International Journal of Periodontics & Restorative Dentistry, 02/2003

The literature supports the efficacy of osseointegrated implants for partially edentulous patients, but care must be exercised in adolescents with incomplete bone formation. Implants do not follow the normal growth of the jaws, and they behave like ankylosed teeth. They may also interfere with the normal growth of the alveolar process and jeopardize the germs of the adjacent permanent teeth or alter eruption. This case report analyzes the unfavorable clinical and radiographic findings of a single-tooth replacement in a young male over a 15-year period.

A field study using four different private periodontal practices and two independent laboratories was conducted to compare two microbiologic cultures sampled simultaneously from the same sites in 20 individual patients. Both paired samples were submitted separately to one of the two independent laboratories for bacterial identification and antibiotic sensitivity testing. The results from the two samples were quite variable. In only two instances did both specimens reveal the presence of identical bacterial species, but these specimens differed in both threshold levels and antibiotic sensitivity. When only bacteria above threshold levels were compared, total agreement was found in 11 of 20 cases. When examining antibiotic sensitivity, using 100% kill as the ideal, agreement between the two specimens was inconsistent. The use or nonuse of tetracycline was in agreement 85% of the time, amoxicillin 75% of the time, metronidazole 70% of the time, and amoxicillin-metronidazole in combination 85% of the time. The two specimens agreed on the empirical use of amoxicillin 45% of the time, tetracycline 60% of the time, and metronidazole 60% of the time. The empirical use of amoxicillin-metronidazole in combination yielded 80% agreement when the results of both specimens were combined. The empirical use of amoxicillin-metronidazole combination therapy may be more clinically sound and cost effective than culturing and antibiotic selection based on the culture from any single microbiologic testing laboratory. This supports the data from a previous study that examined specimens secured simultaneously from the same site and submitted to two different testing laboratories. The failure of microbial testing to achieve a higher level of consistency between samples leaves the clinical efficacy of microbial testing in question.

The purpose of this study was to evaluate the feasibility of using a bioactive alloplast and a physical barrier to augment localized alveolar ridge defects for the subsequent placement of dental implants. Twelve systemically healthy patients (aged 29 to 55 years) with inadequate dental alveolar ridge widths were selected for study. All patients completed initial therapy, which included scaling, root planing, and oral hygiene instruction. All ridge defects were augmented with a bioactive glass alloplast and a titanium-reinforced e-PTFE barrier. Vertical (height) and horizontal (width) hard tissue measurements were taken the day of ridge augmentation surgery (baseline) and at the 6-month reentry surgery. The change in ridge width varied from a loss of 1 mm to a gain of 4.5 mm, with a mean gain of 1.1 mm (P .03). Eight of the 12 sites gained 1 mm or less. The difference in mean ridge width gain between maxillary and mandibular sites was not statistically significant (P > .08). Mean ridge width gain was 1.1 mm for both maxillary and mandibular sites. There was a loss in bone height of 0.3 mm from baseline. Four implants in four patients could not be placed because of inadequate ridge width augmentation. Histologic examination of the grafted sites revealed connective tissue encapsulation of most residual graft particles. In this study, bioactive glass particulate and an e-PTFE barrier did not consistently augment localized ridge defects for dental implant placement.

In fabricating a prosthetic rehabilitation, whether it consists of just a single crown or a complete-mouth reconstruction, one of the main aims of the clinician is to simplify the procedures and reduce the time necessary to integrate it into the mouth of the patient. This article completes the description of the rationale behind the selection of semiadjustable articulators and of a way to transfer to the laboratory technician valuable information that, in the case of extensive rehabilitations, will make occlusal optimization more error free.

The goal of this classification of bone defects related to dental implant placement is to help clinicians accurately discuss proposed treatment regimens and organize treatment for clinical correction. A further goal of this effort to categorize bone defects requiring bone augmentation for implant placement is to standardize terminology to allow for more accurate dental communication. The five most encountered categories of bony defects are described.

This study evaluated periapical healing of induced apical lesions with concomitant loss of the buccal bone plate in a dog model using four foxhounds. In an initial surgery, pulp cavities of mandibular premolars were exposed to induce apical lesions. In the same session, the cortical bone covering the buccal root surfaces was surgically removed to simulate buccal bone loss. After radiographic confirmation of the development of apical lesions, sites were reentered for surgical treatment. Following apical and buccal debridement, root-end resection, and rootend filling, sites were subjected to three different treatment modalities: (1) flap readaptation (controls); (2) placement of a collagen membrane covering the apical defect and denuded root surface; or (3) placement of an anorganic bovine bone filler into the apical defect and onto the exposed buccal root surface, with additional application of a collagen membrane. Animals were sacrificed 7 months following the second surgery. Step sections were analyzed histometrically and morphometrically for periapical healing. Sites with membrane + filler showed a statistically significantly lower mean percentage of new bone formation within the former defect compared to both membrane-alone and control sites. No significant differences were found for tissue components deposited on the cut root face across treatment groups. Formation of a continuous thin layer of new cementum covering the exposed dentin surface and root-end filling material was a frequent finding. Analysis of the tissue regeneration on the buccal root aspect as well as the clinical periodontal parameters will be presented in a separate article.

In narrow alveolar ridges, dehiscences can occur at the time of implant placement. This report describes several cases in which buccal dehiscences at one-stage, nonsubmerged ITI implants were covered with deproteinized bovine bone mineral (Bio-Oss) and a nonresorbable e-PTFE membrane. The dehiscences ranged from 5 to 8.5 mm. The head of the implant perforated the membrane and was not covered by the mucoperiosteal flap. Membranes were removed after 12 to 20 weeks. One of the seven implants failed to osseointegrate. In four cases, no residual defect was found (100% coverage). In two cases, 63.5% and 87.5% coverage was obtained, respectively. At follow-up, 1 year and 5 months to 4 years and 7 months after placement and after loading, clinical probing depth never exceeded 3.5 mm. Radiographically, no resorption was found. In selected cases, dehiscences at the time of placement of nonsubmerged one-stage implants can be successfully treated using deproteinized bovine bone in combination with stiff, nonresorbable membranes.

The purpose of this study was to evaluate the effect of mandibular positioning on measurement of the reformatted cross-sectional image of the mandible in computed tomography (CT) according to the area on the mandible. Five dried mandibles, partially edentulous in the premolar and molar areas, were selected. The inferior border of the mandible was placed at 0-, 5-, 10-, 15-, and 20-degree angles to the CT scanning plane, and CTs were taken. The marked area of the reformatted crosssectional image taken at each angle was found, and the distance from the most superior border of the mandibular canal to the alveolar crest was measured. As the angle between the CT scanning plane and mandibular plane increased, the distance from the most superior border of the mandibular canal to the alveolar crest also increased. The degree of increase was more pronounced in the posterior portion of the mandible than in the anterior portion of the mandible. As mandibular positional change in the CT gantry can affect the vertical measurement of the reformatted cross-sectional image, a correct guiding plane is necessary to accurately position the jaw to the CT scanning plane.

This study evaluated the effects of using a titanium mesh for localized alveolar ridge augmentation. Seven consecutively treated human subjects participated in the study. Clinical, radiographic, laboratory, and histologic/histomorphometric analysis revealed the efficacy of using the titanium mesh in conjunction with intraorally harvested autogenous bone graft and inorganic bovine bone mineral (Bio-Oss). Radiographic measurements detected that a 2.86-mm vertical and 3.71-mm buccolabial ridge augmentation was achieved, while histomorphometry demonstrated that 36.4% of the grafted area consisted of bone. Laboratory measurements revealed 15.08% resorption of the graft for the first 6 months, which appeared to consolidate after placement of the implants. Exposure of the mesh did not appear to compromise the result.