanced connective tissue healing and integration compared to NPT (31.77% vs. 23.3%, respectively; p = 0.009). In the control group, more expressed keratinization was found compared to the PT group, showing significantly higher CK10 (>47.5%). No differences in KM were found between the groups. Significance: PT seems to be a promising protocol for guided peri‐implant soft tissue morphogenesis reducing plaque accumulation and inflammation, and stimulating collagen and soft tissue but without effects on epithelial tissues and keratinization. [ABSTRACT FROM AUTHOR]

Purpose: After tooth extraction, a modeling and remodeling phase of bone and soft tissues occurs. It has been fully demonstrated that bone resorption as high as 50% can take place regarding ridge width and a variable amount concerning ridge height, making it difficult to perform implant surgery. Materials and Methods: Active members of the Italian Academy of Osseointegration (IAO) participated in this Consensus Conference, and three systematic reviews were conducted before the meeting to provide guidelines on alveolar ridge preservation procedures. The systematic reviews covered the following topics: (1) What material best preserves the dimensions of the ridge horizontally and vertically?; (2) what material favors the formation of the highest quantity of new bone?; (3) which technique would best seal the socket?; and (4) what effect does alveolar ridge preservation have on soft tissues? Results: The main conclusions reached by the assembly were that alveolar ridge preservation is advisable after dental extraction, particularly in esthetic areas, in proximity of anatomical structures (ie, maxillary sinus, inferior alveolar nerve, and mental foramen), whenever the treatment plan requires delayed placement, and whenever patients ask to postpone implant insertion for various reasons. Socket debridement is advised before the use of a “regenerative material,” and xenograft is considered the gold standard material to maintain ridge dimensions. Another indication is antibiotic therapy, which is recommended in the case of alveolar ridge preservation (amoxicillin 2 g 1 hour before the intervention and 1 g every 12 hours for 6 days). A membrane or autologous soft tissue should be used to seal the socket and protect the regenerative material, and the indicated reentry time (implant insertion) is 4 to 6 months. Conclusion: This Consensus Conference agreed that the adoption of alveolar ridge preservation can effectively prevent physiologic bone loss, especially in esthetic areas. It is recommended to cover the xenograft material with a membrane or autologous soft tissue, and antibiotic therapy is advisable. [ABSTRACT FROM AUTHOR]

Background: Different biomaterials were suggested for sinus floor augmentation (SFA). Recently, new materials were launched showing true bone formation without remnants. Purpose: The aim of this prospective study was to evaluate an hydroxyapatite‐based, sugar cross‐linked collagen sponge (OSSIX™ Bone) in transcrestal SFA (t‐SFA). Materials and methods: Twenty‐four patients with edentulous posterior maxilla and residual bone height (RBH) >4 mm underwent t‐SFA with OSSIX™ Bone as grafting material and simultaneous implant placement. The implant Stability Quotient (ISQ) was measured by resonance frequency analysis (RFA) directly after implant insertion and at 6 months. Differences in bone height (BH) and volume were determined in CBCT and x‐rays at baseline versus 1 year of follow‐up. Graft volume was evaluated by tridimensional reconstructions. Linear regression analysis was used to evaluate the effect of bucco‐palatal sinus dimension, RBH, and length of the implant protruding (PIL) into the sinus, on the graft height (GH) changes up to 1 year, and on the graft volume at 1 year. Autocorrelation between time lag and augmented bone volume was evaluated through time series analysis correlograms. Health‐related quality‐of‐life outcomes were captured. Results: Twenty‐two patients completed the study. The mean RBH measured at baseline was 5.81 ± 2.2 mm. The mean graft volume was 1085.8 ± 733.4 mm3. The mean GH, measured in the immediate post‐operative period, at 6 and 12 months respectively, was 7.24 mm ±1.94; 6.57 mm ± 2.30; 5.46 mm ± 2.04. The mean ISQ measured after the implant placement was 62.19 ± 8.09, and 6 months later was 76.91 ± 4.50. There was a significant correlation between buccolingual dimension and graft volume at 1 year. Neither buccolingual volume nor RBH had a significant effect on GH change, while the PIL showed a significant positive correlation (P = 0.02 and P = 0.03 at 6 and 12 months, respectively). The correlograms indicated no significant correlation, meaning that there is no tendency for graft volume to increase or decrease over time, therefore suggesting graft stability, at least up to one year of follow‐up. 86% of patients had no chewing interference. Conclusion: Within the limitations of the study, OSSIX™ Bone could be considered a valid material for SFA due to its manageability and its positive results in promoting new bone formation with long‐term stability. T‐SFA is confirmed as a less invasive and less painful method. [ABSTRACT FROM AUTHOR]

Objectives: The aim of the present human observational study is to provide morphologic and morphometric analysis of peri‐implant connective tissue next to abutments with divergent or convergent macro‐geometry and different surface micro‐characteristics. Materials and Methods: Thirty patients were rehabilitated with single implants in the posterior area and one out of three different healing abutments with a one‐stage technique: machined divergent abutment (DIV‐MAC), machined convergent abutment (CONV‐MAC) or convergent abutment with ultrathin threaded surface (CONV‐UTM). At 3 months postimplant insertion, peri‐implant soft tissue was harvested; the following outcomes were investigated: histomorphometry (vertical width of connective and epithelial components) as detected by histology and polarized light; and connective tissue vertical width and 3D organization as detected by synchrotron‐based high‐resolution phase‐contrast‐based tomography (PhC‐μCT). Results: Significant differences in connective tissue vertical dimension (aJE‐AM) were found between DIV‐MAC and both CONV‐MAC and CONV‐UTM, both by histology and PhC‐μCT, with significantly higher values for the last two groups. Moreover, 2D histological analysis did not find significant differences in the junctional epithelium vertical dimension (PM‐aJE). Importantly, PhC‐μCT analysis revealed, at 3D level, significant greater amount and density of collagen bundles for CONV‐UTM compared with the other two groups. Conclusions: Convergent abutment profiles, regardless of their surface micro‐geometry, seem to favor axial development of peri‐implant connective tissue. Moreover, ultrathin threaded surfaces seem associated with denser and greater connective tissue organization, which might improve peri‐implant soft tissue seal. [ABSTRACT FROM AUTHOR]