Dental implants placed in severely atrophic jaws reconstructed with autogenous calvarium, bovine bone mineral, and collagen membranes: A 3- to 19-year retrospective follow-up study.

OBJECTIVES: To present the clinical, radiographic, and patient-related outcomes of patients presenting with severely resorbed ridges reconstructed with autogenous calvarial bone blocks and rehabilitated with implant-supported prostheses. MATERIAL AND METHODS: From 1998 to 2014, 72 patients presenting with severe bone defects were reconstructed with autogenous calvarial bone blocks covered with bovine bone mineral granules and collagen membranes. Four to 9 months later, 330 implants were placed and loaded 3-9 months later. The follow-up ranged from 3 to 19 years (mean: 8.1 years). The following parameters were recorded: (a) complication rate of the reconstructive procedure; (b) bone resorption before implant placement; (c) implant survival rate and implant-related complications; (d) peri-implant bone resorption; and (e) patient's satisfaction inquired with a dedicated questionnaire. RESULTS: No patients developed severe complications, such as complete loss or resorption of the grafts. A dehiscence occurred in six patients, which developed a mild graft resorption. The mean peri-implant bone resorption before implant placement was 0.13 mm (SD ± 0.71). All patients received the planned number of implants. Three patients were lost during the follow-up. The survival rate of implants at the end of the observation period was 98.5%. The mean peri-implant bone resorption ranged from 0.00 to 4.87 mm (mean: 1.11 mm). At last, 90% of the patients were very satisfied as regards the treatment received. CONCLUSIONS: Results from this study suggested that: (a) bone volume in the areas reconstructed with calvarial grafts was stable over time; (b) survival rates of implants were consistent with those reported for implants placed in native bone; (c) patient's satisfaction was high.

Fresh frozen versus autogenous iliac bone for the rehabilitation of the extremely atrophic maxilla with onlay grafts and endosseous implants: preliminary results of a prospective comparative study.

PURPOSE: The purpose of this study was to compare (1) the clinical outcome of the reconstruction of extremely atrophic edentulous maxillae with fresh frozen allogeneic bone (FFB) (group A) and autogenous bone (AB) (group B) iliac blocks; and (2) the peri-implant bone resorption and the survival rate of implants in the two groups. MATERIALS AND METHODS: In a 1-year period, eight patients were treated with FFB and seven with AB iliac grafts. Five to seven months afterward, 108 implants were inserted (59 in group A and 49 in group B). Four to five months afterward, patients were rehabilitated with implant-supported prostheses. The mean follow-up was 24 months. RESULTS: Prior to implant placement, graft exposure occurred in two patients in group A and in one patient in group B. The mean graft resorption prior to implant placement was 0.78 mm and 0.54 mm in group A and B, respectively. After implant placement, bone graft exposures with partial loss of the graft occurred in six out of eight patients in group A and in none of the group B patients. The survival rate of implants was 90.1% and 100% in group A and B, respectively. The mean values of peri-implant bone resorption at the end of the follow-up period were 1.64 mm and 0.92 mm in group A and B, respectively. CONCLUSION: Results of this study seem to demonstrate that FFB does not represent a reliable alternative to AB blocks because of the higher rate of bone exposure and partial loss of the grafts, the lower implant survival, and the higher peri-implant bone resorption in FFB patients.

Implants in reconstructed bone: a comparative study on the outcome of Straumann® tissue level and bone level implants placed in vertically deficient alveolar ridges treated by means of autogenous onlay bone grafts.

PURPOSE: To evaluate: (1) the survival rate of Straumann® Tissue Level and Bone Level implants placed in atrophic edentulous jaws previously reconstructed by means of autogenous onlay bone grafts; (2) to compare peri-implant bone resorption values over time. MATERIALS AND METHODS: From 2005 to 2010, 50 patients presenting with vertical or tridimensional defects of the edentulous ridges were treated with autogenous bone grafts. Three to 7 months afterward, 192 implants were placed (Group A: 97 Tissue Level implants; Group B: 95 Bone Level implants) in the reconstructed areas. After a further waiting period of 2 to 3 months, patients were rehabilitated with implant-supported fixed prostheses. The follow-up ranged from 12 to 68 months after the start of prosthetic loading (mean: 33 months). RESULTS: No implants were removed (survival rate: 100%), but in Group B 13 implants (8 placed in iliac grafts, 2 placed in ramus grafts, and 3 placed in calvarial grafts) presented peri-implant bone resorption values higher than those proposed by Albrektsson and colleagues. for successful implants: the overall implant success rate was then 100% for Group A and 86.8% for Group B. No prosthetic failures were recorded, thus leading to a 100% prostheses success rate. CONCLUSION: No significant differences were found between the two types of implants as far as implant survival rate is concerned, but results from this study seem to demonstrate that Tissue Level implants may present better long-term results in terms of peri-implant bone maintenance, as compared with Bone Level implants, when placed in reconstructed areas.

Sinonasal complications resulting from dental treatment: outcome-oriented proposal of classification and surgical protocol.

BACKGROUND: Odontogenic sinusitis is a relevant infectious condition of the paranasal sinuses. The widespread use of dental implants and reconstructive procedures for dental implant placement has led to new types of complication. To the authors' knowledge, no publication has extensively examined sinonasal complications resulting from dental treatment, and no classification system allowing standardization and comparison of results is currently available. This study was designed to (a) analyze the results obtained from surgical treatment of complications resulting from dental procedures combining functional endoscopic sinus surgery (FESS) and an intraoral approach and (b) propose a new classification system and standardized treatment protocols for sinonasal complications resulting from dental procedures. METHODS: A total of 257 patients consecutively treated with FESS (136 in conjunction with oral surgery) were included in the study. Different clinical situations were integrated into a new classification system based on the pathogenesis and clinical aspects of each case, with the aim of identifying homogenous treatment groups. Results were evaluated for each class. RESULTS: Of the 257 patients, 254 were successfully treated with surgery performed according to the proposed protocols. Three of 257 patients required a second surgery, after which they completely recovered. Complications of implant and preimplant surgery (maxillary sinus floor elevation) showed longer recovery times. CONCLUSION: The results obtained are very encouraging. The majority of patients (254/257; 98.8%) were successfully treated with the proposed protocols. These results seem to indicate that the rationalization of surgical treatment protocols according to the initial clinical situation may significantly improve the clinical outcome.

The role of pericranium grafts in the reduction of postoperative dehiscences and bone resorption after reconstruction of severely deficient edentulous ridges with autogenous onlay bone grafts.

PURPOSE: To compare: (i) the incidence of soft tissue dehiscences; (ii) bone resorption before and after implant placement; and (iii) the survival and success rates of implants placed in two groups of patients with severe bone defects of the jaws reconstructed with autogenous onlay bone grafts alone (control group) or in association with autogenous pericranium coverage (study group). MATERIAL AND METHODS: Forty-four patients affected by severe atrophy of the alveolar ridges underwent bone reconstruction with vertical/tridimensional autogenous onlay grafts harvested from the calvarium or the mandibular ramus. In 23 patients (study group), grafts were covered with autogenous pericranium before suturing, while in 21 patients (control group) no coverage of the grafts before suturing was performed. After a 4-7 month waiting period, 199 implants were placed (105 in the study group, 94 in the control group) and 3-4 months afterward prosthetic rehabilitation was carried out. The mean follow-up after the start of prosthetic loading was 23.9 months (range: 12-48 months). RESULTS: The incidence of soft tissue dehiscences was 5,7% in the study group and 16% in the control group. The mean graft resorption before implant placement was 0.12 mm (SD ± 0.32) in the study group and 0.98 mm (SD ± 2.79) in the control group. The mean peri-implant bone resorption at the end of the follow-up period was 0.21 mm (SD ± 0.48) in the study group and 0.43 mm (SD ± 0.83) in the control group. The survival rate of implants was 99.1% in the study group and 100% in the control group, while success rate was 96.2% in the study group and 93.6% in the control group. CONCLUSIONS: The use of pericranium as an autogenous membrane for the coverage of onlay bone grafts seems to reduce the risk of soft tissue dehiscences after the reconstruction of atrophic edentulous ridges to reduce peri-implant bone resorption over time, while it seems to have no significant effect in reducing bone resorption in the reconstructed areas before implant placement.

Evaluation of peri-implant bone resorption around Straumann Bone Level implants placed in areas reconstructed with autogenous vertical onlay bone grafts.

AIM OF THE STUDY: To evaluate the survival and success rate of Straumann Bone Level implants placed in vertically atrophied edentulous jaws previously reconstructed with autogenous onlay bone grafts taken from the calvarium or the mandibular ramus. MATERIALS AND METHODS: From 2007 to 2009, 18 patients presenting with vertical deficits of the edentulous ridges were treated with autogenous cortical bone grafts harvested from the mandibular ramus or the calvarium. Four to seven months afterward, 60 Straumann Bone Level implants were placed in the reconstructed areas. After a further waiting period of 2-3 months, patients were rehabilitated with implant-supported fixed prostheses. Follow-up ranged from 12 to 36 months (mean: 19 months) after the start of prosthetic loading. Graft resorption before implant placement, as well as survival and success rates of implants, were recorded. RESULTS: The mean bone resorption prior to implant placement was 0.18 mm for calvarial grafts and 0.42 mm for ramus grafts. Survival rate was 100% either for implants placed in calvarial grafts or implants placed in ramus grafts, while success rate was 90.3% for implants placed in calvarial grafts, and 93.1% for implants placed in ramus grafts. CONCLUSION: Results from this study seem to demonstrate that implants with a platform-switching design may predictably integrate in edentulous areas reconstructed with autogenous bone grafts, with survival rates consistent with those reported in recent literature reviews on the same topic, and also with implants placed in native bone. Conversely, this study was not able to demonstrate that implants with platform-switching design may reduce bone resorption around implants placed in reconstructed areas.

Failures in jaw reconstructive surgery with autogenous onlay bone grafts for pre-implant purposes: incidence, prevention and management of complications.

Dental rehabilitation with oral implants has become a routine treatment modality in the last decades, with reliable long-term results. However, insufficient bone volume or unfavorable intermaxillary relationships may render implant placement impossible or incorrect from a functional and esthetic viewpoint. Among the different methods for the reconstruction of deficient alveolar ridges, the use of autogenous bone blocks represents the most frequently used treatment modality both for limited and extended bone defects. Prerequisites for a successful outcome are represented by accurate preoperative planning, proper reconstructive procedure, and adequate prosthetic rehabilitation. Even if all these principles are followed, complications involving the grafts may occur, such as dehiscence, infection, or relevant resorption of the graft. The aim of this article is to present an updated overview on the incidence, prevention and treatment of these complications.

Bone augmentation procedures in implant dentistry.

PURPOSE: This review evaluated (1) the success of different surgical techniques for the reconstruction of edentulous deficient alveolar ridges and (2) the survival/success rates of implants placed in the augmented areas. MATERIALS AND METHODS: Clinical investigations published in English involving more than 10 consecutively treated patients and mean follow-up of at least 12 months after commencement of prosthetic loading were included. The following procedures were considered: onlay bone grafts, sinus floor elevation via a lateral approach, Le Fort I osteotomy with interpositional grafts, split ridge/ridge expansion techniques, and alveolar distraction osteogenesis. Full-text articles were identified using computerized and hand searches by key words. Success and related morbidity of augmentation procedures and survival/success rates of implants placed in the augmented sites were analyzed. RESULTS AND CONCLUSION: A wide range of surgical procedures were identified. However, it was difficult to demonstrate that one surgical procedure offered better outcomes than another. Moreover, it is not yet known if some surgical procedures, eg, reconstruction of atrophic edentulous mandibles with onlay autogenous bone grafts or maxillary sinus grafting procedures in case of limited/moderate sinus pneumatization, improve long-term implant survival. Every surgical procedure presents advantages and disadvantages. Priority should be given to those procedures which are simpler and less invasive, involve less risk of complications, and reach their goals within the shortest time frame. The main limit encountered in this literature review was the overall poor methodological quality of the published articles. Larger well-designed long-term trials are needed.

Clinical outcomes of GBR procedures to correct peri-implant dehiscences and fenestrations: a systematic review.

OBJECTIVE: To analyze the clinical outcomes of endosseous implants following guided bone regeneration (GBR) procedures to correct dehiscence/fenestration defects associated with implant placement. METHODS/SEARCH STRATEGY: A Medline search was performed for human studies published in English focusing on GBR procedures for the correction of dehiscence/fenestration defects associated with the placement of screw-shaped titanium implants. The selected studies had to include at least 10 consecutively treated patients with a minimum follow-up of 12 months after the start of prosthetic loading. The clinical outcomes in terms of the complication rate of the GBR procedure, implant survival, and stability of marginal soft tissues around implants were evaluated. RESULTS: Seven publications were included in this review. A total of 238 patients received 374 implants. Defects were treated with resorbable or non-resorbable membranes, in association with or without graft materials. Patients were followed for 1-10 years after the start of prosthetic loading. In the postoperative period, 20% of the non-resorbable membranes and 5% of the resorbable ones underwent exposure/infection. However, in the majority of cases, a complete or an almost complete coverage of the initial defect was obtained. The overall survival rate of implants, irrespective of the type of membrane and grafting materials, was 95.7% (range: 84.7-100%). No significant modifications of probing depth and/or variation of clinical attachment level around implants were observed during the follow-up period. CONCLUSION: Despite the favorable results obtained, it was difficult to draw a significant conclusion as far as the more reliable grafting material and membrane barrier for the correction of dehiscence/fenestration defects are concerned, due to the limited sample of patients and the wide variety of grafting materials and membranes, used alone or in combination. Moreover, due to the lack of randomized clinical trials, it was impossible to demonstrate that such augmentation procedures are actually needed to allow the long-term survival of implants.

Methods to treat the edentulous posterior maxilla: implants with sinus grafting.

Prosthetic rehabilitation of the edentulous posterior maxilla with implant-supported prostheses frequently presents a challenge for the oral surgeon because of the lack of bone due to alveolar ridge resorption or maxillary sinus pneumatization. To overcome these problems, different solutions were proposed over the years, such as the use of short implants or tilted implants (including zygoma implants), with the aim of avoiding maxillary sinus floor elevation. Both of these techniques have advantages and disadvantages that should be evaluated carefully to choose the most appropriate treatment. Zygoma implants or short/tilted implants are not a panacea for the treatment of patients with inadequate posterior maxillary bone stock. Instead, treatment should be based on the characterization of resorption patterns of the posterior maxilla, and may include the need for sinus grafting or other grafting procedures to reestablish not only adequate bone volume for implant placement, but also a favorable intermaxillary relationship, to optimize the functional and esthetic outcome of the final prosthetic rehabilitation. The authors discuss the indications, advantages, and disadvantages of sinus-grafting procedures in association with or without other reconstructive procedures.

Long-term results of mandibular reconstruction with autogenous bone grafts and oral implants after tumor resection.

OBJECTIVES: (a) To evaluate retrospectively the clinical outcome of non-vascularized bone grafts used for the reconstruction of mandibular defects following tumor resection; (b) to evaluate the clinical outcome of implants and implant-supported prostheses placed in the reconstructed areas; and (c) to evaluate patients' satisfaction regarding function and esthetics after oral rehabilitation. MATERIAL AND METHODS: In a 9-year period (1995-2003), 29 patients affected by mandibular tumors involving to tooth bearing areas were treated by means of tumor resection and immediate or delayed reconstruction with autogenous non-revascularized calvarial or iliac bone grafts. Among these patients, 16 patients were selected for dental rehabilitation of the lost dentition with implant-supported 3fixed prosthese333s. For to 7 months later, the patients received 60 oral implants for the prosthetic rehabilitation of the reconstructed edentulous areas. RESULTS: No total failure of the graft was observed, while partial loss of the graft was observed in one patient. The mean follow-up of patients after the start of prosthetic loading of implants treated was 94 months (range: 36-132 months). Two patients dropped out of the follow-up after 3 and 4 years of observation, respectively. Two implants were removed due to loss of osseointegration, while two implants, although still integrated, presented peri-implant bone resorption values higher than those proposed by Albrektsson et al. for successful implants. Cumulative survival and success rates of implants were 96.7% and 93.3%, respectively. CONCLUSION: Results from this study demonstrated that bone defects following resection of mandibular tumors can be predictably reconstructed with autogenous bone grafts taken from the calvarium or the anterior iliac crest. It has also been shown that the long-term survival and success rates of implants placed in the reconstructed areas (96.7% and 93.3%, respectively) may guarantee an excellent prognosis of implant-supported prostheses.

Dental implants placed in grafted maxillary sinuses: a retrospective analysis of clinical outcome according to the initial clinical situation and a proposal of defect classification.

OBJECTIVE OF THE STUDY: To present a classification of maxillary defects necessitating sinus floor elevation procedures (SFEPs) with two objectives: (a) to propose a standardization of surgical procedures according to initial type of atrophy and (b) to allow the evaluation of the success/survival rates of implants placed in the grafted areas according to the initial situation. MATERIALS AND METHODS: Nine-hundred and fifty-two consecutive SFEP were performed on 692 patients. Initial defects were classified according to a new classification, which considered not only residual bone height below the sinus but also the width of the alveolar crest and horizontal/vertical intermaxillary relationship. Results were evaluated according to the different classes. The sinuses were grafted with autogenous bone taken from intra-oral or extra-oral sites: 579 SFEP were associated with vertical and/or horizontal onlay grafts to correct concomitant alveolar ridge deficits. A total of 2037 implants were inserted into the grafted sinuses either immediately or 4-6 months later. Three to 6 months afterwards, implants were loaded. The mean follow-up was 59 months (range: 12-144 months). RESULTS: The success rate of the reconstructive procedures varied between 93.2% and 100%, according to class of atrophy; the overall survival and success rates of implants were 95.8% and 92.5%, respectively, whereas the survival and success rates according to class of atrophy varied between 90% and 97.6%, and between 85.4% and 95.5%, respectively. Lower success rates were found in classes presenting with more severe atrophy. CONCLUSION: The results obtained demonstrated that sinus floor elevation, alone or in association with reconstructive procedures with autogenous bone grafts, is a reliable procedure to allow implant placement in atrophic edentulous maxillae, irrespective of the initial clinical situation. However, it must be underlined that the success rates of reconstructive procedures and implants differ according to class of atrophy, showing lower success rates in classes presenting with more severe atrophy.

Autogenous onlay bone grafts vs. alveolar distraction osteogenesis for the correction of vertically deficient edentulous ridges: a 2-4-year prospective study on humans.

OBJECTIVES: The purposes of this study were to compare: (a) autogenous bone grafts (ABG) and distraction osteogenesis (DO) for their ability in correcting vertically deficient mandibular ridges and their capability in maintaining over time the vertical bone gain obtained before and after implant placement; and (b) the survival and success rates of implants placed in the reconstructed or distracted areas. MATERIAL AND METHODS: In a 2-year period (2001-2002), 17 patients presenting with vertically atrophied partially edentulous mandibles requiring implant-supported prosthetic rehabilitation, were included in this study. Patients were randomly assigned to two groups. Eight patients (group 1) were treated with ABG harvested from the mandibular ramus, while nine patients (group 2) were treated by means of DO. In group 1, patients received implants 4-5 months after the reconstructive procedure, while in group 2 implants were placed at the time of distraction device removal (approximately 3 months after the completion of distraction). A total of 19 endosseous implants were placed in group 1, and 21 implants were placed in group 2 patients. For both groups, after an additional 3-5-month period, prosthetic rehabilitation was started. RESULTS: Bone resorption before implant placement was significantly higher in group 1 (P=0.01), while no statistically significant differences were found between the two groups as far as survival and success rates of implants and peri-implant bone resorption after the start of prosthetic loading were concerned. CONCLUSION: The results suggested that: (a) both techniques may effectively improve the deficit of vertically resorbed edentulous ridges; (b) survival and success rates of implants placed in the reconstructed/distracted areas are consistent with those of implants placed in native bone.

Augmentation procedures for the rehabilitation of deficient edentulous ridges with oral implants.

OBJECTIVES: To analyze publications related to augmentation procedures and to evaluate the success of different surgical techniques for ridge reconstruction and the survival/success rates of implants placed in the augmented areas. MATERIAL AND METHODS: Clinical investigations published in English involving at least 5 patients and with a minimum follow-up of 6 months were included. The following procedures were considered: a) Guided bone regeneration (GBR); 2) Onlay bone grafts; 3) Inlay grafts; 4) Bone splitting for ridge expansion (RE); 5) Distraction osteogenesis (DO); and 6) Revascularized flaps. Success rates of augmentation procedures and related morbidity, as well as survival and success rates of implants placed in the augmented sites were analyzed. RESULTS: Success rates of surgical procedures ranged from 60% to 100% for GBR, from 92% to 100% for onlay bone grafts, from 98% to 100% for ridge expansion techniques, from 96,7% to 100% for DO, and was 87.5% for revascularized flaps, whereas survival rates of implants ranged from 92% to 100% for GBR, from 60% to 100% for onlay bone grafts, from 91% to 97.3% for RE, from 90.4% to 100% for DO, and, finally, was 88.2% for revascularized flaps. CONCLUSION: On the basis of available data it was shown that it was difficult to demonstrate that a particular surgical procedure offered better outcome as compared to another. The main limit encountered in this review has been the overall poor methodological quality of the published articles. Therefore larger well-designed long term trials are needed.

Dental implants placed in expanded narrow edentulous ridges with the Extension Crest device. A 1-3-year multicenter follow-up study.

OBJECTIVE: This study has been designed to evaluate the capability of a new surgical device (Extension Crest) to widen narrow edentulous alveolar ridges and to allow a correct placement of endosseous implants in horizontally atrophied sites. MATERIAL AND METHODS: Forty-five patients, 20 males and 25 females, aged 20-66 years, affected by edentulism associated to horizontal resorption of the ridges, were treated by means of a sagittal osteotomy and expansion of the ridge with a new surgical device (Extension Crest) to obtain a wider bony base for ideal implant placement. In the same procedure in 33 patients, and 1 week afterwards in 12 patients, 110 endosseous titanium implants (ITI TE) were placed. Three to four months later, the patients were rehabilitated with implant-supported prostheses. RESULTS: The success rate of the expansion technique was 97.8%. A total of 110 implants were inserted in the expanded ridges. The mean follow-up after the start of prosthetic loading was 20.4 months. Three implants were removed before the start of prosthetic loading, because of non-integration, while no other implants failed after the completion of the prosthetic rehabilitation. Three implants, although integrated and in function, did not fulfill success criteria: cumulative success and survival rates at the end of the observation period were 95.4% and 97.3%, respectively. CONCLUSION: Within the limits of this study, this technique appeared to be reliable and simple, with reduction of morbidity and times of dental rehabilitation as compared with other techniques such as autogenous bone grafts and guided bone regeneration. Survival and success rates of implants placed in the treated areas are consistent with those placed in native bone.