The successful use of osseointegrated implants for the treatment of the recalcitrant periodontal patient.

This study reports the successful use of osseointegrated implants to replace teeth in patients whose periodontal disease has been categorized as recalcitrant. It includes partially and totally endentulous jaws. A total of 309 implants placed by two periodontists practicing in traditional office settings were included in the survey. Of the 132 mandibular implants, 4 failed, for a success rate of 97%; and 3 of the 177 maxillary implants failed, for a success rate of 98%. There were 21 implants placed in 1985; 38 in 1986 and 1987; 185 from 1988 to 1990; 42 in 1991; and 23 in 1992. The report includes 42 mandibular and 50 maxillary prostheses, none of which has failed. One female mandibular case was converted from 2 posterior free-standing to a full arch prosthesis when the anterior teeth failed periodontally. These results demonstrate that individuals with a strong susceptibility to periodontal disease can be treated successfully with osseointegrated implants.

Early career experiences of young periodontists.

Studies conducted in 1979 and 1984 suggested that young periodontists in the early eighties were faced with a variety of stresses and challenges not faced by their counterparts of previous generations. Among the changes observed was the fact that sharply increased numbers of younger periodontists were practicing in multiple locations. The present study focused on multiple location practice and on other early career experiences in periodontology. Multiple site practice appears to be an outgrowth of expanding group practices and the increased popularity of part-time associateship opportunities. Costs of establishing solo practice, as well as other factors, serve to encourage young specialists to seek such positions. Many specialists see this style of practice as one way to increase their market share, but stresses arising from multiple site practice include travel time and lack of continuity with patients. Thus far, younger periodontists remain satisfied with their careers, but the job market suggests that more and more periodontists will be practicing in multiple locations during the early years of their careers, thus prolonging stabilization of their economic and professional lives.

Practice styles in periodontics. II.

In 1980 the American Academy of Periodontology published the results of its first major survey of practice characteristics in the Journal of Periodontology. That first study arose from membership concerns about the lack of knowledge about career patterns of periodontists and, more specifically, about employment opportunities for graduating periodontists. Three years later, the Committee on Practice Styles and Opportunities in Periodontics was appointed to replicate the earlier study in order to provide information on recent changes in the practice of periodontics. This decision is commendable since few dental specialty organizations collect data from their membership which can be systematically compared to data from an earlier study. The Academy's Committee contacted David O. Born, PhD, a dental manpower specialist at the University of Minnesota and a technical advisor on the earlier study, for assistance in conducting a replication in 1984. Based on feedback on the first survey and on comments and suggestions from committee members, a revised questionnaire was developed. This questionnaire was, for the most part, a replication of the earlier survey instrument, although several problematic items were deleted or modified and new items, reflecting more recent concerns, were added. The revised questionnaire was distributed in the Spring of 1984 through two mailings to 2937 Active members and 798 Affiliate members. After unusable and undeliverable questionnaires were deleted from the returns, an effective response rate of 55% (N = 2082) was obtained. This report is based on the information supplied by those 2082 members. In the tables and text which follow, the figures reported at the national level refer to "Private practice" periodontists responding to the survey; Academy members who are a part of the Federal services (e.g., Military, Veterans' Administration, Indian Health Service, etc.) are tabulated separately as "District 8" data. While several members from foreign countries responded to the survey, their data have not been included since the information was too dispersed to permit conclusions to be drawn.

Comparison of manual and automated probing in an untreated periodontitis population.

Diagnosis of periodontal disease progression involves recording two probing attachment level measurements over an adequate time interval. A diagnostic instrument which exhibits less measurement variability allows for increased sensitivity and earlier disease detection. Traditionally, a manual probe with an occlusal stent of the cementoenamel junction (CEJ) as a reference landmark has been the method of choice. Automated probes that use an occlusal disk as the reference landmark have been developed as an alternative means of measure. The aim of this study was to compare the variability of these two probing methods. Four hundred eleven (411) interproximal sites in 46 untreated periodontitis patients were monitored by a single examiner over a 6-month period. Each site was measured on a monthly basis, first with an automated probe (AP) followed by a manual probe (MP) in combination with a custom-fabricated acrylic stent. Measurement variability of the two probing methods was also compared over a 7-day interval. The AP measurements were significantly more variable than the MP measurements (P < 0.001) when considering the variability between two passes at the same visit. Over the 6-month period, the MP measurements demonstrated significantly more variability than the AP measurements (P < 0.001). It was also noted that MP measurements exhibited more variability at sites with frequent bleeding during the 6 months of the study (P = 0.006). The results of this study demonstrate that AP may have less variability of attachment level measurements over a 6-month period and may be less influenced by local inflammatory changes. However, future comparison studies should include multiple examiners to reduce examiner bias and should alternate the probing method to reduce bias created by local tissue changes from multiple probings.

Relationship between crevicular aspartate aminotransferase levels and periodontal disease progression.

BACKGROUND: Aspartate aminotransferase (AST), an enzyme released from necrotic cells, has been identified in gingival crevicular fluid (GCF), and elevated levels are associated with periodontal tissue destruction. The aim of this study was to examine the relationship between elevated GCF levels of AST and periodontal disease progression. METHODS: Over a 12-month period, 8 to 10 interproximal sites in 41 periodontitis subjects (PS) and 15 healthy subjects (HS) were monitored. Clinical measurements included relative attachment level (RAL), probing depth, and bleeding on probing (BOP). Semiquantitative levels of GCF AST (< 800 microIU, > or = 800 microIU, and > or = 1,200 microIU) were determined using a chairside assay. At the 6- and 12-month visits, scaling and root planing and prophylaxis were performed in the PS and HS, respectively. Sensitivity, specificity, positive predictive values (PPV), and negative predictive values (NPV) were calculated for 2 diagnostic criteria (AST > or = 800 microIU, AST > or = 1,200 microIU) utilizing 4 thresholds of disease progression as determined by 2 methods (absolute change in relative attachment level and cumulative sum [CUSUM]). RESULTS: The percentage of sites exhibiting AST > or = 800 microIU, AST > or = 1,200 microIU, and BOP in the PS was significantly (P<0.02) lower at 6 and 12 months compared to baseline. The use of crevicular AST activity to monitor periodontal disease progression was associated with many false-positive results. Overall, low specificities, PPV, and odds ratios were demonstrated by the assay when using 2 diagnostic criteria and 4 thresholds of disease progression. The high NPV suggest that a negative AST test result was indicative of a periodontally stable site. CONCLUSIONS: These results demonstrate that elevated levels of AST were present at sites that did not subsequently exhibit disease progression. The high prevalence of AST-positive sites due to gingival inflammation diminished the test's ability to discriminate between progressive and stable, but inflamed, sites.

The successful application of osseointegrated implants to the posterior jaw: a long-term retrospective study.

This long-term study has demonstrated the successful use of osseointegrated implants to replace posterior teeth in the partially dentate patient. A total of 1,203 Nobelpharma implants placed by two periodontists practicing in traditional office settings were included in the survey. Of the 551 implants placed in the mandible, 25 failed, for a success rate of 95.5%. Of the 247 mandibular prostheses fabricated for 200 mandibles, 8 failed, for a prosthesis stability rate exceeding 97%. Of the 652 implants placed in the maxilla, 31 failed, for a success rate of 95.2%. Of the 250 maxillary prostheses fabricated for 193 maxillae, 2 failed, for a success rate exceeding 99%. The results compare favorably to previous reports in terms of implant survival and stability.

A new animal model for maxillary sinus floor augmentation: evaluation parameters.

This study describes a novel animal model of the maxillary sinus floor augmentation procedure used to assess bone formation during 12 weeks in response to a recombinant human bone morphogenetic protein-2 (rhBMP-2)/absorbable collagen sponge (ACS) sinus implant. A buffer-ACS implant was used as a control. Animal response was monitored using computerized tomography and physical, hematologic, gross pathologic, and histologic evaluations. The rhBMP-2/ACS implants maintained a relatively constant size postsurgery and showed a time-dependent increase in mineralization. The buffer/ACS control implants failed to mineralize and were resorbed by 4 weeks. The model served effectively and without complication. Results indicate rhBMP-2/ACS implants deserve consideration as alternatives to traditional grafting procedures.

Wound healing around endosseous implants in experimental diabetes.

Wound healing has been shown to be altered in diabetes mellitus. The aim of this study was to identify the effects of streptozotocin-induced diabetes on osseointegration. Diabetes was induced in 40-day-old rats by intraperitoneal injection of 70 mg per kg streptozotocin. At 14 days postinjection, implants were placed in the femora of 10 diabetic and 10 age-matched normal rats. Animals were sacrificed at 28 and 56 days following implantation. Histometric results indicated that the quantity of bone formation was similar for diabetic and control animals (P > .05). However, less bone-implant contact was observed for diabetic compared to control animals at both 28 and 56 days (P < .0001). This study demonstrates that the process of osseointegration is affected by streptozotocin-induced diabetes.

Correlation of peri-implant health and aspartate aminotransferase levels: a cross-sectional clinical study.

At present, there are no diagnostic tools that permit early detection of peri-implantitis. The purpose of this cross-sectional study was to evaluate the correlation of aspartate aminotransferase (AST) levels with traditional periodontal clinical parameters around dental implants, since AST has been associated with destruction of cardiac, hepatic, and periodontal tissues. Twenty healthy volunteers with 59 implants were recruited from the Harvard School of Dental Medicine clinics. Clinical parameters evaluated included: AST level, probing depth (mm), Gingival Index (0, 1, 2, or 3), and bleeding on probing (0 or 1). Utilizing the site or implant as the unit of measure, the authors found a statistically significant association of increased AST activity with positive bleeding on probing, increased probing depth, and increased Gingival Index. No statistical correlations were found between clinical indices and increased AST levels when the results were examined on an individual patient basis. This cross-sectional study was able to demonstrate a statistical correlation between diseased clinical periodontal parameters and elevated AST levels.

Diagnosing periodontal diseases.

At present, the diagnosis of periodontal disease requires a clinical evaluation of the patient including visual findings, the use of the periodontal probe, and radiographs. No test is available to evaluate disease activity. In specific cases, adjunctive procedures may also be useful. The identification of pathogenic microorganisms may aid in evaluating the periodontal status of special patients. However, these are not required for an adequate diagnosis of the common adult form of chronic periodontitis.

Treatment of Class II furcations with autogenous bone grafts and e-PTFE membranes.

This article reports a successful clinical regimen of treatment for the Class II furcation defect. Twenty-eight patients with molar teeth demonstrating Class II furcations were treated with regenerative therapy with the goal of regenerating lost interradicular periodontium. The treatment selected included scaling and root planing, surgical flap design that would enable the flap to completely cover the surgical site, complete enucleation of granulation tissue, tetracycline root conditioning, a particulate autogenous bone graft, and an expanded polytetrafluoroethylene (e-PTFE) membrane. Of the twenty-eight consecutive patients treated, twenty-five demonstrated no postoperative clinical evidence of furcation invasion, for a success rate of 89%. Eleven sites were reopened 8 to 9 months postsurgical and presented complete furcation fill with a hard, bone-like tissue. Three teeth were judged to be failures because clinical assessment revealed persistent furcation invasion. The absence of histologic evidence precludes the presumption that complete periodontal regeneration occurred.

A retrospective study of dental implants in diabetic patients.

The efficacious placement of dental implants in diabetic patients remains controversial. Definitive guidelines with objective criteria, including the type of diabetes, age of onset, and level of long-term control, have not been determined. In addition, few relevant literature citations assess the survival rate of implants in diabetic patients. Therefore, it is the purpose of this study to assess the success and survival rates of dental implants in diabetic patients. In this retrospective analysis, 215 implants placed in 40 patients at 2 clinical centers were evaluated. Chart reviews and interviews provided medical and implant data. From the analysis, 31 failures occurred, for an overall success rate of 85.6%. Of these failures, 24 occurred within the first year of functional loading. The mean time of functional load was 4.05 +/- 2.6 years. When the success rate was analyzed by implant location, success rates for the maxilla and mandible were 85.5% and 85.7%, respectively. For the anterior and posterior regions, success rates were 83.5% and 85.6%, respectively. The lifetable analysis revealed a cumulative success rate of 85.7% after 6.5 years of function. Based on the data, the survival rate of dental implants in controlled diabetic patients is lower than that documented for the general population, but there is still a reasonable success rate. The increase in failure rate occurs during the first year following prosthetic loading.

Enhancement of the damaged edentulous ridge to receive dental implants: a combination of allograft and the GORE-TEX membrane.

A severely damaged edentulous ridge frequently obviates the placement of dental implants or results in placing them at an angle that compromises the prosthetic restoration. This paper demonstrates the repair of severely resorbed edentulous ridges by a combination of bone allografting and the placement of a barrier membrane. The damaged edentulous ridge is treated first in this two-stage process. The implants are then installed at a second surgery.

Bone formation utilizing titanium-reinforced barrier membranes.

Advances in bone reconstructive techniques have increased the indications for implant placement in sites previously thought to be unsuitable. This clinical study evaluated a new surgical technique for the treatment of a variety of localized bone defects in four patients utilizing a titanium-reinforced membrane. The membrane material was developed to maintain a large protected space between the membrane and the bone surface without the need for a supportive device. Healing was uneventful in all sites, and the membranes were retrieved after 6 to 12 months. No residual defects were noted, resulting in an average change of implant exposure of 8.2 +/- 2.3 mm for sites with buccal dehiscences and from 5 to 6 mm ridge enlargement in localized bone defects. The quality of the regenerated tissue under the titanium-reinforced membrane appeared as bone structure with a superficial fibrous layer. This fibrous layer was more pronounced in sites treated with a membrane alone but was more than compensated by the quantity of new bone under the soft tissue. The results demonstrated that the use of a reinforced membrane appears to be a viable alternative for the clinical treatment of non-space-maintaining implant/bone defects. Further clinical and experimental investigations are recommended.

Guided bone regeneration of bone defects associated with implants: an evidence-based outcome assessment.

Guided bone regeneration is a new technique that evolved following the guided tissue regeneration procedure for regeneration of lost periodontium. The objective of guided bone regeneration is to promote bone formation in osseous deformities either before or in conjunction with endosseous implant placement. Osseous defects consist mainly of extraction sites, dehiscences or fenestrations, and localized ridge deformities. In addition, bone defects may either provide natural spacemaking or be nonspacemaking. A plethora of publications indicate that the guided bone regeneration technique can be used successfully in all types of defects. Nonspacemaking defects usually require bone graft materials to assist in space maintenance and enhance bone formation. Fixation pins are also used, either with or without graft materials, in this regard. The scientific literature on guided bone regeneration was reviewed by a task force to determine techniques proven to increase predictability relative to successful patient outcomes and to develop specific evidence based diagnostic and treatment decision trees.

Osseointegration and nerve transposition after mandibular resection to treat an ameloblastoma: a case report.

This case report demonstrates the use of osseointegrated implants to replace the mandibular left second premolar and first and second molars removed during a surgical resection of a walnut-sized ameloblastoma. The first-stage surgery was performed 2 years after the oncologic surgery, and it was necessary to laterally reposition the inferior alveolar nerve prior to placement of implants. The patient has been restored to full dental function. There was no occurrence of paresthesia at any time. The treatment plan and the treatment were a collaboration of an oral surgeon, a periodontist, and a restorative dentist, located in Sweden, the United States, and Italy, respectively, and is an indication of what can be accomplished to the benefit of the patient when teamwork is exercised.

The advantages of localized ridge augmentation prior to implant placement: a staged event.

This paper demonstrates the successful reconstruction of alveolar bone destroyed by advanced periodontitis and endodontic failure. It offers a staged approach that is predictable and is superior to extracting the tooth and not performing a ridge enhancement procedure. Four cases using guided tissue regeneration in combination with bone grafts prior to the placement of endosseous dental implants are discussed.

Periodontal regeneration with an autogenous bone-Bio-Oss composite graft and a Bio-Gide membrane.

This study evaluated the clinical, radiographic, and histologic response to the composite use of Bio-Oss porous bone mineral and autogenous bone in combination with a Bio-Gide bilayer collagen membrane to achieve regeneration when treating human periodontal bone defects. Preoperative recordings for four treatment areas included radiographs, clinical probing depths, and attachment levels; these recordings were repeated at 9 months. Histologic evaluation revealed new cementum with inserting collagen fibers and new bone formation on the surface of both types of graft materials. This grafting combination not only compared favorably with the previous use of Bio-Oss and Bio-Gide, but exceeded that result with almost complete periodontal regeneration. This human histologic study demonstrates that autogenous bone in combination with porous bone mineral matrix, together with the Bio-Gide collagen membrane, has the capacity to stimulate substantial new bone and cementum formation with Sharpey's fiber attachment.

Bone formation in the goat maxillary sinus induced by absorbable collagen sponge implants impregnated with recombinant human bone morphogenetic protein-2.

This study assessed the efficacy, safety, and technical feasibility of inducing bone formation in an animal model of maxillary sinus floor augmentation using recombinant human bone morphogenetic protein-2 (rhBMP-2) impregnated on an absorbable collagen sponge (ACS). Bilateral antral maxillary sinus floor elevation procedures were surgically performed in six adult female Alpine-Saanen goats. Bone formation in response to the implant was evaluated using sequential radiographs, computerized tomography, and gross pathologic and histologic analysis performed at necropsy. Computerized tomographic scans documented nonosseous radiopacity in both sinuses postimplantation. Sinuses implanted with the rhBMP-2/ACS subsequently demonstrated increasing radiopacity local to the implant site, while radiopacity of the negative control sinuses remained unchanged or decreased. The results demonstrated the ability of an rhBMP-2/ACS implant to induce substantive new bone formation within the maxillary sinus of goats without adverse sequelae. The rhBMP-2/ACS composite implant may represent an acceptable alternative to traditional bone grafts and bone substitutes for maxillary sinus floor augmentation procedures in humans.

Evaluation of a bioabsorbable physical barrier for guided bone regeneration. Part I. Material alone.

This study evaluates a prototype bioabsorbable physical barrier material for guided bone regeneration. Nonspacemaking dehiscence-type defects were surgically created in the right and left mandibles of six adult dogs. Each animal received six root-form threaded titanium implants. The osseous defects were randomized to receive treatment by either the prototype bioabsorbable barrier composed of a copolymer of lactide and glycolide, an expanded polytetrafluoroethylene nonresorbable barrier, or no barrier (control), Clinical and histologic results after 3.5 months of wound healing indicated that exposed threads were covered when treated with the expanded polytetrafluoroethylene barrier. Minimal thread coverage was evident with the bioabsorbable barrier and the control.