Retrospective studies of dental implant placement at each intraoral site and situation / 대한치주과학회지

PURPOSE: Developments in micro/macrostructures of implants and surgical techniques brought out stable outcomes of implant dentistry. The aim of this study was to evaluate the distributions of implant patients, the types of implanted sites, and the success or survival rates of various implant systems and to analyze the implant placement done at each specificintraoral site and situation. MATERIALS AND METHODS: The data of dental implantations collected between 1992 and 2006 at the Department of Periodontology in 00000 University Hospital were analyzed. RESULTS: 1. Largest part of the patients were at the age of 40s and 50s in bothgender who lost their teeth mostly by periodontaldiseases and caries at the posterior intraoral sites as major ones. Bone densities of type II(mandible) and III(maxilla) were likely to be seen with quantity of type B. Lengths of the implants between 10 and 15 mm and wide platform took the largest part. 2. Survival rates of Implantium(R)(98.8%), Xive(R)(100%) and ITI TE(R)(100%) were high when Frialit-2(R) showed 82%(poor bone density area) or 87.2%(combined with additional therapy). IMZ(R) had lowest cumulative survival(67.5%) and success rate(49.4%) amongst all. 3. Replacement with 2 wide or 3 regular platforms showed no significant differences in survival rate and marginal bone loss atmandibular posterior area. In single restoration of mandibular second molar, 5-year success rate of machined surface Branemark(R)(70.37%) was lower than that of rough surface ITI(R) SLA(100%). 4. Replacement of single tooth in anterior area showed high survival rate of 94.5%. 5. The success rates of Branemark Ti-Unite and ITI SLA at posterior maxilla with poor bone density both showed stable outcomes. 6. 10-year cumulative survival rate of implants with maxillary sinus augmentation by lateral window approach appeared to be 96.60%. Low survival rate(75%) was shown when there were more than two complications combined. Height of grafted bone remained stable above the implant apex. CONCLUSIONS : Rough surfaced implants showed stable outcomes in most of the situation including poor bone density and additional therapy combined.

Evaluation of peri-implant bone density changes in Branemark implants by computer assisted densitometric image analysis (CADIA) / 대한치주과학회지

CADIA(Computer-assisted densitometric image analysis) method is used to analyze bone density changes around the implants. The usefullness and reproducibility of the method was assessed. We tried to find out if there is any possibility to quantitiate and qualitify peri-implant bone density change as time passes. And we concluded that this newly developed linear analysis is efficient for analyzing peri-implant bone density change non-invasively. In this study, 2152 machined Branemark fixtures installed from 1994 to 2002 in the department of Periodontics, Dental hospital of College of Dentistry, Yonsei University were included. Of these fixtures 22 radiographically analyzable failed fixtures were used as experimental group, and 22 successful implants placed in the same patient were used as control group. 1. 57 out of 1635 machined Branemark standard and Mk II implants system failed, the survival rate was 96.5%. And 11 out of 517 machined Branemark Mk III and Mk IV implants system failed, the survival rate was 97.9%. Total survival rate was 96.8%. 2. 22 failed implants were used for the analysis, 10 of which failed before prosthetic treatment due to infection and overheating. 12 failed due to overload after prosthetic treatment, 63.6% of which failed during the early phase of functional loading, i.e. before 1 year of loading. 3. Bone density change values around coronal region of the failed implants were -6.54 +/- 6.35, middle region were -3.53 +/- 5.78, apical region were -0.75 +/- 10.33, resulting in average of -3.71 +/- 8.03. 4. Bone density change values around coronal region of the successful implants were 4.25 +/- 4.66, middle region were 6.33 +/- 5.02, apical region were 9.89 +/-4.67, resulting in average of 6.27 +/- 5.29. 5. There was a statistically significant difference between two groups (p<0.01). In conclusion, the linear analysis method using computer-assisted densitometric image analysis could be a useful method for the analysis of implants, and could be used for future implant researchs.

The Bone regenerative effects of tetracycline blended chitosan membranes on the calvarial critical size defect in Sprague dawley rats / 대한치주과학회지

The major goals of periodontal therapy are the functional regeneration of periodontal supporting structures already destructed by periodontal disease as well as the reduction of signs and symptoms of progressive periodontal disease. There have been many efforts to develop materials and therapeutic methods to promote periodontal wound healing. There have been increasing interest on the chitosan made by chtin. Chitosan is a derivative of chitin made by deacetylation of side chains. Chitosan has been widely studied as bone substitution and membrane material in periodontology. Many experiments using chitosan in various animal models have proven its beneficial effects. Tetracycline has been considered for use in the treatment of chronic periodontal disease and gingivitis. The aim of this study is to evlauate the osteogenesis of tetracycline blended chitosan membranes on the calvarial critical size defect in Sprague Dawley rats. An 8mm surgical defect was produced with a trephine bur in the area of the midsagittal suture. The rats were divided into five groups: Untreated control group versus four experimental group. Four types of membranes were made and comparative study was been done. Two types of non-woven membranes were made by immersing non-woven chitosan into either the tetracycline solution or chitosan-tetracycline solution. Other two types of sponge membranes were fabricated by immersing chitosan sponge into the tetracycline solution, and subsequent freeze-drying. The animals were sacrificed at 2 and 8 weeks after surgical procedure. The specimens were examined by histologic analyses. The results are as follows: 1. Clinically the use of tetracycline blended chitosan membrane showed great healing capacity. 2. The new bone formations of all the experimental group, non-woven and sponge type membranes were greater than those of control group. But, there was no significant difference between the experimental groups. 3. Resorption of chitosan membranes were not shown in any groups at 2 weeks and 8 weeks. These results suggest that the use of tetracycline blended chitosan membrane on the calvarial defects in rats has significant effect on the regeneration of bone tissue in itself. And it implicate that tetracycline blended chitosan membrane might be useful for guided tissue regeneration.