Clinical effectiveness of International Team for Oral Implantology dental implant treatment in Taiwan: a seven-year longitudinal study.

BACKGROUND: International Team for Oral Implantology (ITI) dental implant has been clinically tested for the most parts of the world, especially in Europe and America, and has not been conducted on Asian population. The purpose of this study was to evaluate the cumulative survival and success rates over 7 years of ITI dental implants. MATERIALS: The ITI dental implant system has been used in the Dental Department of Chi Mei Medical Center since August of 1997. At the end of 2005, 717 solid-screw implants had been placed and loaded at least 6 months in 316 patients. The patient population included 145 males and 171 females, with a mean age of 43.18 +/- 11.60 years. The follow-up interval was from 6 months after the prosthesis was completed to 7 years. The success criteria of dental implant survival was based on Buser et al, Clin Oral Implants Res. 1990;1:33-40. RESULTS: Most implants (486, 67.8%) were placed in the mandible and 231 (32.2%) were placed in the maxilla. Two implants were removed before prostheses fabrication because of postsurgical infections. One implant was removed due to a periapical infection of an adjacent natural tooth. The life table analysis of survival rate and success rate were 99.58% and 96.13%, respectively. CONCLUSION: This 7-year clinical effectiveness study demonstrated this dental implant system gave a clinical reliable result in a Taiwanese population.

The negative effect of platelet-rich plasma on the growth of human cells is associated with secreted thrombospondin-1.

OBJECTIVE: Earlier studies have suggested that platelet-rich plasma (PRP) enhances oral wound healing because of its concentrated growth factors. Few studies have investigated whether negative regulators exist in the PRP and influence its biological effects on human wound healing. The aim of this study was to investigate whether PRP contains an angiogenesis inhibitor, thrombospondin-1 (TSP-1), and whether this factor negatively affects human cells associated with oral healing in vitro. STUDY DESIGN: Using centrifugation, platelet-poor plasma (PPP) and PRP were obtained sequentially from 20 volunteers. We used an Alamar Blue assay to compare the proliferation rates of various oral cells, cocultured for 6 days with different concentrations of PRP and PPP. The levels of TSP-1 in PRP were estimated using ELISA. Finally, we tested the antiproliferative effect of purified TSP-1 protein on oral cell cultures. RESULTS: After 6 days of incubation, there were significantly more cells in the low-PRP-concentration group (<5%) and fewer cells in the high-PRP-concentration group (15%-30%). The ELISA showed that the quantities of TSP-1 were approximately 183.3 +/- 21.6 microg/mL in PRP lysate and 9.7 +/- 1.6 microg/mL in the supernatant of the 30% PRP gel. Serial concentrations of exogenous TSP-1, corresponding to those of the 30% PRP gel, dose-dependently inhibited oral cell proliferation. CONCLUSION: Within the limits of this study, the proliferation of oral cells significantly decreased when treated with high concentrations of PRP. Abundant secretion of TSP-1 from concentrated PRP may contribute to the antiproliferative effect.

New classification of crown forms and gingival characteristics in taiwanese.

OBJECTIVES: The aim of the investigation was to examine the forms of the crowns in the maxillary anterior tooth segment and corresponding gingival characteristics among healthy Taiwanese subjects. MATERIALS AND METHODS: The crown width at the apical third (CW), length (CL), gingival angle (GA) and the interdental papilla height were assessed from the diagnostic stone model using a calibrated periodontal caliper. A CW/CL-ratio was calculated for each tooth and averaged for each tooth region. Gingival thickness (GT) and width of keratinized gingiva (WG) were measured clinically. RESULTS: The cluster analysis revealed 3 classifications of crown forms: narrow (N), compound (C) and square (S) types. There was a significant difference among the 3 classifications with respect to CW/CL-ratio, GT, and WG (p < 0.0001). CONCLUSIONS: The results demonstrated varied crown forms and corresponding gingival characteristics in Caucasian and Taiwanese. The new classifications hinted that there was a polymorphism in different races and could be a valuable esthetic guideline and reference for anterior tooth rehabilitation, including various periodontal and restorative treatments and anterior implant placement procedures in Taiwanese.

Peri-implant pathology caused by periapical lesion of an adjacent natural tooth: a case report.

An implant was removed 6 months after restoration because of peri-implant pathosis. The implant had been placed adjacent to the mandibular right second premolar and close to a periapical lesion of the endodontically treated adjacent first premolar. Along with removal of the failed implant and an apicoectomy of the problem tooth, guided bone regeneration was used to restore the alveolar ridge defect at the site of the failed implant. A replacement implant was placed 6 months later and successfully restored after healing.