Mi-Ae Jeong

Autogenous teeth used for bone grafting: a comparison with traditional grafting materials.

OBJECTIVES This study evaluated the surface structures and physicochemical characteristics of a novel autogenous tooth bone graft material currently in clinical use. STUDY DESIGN The materials surface structure was compared with a variety of other bone graft materials via scanning electron microscope (SEM). The crystalline structure of the autogenous tooth bone graft material from the crown (AutoBT crown) and root (AutoBT root), xenograft (BioOss), alloplastic material (MBCP), allograft (ICB), and autogenous mandibular cortical bone were compared using x-ray diffraction (XRD) analysis. The solubility of each material was measured with the Ca/P dissolution test. RESULTS The results of the SEM analysis showed that the pattern associated with AutoBT was similar to that from autogenous cortical bones. In the XRD analysis, AutoBT root and allograft showed a low crystalline structure similar to that of autogenous cortical bones. In the CaP dissolution test, the amount of calcium and phosphorus dissolution in AutoBT was significant from the beginning, while displaying a pattern similar to that of autogenous cortical bones. CONCLUSIONS In conclusion, autogenous tooth bone graft materials can be considered to have physicochemical characteristics similar to those of autogenous bones.

Clinical study of graft materials using autogenous teeth in maxillary sinus augmentation.

Purpose:The purpose of this study was to evaluate the effectiveness of autogenous tooth bone graft materials. Materials and Methods:Hundred implants in 51 patients were selected, and the patients received maxillary sinus augmentation and implant placement using autogenous tooth graft materials at the Chosun University Dental Hospital and Seoul National University Bundang Hospital between July 2009 and November 2010. Results:In cases using autogenous tooth bone graft alone, or together with other graft material, the implant survival rate was 96.15%. On histomorphologic examination, autogenous tooth bone graft materials showed gradual resorption and new bone formation through osteoconduction and osteoinduction. Conclusions:The results indicated that autogenous tooth bone graft materials are appropriate for use in maxillary sinus augmentation.

Development and structure of a novel barrier membrane composed of drug-loaded poly(lactic-co-glycolic acid) particles for guided bone regeneration

A novel barrier membrane composed of poly(lactic-co-glycolic acid) particles loaded with dexamethasone (DEX) as a bioactive molecule was produced via a modified nanoprecipitation method without any mixing. The particle membranes had a bilayer structure: one side was smooth and had a compact surface that was connected to larger particles, while the opposite side was rough, porous and connected to smaller particles. Additionally, a cross-section of the particle membrane had a porous structure with nano and micro sized irregular pores. Process optimization revealed that NaCl concentration in the water phase, with acetone as solvent and water as a non-solvent, played critical roles in determining the properties of the particle membranes, such as DEX encapsulation efficiency, thickness and surface morphologies of the particle membranes. A novel barrier membrane containing DEX using polymer particle drug capture technology has been successfully developed.

A multicenter prospective study in type IV bone of a single type of implant.

Purpose:To analyze the success and survival rates of the Osstem GSII (Osstem, Busan, Korea) implant in type IV bone. Materials:A prospective, multicenter (5 centers) study was conducted by examining the relationship between implant success and survival rates, and several patient and surgical parameters. The implants were placed in 82 patients who visited several nationwide dental hospitals and clinics between 2007 and 2008, followed by clinical and radiographic analyses. Results:In type IV bone, the implant success and survival rates were 93.23% and 95.83%, respectively. The maxillary premolar and mandibular anterior tooth areas showed success rates of 100%. The most widely used implant diameter and length was 5.0 and 13 mm, respectively, but the diameter and length had no effect on success rates. However, success rates appeared to decrease with age. Conclusions:The results indicated that the Osstem GSII implant is highly effective in poor-quality type IV bone.

Early Bone Formation at a Femur Defect Using CGF and PRF Grafts in Adult Dogs: A Comparative Study.

Purpose:The purpose of this study was to compare the predictability of new bone formation using an autologous concentrated growth factor (CGF) graft alone and platelet graft alone. Materials and Methods:Four bony defects of 8 mm were formed, and 3.7- × 10-mm implants were placed in the right femur. The platelet-rich fibrin (PRF), CGF, and synthetic bone were grafted to the bone defect area. Enzyme linked immunosorbent assay quantitative analysis and microscopic analysis of the fibrinogen structure were performed. Results:At 4 weeks, the comparisons of each experimental group showed a significant difference between the CGF group and the synthetic bone graft group. When comparing the CGF and allograft material groups, the allograft group showed significantly more new bone formation. In the case of vascular endothelial growth factor, CGF had 1.5 times more than PRF. CGF showed a fibrinogen structure with a constant diameter. Conclusion:When applied to a clinical case, CGF is predicted to show better results than PRF.

Consideration of various bone quality evaluation methods.

Purpose:Bone quality at the implant site has a significant effect on the success and prognosis of implants. The purpose of this article was to evaluate several methods used in evaluating bone quality and discuss the advantages and disadvantages. Methods:The search was made using PubMed database about quantitative computed tomography (QCT), and quantitative cone-beam computerized tomography (QCBCT), dual energy x-ray absorptiometry (DXA) scans, the resistance force against the hands of the surgeon, assessment of the effect of the torque of the drill, the initial fixed value of the implant, and fractal analysis according to the Lekholm and Zarb, and Misch classifications as the standard. Results:The method for measuring the resistance force and torque during implant placement and the method used to determine the implant’s initial implant fixed value were easy and simple. QCBCT was reported to involve less radiation and to be more objective than QCT. DXA and fractal analysis have limits when used to classify bone quality as Type II or Type III. Conclusion:Among the methods used to evaluate bone quality in implants, a method using computed tomography, measured in Hounsfield units, was found to be the most predictive.

Incidence and Management of Fractured Dental Implants: Case Reports

The fracture of dental implants is a rare occurrence in clinical settings. Possible causes of implant fracture include design or production flaws, overloaded occlusion force, implant location, metal fatigue, and bone resorption around the implant. This study reports on the successful removal and reimplantation of fractured implants.

Comparative study on the osseointegration of implants in dog mandibles according to the implant surface treatment

Objectives This study compared the impact of implant surface treatment on the stability and osseointegration of implants in dog mandibles. Materials and Methods Six adult dogs received a total of 48 implants that were prepared using four different surface treatments; resorbable blast media (RBM), hydroxyapatite (HA), hydrothermal-treated HA, and sand blasting and acid etching (SLA). Implants were installed, and dogs were separated into 2- and 4-week groups. Implant stability was evaluated via Periotest M, Osstell Mentor, and removal torque analyzers. A histomorphometric analysis was also performed. Results The stability evaluation showed that all groups generally had satisfactory values. The histomorphometric evaluation via a light microscope revealed that the HA surface implant group had the highest ratio of new bone formation on the entire fixture. The hydrothermal-treated HA surface implant group showed a high ratio of bone-to-implant contact in the upper half of the implant area. Conclusion The hydrothermal-treated HA implant improved the bone-to-implant contact ratio on the upper fixture, which increased the implant stability.

Histomorphometric Analysis of Contaminated Autogenous Tooth Graft Materials After Various Sterilization.

Purpose:The purpose of this study was to evaluate histomorphometrically contaminated autogenous tooth graft materials, which were resterilized. Materials and Methods:The intentional defects (diameter: 8 mm, depth: 4 mm) were formed around implant fixture on the iliac crest of 6 mongrel dogs. Autogenous tooth graft materials were made by extracted premolars. After the contamination of the tooth materials, graft procedure was performed; no contaminated group (control group), contaminated groups (nonsterilization group [group 1], ethylene oxide [EO] gas group [group 2], and autoclave group [group 3]). The bone-to-implant contact (BIC) and the new bone formation rate (NBFR) were evaluated after sacrifice. Results:The BIC and NBFR of groups 1 and 3 were significantly lower than the control group after 4 weeks. The BIC and NBRF of group 3 were significantly lower than the control group after 8 weeks. However, the BIC and NBRF of group 2 was not significantly different comparing with the control group after 4 and 8 weeks. Conclusion:Sterilization using EO gas may be more favorable than high-pressure sterilization in cases the reuse of contaminated autogenous tooth graft materials.

Implant Stability Measurements in the Long-Term Follow-up of Dentis Implants: A Retrospective Study With Periotest.

Purpose:The purpose of this study was to evaluate retrospectively the stability of Dentis implant with the Periotest. Methods:In total, 36 patients and 88 implants were investigated. Periotest was used to measure implant stability, and a periapical view was taken immediately after surgery and again immediately after, 3 months after, 6 months and 5 years after prosthesis placement. Bone loss on the periapical view, bone quality according to tactile sensation, and area of implant installation were assessed. Results:The mean Periotest value (PTV) immediately after surgery was −1.02, and the mean bone loss rate (bone loss/fixture length × 100) at 6 months after prosthesis placement was 8.42%. PTV was higher with more bone loss (types III, IV vs types I, II bone). The lowest mean PTV was in the lower molar area (−1.48), followed by the lower anterior (−1.41), upper molar (0.11), and upper anterior area (5). One implant failed and survival rates were 98.9%. Conclusion:Implant stability was lower in cases with more bone loss and poor bone quality and in the maxilla versus the mandible.