Customized-3D zirconia barriers for guided bone regeneration (GBR): clinical and histological findings from a proof-of-concept case series.

OBJECTIVES: The aim of this case series was to evaluate, clinically and histologically, customized-3D zirconia barriers manufactured for guided bone regeneration (GBR) procedures. METHODS: Seven healthy consecutive patients with severe bone atrophy (two of them with a bilateral atrophy) were selected for a GBR procedure with a zirconia barrier. In a 3D software (DentalCad, Exocad GmbH, Germany), a virtual bone graft was designed and a shell was designed covering the graft; a standard tessellation language (.STL) file was obtained and milled (M1, Zirkonzahn, Italy) using a 1200 MPa zirconia (Prettau, Zirkonzahn, Italy). Nine GBR surgeries (8 upper-posterior jaw, 1 lower-posterior jaw) were performed using autogenous bone chips mixed with xenograft (SmartBone, IBI-SA, Switzerland / BioOss, Geistlich, Switzerland) covered with a zirconia barrier, fixed by means of screws. After healing, implant sites were prepared with a trephine bur, collecting a bone biopsy, and dental implants were inserted (Neodent, Straumann Group, Switzerland). Specimens were histologically analyzed. RESULTS: Eight successful surgeries were recorded; one zirconia barrier got exposed after one month of healing but no signs of infection were present till the barrier was removed. In all cases it was possible to insert implants with no additional bone augmentation procedures. Histological evaluations showed the presence of intense deposition of new bone. CONCLUSIONS: Within the limitations of the present case series, the tested customized-3D zirconia barriers confirmed good clinical and histological performances, and, even in case of premature exposure, did not show signs of infection. Preliminary results suggest they are effective for GBR procedures. Further research is necessary with a larger sample size. CLINICAL SIGNIFICANCE: The presented barriers could be a viable alternative to titanium-reinforced polytetrafluoroethylene membranes and customized meshes.

Alveolar socket preservation with demineralised bovine bone mineral and a collagen matrix.

PURPOSE: The aim of the present study was to evaluate the healing of post-extraction sockets following alveolar ridge preservation clinically, radiologically, and histologically. METHODS: Overall, 7 extraction sockets in 7 patients were grafted with demineralised bovine bone mineral and covered with a porcine-derived non-crosslinked collagen matrix (CM). Soft tissue healing was clinically evaluated on the basis of a specific healing index. Horizontal and vertical ridge dimensional changes were assessed clinically and radiographically at baseline and 6 months after implant placement. For histological and histomorphometric analysis, bone biopsies were harvested from the augmented sites during implant surgery 6 months after the socket preservation procedure. RESULTS: Clinically, healing proceeded uneventfully in all the sockets. A trend towards reduced horizontal and vertical socket dimensions was observed from baseline to the final examination. The mean width and height of resorption were 1.21 mm (P=0.005) and 0.46 mm (P=0.004), respectively. Histologically, residual xenograft particles (31.97%±3.52%) were surrounded by either newly formed bone (16.02%±7.06%) or connective tissue (50.67%±8.42%) without fibrous encapsulation. The CM underwent a physiological substitution process in favour of well-vascularised collagen-rich connective tissue. CONCLUSIONS: Socket preservation using demineralised bovine bone mineral in combination with CM provided stable dimensional changes of the alveolar ridge associated with good re-epithelialisation of the soft tissues during a 6-month healing period.

Implantology and otorhinolaryngology team-up to solve a complicated case.

PURPOSE: The aim of this article was to highlight the importance of the collaboration between implantologists and ear, nose, and throat (ENT) specialists to treat complex cases. MATERIALS AND METHODS: A 46-year-old patient underwent a maxillary sinus elevation and implant placement 3 years before but because of a severe postop infection, the patient was treated with functional endoscopic sinus surgery (FESS) and lost the graft and the implants. Later, the patient consulted us and was referred to an ENT specialist because of sinus opacity. She underwent a second functional endoscopic sinus surgery (FESS); various ENT consultations and computer tomographies (CTs) were performed to assess sinus health. RESULTS: After having confirmed with sinus health, sinus elevation, implant placement, and loading were performed with success. CONCLUSION: Collaboration between the implantologist and ENT specialist is necessary to distinguish between nonpathological membrane thickening because of the healing process after FESS and a pathological thickening due to infection.

A novel technique to prevent the loss of graft material through the antrostomy after sinus surgery: technical note.

Maxillary sinus surgery has been shown to be a reliable procedure for increasing vertical bone height prior to implant placement. A variety of grafting materials have been proposed, with particulate bone substitutes showing similar clinical results to autogenous bone when rough surfaces implants are used. A barrier membrane is usually placed external to the grafted sinus, covering the antrostomy. In this technical report, the membrane is placed over the window and its borders gently tucked between the inner side of the bony wall and the graft material. This procedure stabilizes the membrane without tacks and prevents graft dislodgement through the antrostomy.

Tilted trans-sinus implants for the treatment of maxillary atrophy: case series of 35 consecutive patients.

PURPOSE: To evaluate tilted trans-sinus implants for rehabilitation of the atrophic maxilla. MATERIALS AND METHODS: A case series of 35 patients (32 consecutive edentulous and 3 partially edentulous patients) treated with trans-sinus dental implants is presented. Edentulous patients received 4 or 6 implants depending on anatomic conditions and a 12-unit final restoration; partially edentulous patients received 2 implants supporting a 3-unit partial fixed bridge. RESULTS: Thirty-five patients (14 men, 21 women) underwent rehabilitation. Thirty-two patients with 190 implants placed received a full-arch fixed prosthesis supported by axial and trans-sinus tilted implants. Three patients each received 2 implants with a 3-unit fixed restoration. The mean age at surgery was 59.2 ± 9.5 years. The cumulative survival rate was calculated only for the full-arch fixed prosthesis group and was 98.42%. Crestal bone loss averaged 0.9 ± 0.4 and 0.8 ± 0.5 mm for the axial and tilted implants, respectively, at the 12-month evaluation. Biological complications at the implant level were 1 case of peri-implantitis and 3 cases of mucositis; no patient developed sinus infections. The prosthetic complications encountered were screw loosening in 17.5% of cases and chipping of the esthetic part in 30% of cases. These complications were easily resolved chairside and did not lead to prosthetic failure. CONCLUSIONS: Trans-sinus tilted implants and sinus membrane distal displacement appear to be a viable minimally invasive alternative for the treatment of maxillary atrophy.