Dental implants and onlay bone grafts in the anterior maxilla: analysis of clinical outcome

PURPOSE: Loss of alveolar bone in the anterior maxilla may preclude implant placement or compromise positioning and thus diminish the final esthetic result of the restoration. Bone augmentation can overcome such difficulties but may affect osseointegration. The aim of this study was to report the outcome of buccal onlay bone grafting in the anterior maxilla in routine dental implant practice. MATERIALS AND METHODS: Seventeen consecutive patients (12 men and 5 women, mean age 31.4 years) received autogenous bone grafts from the mandibular symphysis to the anterior maxilla. A total of 35 Br?nemark System MK II implants were placed in grafted bone. RESULTS: Fifteen patients had a mean period of graft consolidation of 19.7 weeks (range 13 to 32 weeks). Two patients had simultaneous graft and implant placement; 1 implant failed to Integrate in this group. This represents a survival rate of 97.1% of implants in functional loading after a mean follow-up period of 153.6 weeks from occlusal loading (range 74 to 283 weeks). DISCUSSION AND CONCLUSION: Mandibular block onlay grafts appear to be a predictable method for augmenting the width of the anterior maxilla prior to implant placement.     

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.     

Tilting of posterior mandibular and maxillary implants for improved prosthesis support

Rehabilitation of atrophied edentulous arches with endosseous implants in the posterior regions is often associated with anatomic problems such as jaw shape and location of the mental loop, mandibular canal, and maxillary sinuses. The purpose of this investigation was to modify the method for implant placement in the posterior part of the jaws to extend fixed implant-connected prostheses further distally, and to reduce the length of cantilevers in complete-arch prostheses without transpositioning the mandibular nerve or performing bone grafting in the maxilla. Forty-seven consecutive patients were treated with implants (25 patients/36 mandibular implants, 22 patients/30 maxillary implants) placed in tilted positions. They were followed a mean of 40 months (mandibles) and 53 months (maxillae). In the mandible, implants close to the mental foramina were tilted posteriorly approximately 25 to 35 degrees. In the maxilla, the posterior implants were placed close to and parallel with the sinus walls and were titled anteriorly/posteriorly approximately 30 to 35 degrees. Patients gained a mean distance of 6.5 mm of prosthesis support in the mandible and 9.3 mm in the maxilla, as a result of implant tilting. There were no implant failures in mandibles. The cumulative success rates in the maxilla at 5 years were 98% for tilted implants and 93% for non-tilted implants. Paresthesias of the mental nerve were observed on 4 sides during the first 2 to 3 weeks after implant placement. Analysis of the load distribution in one mandibular case showed no significant difference between tilted and the non-tilted implants, and the improved prosthesis support was confirmed. Satisfactory medium-term results concerning osseointegration and significant extension of prosthesis support show that the method can be recommended. This technique may allow for longer implants to be placed with improved bone anchorage.     

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.     

Monitoring of implant stability in grafted bone using resonance frequency analysis. A clinical study from implant placement to 6 months of loading

The aim of this prospective study was to compare implants placed in grafted and normal non-grafted maxilla by means of resonance frequency analysis (RFA), clinical stability and implant failure.Twenty-nine patients with severe atrophy of the edentulous maxilla were treated with autogenous bone grafts as onlay (24 patients) or as interpositional grafts in conjunction with a Le Fort I osteotomy (five patients) 6 months prior to placement of 222 implants. Ten non-grafted patients treated with 75 Brånemark implants in the edentulous maxillae served as a control group. RFA was performed at implant placement, abutment connection and after 6 months of bridge loading.Seventeen (8%) implants were lost in the grafted bone and one (1%) in normal bone. RFA revealed a similar pattern in both grafted and normal maxillae, i.e. increasing resonance frequency (RF) with time (Wilcoxon Signed Rank test for paired data). Twenty implants that were rotation mobile (low primary stability) at the time of insertion showed a significantly lower value at implant placement according to RFA (Mann–Whitney U-test, P=0.020). The RF for the failed implants revealed a tendency towards lower values (Mann–Whitney U-test, P=0.072), compared to the successful implants.It is concluded that implants placed in grafted bone when using a two-stage technique achieve a stability similar to that of implants placed in normal non-grafted bone.     

Survival rate of zygomatic implants in atrophic or partially resected maxillae prior to functional loading: a retrospective clinical report

PURPOSE: The purpose of this article was to evaluate the survival rate of 34 remote anchorage implants placed in 18 patients from placement to uncovering, prior to any prosthetic loading. MATERIALS AND METHODS: A total of 18 patients (9 women and 9 men with a mean age of 63 years) who required rehabilitation with a fixed prosthesis because of severely atrophic maxillae (including 1 patient who had undergone primary and secondary cleft lip and palate repair), traumatic maxillary bone loss, and maxillectomy procedures received 1 or 2 zygomatic implants and 2 to 4 standard maxillary dental implants. The survival rate of the 34 zygomatic implants from placement to uncovering was investigated. Aspects of the placement technique or postoperative complications related to surgical procedures likely to affect the implant failure rate were detected and critically discussed. RESULTS: Osseointegration was evaluated using the reverse torque test and percussion after uncovering. Only 1 patient (5.6%) sustained postoperative clinical complications during the evaluation period which resulted in the loss of both zygomatic implants (5.9%). CONCLUSION: Although the handling of this anchorage implant system is somewhat complex, and the design has certain shortcomings, it might be an alternative to more extensive bone augmentation procedures. However, rehabilitation of partially or completely edentulous patients with fixed implant-supported prosthesis is only feasible when 2 to 4 standard implants are placed in the anterior maxilla and splinted with the zygomatic implants.     

Peri-implant bone changes following tooth extraction, immediate placement and loading of implants in the edentulous maxilla

The aim of this study was to clinically and radiographically evaluate peri-implant bone level changes after rehabilitation of a fully edentulous maxilla by placement of six implants in either fresh extraction sites or healed edentulous ridges up till 18 months after implant placement. Twenty patients with a terminal dentition in the maxillae (11 men, 9 women) received a total of 120 OsseoSpeed implants; 118 implants could be loaded immediately of which 59 were placed in extraction sockets and 59 were placed in healed sites. Within 24 h after surgery, all patients received a chairside-assembled, fibre-reinforced temporary fixed prosthetic reconstruction in occlusion. Six months post-surgery, final screw-retained CoCr (15) or Ti (5) computer numerical control-milled and acrylic-veneered frameworks were placed directly at implant level without interposing abutments. Intraoral radiographs were taken 6 and 18 months after implant placement. Implant survival rate was 100%. Mean marginal bone level was located on average -0.35 mm below the reference point (standard deviation 0.29, range -1.20 to +0.02 mm) 18 months after loading. Whether implants were placed in healed bone sites or fresh extraction sockets did not significantly affect the bone level changes. Furthermore, the use of either CoCr or Ti at the implant level did not significantly affect marginal bone loss. Within the limits of this prospective clinical trial, results seem to indicate that immediate placement and occlusal loading of five to six implants in the edentulous maxilla can be carried out successfully. Whether or not those implants are placed in fresh extraction sockets does not seem to alter the outcome. The present data show a successful 1-year outcome of a treatment protocol involving tooth extraction immediately combined with implant placement and loading.     

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.     

Sinus augmentation bone grafts for the provision of dental implants: report of clinical outcome

PURPOSE: The aim of this study was to report the outcome of sinus augmentation surgery with autogenous bone grafting in routine dental implant practice. MATERIALS AND METHODS: Twenty-seven sinus augmentation procedures were undertaken on 18 consecutive patients (mean age 43.7 years). The mandibular symphysis was used as the donor site for 11 patients. The iliac crest was used as a donor site for 7 bilateral cases. RESULTS: Six patients had implants placed at the time of grafting: the other 13 had a mean bone graft consolidation period of 24.7 weeks (range 9 to 39 weeks) before implants were placed. One patient who had a repeat procedure had both immediate and delayed techniques. A total of 79 Br?nemark System Mk II implants were placed in grafted bone (and 2 Mk IV implants were placed in a patient who had to have a repeat procedure) and proceeded to occlusal loading. After a mean follow-up period of 162 weeks (range 76 to 288 weeks), 16 implants failed to integrate in grafted bone, representing an 80.25% survival rate. Fourteen patients proceeded to the planned prosthesis, 3 patients had a compromised treatment plan, and 1 patient was restored conventionally. This represents 94% of patients who were rehabilitated. DISCUSSION AND CONCLUSION: The sinus augmentation procedure using autogenous bone grafting can Increase bone volume to allow implant placement where there is insufficient bone. The survival of implants in the grafted bone, as measured by integration and successful loading, was reduced compared to implants placed in normal maxillary bone. Infection during the healing of the grafted site reduces the success of subsequent implant osseointegration.     

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.     

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.     

Implant reconstruction of the bone-grafted maxilla: review of the literature and presentation of 8 cases.

PURPOSE: This study prospectively investigates the long-term success of iliac crest bone grafting and the secondary placement of osseointegrated implants in reconstructing maxillae with severely reduced bone mass. MATERIALS AND METHODS: Eight consecutive patients (7 women, 1 man), aged 18 to 69 (mean, 49.6), were treated by augmentation of their maxillae with corticocancellous autogenous iliac bone blocks. Forty-one Branemark implants of 7 to 15 mm in length and 3.75 mm in diameter were placed after a minimum delay of 6 months. Bone healing, maintenance of bone height, and implant stability were measured by clinical examination and radiographic control. RESULTS: One patient was lost to follow-up at 24 months after delivery of the prosthesis and one was lost at 75 months. The average duration of follow-up after loading of the implants was 90.5 months, and the longest was 154 months. Thirty-four of 41 (83%) of the implants survived to the end of the observation period. Four of 6 implants that failed were 7 mm in length and the other 2 were 10 mm in length. One 10-mm implant was "slept" because of poor positioning. All prostheses survived. There was one significant gingival infection that resulted in loss of 1.5 mm of bone after which the implant remained stable. None of the other implants were associated with crestal bone loss of more than 0.5 mm for the duration of this study. CONCLUSIONS: Delayed placement of osseointegrated implants in maxillae augmented by iliac bone grafts is predictable and successful in the long term.     

Complete artificial dentition supported by endosseous implants: a case report of total in-office treatment

This case report demonstrates the construction of a complete restoration of the dentition by the surgical placement of endosseous titanium implants that support a fixed prosthesis in each jaw. The positioning of the implants and teeth in the prostheses are important factors for a successful long-term result. Distribution of the occlusal biting forces over as many implants as possible is important. Off-axial occlusal biting forces should be diverted to the anterior prostheses, where the forces are not as great and the posterior teeth are designed with flat occlusal surfaces that separate during excursionary chewing movements. Medial mandibular flexure caused by the contraction of the medial pterygoid muscle can be addressed by constructing the prosthesis in segments. This is so as not to have a rigid entity encased in flexing bone that may induce stress to the bone, leading to loss of implant integration and failure. Segmenting also insures an appropriate fit of the prosthesis with respect to casting and porcelain firing distortion. Lip support by means of a flange in the prosthesis may be necessary when there has been a large amount of bone loss from edentulous resorption. Cleaning and maintenance of the prostheses every 3 to 6 months is essential.     

Full mouth implant rehabilitation of a patient with ectodermal dysplasia after orthognathic surgery, sinus and ridge augmentation: a clinical report

An 18-year-old male presented severe hypodontia due to hypohidrotic ectodermal dysplasia was treated with Le Fort I maxillary osteotomy with simultaneous sinus floor augmentation using the mixture of cortical autogenous bone graft harvested from iliac crest and organic Bio-Oss to position the maxilla in a right occlusal plane with respect to the mandible, and to construct adequate bone volume at posterior maxilla allowing proper implant placement. Due to the poor bone quality at other sites, ridge augmentation with onlay graft was done to construct adequate bone volume allowing proper implant placement, using tissue harvested from the iliac bone. Seven implants were placed in the maxilla and 7 implants were inserted in the mandible and screw-retained metal ceramic FPDs were fabricated. The two year follow up data showed that dental implants should be considered as a good treatment modality for patients with ectodermal dysplasia.     

Immediate function with fixed implant-supported maxillary dentures: a 12-month pilot study

STATEMENT OF PROBLEM: Immediate occlusal loading of dental implants in the edentulous mandible has proven to be an effective, reliable, and predictable procedure. There is little long-term data available on similar treatments in the edentulous maxilla. PURPOSE: The purpose of this study was to evaluate the 12-month implant survival after immediate loading of 4 to 6 implants with fixed screw-retained prostheses in edentulous maxillae. MATERIAL AND METHODS: Twenty-one patients, edentulous or with remaining teeth to be extracted in the maxilla, received 4 to 6 implants (n=111). The patients were restored with screw-retained fixed provisional prostheses supported by palladium-alloy frameworks within 24 hours after surgery. Insertion torques for implants were at least 40 Ncm. Implants, grouped as tapered or cylindrical screws, were placed in healed bone or extraction sockets. Implants were also classified as either vertical or off-angle. Definitive prostheses were placed after a mean healing time of 18 weeks. Radiographic examinations were made at the time of placement of provisional prostheses and 12 months later. Between-groups bone resorption was compared using 2-way ANOVA (alpha=.05). RESULTS: The mean follow-up time for all of the patients was 20 months (range, 13 to 28 months). The cumulative implant survival rate at the 12-month follow-up visits (after surgery) was 92.8%; the prostheses survival rate was 100%. No significant differences were found between the survival of tapered or cylindrical screw-type implants placed in postextraction sockets versus those in healed edentulous sites or between vertical and off-angle placed implants. Eight implants failed during the first 3 months, 5 of which were the most distal implants. The mean reduction in marginal bone height over the 12-month observation period was 0.84 mm (CI 95%; 0.68-0.99 mm). CONCLUSIONS: In this study with 12-month follow-up, 4 to 6 implants were sufficient to successfully support fixed implant screw-retained prostheses in the edentulous maxillae of 21 patients.     

Long-term marginal periimplant bone loss in edentulous patients

PURPOSE: The aim of this study was to examine the long-term periimplant bone loss in patients treated with implant-supported fixed prostheses in both jaws. MATERIALS AND METHODS: The participants comprised 44 edentulous patients who have been followed for a 15-year period after treatment with a fixed implant-supported prosthesis in the mandible. Thirteen of them also received an implant-supported fixed prosthesis in the maxilla, on average 4.5 years after the mandibular treatment. The periimplant bone level was measured on intraoral radiographs. RESULTS: The long-term results of the implant treatment were successful, and only 1% (3/273) of the implants were lost in the mandible and 7% (5/75) in the maxilla. All but one of the failures occurred before the connection of the prostheses. The mean marginal bone loss around the implants was small (less than 1 mm for a 10-year period after implant placement), and was of similar magnitude in both jaws. However, the individual variation was relatively great. There was no significant difference in marginal bone loss between those who had a maxillary complete denture during the entire observation period and those who had received a fixed implant-supported maxillary prosthesis. Smokers lost more periimplant bone than did the nonsmokers; the difference was significant in the mandible but small and nonsignificant in the maxilla. CONCLUSION: The long-term periimplant bone loss was small and of similar magnitude in the mandible and the maxilla in subjects who had received implant-supported fixed prostheses in both jaws. The prosthetic status in the maxilla, i.e., complete denture or fixed implant-supported prosthesis, had no significant influence on the mandibular periimplant bone loss.     

Provisional implants for anchoring removable interim prostheses in edentulous jaws: a clinical study

PURPOSE: The behavior of provisional implants in edentulous maxillae/mandibles used for anchoring removable interim overdentures was followed for the time of the intended healing of the definitive implants. MATERIALS AND METHODS: Twenty-eight edentulous arches (19 maxillae, 9 mandibles) were provided with 77 provisional implants (2 to 4 in maxillae; 2 or 3 in mandibles) for anchoring removable interim prostheses (overdentures). The provisional implants were to be maintained until final restoration (6 to 9 months in the maxilla and 3 months in the mandible). The loss rate of provisional implants and handling and behavior of the anchored overdenture were monitored until the definitive prosthetic restoration was placed. RESULTS: Twenty-three (29.8%) of the 77 provisional implants were lost prematurely. The loss rate of maxillary provisional implants (21/58; 36.2%) was significantly higher than that of mandibular implants (2/19; 10.5%) (P < .01). Determination of terminal stability (by means of the Periotest) of the provisional implants showed higher stability in the mandible (+3.8 +/- 2.3) than in the maxilla (+8.6 +/- 3.9) (P < .05). In obvious contrast to mandibular interim overdentures, handling of maxillary interim overdentures was found to improve significantly during the follow-up period (P < .01). DISCUSSION AND CONCLUSION: With both the low loss rate in the mandible and the higher loss rate seen in the maxilla, placement of provisional implants fulfills the requirements for initiating immediate prosthetic rehabilitation. The removable interim overdenture can be adequately stabilized and provides for added patient comfort and satisfaction as compared to a conventional complete denture. An important aspect of the continued use of provisional implants concerns the expectations placed in these implants by both clinician and patient, which are quite different than those for definitive implants.     

The effect of smoking on osseointegrated dental implants. Part I: implant survival

PURPOSE: Recent studies implicate smoking as a significant factor in the failure of dental implants. The purpose of this long-term retrospective study was to evaluate the survival of Br?nemark endosseous dental implants in relation to cigarette smoking. MATERIALS AND METHODS: The sample consisted of 464 consecutively treated completely and partially edentulous patients who had a total of 1852 implants placed between 1979 and 1999, and who were part of a surgical/prosthodontic prospective treatment outcomes study. The effect of cigarette smoking on implant survival in relation to the time of implant failure, gender, age, surgeon, date and site of implant placement, implant length and diameter, prosthesis design, and occlusal loading considerations was assessed in bivariate and multivariate survival analyses. RESULTS: The overall implant failure rate was 7.72%. Patients who were smokers at the time of implant surgery had a significantly higher implant failure rate (23.08%) than nonsmokers (13.33%). Multivariate survival analysis showed early implant failure to be significantly associated with smoking at the time of stage 1 surgery and late implant failure to be significantly associated with a positive smoking history. Short implants and implant placement in the maxilla were additional independent risk factors for implant failure. CONCLUSION: Cigarette smoking should not be an absolute contraindication for implant therapy; however, patients should be informed that they are at a slightly greater risk of implant failure if they smoke during the initial healing phase following implant insertion or if they have a significant smoking history.     

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.     

Vertical alveolar ridge augmentation by means of a titanium mesh and autogenous bone grafts

The aim of this study is to evaluate a surgical protocol for vertical ridge augmentation in the maxilla and mandible using autogenous onlay bone graft associated with a titanium mesh. A group of 18 partially edentulous patients, presenting the need for vertical bone augmentation of at least 4 mm, were treated before implant placement. During the first surgery, an autogenous bone graft was harvested from either the mandibular ramus or the mental symphysis and secured by means of titanium screws. Particulate bone was added and a titanium micro-mesh was used to stabilize and protect the graft. After a mean interval of 4.6 months, meshes and screws were removed and 37 endosseous implants were successfully placed. The desired bone gain was reached in all patients. Mean vertical bone augmentation obtained was 4.8 mm (range 4-7 mm). No major complications were recorded at recipient or donor sites. Abutment connection was carried out 2-3 months after implant placement. No implant was lost. Clinical parameters and probing depth, after prosthetic reconstruction, demonstrated the presence of a healthy peri-implant mucosa. The preliminary results suggest that, by using the presented technique, patients can be successfully rehabilitated by means of implant-supported prosthesis 6-7 months after the first surgery, even in case of severely atrophied maxilla.