International Journal of Periodontics & Restorative Dentistry, 04/2000

Many paradigms concerning the epidemiology, pathogenesis, and systemic impact of periodontal diseases have been modified. For example, bacterial biofilms are essential to induce periodontitis, but their mere presence is not sufficient to initiate disease. It is also now recognized that the host response to these biofilms causes most of the destruction of the periodontal tissues. Codeterminants that influence the clinical severity of the disease process include environmental, genetic, and acquired factors. In general, the prevalence of advanced periodontitis and the incidence of disease progression are lower than previously believed. However, periodontitis remains the most common chronic illness. In addition, the finding that acquired systemic diseases may predispose individuals to periodontitis, and conversely that periodontitis may be a risk factor for certain systemic diseases, has expanded the scope of periodontics. These changed paradigms and their consequences with regard to selecting therapies are discussed in this review article.

The purpose of this preliminary article is to present a new surgical technique that, thanks to the use of modulated-frequency piezoelectric energy scalpels, permits the expansion of the ridge and the placement of implants in single-stage surgery in positions that were not previously possible with any other method. The technique involves the separation of the vestibular osseous flap from the palatal flap and the immediate positioning of the implant between the 2 cortical walls. The case report illustrates the ridge expansion and positioning of implants step by step in bone of quality 1 to 2 with only 2 to 3 mm of thickness that is maintained for its entire height. To obtain rapid healing, the expansion space that was created for the positioning of the implant was filled, following the concepts of tissue engineering, with bioactive glass synthetic bone graft material as an osteoconductive factor and autogenous platelet-rich plasma as an osteoinductive factor. The site was covered with a platelet-rich plasma membrane. A careful evaluation of the site when reopened after 3 months revealed that the ridge was mineralized and stabilized at a thickness of 5 mm and the implants were osseointegrated.

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.

An enamel matrix protein derivative (Emdogain) has been recently shown to promote periodontal regeneration in experimentally created recession-type defects. However, only limited histologic data from human material are available concerning the healing of intrabony periodontal defects following treatment with Emdogain. The aim of the present study was therefore to present the clinical and histologic results following the application of Emdogain in intrabony defects. Two patients with marginal periodontitis and deep intrabony defects adjacent to teeth scheduled for extraction were treated with Emdogain. The postoperative healing phase was uneventful in both cases. At 6 months following treatment, newly formed cementum with inserting collagen fibers was found in both specimens. In one case, the new attachment formation was also accompanied by bone neoformation. The results of this human histologic study indicate that Emdogain possesses the potential to stimulate new connective tissue attachment formation in human intrabony defects.

Twelve patients with isolated alveolar ridge defects bordered by teeth on each side were treated and followed for 12 months. The treatment involved use of a resorbable membrane and a particulate graft without complete flap closure. Measurements taken at 12 months showed a significant mean osseous gain of 3.27 ± 3.73 mm in mid-defect ridge width and an increase in height of 1.90 ± 2.50 mm.

This investigation evaluated the predictability of dental implants subjected to bone regeneration procedures at the time of insertion. Fifty-two test implants were inserted into sites with periimplant bone defects. A calcium carbonate allograft material with or without a fibrin-fibronectin sealing system was used to fill the defects. Sixty control implants were inserted into an adequate volume of nonaugmented bone. Each of the 29 study patients received at least one test implant and one control implant. At the second-stage surgery, fill of the bone defect was assessed as complete or incomplete. The cumulative success rate was 91.7% (mean follow-up 55 mo) for the test implants and 93.2% (mean follow-up 59 mo) for the control implants. Within the test group, implants with complete bone fill achieved 97.6% success versus 59.1% success for implants with incomplete bone fill. These preliminary results suggest that implants placed with simultaneous bone regeneration procedures achieve long-term predictability that is comparable to that of implants placed in an adequate volume of bone, provided that complete bone fill of the periimplant defect is achieved. Long-term studies with other augmentation materials are needed to fully validate these findings.

Twelve patients with 2 Miller Class I or II buccal recession defects measuring = 3.0 mm were treated using the principles of guided tissue regeneration and followed for 12 months. The effectiveness of a polylactide (Guidor) resorbable membrane (GA sites) was compared to a combination treatment of polylactide membrane plus polyglactin root-lining mesh (Vicryl) and demineralized freeze-dried bone allograft (DFDBA) (GVB sites) designed to enhance cell migration and bone regeneration. There was 90% mean soft tissue root coverage for the GVB sites and 78% for the GA sites. The mean osseous dehiscence area coverage with hard tissue was 75% for GVB sites and 30% for GA sites.

The longevity of teeth depends directly on the state of the periodontal tissues. Many etiologic factors can lead to the loss of a tooth. Tooth loss is frequently associated with bone resorption. The diagnosis of a condition and knowledge of its etiology are essential to assess the prognosis of the remaining teeth and to formulate the correct treatment plan. Many parameters must be investigated to ascertain an accurate diagnosis. An understanding of the patient's needs and the length and likely success of treatment guides the decision of whether to preserve teeth or extract them and place implants. Advanced periodontitis poses a major therapeutic dilemma. Judicious, strategic extractions may permit the placement of long implants in ideal positions.