Surgical Management of Significant Maxillary Anterior Vertical Ridge Defects.

Severe vertical ridge deficiency in the anterior maxilla represents one of the most challenging scenarios in bone regeneration. Under ideal circumstances, guided bone regeneration in combination with soft tissue management has shown predictable esthetic and functional outcomes. Success largely relies on primary wound closure during and after the surgical procedure. Surgical sites present different challenges that need to be considered when designing the flap. The goal of this article is to propose a classification of flap designs that considers vestibular depth and scar formation around the periosteum when performing vertical ridge augmentation in the atrophic anterior maxilla. The four clinical conditions proposed under this classification are (1) shallow vestibule with healthy periosteum, (2) deep vestibule with healthy periosteum, (3) shallow vestibule with scarred periosteum, and (4) deep vestibule with scarred periosteum. The classification will allow clinicians to achieve tension-free closure and more predictable vertical bone gain.

Facial gingival tissue stability following immediate placement and provisionalization of maxillary anterior single implants: a 2- to 8-year follow-up.

PURPOSE: This is a follow-up of an earlier 1-year prospective study on implant success rates and the peri-implant response after immediate placement and provisionalization of single implants in the esthetic zone. The effects of gingival biotype on the peri-implant tissues were also evaluated. MATERIALS AND METHODS: Thirty-five patients were evaluated clinically and radiographically at presurgical examination (T0), immediately after immediate implant placement and provisionalization (T1), 1 year after implant surgery (T2), and the latest follow-up appointment (T3). Data were analyzed using t tests and repeated-measures analysis of variance at the significance level of alpha = .05. RESULTS: After a mean follow-up time of 4 years (range, 2 to 8.2 years), all implants remained in function. At T3, the mean mesial and distal marginal bone level changes were significantly greater than those observed at T2. At T3, the mean mesial and distal papilla level changes were significantly smaller than those observed at T2, whereas the mean facial gingival level change was significantly greater than that observed at T2. Sites with a thick gingival biotype exhibited significantly smaller changes in facial gingival levels than sites with a thin gingival biotype at both T2 and T3. CONCLUSIONS: Favorable implant success rates and peri-implant tissue responses can be achieved with this procedure. While the results suggest the possibility of spontaneous papilla regeneration over time following this procedure, continuing recession of the facial gingival tissue was also observed. The effect of gingival biotype on peri-implant tissue response seemed to be limited only to facial gingival recession and did not influence interproximal papilla or proximal marginal bone levels.

Immediate loading of unsplinted implants in the anterior mandible for overdentures: a case series.

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.

Study of an experimental microthreaded scalloped implant design: proximal bone healing at different interimplant distances in a canine model.

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.

Immediate loading of two freestanding implants retaining a mandibular overdenture: 1-year pilot prospective study.

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.