Intraoral autogenous block onlay bone grafting for extensive reconstruction of atrophic maxillary alveolar ridges

BACKGROUND: Endosseous implants require sufficient bone volume for complete bone coverage. Alveolar deficiency can prevent ideal implant placement. Local bone grafts are a convenient source of autogenous bone in alveolar reconstruction. The aim of this study was to describe a technique, and to evaluate the success of extensive bone reconstruction of atrophic maxillary alveolar ridges using only intraoral block bone grafts prior to dental implantation. METHODS: Files of 10 healthy patients with extensive bone reconstruction of the maxillary alveolar ridge using intraoral block bone graft operations were reviewed. Medical history, smoking status, bone origin (donor sites), number of bone blocks, and complications were recorded. RESULTS: Of the 10 extensive bone maxillary reconstructions, four were uneventful, two required additional bone augmentation at the time of dental implant placement, two had a minimal graft exposure, one had a minor adverse effect (temporary paresthesia), and one operation partially failed and required partial graft removal. CONCLUSION: Intraoral bone block grafting is a predictable operation with a high success rate for long-span augmentation, up to complete jaw augmentation/ extensive bone reconstruction of the maxillary alveolar ridge.     

The management of a severely resorbed edentulous maxilla using a bone graft and a CAD/CAM-guided immediately loaded definitive implant prosthesis: a clinical report

Functional reconstruction of an occlusion with severe residual ridge resorption is a clinical challenge. Removable prostheses are unsuccessful in situations with severe bone resorption. A patient with an edentulous maxilla received bone grafts from the anterior iliac crest to augment the maxillary alveolar residual ridges. The maxilla underwent bilateral sinus lift in the posterior area and onlay bone graft on the anterior maxilla using platelet-rich plasma. Eight endosseous implants were placed using a CAD/CAM surgical template approximately 6 months after the bone augmentation procedure. A prefabricated definitive implant-supported fixed complete denture was connected immediately after implant placement using a CAD/CAM-guided surgical implant placement protocol.     

Inlay–onlay grafting for three-dimensional reconstruction of the posterior atrophic maxilla with mandibular bone

This prospective study describes and evaluates a surgical approach for 3D reconstruction of the posterior maxilla with autogenous mandibular bone in 16 patients (mean age 51 years). Bone blocks were harvested from the mandible and used as lateral or vertical block grafts (onlay); they were also partially milled and used for sinus elevation (inlay). In 4 cases, anorganic bovine bone was added at the periphery of the blocks. 4 months after grafting, implants were placed in a second operation and loaded after 12 weeks. Lateral and vertical augmentations were measured immediately after grafting and at re-entry for implant placement. Mean lateral augmentation performed was 5.5 mm, reduced to 4.3 mm (p < 0.01) after 4 months’ healing. Mean vertical augmentation was 3.2 mm, reduced to 2.1 mm (p < 0.01) after healing. The amounts of lateral and vertical graft resorption were similar (1.2 mm vs. 1.1 mm) but were different when compared with the original graft (22% vs. 34%). 49 implants were placed 4 months after grafting. Implant parameters were evaluated after 32–48 months follow up and demonstrated 100% survival rates. The use of mandibular bone grafts for 3D augmentation of the posterior maxilla has shown good results and minor complications.     

Histologic evaluation of autogenous calvarial bone in maxillary onlay bone grafts: a report of 2 cases

Bone augmentation for implant dentistry has become a necessary procedure for a number of edentulous patients. Calvarial bone grafting constitutes an important tool in achieving maxillary augmentation and sinus elevation. Much effort has been directed toward improving graft survival and volumetric maintenance. The purpose of the present study was to evaluate the histologic results of the calvarial onlay graft for maxillary reconstruction before implant placement. Two patients underwent maxillary augmentation using autogenous calvarial onlay grafts. After a 4-month healing period, biopsies of the augmented regions were performed and implants were placed. The implants were loaded after 5 months and then clinically examined after 15 months of function. Biopsies showed that calvarial onlay grafts were well incorporated into the preexisting bone after a 4-month period. Histologic and histomorphometric findings demonstrated a living bone that showed features characteristic of mature and compact osseous tissue. The restored Implants were stable and osseointegrated after a 15-month period of follow-up. The use of calvarial onlay grafts can be a predictable and successful method to achieve maxillary augmentation, allowing appropriate placement of implants and stable prosthetic restorations.     

Maxillary alveolar ridge reconstruction with nonvascularized autogenous block bone: clinical results.

PURPOSE: The purposes of this study were to evaluate the clinical success of bone reconstruction of the severely atrophic maxilla using autogenous bone harvested from the anterosuperior edge of iliac wing and to analyze the clinical success and the marginal bone level of dental implants placed 4 to 5 months after bone grafting and before prosthetic rehabilitation. PATIENTS AND METHODS: Fifty-six patients (18 men, 38 women) aged 27 to 63 years were included in the study and required treatment for maxillary atrophy. All patients selected were scheduled for onlay bone graft and titanium implants in a 2-stage procedure. The dental implants were inserted 4 to 5 months after grafting. RESULTS: No major complications were observed from the donor sites. A total of 129 onlay bone grafts were used to augment 56 severely resorbed maxillas. Three out of 129 bone grafts had to be removed because of early exposure occurring with bone grafts placed to increase the vertical dimension of the alveolar ridge. One hundred sixty-two implants were placed in the area of bone augmentation. Seven implants failed to integrate and were successfully re-placed without any need for additional bone grafting. The clinical measurements for bone resorption around implants revealed a mean bone loss of 0.05 mm (+/- 0.2); the marginal bone level evaluated with periapical radiographies was 0.3 mm (+/- 0.4) at implant placement and 0.1 mm (+/- 0.3) 6 months after placement. CONCLUSION: The success rate of the block grafts was very good. The clinical and radiographic bone observations showed a very low rate of resorption after bone graft and implant placement. Therefore, on the basis of this preliminary study, iliac bone grafts (from the anterosuperior edge of the iliac wing) can be considered a promising treatment for severe maxillary atrophy.     

Cortical tenting grafting technique in the severely atrophic alveolar ridge for implant site preparation

OBJECTIVES: Alveolar ridge augmentation using intraoral autogenous block grafts to augment localized alveolar ridge defects before implant placement is a predictable method. However, large severely atrophic edentulous segments may require extraoral donor sites. The purpose of this study was to evaluate the effectiveness of using intraoral cortical block grafts in combination with particulate human mineralized allograft, in a "tenting" fashion, to augment large atrophic alveolar ridge defects for implant placement. MATERIALS: This prospective case study evaluated augmentation in 10 consecutive patients with severely resorbed alveolar ridges missing a minimum of 4 adjacent teeth. Before augmentation, all grafted sites were deemed inadequate for placement of a standard 4-mm-diameter implant. Horizontal ridge augmentation was performed using autologous membranous cortical bone grafts from an oral donor site to tent out the soft tissue matrix and periosteum for the adjacent particulate allograft. The ridges were clinically evaluated 4 to 5 months after augmentation, and 42 implants were placed at that time. RESULTS: Implants were successfully placed at all grafted sites 4 to 5 months after the original graft date. Clinical evaluation of the grafted sites upon re-entry revealed uniform ridge anatomy. All edentulous segments had at least 2 implants placed of at least 4.0 mm diameter. In all, 42 implants were placed into grafted sites in the 10 patients. Implants were checked for osseointegration by using a counter torque of 35 N.cm. One implant failed to integrate. Mean follow-up was 22 months after implant placement. All augmented ridges had retained their functional and esthetic integrity at 1 year after original augmentation. CONCLUSION: Tenting of the periosteum and soft tissue matrix using a cortical bone block maintains space and minimizes resorption of the particulate allograft volume. In addition, bridging the cortical blocks with particulate bone avoids unaesthetic ridge defects between cortical block grafts in larger ridge defects. The result was a more uniform and esthetic alveolar ridge, capable of maintaining an implant-supported prosthesis. The technique offers predictable functional and esthetic reconstruction of large-volume defects without extensive amounts of autogenous bone. This offers a superior functional and esthetic result than with either cortical or particulate grafting alone.     

Dental implant treatment with different techniques for sinus floor elevation--a case report

A 60-year-old man with missing maxillary molar teeth received dental implant therapy for reconstruction of occlusion. Sinus floor elevation with autogenous bone graft consisting of iliac bone block and particulate cancellous bone and marrow (PCBM) was performed in the bilateral maxillary sinuses for implant placement. On the right side, bone height in the molar region was less than 2mm. Therefore, a delayed protocol was applied, and 2 implants were placed 4 months after bone grafting. Bone graft resorption occurred during the healing period of 4 months. On the left side, 3 implants were placed simultaneously with sinus floor elevation, as bone height in the molar region was more than 4-5mm. The bone graft was carried out at the same time as implant placement. After implant placement, resorption of the bone graft stopped, and the superstructures were delivered on both sides. The tissues around the implants were clinically healthy at one year after examination. Sinus floor elevation with autogenous bone graft is an acceptable option for implant treatment in the maxillary molar region where there is adequate height of existing bone. In postoperative care, it is important to undertake adequate follow-up to ascertain occurrence of bone graft resorption.     

A 9–14 year follow-up of onlay bone grafting in the atrophic maxilla

Treatment of the atrophic edentulous maxilla is challenging especially when bone graft procedures are necessary. In this study an onlay bone graft, a saddle or veneer, with or without maxillary sinus floor inlay graft, harvested from the anterior iliac crest, in combination with implants was used in the reconstruction of patients with extreme atrophy in their maxillae. The aim was to investigate treatment outcome, and the impact of gender and smoking, in 44 patients in a prospective, long-term, follow-up study concerning implant survival rate and marginal bone loss adjacent to the surfaces of the implant.Mean follow-up time was 11 years. Of 334 inserted Brånemark implants, with machined surface, 27 failed. Estimated implant survival rate was 90%. Marginal bone loss was 1.8 mm 1 year after implant surgery; 2.3 mm after 5 years; and 2.4 mm after 10 years. There was a significant difference between genders in implant survival. Marginal bone loss differed significantly between smokers and non-smokers up to the 5-year examination and between genders after the 4-year examination. The onlay bone graft, with or without a maxillary inlay graft, results in high implant survival rate, good oral function and stabilised marginal bone. All patients are still wearing their original fixed bridges.     

Stability Evaluation of Implants Integrated in Grafted and Nongrafted Maxillary Bone: A Clinical Study from Implant Placement to Abutment Connection

Background: Clinical studies have shown a higher degree of implant failures in grafted bone compared with normal nongrafted maxillary bone. Additionally, a prolonged time for integration of titanium implants in grafted block bone has been shown by means of resonance frequency analysis (RFA). Purpose: The aim of this prospective study was to compare the stability of implants placed in particulate bone, onlay block bone, interpositional bone, and nongrafted maxillary bone during the early phase of osseointegration using RFA and implant failure. Material and Methods: Thirty‐five patients with edentulism in the maxilla were included in the study. In all, 260 Astra Tech TiOblast? implants (Astra Tech AB, Mölndal, Sweden) were installed. Twenty‐five of these patients had severe maxillary atrophy and were treated with iliac bone grafts 5 to 6 months prior to implant placement, 19 with lateral onlay block grafts on one side (group A, 38 implants) and particulate bone for lateral augmentation on the other (group B, 38 implants). These 19 patients also got bilateral sinus floor augmentation with particulate bone (group C, 76 implants). Six patients had an unfavorable sagittal relation between the jaws and underwent a LeFort I operation with interpositional bone blocks grafted to the nasal and sinus floors (group D, 48 implants). The remaining 10 patients could be treated with implants without bone augmentation and served as control (group E, 60 implants). RFA was performed at implant placement and abutment connection 6 months later and an implant stability quotient (ISQ) value was given for each implant. Results: Four implants (1.5%) were found mobile at abutment connection and removed (two in group A and two in group D). RFA showed a slight increase in stability from installation to abutment connection but the differences were not statistically significant in any of the groups (Wilcoxon signed rank test for comparison of paired data). Implants installed in group D had a significantly lower ISQ value at both measurements compared with the other groups (Wilcoxon Rank Sum test for comparisons of independent samples, p = .05). Conclusion: It is concluded that TiO₂‐blasted implants placed in nongrafted and grafted maxillary bone using a two‐staged protocol show similar stability during the early phase of osseointegration. Patients reconstructed with interpositional bone graft after a LeFort I osteotomy showed lower implant stability values than nongrafted patients and other grafting techniques.     

Effects of anodized implants coated with Escherichia coli-derived rhBMP-2 in beagle dogs

This study evaluated the effects of Escherichia coli-derived rhBMP-2 (ErhBMP-2) coated onto anodized implants to stimulate bone formation, osseointegration and vertical bone growth in a vertical bone defect model. Six young adult beagle dogs were used. After a 2-month bone healing period, anodized titanium implants (8 mm in length) were placed 5.5 mm into the mandibular alveolar ridge. Eighteen implants coated with ErhBMP-2 (BMP group) and another 18 uncoated implants (control group) were installed using a randomized split-mouth design. The implant stability quotient (ISQ) values were measured. Specimens were fabricated for histometric analysis to evaluate osseointegration and bone formation. The ISQ values at 8 weeks after implant placement were significantly higher in the BMP group than in the control group (p < 0.05). Histological observations showed that the changes in bucco-lingual alveolar bone levels were higher in the BMP group than in the control group (p < 0.05). The ErhBMP-2 coated anodized implants can stimulate bone formation and increase implant stability significantly on completely healed alveolar ridges in dogs. Further studies evaluating the effects of ErhBMP-2 on osseointegration in the bone–implant interface are warranted.     

Predictability of simultaneous implant placement in the severely atrophic posterior maxilla: A 9-year longitudinal experience study of 2132 implants placed into 731 human sinus grafts

PURPOSE: One-stage implant placement in the grafted maxillary sinus has traditionally been limited to patients with at least 5 mm of residual bone to ensure complete implant stabilization. The aim of this prospective study was to determine the long-term survival rates of implants with roughened surfaces placed immediately into maxillary sinus grafts in patients with 1 to 5 mm of residual bone. MATERIALS AND METHODS: A total of 2132 microtextured screw-type (n=1374) or hydroxyapatite-coated cylinder-type (n=758) implants were immediately placed into the grafted sinuses of 731 patients. The implants were restored and monitored for up to 9 years of clinical follow-up. RESULTS: Cumulative survival at 9 years was 97.9% (n=2091 implants); 20.4% of the implants were placed in 1 to 2 mm of residual bone. Discussion: Initial implant stability and parallelism were achieved through a combination of meticulous condensation of the particulate bone graft material around the implants, the frictional interface of the roughened implant surfaces and the host tissues, and selection of an appropriate graft material. CONCLUSIONS: Simultaneous implant placement into sinus floor grafts can be a predictable treatment option for patients with at least 1 to 2 mm of vertical residual bone height when careful case planning and meticulous surgical techniques are used.     

Il rialzo del seno mascellare con osso bovino deproteinizzato: studio clinico prospettico

ObjectivesThe aim of this study was to evaluate success and survival rates of implants inserted following maxillary sinus lift procedures in patients with a residual bone height of up to 6 mm, a residual bone width of at least 5 mm, and preservation of normal intermaxillary relationships.Materials and methodsWe performed 68 maxillary sinus lifts in 60 patients. Bovine bone mineral was the only graft material used. In subsequent surgical procedures, a total of 120 implants were inserted, and prosthetic loading was done 5 months after implant placement.ResultsAll sinus grafts showed evidence of full integration. The mean follow-up after prosthetic loading was 24 months. The mean (± SD) marginal bone loss was 0.85 mm (± 0.36 mm). The overall implant survival and implant success rates were 100% and 97.5%, respectively.ConclusionsThe results of this study seem to confirm that use of bovine bone mineral as the sinus graft material offers reliable and predictable results in terms of the survival and success of dental implants in the atrophic posterior jaw.     

Particulate vs. block bone grafts: Three-dimensional changes in graft volume after reconstruction of the atrophic maxilla,a 2-year radiographic follow-up

BackgroundExtensive alveolar bone resorption in the maxilla limits the possibility of successful placement and osseointegration of endosseous implants for future prosthetic rehabilitation. Autogenous bone from the iliac crest may be used as lateral onlays in the atrophic maxilla, both as block and particulate bone. To our knowledge, there is no three-dimensional 2-year follow-up study measuring the volumetric reduction of the augmented areas comparing particulate and block bone grafts.PurposeThe aim of this study was to conduct a radiographic 2-year follow-up study, using computed tomographic (CT) images in order to evaluate and compare the extent of bone graft resorption in the frontal maxillae augmented by particulate (test) and block bone (control).Material and methodsEleven patients treated with iliac bone grafts and oral implants in the maxilla were followed with CT examinations directly post grafting and after 2 years.ResultThe volumetric changes after 6 months were extensive. Additionally, the changes in particulate bone tended to be larger after 2 years compared to block bone, using this protocol. However, the difference was not statistically significant.ConclusionThe present follow-up study showed that there is radiographically complete integration and embedding of implants installed in grafted bone despite extensive initial graft resorption. There was no significant difference in the amount of volumetric reduction between particulate bone and block bone grafts.     

自体胫骨骨松质移植提升上颌窦与骨内牙种植

本文通过8例自体胫骨骨松质移植提升上颌窦的成功．认为上颌窦底自体胫骨骨松质移植对于解决上颌后区牙槽嵴萎缩、上颌窭与牙槽嵴接近而又需要进行骨内种植牙的病人提供了一种良好的方法。胫骨近中外上髁作为供骨区有明显的优点，可以获得质量高、数量较多的骨质．骨面与皮肤接近．创口小，并发症少。     

Implant placement in three-dimensional grafts in the anterior jaw

A series of 12 men and 13 women ranging in age from 24 to 71 years underwent two- or three-dimensional reconstruction of type C, D, or E ridges and placement of anterior implants. The mean horizontal augmentation was 6.4 mm (range 2 to 17 mm), and the mean vertical augmentation was 4.22 mm (range 0 to 15 mm). The 67 implants were all loaded, with the time averaging 34.4 months for the maxillary implants and 19 months for the mandibular implants. None of the implants have been lost to date. Two patients had flap retraction within the first 2 weeks that necessitated reapproximation. One patient had total failure of a J graft of iliac crestal bone from the maxillary left central incisor to canine starting 3 weeks after placement as the result of infection. The graft was removed at 6 weeks, and no implants were placed. Two patients suffered partial anterior graft loss, but their implants were successful in location and angulation. Implants and grafts can be combined with acceptable rates of complications and failure.     

Factors Affecting Survival and Usefulness of Implants Placed in Vascularized Free Composite Grafts Used in Post–Head and Neck Cancer Reconstruction

Background: Bone‐containing vascularized grafts have been used successfully to reconstruct post‐cancer surgical defects. Dental implants can be placed in these bone‐containing grafts to allow implant‐supported prosthodontic reconstruction of these patients. Purpose: The aim of this study was to evaluate the survival of dental implants used in the rehabilitation of subjects treated with bone‐containing vascularized grafts to compare usability of implants placed at the time of reconstruction and after healing. Materials and Methods: A cross‐sectional study was undertaken to examine survival rates of implants placed in vascularized bone‐containing grafts either immediately at the time of surgical reconstruction or after 3 months healing. Other factors such as graft type, whether radiation therapy was given, and implant type were recorded. Results: A total of 41 patients had 145 implants placed in 47 vascularized bone‐containing flaps. Increased failure rate of implants was seen in immediately placed implants. There was also a significant increase in the number of osseointegrated implants that were prosthodontically unusable or sub‐optimally placed in the immediate placement group. Radiation therapy was associated with a significant increase in failure rate. Modern implant surfaces appeared to perform better than machined/turned surfaces. Graft donor site did not influence implant survival. Conclusion: This study demonstrated the difficulties encountered with immediate placement of dental implants at the time of post‐cancer reconstructive surgery.     

Implant survival rates after maxillary sinus augmentation

Implant therapy in the atrophic posterior maxilla becomes challenging in the presence of reduced maxillary bone height. Sinus augmentation can be performed for resolving this condition prior to implant placement. The aim of this article was therefore to evaluate implant survival rates in the grafted sinus taking into account the influence of the implant surface, graft material, and implant placement timing. A systematic review of the literature was performed. Articles retrieved from electronic databases were screened using specific inclusion criteria, and data extracted were divided according to: graft material (autogenous, non‐autogenous, composite graft), implant surface (machined or textured), and implant placement (simultaneous with grafting or delayed). Fifty‐nine articles were included. Survival rates for implants placed in grafts made of bone substitutes alone and grafts of composite material were slightly better than the survival rates for implants placed in 100% autogenous grafts. Over 90% of implants associated with non‐autogenous grafts had a textured surface. Textured surfaces achieved better outcomes compared with machined surfaces, and this was independent of the graft material. Simultaneous and delayed procedures had similar outcomes. It may be concluded that bone substitutes can be successfully used for sinus augmentation, reducing donor‐site morbidity. Long‐term studies are needed to confirm the performance of non‐autogenous grafts. The use of implants with a textured surface may improve the outcome in any graft type.     

Localized ridge augmentation using a micro titanium mesh: a report on 27 implants followed from 1 to 3 vears after functional loading

The present paper describes the clinical and radiographic healing results of 27 implants followed from 1 to 3 years after functional implant loading. Prior to implant placement, alveolar ridges with insufficient bone volume were augmented using autogenous bone grafts and a micro titanium mesh for graft stabilization. After a mean interval of 5.2 months implants were installed. Following an osseointegration period of on average 7.2 months, implants were supplied with suprastructures. The mean loading period for the 27 implants was 21 months. All implants exhibited ankylotic stability and healthy peri‐implant soft tissues. The detailed analysis of clinical parameters (probing depth, level of mucosal margin, attachment level, modified plaque and sulcus bleeding indices) and radiographic measurements (crestal bone level), revealed findings similar to those at implants placed into non‐augmented bone. Peri‐implant bone resorption was calculated to be 1.0 mm for the 1st year after implant loading and 0.1 mm for the following year. Pain, suppuration or semilunar bone defects were absent at all implants. It was concluded that loaded dental implants which have been inserted into an augmented alveolar ridge using autogenous bone grafts and a micro titanium mesh for graft stabilization, demonstrate clinical and radiographic findings similar to those of implants placed into a pristine ridge.     

Impact of surface contamination of implants with saliva during placement in augmented bone defects in sheep calvaria

Our aim was to try and find out whether contamination with saliva during insertion of dental implants affects osseointegration in bone that has been augmented with different grafts. Six bony defects were created in each of the calvaria of six sheep, and then augmented with three different materials (autogenous bone, bovine bone, and resorbable biphasic ceramic bone substitute) After five weeks of healing, three implants contaminated with saliva (contaminated group) and three not contaminated (uncontaminated group) were placed in the centre of the augmented areas. For histomorphometric analysis, bone implant contact, bone area fraction occupancy, bone and material area, and bony area were measured after a healing period of five weeks. There was a significant difference between the contaminated and uncontaminated groups (p = 0.036) for bone implant contact only in the augmented areas, but there were no significant differences in bone area fraction occupancy, bone and material area, and bony area. We conclude that contamination with saliva during placement of dental implants can significantly compromise bone implant contact in augmented areas, but had no significant effect on the formation of bone in areas more distant from the surface of the implant. We suggest that salivary contamination should be avoided during placement of dental implants in augmented areas.     

Clinical,histological and histomorphometrical study of maxillary sinus augmentation using cortico-cancellous fresh frozen bone chips

BackgroundInsufficient bone volume in the posterior maxilla can be a major problem when placing dental implants. One of the goals of sinus augmentation procedures is the creation of sufficient volume of vital bone for the subsequent insertion and complete osseointegration of implants placed in the posterior maxilla.The aim of the present study was a clinical, histological and histomorphometrical analysis of maxillary sinus augmentation using human fresh frozen bone (FFB) allografts for maxillary sinus lift augmentation procedures.MethodsFifteen patients were treated with maxillary sinus augmentation using FFB. After three months, a bone biopsy was taken before implant placement in order to evaluate the healed bone from a histological and histomorphometrical point of view. After further three months, all implants were osseointegrated according to radiographic and clinical examinations. Abutment connection was performed and the patients received prosthetic restoration of the missing teeth.ResultsHistologically all the specimens showed signs of active remodelling and all the tissues were free of inflammatory cells. After 12 months of assessment, no implants had failed.ConclusionOur findings suggest that FFB is a biocompatible material that can be successfully used for maxillary sinus augmentation.