Both approaches may represent a predictable treatment option for the rehabilitation of complete edentulous patients in the medium term. Longer randomized controlled studies are needed to confirm these results.

Within the limitation of the present study, high implant survival rate and high average bone augmentation seem to validate the use of collagen resorbable membranes with a 1:1 mixture of particulated anorganic bovine bone and autogenous bone, for the reconstruction of severe horizontal ridge defects.

Background The insertion of dental implants by means of computer‐assisted template‐based surgery is an established method. Purpose To investigate the accuracy of a newly developed sleeve‐designed template and to evaluate differences between maxillary and mandibular implants as well as anterior versus posterior area. Materials and Methods Any partially edentulous patients requiring at least one implant to be planned on three‐dimensional cone beam computed tomography scan, according to a computer‐assisted template‐based protocol, were consecutively enrolled at two centers. Any potential implant position was considered eligible for the present trial. Outcome measures were: implant failure, complications, and accuracy. Results A total of 39 patients with 119 implants were evaluated. No patients dropped out during the study period (mean follow‐up 12.4 ± 7.1 months). Three implants failed at centre two, whereas, one complication was experienced at centre one (limited access in posterior area). Differences were not statistically significant (P > .05). The mean deviations were 0.53 ± 0.46 mm (range 0.05‐3.38 mm; 95% CI 0.32‐0.48 mm) in the horizontal plan (mesio‐distal); 0.42 ± 0.37 mm (range 0.0‐1.53 mm; 95% CI 0.26‐0.40 mm) in the vertical plan (apico‐coronal); and 1.43 ± 1.98° (range 0.03‐11.8°; 95% CI 0.31‐1.01°) in angle. Differences between centers were compared using the nonparametric Mann‐Whitney U test (P > .05). More accurate results were found for anterior implants in both horizontal plan and angle. Conclusion This study showed good precision in all the parameters measured. The results were thus in a range equal to or better than the mean precision found in numerous clinical trials described in the literature. Posterior implants were less accurate because of the use of open sleeves template.

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Background: Cawood-Howell class IV atrophies, also known as "knife-edge" ridges, represent a serious horizontal defect, making the placement of regular implants challenging.Aim: To clinically and radiographically evaluate bone regeneration of severe horizontal bone defects with 3 years of follow-up.Materials and Methods: This study was designed as a single cohort, prospective clinical trial. Patients having horizontal bone width of 4 mm or less in the posterior mandible or maxilla were treated with resorbable collagen membranes and a 1:1 mixture of anorganic bovine bone (ABB) and autogenous bone. Implants were inserted and loaded 7 months later. Outcomes were implant and prosthetic survival rates, any biological and prosthetic complications, horizontal and volumetric bone dimensional changes measured on cone beam computer tomography (CBCT), peri-implant marginal bone level (MBL) changes measured on periapical radiographs, plaque index (PI), and bleeding on probing (BOP). Results: Eighteen patients received 55 implants. No patient dropped-out. No implant and prosthetic failures and no complications were recorded. Super imposition of pre and 7-month postoperative CBCT scans revealed an average horizontal bone gain of 5.03 ± 2.15 mm (95% CI: 4.13-5.92 mm). After 3 years, mean MBL was 1.15 ± 0.28 mm (95% CI 0.84-1.22 mm). The PI was 11.6%, and BOP was 5.2%. Conclusion: Within the limitations of the present study, high implant survival rate and high average bone augmentation seem to validate the use of collagen resorbable membranes with a 1:1 mixture of particulate ABB and autogenous bone for the reconstruction of Cawood-Howell class IV alveolar ridge atrophies. K E Y W O R D S bone reconstruction, collagen membranes, GBR, horizontal GBR implant threads. All readable radiographs were displayed in an image analysis program (DFW2.8 for windows, Soredex) on a 24-in. LCD screen (iMac, Apple, Cupertino, California) and evaluated under standardized conditions (SO 12646:2004). The software has been calibrated for all single images using the known distance of two adjacent threads. Measurements of the mesial and distal bone crest level adjacent to each implant were made to the nearest 0.01 mm and averaged at patient level. | Periodontal parametersPlaque index (PI), defined as plaque absent or present (0/1), and bleeding on probing (BoP), defined as absent or present bleeding on probing (0/1), were recorded 1 year after final prosthesis delivery and 3 years after final loading.Complications were evaluated and treated by the same clinician that performed the augmentation and implant placement procedure.Volumetric dimensional changes, as well as the peri-implant marginal bone level changes were evaluated by an expert radiologist not previously involved in the study. Another clinician (G.F.) not previously involved in the study, made all the others outcomes.

ObjectiveTo compare clinical performance of a new resorbable non‐cross‐linked collagen membrane, creos xenoprotect (CXP), with a reference membrane (BG) for guided bone regeneration at dehisced implant sites.Materials and methodsThis randomized controlled clinical trial enrolled patients with expected dehiscence defects following implant placement to restore single teeth in the maxillary and mandibular esthetic zone and premolar area. Implants were placed using a two‐stage surgical protocol with delayed loading. Bone augmentation material placed at the implant surface was immobilized with CXP or BG membrane. Soft tissue health was followed during the healing period, and the defect size was measured at reentry and 6 months after implant placement.ResultsOf the 49 included patients, 24 were treated with CXP and 25 with BG. Patient characteristics did not differ between the two arms. In the CXP arm, the defect height at implant insertion was (mean ± SD) 5.1 ± 2.1 mm (n = 24) and reduced at reentry by 81% to 1.0 ± 1.3 mm (n = 23). In the BG arm, the defect height at implant insertion was 4.9 ± 1.9 mm (n = 25) and reduced at reentry by 62% to 1.7 ± 2.1 mm (n = 24). Assuming a margin of non‐inferiority of 1 mm, CXP was non‐inferior to BG. Membrane exposure rate was highest at week 3 in both arms, reaching 16.7% for BG and 8.7% for CXP.ConclusionsThe new resorbable non‐cross‐linked collagen membrane facilitates bone gain to support implant placement in expected dehiscence defects. The observed trend toward higher mean bone gain and lower exposure rate with CXP compared to BG should be further investigated.

Purpose: To compare virtual planning accuracy of novel computer-assisted, template-based implant placement techniques, which make use of CAD/CAM stereolithographic surgical templates with or without metallic sleeves. Furthermore, to compare open versus closed sleeves for templates without metallic sleeves. Materials and methods: Any partially edentulous patients requiring at least one implant to be placed according to a computer-assisted template-based protocol were enrolled. Patients were randomized according to a parallel group design into two arms: Surgical template with or without metallic sleeves. Three deviation parameters (angular, horizontal, vertical) were defined to evaluate the discrepancy between the planned and placed implant positions. Results: No implants failed, and no complications were experienced. Forty-one implants were placed using surgical templates with metallic sleeves while 49 implants were placed with a surgical template without metallic sleeves. Of these, 16 implants were placed through open sleeves and 33 through closed sleeves. There was a statistically significant difference in angle (p = 0.0212) and in the vertical plan (p = 0.0073) with lower values for implants placed with a surgical template without metallic sleeves. In the test group, close sleeves were more accurate compared with open sleeves in angle (p = 0.0268) and in horizontal plan (p = 0.0477). Conclusion: With the limitations of the present study, surgical templates without metallic sleeves were more accurate in the vertical plan and angle compared to the conventional template with metallic sleeves. Open sleeves should be used with caution in the molar region only in case of reduced interarch space. Further research is needed to confirm these preliminary results.