Influence of Implant transmucosal design on early peri-implant tissue responses in beagle dogs.

OBJECTIVES: This study was undertaken to evaluate the influences of concave, machined and concave-roughened profiles of transmucosal implant designs on early peri-implant tissue responses. MATERIALS AND METHODS: Implants were used and classified by transmucosal profile and surface type as straight-machined implants (SM), concave-machined implants (CM), or concave-roughened implants (CR). A total of 30 implants (10 per each type) with matching transmucosal profiles were placed directly on alveolar crests in randomized order in the edentulous mandibular ridges of three beagle dogs. Healing abutments were connected 4 weeks after implant placement, and prostheses were connected 8 weeks after implant placement and functionally loaded. All animals were sacrificed at 16 weeks. Peri-apical radiographs were obtained and measured to evaluate peri-implant marginal bone levels. Histological specimens were prepared to measure bone resorption, connective tissue contact, epithelial tissue height, biological width, and length of implant-abutment junction to the apical portion of junctional epithelium. RESULTS: Radiographic and histometric analysis showed that least bone resorption occurred around CM implants and greatest bone resorption around SM implants (P < 0.05). Histometric analysis showed that highest connective tissue attachment and shortest biological width had formed around CM implants. CONCLUSION: Concave-machined profiled implants with a transmucosal design may induce less bone resorption and better connective tissue attachment around implants than the straight-machined profiled implants during the early healing phase.

Risk assessment for clinical attachment loss of periodontal tissue in Korean adults.

PURPOSE: The purpose of this study was to assess the prevalence and extent of clinical attachment loss of periodontal tissue and to find out variables related to clinical attachment loss (CAL) in Korean adults older than 40 years of age. MATERIALS AND METHODS: Data were collected from 2,519 subjects who were part of a cohort study conducted in Ansan city by Korea University Medical School for Korean Genome project. Age, sex, smoking, drinking, fast glucose, blood pressure, obesity and total cholesterol levels were examined. The oral examination included probing pocket depth, gingival recession and CAL of Ramford's teeth. The severity of periodontitis was classified based on the mean value of CAL. The relationship between each risk factor and the severity of CAL was independently estimated using the chi-square test, the test or one-way ANOVA. Multiple regression analysis was used to determine the significance of each factor in the periodontal disease. RESULTS: The prevalences of clinical attachment between 1 and 3 mm, between 3 and < 5 mm, and ≥ 5 mm were 80.27%, 16.75% and < 1%, respectively. Although the univariate analysis showed age, gender, smoking, fasting glucose, blood pressure and total cholesterol levels were significantly related to the severity of CAL, multiple regression analysis indicated that age (P < .0001), gender (P < .0001) and smoking (P < .05) were only significantly related. CONCLUSION: Older age, male gender and smoking were significant risk factor for the increase of CAL, and these may be useful indicators of periodontitis high-risk groups.