Placement Of Endosseous Implants Research Articles

Treatment of the severely resorbed maxilla

Moderately to severely resorbed edentulous maxillae present unique problems for the restorative dentist. The lack of internal loading of the edentulous alveolar bone, leading to its further resorption, has resulted in research involving reconstruction of the osseous topography of edentulous ridges prior to the placement of endosseous implants.

Results of Maxillary Sinus Elevation for Endosseous Implant Placement

Background: Although dental implantation has become widespread and acceptable treatment for dental prosthodontics, maxillary posterior jaw region is often complicated by the pneumatization of the maxillary sinus and physiological resorption of the alveolar bone. When this occurs, the residual bone between the floor of the sinus and the crestal ridge is inadequate for the placement of implants. The sinus elevation procedure provides a way to increase the amount of available bone and to allow the placement of longer implants. Materials & methods: We studied 11 patients requiring the implant placements and the maxillary sinus elevation simultaneously from 1996 to 2003 in our clinic. Nine patients were males and two patients were females, aged from 39 to 72(mean=51.6). Four patients had medical compromised states; angina pectoris, diabetes, hypertension, hepatitis. Patients didn't show any pathologic findings clinically or radiographically. We studied the success and survival rate of implants, factors increasing the osseointegrating capacity of implants. Results: The success rate of osseointegration of implants was 93%. At least 6 months after loading on implants, the survival rate of implants was 78.5%. Autogenous bone graft and adequate residual bone height(>6mm) increased survival rate of implants. Conclusion: Successful implant placement with maxillary sinus elevation mainly depends on sufficient residual bone height, healthy maxillary sinus, autogenous bone graft.

Clinical application of spiral tomography in anterior implant placement: case report.

Placement of endosseous dental implants in edentulous areas of the anterior maxilla poses a unique challenge due to variations in the amount of residual alveolar bone. Implant position becomes crucial in cases demanding high esthetic results but possessing minimal ridge width or in cases requiring augmentation. Recent advances in spiral tomography have allowed for more precise planning and placement of endosseous implants in these challenging areas. The purpose of this report is to describe a series of clinical cases in which spiral tomography was utilized in the planning and placement of endosseous dental implants. Two cases will be described utilizing initial spiral tomographic radiographs for implant planning and surgical guide fabrication, followed by post-insertion tomography to evaluate the results of implant position and inclination. Preimplant spiral tomograms revealed that the initial prosthetic trajectory through the proposed incisal edge of each tooth replacement would result in a final osteotomy site that would compromise the overall thickness of the facial cortical plate. After adjusting for magnification and distortion factors, new prosthetic/surgical trajectories were fabricated into the surgical guide, and this information was utilized to prepare the final implant osteotomy site. This adjustment resulted in 2 mm of residual crestal facial bone postimplant insertion, which became wider at more apical measurements. These findings were verified in the postimplant serial tomograms. Spiral tomography was a valuable adjunct in the treatment planning phases of endosseous dental implant placement especially in cases with minimal crestal width, high esthetic demands, or where exact implant placement is critical for successful treatment outcomes.

Maxillary sinusitis after augmentation of the maxillary sinus floor: A report of 2 cases

Augmentation of the floor of the maxillary sinus with an autogenous bone graft is a generally accepted pre-implantology procedure to enable successful placement of endosseous implants in an optimal prosthetic position. As reported in the literature, complications of the sinus augmentation procedure predominantly consist of disturbed wound healing, hematoma, sequestration of bone, and transient maxillary sinusitis. 1,2 The last complication can occur as a result of contamination of the maxillary sinus with oral or nasal pathogen or because of a lack of asepsis during the surgical procedure. 3 Other causes are ostial obstruction due to postoperative swelling of the maxillary mucosa 4-6 and nonvital bony fragments freely floating in the maxillary sinus. 7 The incidence of maxillary sinusitis after augmentation of the sinus floor with iliac crest bone grafts ranges from 0% to 27%. 8-16 However, one has to consider that these data are derived from clinical studies in which the presence of maxillary sinusitis was not scored according to standard criteria in the field of otolaryngology for the diagnosis of sinusitis, 17-24 and specific preoperative evaluation of sinus drainage was not performed. Timmenga et al 25 reported that clearance of the maxillary sinus is rarely compromised after sinus floor augmentation, and that the development of a chronic maxillary sinusitis, with all its therapeutic consequences, still has to be considered as a rare condition. Between 1988 and 1998, 156 patients were treated in our clinic; 7 patients (4%) developed a transient (subacute) sinusitis, and 2 patients (2%) developed a chronic purulent maxillary sinusitis. In this report, these 2 complicated cases of chronic purulent maxillary sinusitis following augmentation of the maxillary sinus with autogenous bone grafts are discussed and guidelines for specific treatment of both transient and chronic maxillary sinusitis are given.

Placement of endosseous implants in patients with oral epidermolysis bullosa

To evaluate the feasibility of placing endosseous implants in patients with recessive dystrophic epidermolysis bullosa. This article reports on 4 patients subjected to follow-up. Implants were placed in 4 cases. All patients have marked oral involvement, with devastating alterations in the soft and hard tissues in all cases. A total of 15 implants (7 maxillary, 8 mandibular) were placed. All implants integrated successfully and have been restored. The average follow-up from implant placement was 2.5 years (range, 1-4). Our preliminary findings suggest that endosseous implants can be successfully placed and can provide support for prosthetic restoration in patients with recessive dystrophic epidermolysis bullosa.

Bony augmentation of the maxillary sinus via a Le Fort I osteotomy: A report of 3 cases

The patient with partial edentulism and accompanying interarch alveolar positional discrepancies poses a particular dilemma with respect to prosthetic reconstruction. Placement of endosseous implants is a viable option, but the interarch alveolar discrepancy must be addressed, along with the confounding situation of limited bone height below the floor of the maxillary sinus secondary to ridge atrophy and sinus morphology.

Clinical applications of composite intramembranous bone grafts

The aim of this article is to introduce the composite intramembranous bone graft mixed with demineralized bone matrix to the clinician and to demonstrate its various clinical applications in the field of clinical orthodontics in the form of case reports. Understanding the mechanism of healing of this composite bone graft provides sound experimental precedent that allows this graft material to become a predictable part of our future orthodontic management. The cases highlighted here took advantage of the several properties of the composite intramembranous demineralized bone matrix graft. An accidental loss of the buccal plate of bone occurred during extraction of a buccally placed premolar for orthodontic purposes. The defect was repaired using chin bone mixed with demineralized bone matrix, and the teeth were successfully moved into the grafted area. A 5-year follow-up showed a stable gingival condition at the grafted area. In this report, ridge augmentation with intramembranous demineralized bone matrix as an adjunct to orthodontic treatment allowed successful placement of endosseous implants. In conclusion, the same graft material was successfully used in the repair of a massive alveolar cleft. Long-term follow-up of these cases showed that this graft is a promising graft material that could be integrated into our orthodontic practice. (Am J Orthod Dentofacial Orthop 2000;117:375-83)

Behavior of implants in bone grafts or free flaps after tumor resection

The authors compared bone resorption of autogenous bone grafts and revascularized free flaps used for the reconstruction of mandibular continuity defects following resection for tumors, before and after the placement of endosseous implants. Ten patients (group 1) were treated with autogenous bone grafts taken from the fibula or the anterior iliac crest; 8 patients (group 2) were treated with iliac or fibula revascularized flaps. Four to 8 months later, 72 endosseous implants were placed in the reconstructed areas. After a further healing period of 4-6 months, patients were rehabilitated with implant-borne prostheses. The following parameters were evaluated and compared between the two groups: 1) bone resorption of grafts and free flaps before and after implant placement; 2) peri-implant bone resorption mesial and distal to each implant, immediately after prosthetic rehabilitation and then during yearly follow-ups. Bone resorption before implant placement showed mean values of 3.53 mm in group 1, and 0.96 mm in group 2. Peri-implant bone resorption was: 0.49 mm (39 implants) in group 1, and 0.45 mm (30 implants) in group 2, at time of prosthetic rehabilitation; 0.78 mm (39 implants) in group 1, and 0.89 mm (30 implants) in group 2, 12 months after prosthetic load; 1.16 mm (24 implants) in group 1, and 1.02 mm (13 implants) in group 2, 24 months after the prosthetic load. A significant difference in bone resorption before implant placement was found between the two groups, whereas it was not found after implant placement and prosthetic load. The failure rate according to Albrektsson criteria was 4.9% (2/41 implants) in group 1, and was 3.2% (1/31) in group 2.

Histologic analysis of implant sites after grafting with demineralized bone matrix putty and sheets.

Grafting to restore lost alveolar bone is frequently used to enable placement of endosseous implants and improve cosmesis. Conflicting reports concerning the osteoinductivity of demineralized bone matrix (DBM) and historical use of synthetic bone graft substitutes has limited the use of DBM in oral and maxillofacial applications. Implant placement after bone grafting provides the unique opportunity to biopsy and histologically evaluate new bone formation. Bone grafting of the mandible or maxilla was performed to fill extraction sockets and restore ridge structures in a consecutive series of eight patients. DBM prepared as malleable putty (Grafton DBM Putty) or flexible sheets (Grafton DBM Flex) was used. Biopsies were taken at reentry, and histologic analysis determined the amount and quality of regenerated bone. Extensive new bone formation and minimal residual bone graft matrix were observed at an average of 5 months postoperative. The pattern of new bone maturity and remodeling varied by patient and the time in situ. Putty and Flex regenerated excellent bone height and width for the placement of dental implants, were easy to handle intraoperatively, and readily conformed to bony defects.

Placement of endosseous implants in children and adolescents with hereditary ectodermal dysplasia

Objective. The purposes of this investigation were to study the feasibility of placing endosseous implants in children and adolescents with ectodermal dysplasia and to assess the position and stability of such implants during growth. This article reports on 6 subjects with long-term follow-up. Study design. A prospective study was commenced in 1991. Patients with hereditary ectodermal dysplasia who were over the age of 5 years and who presented to the University of California San Francisco Ectodermal Dysplasia Clinic for dental treatment were included and maintained in the study. In each case, clinical and radiographic records were obtained before treatment, immediately after implant placement, at delivery of the prosthesis, and subsequently at yearly intervals. Six subjects are reported, 4 as members of the prospective study group and 2 who had been treated before the study began. Results. A total of 41 implants (19 maxillary, 22 mandibular) were placed. The average follow-up after implant placement was 7.8 years (range, 6-11 years), and the average time since restoration was 6 years (range, 5-10 years). Forty implants successfully integrated and have been restored. There was no evidence that implant placement or prosthetic rehabilitation resulted in restriction of transverse or sagittal growth. One mandibular implant, placed in a partially dentate 5-year-old, became submerged because of adjacent alveolar development and required placement of a longer abutment. Four maxillary implants placed in a partially dentate 7-year-old also became submerged and required prosthetic revision and the placement of longer abutments. Conclusions. This preliminary report suggests that endosseous implants can be successfully placed and can provide support for prosthetic restoration in patients with hereditary ectodermal dysplasia. However, vertical dentoalveolar growth results in submergence of the implant relative to the adjacent natural dentition when implants are placed adjacent to erupting permanent teeth. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1999;88: 5-10)

Morbidity and complications of bone grafting of the floor of the maxillary sinus for the placement of endosseous implants.

Placement of endosseous implants in the atrophic maxilla is often limited because of a lack of supporting bone. A technique to augment the floor of the maxillary sinus with autogenous bone graft seems to be a new reliable treatment modality. The morbidity and complication rate of augmentation of the maxillary sinus floor was studied in 75 patients. The sinus floor was augmented with iliac crest (n = 65, 128 sinuses, 276 implants), mandibular symphysis (n = 8, ten sinuses, 21 implants), or maxillary tuberosity grafts (n = 2, two sinuses, two implants). The width of the alveolar crest had to be reconstructed in 52 patients, while in the other 23 patients augmentation and implantation were performed simultaneously. Perforation of the sinus membrane occurred in 45 patients, but this did not predispose them to the development of sinusitis. Loss of bone particles and sequesters were observed in one (diabetic) patient only, in whom a mucosal dehiscence occurred. A second augmentation procedure was successful. Symptoms of transient sinusitis were observed in two of the seven patients with a predisposition for sinusitis. These symptoms were successfully treated with decongestants and antibiotics. One patient developed a purulent sinusitis which resolved after a nasal amrostomy. The bone volume was sufficient for insertion implants in all patients. Twenty of 299 patients (6.7%) in whom Brånemark implants had been inserted were lost to follow-up (mean, 32 months); no sinus pathology was observed. The patients received implant-supported overdentures (58 patients) or fixed bridges (17 patients) and experienced no complaints with regard to the grafts or implants. We conclude that the morbidity and complication rate of bone grafting of the floor of the maxillary sinus floor with autogenous bone is low.

Punch Technique for Preservation of Interdental Papillae at Nonsubmerged Implant Placement

Surgical flap procedures currently used for the placement of endosseous implants often can result in damage to the interdental papilla with subsequent poor esthetics. A simple technique is presented whereby the implants are placed by using a tissue punch and without raising a full thickness flap. At no time is the subperiosteal soft tissue flap raised, and the integrity of the interdental papilla is never disrupted. There is no discontinuation of the alveolar blood supply of the surrounding osseous tissue. In the authors' experience, there has been a significant reduction in postoperative discomfort. It is proposed that this technique warrants further evaluation, especially to compare the rate of bone resorption, because it is hypothesized that because of lack of discontinuation of the blood supply, there might be reduced bone resorption compared with conventional flap procedures.

Bone Grafting of Cleft Lip and Palate Patients for Placement of Endosseous Implants

Bone Grafting of Cleft Lip and Palate Patients for Placement of Endosseous Implants

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

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

Reconstruction of the extremely resorbed mandible with interposed bone grafts and placement of endosseous implants: A preliminary report on outcome of treatment and patients' satisfaction

During recent decades many surgical techniques have been developed to enlarge the denture-bearing area of the mandible. Most of these techniques improved retention and stability of the lower dentures only temporarily. Since the advent of endosseous implants to stabilize overdentures, combinations of augmentation procedures and placement of endosseous implants have been introduced to restore the severely resorbed mandible. In this study we describe the preliminary results of such a combined approach using sandwich osteotomy with an autogenous bone graft (iliac crest) followed by placement of four endosseous implants in the interforaminal region in 10 women. After a mean follow-up period of 31 months (range 19–57) several variables were measured including condition of the peri-implant tissues, radiographic bone changes and patient satisfaction. The first results indicate that the technique described offers a solid base for implant-stabilized overdentures: no implants were lost, the peri-implant tissues were in good condition, bone loss was limited, and patients were satisfied. Future studies will evaluate the permanence of these results.

The Influence of Preoperative Antibiotics on Success of Endosseous Implants Up to and Including Stage II Surgery: A Study of 2,641 Implants

According to the American College of Surgeons, complex oral surgical procedures, including the transoral placement of endosseous implants, are of the type that may require prophylactic antibiotics. However, the routine use of prophylactic antibiotics in the field of dental implantology continues to be controversial, and their utilization varies widely. No data from a randomized prospective clinical study of the prophylactic use of antibiotics in implant surgery have been previously published. As part of the comprehensive Dental Implant Clinical Research Group clinical implant study, the preoperative or postoperative use of antibiotics, the type used, and the duration of coverage was left to the discretion of the surgeon. These data were recorded and correlated with failure of osseointegration during healing (stage I) and at stage II surgery (uncovering). The results showed that significantly fewer failures occurred when preoperative antibiotics were used.

Placement of Endosseous Implants in Grafted Alveolar Clefts

Placement of Endosseous Implants in Grafted Alveolar Clefts

Use of endosseous implants for dental reconstruction of patients with grafted alveolar clefts

Purpose : The purpose of this study was to investigate the clinical application of endosseous implants placed into grafted alveolar clefts and to evaluate the short-term outcome. Patients and Methods : Nineteen patients (6 males and 13 females; mean age, 17.9 years; range, 9.7 to 33.6 years at first implant surgery), including 11 with unilateral cleft lip and palate, and eight with unilateral cleft lip and alveolus, were studied. All patients except for one who underwent periosteoplasty received grafts of autogenous particulate cancellous bone and marrow (PCBM) obtained from the ilium. After bone bridge formation, orthodontic treatment and preparation for implant placement were performed. Results : A total of 21 implants were placed in the bone-grafted alveoli of the 19 patients. The most frequently used length was 15 mm. In five patients with insufficient alveolar bone height, a chin bone onlay graft was combined with simultaneous implant insertion. The follow-up period ranged from 1 year to almost 3 years after implant placement, and the clinical outcome was excellent in all except one patient. In this short-term study, the overall survival rate was 90.5%. Conclusion : The grafted alveoli were well suited to the placement of endosseous implants, and this treatment was shown to be a viable option for the dental reconstruction of alveolar clefts. However, the interdental alveolar bone height was insufficient for implant installation in a few patients. Further longitudinal studies are required to determine the optimal timing between secondary bone grafting and implant placement.

Bone grafting of the floor of the maxillary sinus for the placement of endosseous implants

This study describes and evaluates a technique to augment the floor of the maxillary sinus and to widen the alveolar crest of the atrophic posterior maxilla with autogenous bone. The subjects were 43 patients whose maxillary alveolar crest was not high enough to permit reliable placement of endosseous implants in the posterior maxilla. Large autogenous cancellous bone grafts ( n=37) or smaller grafts from the mandibular symphyseal area ( n=5) or the maxillary tuberosity ( n=1) were harvested. The operations were done in either one stage ( n=20 patients, 36 sinuses) or two (bone grafting followed by placement of implants, n = 23, 45 sinuses). In 28 cases the sinus membrane was perforated with no subsequent problems. Nine of the 171 Brånemark implants that were inserted were lost during follow-up (mean 26 months, range 8–62 months). Augmentation of the maxillary sinus with autogenous bone is a reliable way of achieving placement of an implant.

Changes in the density of protein gene product 9.5-immunoreactive nerve fibres in human oral mucosa under implant-retained overdentures

Reduced oral sensitivity and impaired masticatory cycles have been demonstrated in edentulous humans wearing removable dentures, and there is some evidence that these patients have a decreased innervation of the oral mucosa. Clinical and electrophysiological evidence shows that sensory performance improves after oral rehabilitation with implant-retained overdentures. The aim of this study was to compare the density of mucosal innervation in edentulous patients with that in dentate controls and to evaluate changes in the number or type of sensory receptors following placement of endosseous implants in these edentulous individuals. The mucosal innervation was evaluated by immunohistochemical assays for the neurospecific marker protein gene product 9.5, and the innervation pattern was compared with that of dentate controls. Morphometric analysis of the immunohistochemical material demonstrated a decrease in numbers of sensory receptors in the mucosa of edentulous patients and a significant increase in the number of nerve fibres in the mucosa covering the distal edentulous mandibular ridges supporting the prostheses after implant-retained rehabilitation. In contrast, there were only minor increases in the number of nerves in the peri-implant mucosa. These changes in innervation appear to be related either to the new biomechanical situation created by implant support, which favours more physiological tissue conditions, or to an adaptive mechanism in the peripheral processing of sensory stimuli. These changes may explain, at least partially, the clinically observed differences in sensory skills before and after implant placement.