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Purpose: This case series evaluated the implant success rate and peri-implant tissue response of immediately loaded unsplinted implants retaining a mandibular overdenture. Materials and Methods: Eight completely edentulous patients (five men, three women) with a mean age of 69.1 years were included in the study. All participants received new maxillary and mandibular complete dentures prior to implant placement. Two 4.0- 3 13-mm threaded implants with a fluoride-modified microrough titanium surface were placed mesial to the mandibular canine position bilaterally. Individual stud attachments were connected and torqued to 25 Ncm and the overdenture was immediately attached. The patients were evaluated clinically and radiographically at implant placement and at 3, 6, and 12 months after implant placement. The data were analyzed using the paired-samples t test and the Wilcoxon signed-ranks test at a significance level of a = .05. Results: At 12 months, all implants remained osseointegrated and showed an overall mean marginal bone change of -0.36 ± 0.29 mm and a mean Periotest value of -6.94 ± 0.73. The modified Plaque Index scores indicated improvements in oral hygiene over time. Surgical complications involved two episodes of implant rotational instability. Prosthetic complications were attributed to abutment loosening, the patients' inability to insert the prosthesis correctly, and soft tissue shrinkage. Conclusions: The results of this study suggest that favorable implant success rates and peri-implant tissue responses can be achieved with mandibular overdentures retained with two immediately loaded unsplinted threaded implants with a fluoride-modified microrough titanium surface. Int J Oral Maxillofac Implants 2010;25:1028-1035. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this 1-year pilot prospective study was to evaluate the implant success rate, peri-implant tissue response, and complications associated with the immediate loading of two freestanding implants retaining mandibular overdentures. Materials and Methods: Ten adults with a mean age of 59.7 years (range, 43 to 78 years) underwent treatment that included a maxillary removable complete denture opposing a mandibular removable overdenture retained by two freestanding, threaded, titanium oxide-surface implants with a 3-mm machined collar (n = 20 implants). The success of each implant was evaluated clinically and radiographically. Marginal bone levels and changes were evaluated using sequential standardized periapical radiographs. Surgical and prosthetic complications were recorded. Results: Two patients, one with one failed implant, dropped out prior to completion of the study. The failed implants were included in the evaluation of cumulative implant success. The cumulative implant success rate at 1 year was 94% (16/17). The mean marginal bone loss was 1.12 +/- 1.10 mm at 12 months. However, if the expected bone loss of 0.39 mm above the smooth-rough implant surface junction was considered, the mean marginal bone loss was only 0.73 mm. Mean Periotest values of -4.25 +/- 0.93 at 1 year implied that osseointegration had been achieved for all successful implants. Modified Plaque Index scores of 0 and 1 were recorded throughout the duration of the study. No irreversible surgical and/or prosthetic complications were observed. Conclusions: In this 1-year pilot prospective study, two immediately loaded unsplinted mandibular symphyseal implants retaining an overdenture resulted in favorable implant success and peri-implant tissue response. Int J Oral Maxillofac Implants 2010;25:784-790. [ABSTRACT FROM AUTHOR]

Purpose: The aim of the present study was to evaluate the validity of a new experimental microthreaded scalloped (MTS) implant design in comparison to a conventional flat-top (FT) implant by measuring the proximal bone loss at different interimplant distances in a canine model. Materials and Methods: MTS implants were placed in one side of the posterior mandible and conventional flat-top (FT) implants were placed in the other side of the mandible in 10 beagle dogs. In five dogs, four each of the MTS and FT implants were placed with an interimplant distance of 2 mm. In another five dogs, three each of the MTS and FT implants were placed at an interimplant distance of 5 mm. All 70 implants (35 MTS and 35 FT implants) were placed in a nonsubmerged (one-stage) manner. The animals were sacrificed 4 months after implant placement, and the crestal bone levels around the MTS and FT implants were measured and compared on radiographs and histologic sections. Results: The experimental MTS implants showed significantly less crestal bone loss (0.81 +/- 0.34 mm) than the FT implants (1.60 +/- 0.42 mm) on radiographs (P < .001). Histologic measurement also demonstrated that there was significantly less (P < .001) marginal bone loss around the MTS implants (0.74 +/- 0.41 mm) than around the FT implants (1.53 +/- 0.52 mm). There was no statistically significant difference in bone loss between the 2-mm and 5-mm interimplant distances for either MTS or FT implants (P > .05). Conclusion: The experimental MTS implant was more effective in preserving the proximal bone than the conventional FT external-hex implant with the same surface. In this canine model, placement of the implants at either a 2-mm and or a 5-mm interimplant distance did not result in significant differences in marginal bone loss for both MTS and FT implants. This experiment demonstrated a potential benefit of the microthread design on a scalloped implant. Int J Oral Maxillofac Implants 2010;25:681-689. [ABSTRACT FROM AUTHOR]

PURPOSE: The aims of the current study were to: (1) evaluate the results of vertical guided bone regeneration (GBR) with particulate autogenous bone grafts, (2) determine clinically and radiographically the success and survival rates of 82 implants placed in such surgical sites after prosthetic loading for 12 to 72 months, and (3) compare defects that were treated simultaneously with sinus augmentation and vertical GBR to other areas of the jaw treated with vertical GBR only. MATERIALS AND METHODS: Eighty-two implants were inserted in 35 patients with 36 three-dimensional vertical bone defects. The patients were divided into three groups: single missing teeth (group A), multiple missing teeth (group B), and vertical defects in the posterior maxilla only (group C). All group C subjects were treated simultaneously with sinus and vertical augmentations. All patients were treated with vertical ridge augmentation utilizing titanium-reinforced polytetrafluoroethylene (e-PTFE) membranes and particulated autografts. After removal of the e-PTFE membrane, all sites received a collagen membrane. RESULTS: At membrane removal, mean vertical augmentation was 5.5 mm (+/-2.29 mm). Mean combined crestal remodeling was 1.01 mm (+/-0.57 mm) at 12 months, which remained stable through the 6-year follow-up period. There were no statistically significant differences between the three groups in mean marginal bone remodeling. One defect had a bone graft complication (2.78%, 95% CI: 0.00%, 8.15%). The overall implant survival rate was 100% with a cumulative success rate of 94.7%. CONCLUSIONS: (1) Vertical augmentation with e-PTFE membranes and particulated autografts is a safe and predictable treatment; (2) success and survival rates of implants placed in vertically augmented bone with the GBR technique appear similar to implants placed in native bone under loading conditions; (3) success and failure rates of implants placed into bone regenerated simultaneously with sinus and vertical augmentation techniques compare favorably to those requiring only vertical augmentation. [ABSTRACT FROM AUTHOR]

Recently, computer technology has made it possible to simulate implant placement, fabricate a precise surgical template based on the simulated implant locations, and fabricate a prosthesis prior to surgical placement of implants. Many successful patient treatments have been reported using this process, but little has been published regarding complications. This article reports on the misfit of an immediately loaded definitive fixed complete denture that had been fabricated prior to implant surgery. The prosthesis was designed and fabricated using computerized implant data. A surgical template was fabricated (Nobel Guide) from the computer data to guide implant placement using an 'All-on-Four' design concept. Management of the prosthesis misfit is discussed along with subsequent clinical complications. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effects of resorbable membrane on new bone formation in human maxillary sinus graft using anorganic bovine bone material histomorphometrically in a split-mouth study design. Materials and Methods: This prospective pilot study included six patients who required bilateral sinus augmentations prior to implant treatment. Each patient was grafted with anorganic bovine bone (Bio-Oss). The experimental side was covered with resorbable membrane (Bio-Gide) over the grafted sinus, and the control side was left uncovered. After 8 months of healing (range, 7to 9 months), implants were placed. Biopsy samples were obtained from each side through the previously grafted sinus window and evaluated. Statistical analysis was performed using the Mann-Whitney U test at a significance level of a =.05. Results: The control side appeared to have a significantly greater amount of soft tissue than the experimental side (P = .026), whereas no significant differences in the amount of new bone were observed (P = .937). Conclusion: Resorbable membranes significantly reduced the amount of soft tissue formed in the sinus grafted with anorganic bovine bone material but had no effect on new bone formation. [ABSTRACT FROM AUTHOR]

The aim of this prospective study was to histomorphometrically evaluate at various time intervals the mineralization stage and process of an allogeneic-xenogeneic bone graft used in sinus augmentation procedures. One biopsy was taken from 20 patients at either 6, 8, 10, or 12 months after sinus augmentation. Immediately following the biopsy, an endosseous implant was placed into the biopsy site. This protocol provided 4 groups of 5 patients each, based on healing time following sinus augmentation. Using backscattered electron image analysis, the specimens were histomorphometrically analyzed to determine the volume fractions of residual cancellous bone, newly formed bone, soft tissue, bovine hydroxyapatite, and 'remineralized' freeze-dried demineralized bone allograft (rDFDBA). 'Remineralization' of DFDBA particles was observed in a few areas in all specimens. Polarized light microscopy showed that only the 12-month biopsies had a predominance of lamellar bone formation. The area within the biopsies that represented the residual alveolar ridge consisted of 32.6% +/- 8.6% (mean +/- SD) of bone. In the grafted area of the biopsies the volume fraction of newly formed bone at 12 months (20.7% +/- 8.3%) was significantly higher (P < .05, analysis of variance) than at 6 months (8.1% +/- 3.0%). There was no statistically significant difference between newly formed bone in the inferior, central, and superior grafted areas in all 4 time intervals. This prospective study indicates that the mineralization process of an allogeneic-xenogeneic sinus graft is incomplete 6 months after the sinus augmentation procedure. New bone formation increased up to 12 months postaugmentation; however, it remained lower than the volume of residual bone. [ABSTRACT FROM AUTHOR]