Le Fort I osteotomy with interpositional bone grafts and delayed oral implants for the rehabilitation of extremely atrophied maxillae: a 1-9-year clinical follow-up study on humans

AIM: The purpose of this clinical follow-up study was to report the clinical outcome of osseointegrated implants placed in extremely atrophied edentulous maxillae after Le Fort I osteotomy and interpositional autogenous iliac bone grafts. PATIENTS AND METHODS: In a 10-year period (1995-2004), 39 patients, 18 males and 21 females, aged from 32 to 76 years, presenting with severely atrophied edentulous maxillae were treated with Le Fort I osteotomy and interpositional iliac bone grafts. Four to 8 months after the reconstructive procedure, 281 osseointegrated implants were placed in the reconstructed maxillae. Four to 8 months afterwards, abutments were connected and the prosthetic rehabilitation started. The mean follow-up period of implants after the start of prosthetic loading was 45.9 months (range: 12-108 months). RESULTS: The reconstructive procedure was successful in 38 of 39 patients. In one patient, partial loss of the inlay graft occurred before implant placement. Six patients (42 implants) dropped out of the study. Fifteen implants were removed during the follow-up period, due to loss of integration. Thirty-two implants, although integrated, presented with peri-implant bone-level changes higher than those proposed for successful implants. Cumulative survival and success rates of implants were 94.5% and 82.9%, respectively. CONCLUSION: Results from this study showed that Le Fort I osteotomy with interpositional bone grafts followed by delayed implant placement is an acceptable means to rehabilitate edentulous patients affected by extremely atrophied edentulous maxillae. Survival rates of implants are consistent with those related to implants placed in native, non-reconstructed bone. Conversely, the success rate of implants resulted to be lower as compared with those obtained for implants placed in native bone.     

Implant treatment without bone grafting in severely resorbed edentulous maxillae.

PURPOSE: This article describes the surgical technique for implant treatment in severely resorbed edentulous maxillae without any alveolar reconstruction before or combined with implant placement. PATIENTS AND MATERIAL: Fifteen patients with severely resorbed edentulous maxillae were treated with osseointegrated implants and fixed dental prostheses. All patients were initially considered to be treated with bone grafting because of a lack of sufficient bone volume for conventional treatment. Preoperative radiographic examinations showed that the height of the alveolar crest was on average 7.4 mm at the 4-mm-width level (Classes V to VI). RESULTS: By fenestration of the maxillary sinus and uncovering the nasal floor, the maxillary bone could be visualized and used maximally for installation of implants. By angulation of the implants and permitting two to five uncovered fixture threads on the palatal aspect, implants of optimal length could be installed. Eighty-six implants were placed (four to six implants in every patient). One implant was lost during the observation time (range, 36 to 54 months; mean, 45 months). All patients had stable fixed prostheses at the end of the observation time. CONCLUSION: This cost-effective surgical technique may be considered as an alternative to more resource-demanding techniques such as bone grafting in patients with severely resorbed edentulous maxillae. However, further prospective comparative studies are necessary for full evaluation.     

Immediate loading of dental implants placed in severely resorbed edentulous maxillae reconstructed with Le Fort I osteotomy and interpositional bone grafting

Background: Reconstruction and rehabilitation of atrophic maxillae with bone grafts is a lengthy and demanding procedure. This study reports the immediate loading of 50 implants placed on six extremely atrophied edentulous maxillae reconstructed with Le Fort I osteotomy and iliac bone grafting. Methods: Six patients, aged 49 to 68 years, with severely atrophied maxillae were treated with Le Fort I osteotomy and iliac bone grafting to allow for implant‐borne prosthetic rehabilitation. Four to 5 months thereafter, 50 implants (seven to 10 per patient) were placed in reconstructed maxillae and immediately functionally loaded with a screw‐retained definitive prosthesis. The patients were followed by clinical and radiographic examinations for 24 months after prosthetic loading. Results: The grafting procedure and healing period before implant placement were uneventful in all patients. Two implants were lost within 2 months after prosthesis insertion in two patients, with an overall survival rate of 96%. The prostheses success rate was 100%. At the end of the follow‐up period, all remaining implants appeared clinically healthy; crestal bone loss was >1.7 mm for six implants, resulting in a cumulative success rate of 84%. Conclusion: Immediate loading of implants placed after Le Fort I osteotomy and interpositional iliac bone grafting could be considered a viable protocol to rehabilitate extremely atrophied edentulous maxillae, considerably reducing the treatment time.     

A Retrospective Study on 287 Implants Installed in Resorbed Maxillae Grafted with Fresh Frozen Allogenous Bone

Background: Several studies have been performed to evaluate the clinical outcome of implants inserted into maxillae grafted with autogenous bone but few reports have focused on maxillae grafted with fresh‐frozen allogenous bone (FFAB). Purpose: The purpose of this study is to retrospectively evaluate the clinical outcome of implants installed in resorbed maxillae augmented with FFAB. Materials and Methods: A total of 69 patients whom had been treated with FFAB grafts to their maxillae and implant placement 4 to 6 months later were retrospectively evaluated. Edentulism was total and partial in 22 and 47 cases, respectively. A total of 287 implants of various systems had been used. A life table analysis was performed. Marginal bone loss was calculated in radiographs. Results: Five of the 287 implants were lost, giving a survival rate (SVR) of 98.3% over a mean follow‐up time of 26 months. The marginal bone resorption at the implants was 1.68 mm (SD = 0.44) after 1 year and 1.85 mm (SD = 0.98) after 4 years. The cumulative success rate based on defined criteria was 96% in the first year but decreased to 40% at 4 years because of marginal bone loss. The Kaplan–Meier algorithm demonstrated a better outcome for female patients, removable dentures, and total edentulism. No differences were detected among diameters, lengths, and implant site. Conclusion: Implants placed in FFAB showed a high SVR similar to that reported in previous studies on maxillae grafted with autogenous iliac crest bone. Although our data point to more marginal bone loss in partially edentulous patients and for fixed prosthetic restorations, the use of FFAB for reconstruction of the atrophic jaw prior to implant placement can be considered as a reliable alternative to autogenous bone.     

Histomorphometric evaluation and clinical assessment of endosseous implants in iliac bone grafts with shortened healing periods

PURPOSE: In the present study solid monocortical hipbone onlay grafts of the maxilla were analyzed histologically after a healing period of 3 months. The clinical success of the implants placed in the grafted bone was evaluated. MATERIALS AND METHODS: Nineteen patients underwent augmentation with avascular iliac bone. A 2-stage procedure was performed with a 3-month healing period between graft and implant placement. At implant placement bone biopsy samples were taken at the proposed implant sites. RESULTS: Of the 117 implants placed, 1 was not osseointegrated at the time of abutment connection. No implants were lost after loading during an observation period of up to 3 years. Clinical appearance of the augmented bone after 3 months showed a dense cortical layer with good blood perfusion. Histologic specimens were analyzed quantitatively and showed an average of 43.2% newly formed bone. DISCUSSION: Histomorphometry showed that the amount of newly formed bone after 3 months was comparable to that found after a healing period of 4.5 months. The clinical success of the implants placed after the shortened healing period was comparable to that found in nonaugmented bone. CONCLUSION: This study showed that after avascular iliac bone grafting, 3 months of revascularization was sufficient to ensure the secure placement of dental implants in second-stage surgery for this patient population.     

Bone grafting of cleft lip and palate patients for placement of endosseous implants.

OBJECTIVE: Fixation of a prosthesis or single tooth replacement using osseointegrated implants has the potential to overcome functional and psychological inconveniences that many patients experience from such appliances. However, the dimensions of the recipient site are relatively often inadequate for implant placement. This study assessed grafting of this site with autogenous bone as a solution for the latter problem. METHODS: Ten cleft lip and palate patients had bone grafts; six had iliac crest grafts to the maxillary sinus floor (31 implants), and four had chin bone grafts to the local defect in the anterior maxilla (six implants). Implants were inserted during the grafting procedure (one patient) or after 3 months (nine patients). RESULTS: No inflammation of the bone grafts or the maxillary sinus occurred. One implant was lost during the healing phase. Four single tooth restorations, one fixed bridge, and five implant-supported overdentures were made. During the follow-up, which was 47 months (range, 28 to 65 months) in the anterior maxilla group and 56 months (range, 28 to 68 months) in the posterior maxilla group, no loss of implants was observed, and all prosthetic appliances functioned well. CONCLUSIONS: It is concluded that bone grafting followed by placement of dental implants can serve as a reliable alternative for conventional prosthetic rehabilitation of cleft patients.     

Reconstruction of the atrophic edentulous maxilla with free iliac crest grafts and implants: a 3-year report of a prospective clinical study

Purpose: The purpose of this study was to perform a longitudinal follow-up study of implant stability in grafted maxillae with the aid of clinical, radiological, and resonance frequency analysis (RFA) parameters. Materials and Methods: The atrophic edentulous maxillae in 29 patients were reconstructed with free iliac crest grafts using onlay/inlay or interpositional grafting techniques. The endpoint of the resorption pattern in the maxilla determined the grafting technique used. Endosteal implants were placed after 6 months of bone-graft healing. Implant stability was measured four times using RFA: when the implants were placed, after 6 to 8 months of healing, after 6 months and 3 years of bridge loading. Individual checkups were performed at the two later RFA registrations after removal of the supraconstructions (Procera® Implant Bridge, Nobel Biocare AB, Göteborg, Sweden). Radiological follow up of marginal bone level was performed annually. Results: Twenty-five patients remained for the follow-up period. A total of 192 implants were placed and with a survival rate of 90% at the 3-year follow up. Women and an implant position with a class 6 resorption prior to reconstruction were factors with significant increased risk for implant failure (multivariate logistic regression). Twelve of the 20 failed implants were lost before loading (early failures). The change in the marginal bone level was 0.3 ± 0.3 mm between baseline (bridge delivery) and the 3-year follow up. The implant stability quotient (ISQ) value for all implants differed significantly between abutment connection (60.2 ± 7.3) and after 6 months of bridge loading (62.5 ± 5.5) (Wilcoxon signed ranks test for paired data, p=.05) but were nonsignificant between 6 months of bridge loading and 3 years of bridge loading (61.8 ± 5.5). There was a significant difference between successful and failed implants when the ISQ values were compared for individual implants at placement (Mann-Whitney U test, p=.004). All 25 patients were provided with fixed implant bridges at the time of the 3-year follow up. Conclusion: This clinical follow up using radiological examinations and RFA measurements indicates a predictable and stable long-term result for patients with atrophic edentulous maxillae reconstructed with autogenous bone and with delayed placement of endosteal implants. The ISQ value at the time of placement can probably serve as an indicator of level of risk for implant failure.     

非血管化髂骨移植同期种植重建下颌骨节段缺损的临床研究

目的：研究非血管化髂骨移植同期种植重建下颌骨节段缺损的方法及临床效果。方法：选取下颌骨节段缺损的病人，通过非血管化髂骨移植建立下颌骨连续性，同期植入牙种植体。结果：移植的骨块成活，植入的种植体可以实现骨结合并完成种植义齿修复，行使功能。结论：此方法可以实现下颌骨的功能重建。     

The relationship of bone resorption around dental implants to abutment design: a preliminary 1-year clinical study

The influence of abutment design on bone resorption around immediately loaded and osseointegrated implants used to support fixed partial prostheses was investigated in a 1-year study. One hundred ten implants were placed in 24 anterior partially edentulous maxillae. The probing depths of each implant were measured 6 and 12 months after abutment placement and analyzed statistically. Total probing depth was 1.75 ± 0.75 mm. There were significant differences between non- and submerged implants with angled abutments and between submerged implants with straight and angled abutments. No significant differences were observed between non- and submerged implants with straight abutments and between nonsubmerged implants with straight and angled abutments. Bone resorption around dental implants is influenced by the abutment design and the associated implantation protocol.     

Jaw reconstruction with grafted autologous bone: early insertion of osseointegrated implants and early prosthetic loading.

PURPOSE: The aim of the present pilot study was to evaluate the behavior of grafted iliac bone placed in atrophic alveolar ridges, when osseointegrated implants were inserted early (2 months after grafting) and when prosthetic loading was anticipated (2 months after fixture insertion). PATIENTS AND METHODS: Dental panoramic x-rays and computed tomography (CT) scans were carried out before the grafting procedure, after implant placement, and after prosthetic loading (after 30 months). RESULTS: Grafted bone tissue showed a resorption of about 21.8%. Clinical evaluation of implant therapy following Melloning and Triplett criteria showed 91% success considering the total number of implants inserted. CONCLUSION: The follow-up at 6, 12, and 30 months after fixed prostheses placement showed that early implant insertion and early prosthetic loading can lead to better results than those obtained from standard protocols.     

Titanium Mesh Technique in Rehabilitation of Totally Edentulous Atrophic Maxillae: A Retrospective Case Series

Background: This study evaluates implant‐borne prosthetic rehabilitation of 10 totally edentulous atrophic maxillae after bone reconstruction with a titanium‐mesh technique and particulate bone graft. Methods: Ten atrophic maxillae were reconstructed with 19 titanium meshes and particulate autologous‐heterologous bone. Maxillae were rehabilitated at least 5 months, with placement of 67 implants connected to the prostheses after an additional 4 months of rehabilitation. Cases were evaluated retrospectively in terms of complication rates, particularly on the amount of mesh exposure, implant survival, and success rates at the end of follow‐up. Results: In seven cases, two meshes were prematurely exposed (within 4 to 6 weeks), and five were exposed later (after 4 to 6 weeks). Only two of the later exposures extended >1 cm². Nevertheless, reconstructions allowed implant placement and prosthetic rehabilitation in all cases. Two implants were lost before loading. After mean follow‐up at 39.3 (20 to 56) months since prosthetic loading, all 65 implants were functional (100% implant survival), but 15 implants demonstrated a peri‐implant mean bone resorption of 2.96 mm increased bone loss, yielding a cumulative implant success rate of 76.9%. No prosthetic problem was observed. Conclusions: Use of titanium mesh with particulate bone can be considered a valid option in reconstructing atrophic maxillae to allow for implant‐borne prosthetic rehabilitation. A high level of dehiscence did not compromise final outcome.     

Long-term implant survival in the grafted maxilla: results of a 12-year retrospective study

OBJECTIVE: The aim of this study was to determine the long-term outcome of implant insertion in the augmented severely atrophied maxilla. STUDY DESIGN: Three hundred and twenty-four implants were inserted in 35 patients (eight males, 27 females, average age 57.6 years) in extremely atrophied maxillae after osteotomy and interposition of iliac crest bone. One hundred implants were installed in 12 patients simultaneously with the osteotomy and grafting; 224 implants were placed in 23 patients in a second procedure 6-12 months later. Implant parameters like osseointegration and peri-implant bone loss; peri-implant tissue parameters like bleeding, gingival and plaque index; and patients' satisfaction were evaluated. RESULTS: Of 324 implants, 29 (8.9%) were lost during the entire follow-up: 14 in six patients of the one-step and 15 in 11 patients of the two-step group. The overall input-output survival in 141.1 months was 91.1%. The overall 2-year failure-free fraction of implants was 95.5%; the 5-year failure-free fraction was 89.3%. In the one-step group, the 2 (5)-year failure-free fraction was 95.9% (86.9%), and in the two-step group 95% (91.3%) (log-rank test P=0.57). Marginal peri-implant bone loss was 1.7+/-1.3 mm mesial and 1.8+/-1.3 mm distal. CONCLUSION: Implant insertion after osteotomy and iliac bone grafting is a reliable operation method for the dental rehabilitation of the severely atrophied maxilla showing good long-term results.     

Staged reconstruction of the severely atrophic mandible with autogenous bone graft and endosteal implants.

PURPOSE: Vastly different surgical techniques have been advocated for osseous reconstruction of the severely atrophic mandible. Endosseous implants placed in autologous bone grafts have been proposed to minimize graft resorption and restore function; however, sufficient bone must exist to support the implants and prevent pathologic fracture. The purpose of this retrospective analysis was to assess the efficacy of autologous bone grafting and the subsequent placement of endosteal implants as a staged procedure in patients with severely atrophic mandibles. MATERIALS AND METHODS: The records of all patients presenting to The University of North Carolina for treatment from 1997 to 1999 with atrophic mandibles (vertical mandibular height <7 mm as measured on panoramic radiographs in at least 1 site at the mandibular midline and at the thinnest portion of the mandibular body) were reviewed. Bone height was assessed preoperatively, immediately postoperatively, at the time of implant placement (4 to 6 months), and again at 12 and 24 months after bone grafting from posterior iliac crest to the mandible via an extraoral approach. Five endosteal implants were subsequently placed in each patient as a delayed procedure 4 to 6 months after bone grafting, and prosthetic rehabilitation was completed with implant supported prostheses. RESULTS: Fourteen consecutive patients were identified with a median preoperative bone height of 9 mm (interquartile range, 25th to 75th percentile [IQ], 7 to 10 mm) in the mandibular midline and 5 mm (IQ, 2 to 5 mm) in the body region. There were no perioperative complications. Median estimated blood loss during the bone graft procedure, as estimated by the surgeon and the anesthesiologist, was 300 mL (IQ, 150 to 1,100 mL), and 1 patient required blood transfusion secondary to symptomatic anemia. The mean loss of vertical bone height after grafting and during the 4 to 6 months before implant placement was 33%. After implant placement and at 12 months, the vertical bone loss was negligible in the implant-supported region and less than 11% in the body region. CONCLUSION: Reconstruction of the severely atrophic mandible using autogenous corticocancellous bone grafts followed by placement of osseointegrated implants in 4 to 6 months can restore and maintain mandibular bone sufficient to support implants and facilitate successful restoration of occlusion. A prospective study is planned to identify predictors of successful outcomes compared with other surgical/prosthetic treatment.     

Vertical ridge augmentation of the atrophic posterior mandible with interpositional bloc grafts: bone from the iliac crest vs. bovine anorganic bone. Clinical and histological results up to one year after loading from a randomized-controlled clinical trial

Objectives: To compare two different techniques for vertical bone augmentation of the posterior mandible: bone blocs from the iliac crest vs. anorganic bovine bone blocs used as inlays.
Materials and methods: Ten partially edentulous patients having 5–7 mm of residual crestal height above the mandibular canal had their posterior mandibles randomly allocated to both interventions. After 4 months implants were inserted, and after 4 months, provisional prostheses were placed. Definitive prostheses were delivered after 4 months. Histomorphometry of samples trephined at implant placement, prosthesis and implant failures, any complication after loading and peri-implant marginal bone-level changes were assessed by masked assessors. All patients were followed up to 1 year after loading.
Results: Four months after bone augmentation, there was statistically significant more residual graft (between 10% and 13%) in the Bio-Oss group. There were no statistically significant differences in failures and complications. Two implants could not be placed in one patient augmented with autogenous bone because the graft failed whereas one implant and its prosthesis of the Bio-Oss group failed after loading. After implant loading only one complication (peri-implantitis) occurred at one implant of the autogenous bone group. In 16 months (from implant placement to 1 year after loading), both groups lost statistically significant amounts of peri-implant marginal bone: 0.82 mm in the autogenous bone group and 0.59 mm in the Bio-Oss group; however, there were no statistically significant differences between the groups.
Conclusions: Both procedures achieved good results, but the use of bovine blocs was less invasive and may be preferable than harvesting bone from the iliac crest.     

Placement of Branemark Mk IV implants in compromised and grafted bone: Radiographic outcome of 61 sites in 27 patients with 3- to 7-year follow-ups

Objective: Sites in which bone is reduced in quality or height create challenges in esthetic reconstruction and loading support, which leads to a higher risk of failure. The Mk IV system with a TiUnite surface was designed specifically for placement in soft bone. This paper describes postloading outcomes of 103 Mk IV implants, with a focus on bone preservation in compromised bone sites during early remodeling, stability after abutment connection, and a 3- to 7-year follow-up from implant placement. Method and Materials: A series of 103 4-mm (diameter), ≤ 10-mm (length) Mk IV implants were placed in the maxillae of 25 females and 14 males. Twenty-three patients also received staged bone grafts, and two underwent socket augmentation as well as grafts. Areas of previous infection were prepared mechanically and chemically. To ensure primary implant stability, the size of the osteotomy and the number of entries were minimized. Following a delayed loading protocol, all patients were restored with fixed partial dentures. For analysis of bone stability, the marginal levels on the mesial and distal aspects of the implants were measured at 7x magnification by a radiologist not involved in the treatment. Results: Three implants were lost, 1 implant was never loaded although it integrated, 14 implants were not available for follow-up after abutment correction, and 5 had poor-quality radiographs. The mean marginal bone loss between implant insertion and loading was 1.21 ± 0.86 mm (n = 80). The differences in bone-remodeling levels in grafted and nongrafted sites were not significant. Data are reported on 103 implants in 39 consecutive patients through abutment connection, with radiographic follow-up from 3 to 7 years postimplant placement on 27 patients. Conclusion: It is critical to ensure optimal three-dimensional orientation and minimize site preparation, particularly when placing implants in compromised bone. With bone of poor preoperative density using a customized site preparation technique, excellent short-term implant survival and long-term bone stability have been demonstrated. Further follow-up will determine whether the Mk IV implant is the optimal design for compromised bone, including associated soft tissue stability. (Quintessence Int 2012;43:293?303).     

Immediately loaded implants supporting fixed prostheses in the edentulous maxilla: a preliminary clinical and radiologic report

PURPOSE: To evaluate the survival rate of immediately loaded ITI sand-blasted, large-grit, acid-etched (SLA) solid-screw dental implants in the edentulous maxilla after 8 months of loading. MATERIALS AND METHODS: Twenty-eight patients (mean age 63 years) with edentulous maxillae each received 6 implants and 1 implant-supported fixed provisional prosthesis within 24 hours after surgery. After a mean healing time of 15 weeks, the patient received a definitive, screw-retained, implant-supported fixed prosthesis. A total of 168 implants were placed. Clinical parameters were registered after 1 month of loading with the implant-supported fixed prostheses as well as 8 months after implant placement. Radiologic examinations and assessments were made at implant placement and after 8 months. RESULTS: The mean marginal bone level at implant placement was 1.6 mm (range 0 to 5.1; SD 1.1) apical of the reference point (the implant shoulder). The mean marginal bone level at the 8-month follow-up was 3.2 mm (range 0.4 to 5.9; SD 1.1) apical of the reference point. Three implants failed during the healing period. DISCUSSION: The improved results in the present study might be a result of the positive effect of splinting the implants immediately after placement. CONCLUSION: ITI SLA solid-screw implants immediately loaded (ie, loaded within 24 hours of placement) and supporting fixed prostheses had successful survival rates after 8 months. The present results constitute a solid baseline for future follow-up studies.     

Endosseous implants and bone augmentation in the partially dentate maxilla: an analysis of 17 patients with a follow-up of 29 to 101 months

PURPOSE: The aim of this study was to analyze the survival rate of endosseous implants placed in the partially dentate maxilla treated with sinus inlay block bone grafts. MATERIALS AND METHODS: Seventeen patients were subjected to bone augmentation procedures prior to or in conjunction with implant placement. Bone volumes were regarded as insufficient for implant treatment unless a bone grafting procedure was performed. The patients were treated with sinus inlay block bone grafts and endosseous implants in a 1- or 2-stage procedure. A total of 69 implants were placed in the patients who were followed for 29 to 101 months (mean, 53.1 months). The retrospective patient group was also prospectively followed using a standardized clinical and radiographic study design. RESULTS: The implant survival rate was 91.3% (63/69). All implants were lost during the period from abutment connection to connection of the definitive prosthesis. All bone grafts were stable. Bone grafts supported 48 implants, of which 5 failed (10.4%). In the residual bone, 21 implants were placed, of which 1 failed (4.8%). All patients received a fixed partial prosthesis, which was stable during the follow-up period. CONCLUSION: The results of this investigation revealed a satisfactory clinical outcome of implant placement in grafted partially dentate maxillae after a mean follow-up of 53.1 months.     

A prospective study of treatment of severely resorbed maxillae with narrow nonsubmerged implants: results after 1 year of loading.

The aim of the present study was to evaluate the use of reduced-diameter implants as an alternative to bone grafting for treatment of patients with severely resorbed maxillae. Forty patients (25 females, 15 males, mean age of 57 years, range 19 to 86) with insufficient bone volume for placement of standard-size implants in the maxilla (31 totally edentulous) were treated with 3.3-mm-diameter implants (ITI, titanium plasma-sprayed solid screws). Augmentation was considered for all patients because of lack of sufficient bone volume. Preoperative radiographic examination showed that in all cases, the height of the alveolar crest with a width of 4 mm was less than 10 mm. A total of 182 implants with a length of 8 to 12 mm were placed. All but 3 patients planned for overdenture treatment received fixed prostheses or single crowns (n = 3). One implant (8 mm long) was lost 1 month after placement, providing a survival rate of 99.4% after 1 year of loading. Since 4 implants with peri-implantitis were successfully treated and 1 implant left as a "sleeper" because of malposition, the cumulative success rate was 96.4%. The mean marginal bone resorption at baseline was 0.14 +/- 0.67 mm (range 0 to 6 mm). After 1 year of loading the mean resorption was 0.35 +/- 1.05 mm (range 0 to 7 mm); 4.8% of the implants had marginal bone resorption of more than 2 mm.     

Rehabilitation of patients with severely resorbed maxillae by means of implants with or without bone grafts: a 3- to 5-year follow-up clinical report

Forty three patients with severely resorbed maxillae who had been referred for implant treatment were assigned to 1 of 3 treatment options: bone grafting and implant placement (graft group), modified implant placement with no bone grafting (trial group), or optimized complete dentures (no-implant group). Sixteen, 20, and 7 patients, respectively, were assigned to the 3 groups. The patients have been examined annually, and at the time of this report they had been followed for 3 to 5 years after treatment. At the 1-year follow-up, 10% (22 of 221) of the implants had been lost, and at the 2-year follow-up, 18% of the implants had been lost (40 of 221; 25% in the graft and 13% in the trial group); after that time, no further losses occurred. Life table analysis showed cumulative success rates of 82% in the graft group and 96% in the trial group after 1 year, and 74% and 87%, respectively, at the final examination after 3 to 5 years. The failure rate was higher in smokers than in non-smokers. A substantial reduction of the grafted bone, especially of onlay grafts, occurred early after grafting surgery in many patients. Mean marginal peri-implant bone loss was 0.6 mm during the period from prosthesis connection to the 1-year follow-up, and from the 1-year to the 3-year follow-up, average peri-implant bone loss was 0.3 mm in the graft group and 0.5 mm in the trial group. The results corroborated previous findings that patients with severely resorbed maxillae have an increased risk of implant failure in comparison to patients with good bone quantity and quality. However, in this investigation, practically all implant losses occurred during the first 2 years, whereupon a steady state seemed to follow for up to 5 years after loading.     

Immediate function of cortically anchored disk-design implants without bone augmentation in moderately to severely resorbed completely edentulous maxillae.

The completely edentulous maxilla remains a challenge in implant dentistry. Conventional two-stage surgical techniques require two independent invasive surgeries separated by a 5-6-month healing period. In addition, an increased risk of trauma to the implant-bone interface may be caused by a removable transitional complete denture during the interim submerged period, which can compromise implant success or increase crestal bone loss around the implants during initial bone healing. The purpose of this clinical trial was to evaluate the safety and efficacy of immediately loading a fixed implant-supported prosthesis without bone augmentation in moderately to severely resorbed, completely edentulous maxillae. Over a 41-month period, 783 titanium implants (627 laterally inserted disk implants, with or without 156 axially inserted Structure implants) were placed in 72 consecutive patients with completely edentulous maxillae using an immediate loading protocol. After 6 months of function, the fixed restorations were removed and each implant status was verified using radiographs, Periotest evaluations, clinical osseointegration criteria, and torque testing at 20 N-cm. Six months postoperatively, 98% of the implants were radiologically and clinically osseointegrated. Fifty-six gold screws (7%) required retightening after 10 months, but no screw fractures occurred during this study period. The postrestorative follow-up of these patients ranged from 6 to 48 months. As of this report, all of the fixed prostheses remain functional, and no additional implants have been lost. This clinical trial demonstrates that immediate loading of nonsubmerged, laterally inserted disk-design implants may provide adequate primary anchorage and longterm osseointegration in completely edentulous maxillae. The initial multicortical anchorage afforded by the disk-design implant in this study, coupled with biomechanical splinting of the disks (sometimes with more traditional root-form design implants) using a rigid prosthesis, permits a one-stage predictable implant procedure offering rapid restoration of patients to masticatory function.