재생 술식을 동반한 발치 후 즉시 임프란트 식립술

The placement of implants into fresh extraction socket provides many advantages to conventional delayed implant placement. It reduces total treatment time and surgical procedures with placement of the implant in an ideal position. However, it also has disadvantages such as creating a gap defect between the implant and alveolar bone and difficulty in primary closure of the surgical site. Therefore, need of a regenerative procedure is crucial in immediately placed sites for successful functional and esthetical outcomes. The current case report presents two cases with immediately placed implants performed in anterior and posterior region. A careful tooth extraction was performed to avoid any surgical trauma in the alveolar bone, and implants were successfully installed in both cases. Regenerative procedures such as guided bone regeneration and bone graft were performed in conjunction to fill the gap defect and compensate future ridge alterations. Both cases showed clinically successful results with functionally and esthetically high patient satisfaction. Immediate implant placement in conjunction with an appropriate regenerative procedure could provide successful outcome.ope

하악관 신경손상 방지를 위한 Cone beam CT 및 3차원 영상의 활용

For preoperative treatment planning before placement of dental implants, a radiographic examination is needed to obtain accurate information on bone dimensions. Especially, to avoid nerve injury during surgery in the foraminal area, guidelines were developed based on the literature with respect to verifying the position of the mental foramen. These guidelines included leaving a 2mm zone of safety between an implant and the coronal aspect of the nerve through observation of the inferior alveolar nerve and mental foramen on panoramic and periapical radiographs prior to implant placement. However, use of CT scans are becoming more widespread because panoramic and periapical radiographic views do not provide clarity with respect to the position of the nerve in many cases. Problems associated with conventional apparatus include high cost, bulk, and x-ray exposure. Recent advancements in Cone beam CT have made it possible to rapidly obtain higher resolution images using less bulky machines and lower radiation exposure. Moreover currently available software programs in combination with CBCT data allow 3-dimensional treatment planning in demanding clinical situations prior to implant placement.ope

Effect of E Coli Expressed Recombinant Human Bone Morphogenetic Protein-2(rhBMP-2) on Stem Cells for Periodontal Tissue Regeneration: A Preliminary Study

Periodontal disease results in destruction of periodontal tissues(cementum, alveolar bone and periodontal ligament) which may ultimately lead to tooth loss. To date, there is no ideal treatment approach in achieving optimal periodontal tissue regeneration. Recruitment of progenitor cells to the site which could differentiate into cementoblasts, osteoblasts and periodontal ligament-forming cells are needed and recently, using pluripotent stem cells isolated from various tissues in conjugation with growth and differentiation factors have been presented to lead periodontal tissue regeneration. This study evaluated the effect of E coli expressed recombinant human bone morphogenetic protein-2(ErhBMP-2) to periodontal ligament stem cells(PDLSCs) and bone marrow stem cells(BMSCs) on periodontal tissue regeneration. rhBMP-2 those expressed from E coli was treated on ex-vivo expanded human BMSCs and PDLSCs to evaluate its regenerative effect in vivo and in vitro. Cementum, PDL-like tissues and bone were regenerated in transplanting PDLSCs and BMSCs, respectively. There was enhanced tissue regeneration when ErhBMP-2 was treated to PDLSCs, but not with BMSCs. Similar results were observed with in vitro experiments. Though further studies are needed, the results suggest a possible treatment approach in combining ErhBMP-2 and PDLSCs for periodontal tissues regeneration.ope

삼차원 재구성된 CT 영상을 통한 한국인의 하악관 주행 양상

Purpose : The location of the mandibular canal is must be determined before performing implant surgery and other procedures. This study was undertaken to identify the running patterns of mandibular canals in the Korean population using a 3- dimensional reconstructed computed tomographic(CT) image. Materials and methods : CT images of 30 patients were included in the investigation. The vertical and bucco-lingual positions of the mandibular canals were identified under each premolar and molar, and the location of the mental foramen and the anterior extension of the anterior loop were measured using 3-D CT reconstruction software. The vertical position of the canal and mental foramen were measured from the CEJ of the tooth to the upper border of the structure. Results : The mean lengths between the cement-enamel junction of the tooth and the canal were 19.94, 19.07, 17.82, and 15.75mm under the first and second premolars and the first and second molars. Most of the canals were located at the lingual aspect under the molars, and at the buccal aspect under the 1st premolar. The average vertical location of the mental foramen was 15.37mm from the CEJ, and had an average diameter of 2.32mm. The mean length of the anterior loop was found to be 4.23mm. Conclusion : In most subjects, the vertical position of the mandibular canal was closer to the molars than the premolars. The running pattern of the mandibular canal from the molar region to the premolar region tended to be from the lingual to the buccal aspect of the mandible. The mental foramen was located superior to the canal, and the anterior loop extended anteriorly in various lengthsope

The application of Cyanoacrylate-based Filling Material for Surgically Created 1-wall Intrabony Defects in Dogs

Bone grafts are often used as part of a surgical protocol to regenerate periodontal structures. Hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) are used as bone graft materials for periodontal regeneration. N-butyl-2- cyanoacrylate is also used as a tissue adhesive because of its rapid adhesion to hard and soft tissue. We evaluated the bioactive properties of HA/β-TCP and cyanoacrylate filling materials for clinical applications. In four male beagle dogs, we bilaterally created 4 × 4 mm one-wall intrabony defects at the distal aspect of the second mandibular premolars, and at the mesial aspect of the fourth mandibular premolars. These defects were either experimentally treated with a HA/β-TCP and cyanoacrylate combination, cyanoacrylate only, or surgery with no filling material. The dogs were killed eight weeks after surgery, and block sections of the defects were collected for histologic and histometric analysis. Postoperative healing was uneventful. Histological analysis revealed no significant differences in periodontal healing between the experimental sites that received grafted materials and those that did not. Only small amounts of bone fill and cementum regeneration were observed. In this study, we expected that the osteogenic filling material would become fixed in the bony defect more quickly and stably because of the adhesive ability of cyanoacrylate; however, the combination filling material did not result in a higher amount of new bone and cementum formation compared to surgery with no filling materialope

The Effects of Hydroxyapatite Coated with β-Tricalcium Phosphate in One-Wall Intrabony Defects in Dogs

The purpose of this study was to evaluate the effect of hydroxyapatite coated with β-tricalcium phosphate (HCT) in surgically prepared one-wall periodontal intrabony defects in dogs. Four beagle dogs were used as the subjects. One-wall intrabony defects were prepared surgically at the mandibular second and fourth premolars in both right and left jaw quadrants. The experimental groups were divided into two, according to the kind of graft material used. In the HCT group, the defect was filled with HCT. In the HCT/ACS group, the defect was filled with HCT and then covered by an absorbable collagen sponge (ACS). The control group was treated by root planing only. Histologic and histometric analyses revealed statistically significant bone formation in the HCT and HCT/ACS groups, compared with the control group. New bone was observed along the root surface or in close contact with the residual graft particles in the HCT and HCT/ACS groups. The HCT/ACS group showed statistically greater bone formation than the HCT group. It can be concluded that HCT provides osteoconductivity in one-wall intrabony defects. In addition, HCT in one-wall intrabony defects provide new cementum formation and periodontal ligament fiber formation with neither root resorption nor ankylosis.ope

Piezosurgery® 를 이용한 하악 정중결합부의 block bone 시술 및 임프란트 식립 치험례

Purpose: The aim of this case report is to describe block bone graft from mandibular symphysis using Piezosurgery￠A and implant installation procedure. Materials and Methods: A 19 year old male patient walked in with complaint of missing tooth on #31, 41 due to congenital missing. Block bone was grafted from mandibular symphysis and fixed with screws. After 4 months, implant was installed(Replace NP ⓒ™3.5x13mm). The patient requested early restoration and the final restoration was delivered 6 weeks after implant 1st surgery. Results: Relatively enough bone was acquired using block bone even though there was considerable bone loss in vertical dimension. Bone quality was good enough to place implant fixture. Slight gingival recession took place during soft tissue healing period after 1st surgery, and the patient agreed re-visit for final restoration check up. Conclusion: Block bone graft from symphysis using Piezosurgery￠A can be used as a predictable procedure for ridge augmentation when certain precautions are observedope

The effects of bone regeneration in rabbit calvarial defect with particulated and block type of hydroxyapatite

PURPOSE: The purpose of this study was to evaluate the bone regeneration of particulated hydroxyapatite(HA) and block type of hydroxyapatite graft in rabbit calvarial defects. METHODS: An 8 mm calvarial circular defects were created in sixteen young adult New Zealand white male rabbits (weight 3.0~3.5 kg). Each defects were filled with Bio-Oss, particulated HA and block type HA. Sham surgery control defects were filled with blood clots. The pecimens were harvested at 4 weeks and 8 weeks for histologic and histomorphometric evaluation. RESULTS: Histomorphometric analysis demonstrated statistical differences in defect closure, new bone formation, and bone density of the four groups. Block type of HA group showed increased bone formation and bone density at 4 weeks and 8 weeks compared with Bio-Oss group or sham surgery control group(p<0.05). CONCLUSIONS: Block type of HA is an effective material for osteoconduction in rabbit calvarial defects, which may acts as a guide in use of these products in human applicationope

A retrospective study of the dental implants placed in the controlled diabetes mellitus patients.

PURPOSE: The aim of the present study was to analyze 7-year cumulative survival rate (CSR, %) of dental implants in the controlled diabetic patients and to evaluate the influence of the position, diameter and length of fixture, bone quality, age, gender and the method of maxillary sinus elevation on the survival rate. METHODS: The data of 342 placed implants in the 104 diabetic patients collected between 1995 and 2007 at the Department of Periodontology in Yonsei University Hospital were analyzed. RESULTS: Seven-year CSR of the 342 dental implants in the 104 controlled diabetic patients was 96.5%. The survival rates of the placed implants according the position have no statistically significant difference. The survival rates according to the length or diameter of the fixtures have no statistically significant difference. The survival rates according to the bone quality were 100% (Type I), 97.1% (Type II), 97.7% (Type III) and 85.7%(Type IV). The difference between the survival rate of Type I, II and III and that of Type IV was statistically significant. The survival rates according to patient gender were 96.8% (male), 95.5% (female). The survival rates according to patient age were 100% ( or = 60). The survival rates according to the method of sinus elevation in the maxillary posterior area were 96.8% (without sinus elevation), 92.9% (lateral approach) and 89.8% (crestal approach). CONCLUSIONS: Dental implants can be used successfully in the controlled diabetic patients. In case of upper posterior region which has poor bone density and older patients, the implant treatment should be more properly planed, executed, and followed-up.ope

The Evaluation of Calcium Phosphate Coated Implants by Ion-beam Assisted Deposition (IBAD) Method in Dogs : A Preliminary Study

Rough surfaced implants have been reported to favor early bone healing than smooth surfaced implants. Among various methods introduced to roughen the implant surface, coating with calcium phosphate(CaP) is one of them. The purpose of this study was to evaluate the bone healing response of anodized implants with two different coating thickness of CaP(200 nm and 500 nm) deposited by ion beam assisted method. CaP coated implants were placed on circumferencial coronal defects of four mongrel dogs and the amount of defect fill was evaluated histologically after 8 weeks. The amount of coronal defect filling varied among the implants according to its surface characteristics. The CaP coating thickness of 500 nm showed the greatest amount of defect fill than implants with 200 nm of CaP coating thickness and non coated implants. Within the limits of this study, when coating implants with CaP by ion-beam assisted deposition method, coating thickness of 500 nm seemed to be effectiveope