• Journal of the Korea Society of Computer and Information
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• v.12 no.5
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• pp.285-292
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• 2007

This study was developed the metallic plate for fixation in the femur fracture for the orthopedic region and rigid fixation with plates has a firm place in fracture treatment. Most plates can be used for rigid as well as biological and dynamical fracture fixation. The device's designation and sizing has a specific with bending structural stiffness and strength, known meaning that is reliable regardless of the plate by the short type and long type. Short plate have a wrapping of femur and long plate have to preserve a pole of femur. The bending strength of the curved metallic long plate has to evaluate a 11,000N and The bending strength of the curved metallic short plate has to evaluate a 6,525N. The tensile stress through to press a plate is $1573N/m^2\;and\;1539N/m^2$. The device can be used to support Revision case of Hip Implant and to use a case of Hip screw compression of Hip Neck Fracture.

• Journal of Periodontal and Implant Science
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• v.36 no.2
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• pp.555-565
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• 2006

The purpose of the present study is to evaluate the biological stability of the zirconia/alumina composite abutment by histologic and radiographic examination in clinical cases. 17 partially edentulous patients (5 men and 12 women, mean age 47) were treated with 37 implants. The implants were placed following the standard two-stage protocol. After a healing period of 3 to 6 months, zirconia/alumina composite abutments were connected. All radiographs were taken using paralleling technique with individually fabricated impression bite block, following insertion of the prosthesis and at the 3-, 6-, 12 month re-examinations. After processing the obtained images, the osseous level was calculated using the digital image in the mesial and distal aspect in each implant. An ANOVA and t-test were used to test for difference between the baseline and 3-, 6-, 12 months re-examinations, and for difference between maxilla and mandible. Differences at P <0.05 were considered statistically significant. For histologic examination, sample was obtained from the palatal gingiva which implant functioned for 12 months. Sections were examined under a light microscope under various magnifications. Clinically, no abutment fracture or crack as well as periimplantitis was observed during the period of study. The mean bone level reduction(${\pm}standard$ deviation) was 0.34 rom(${\pm}\;0.26$) at 3-months, 0.4 2mm(${\pm}\;0.30$) at 6-months, 0.62 mm(${\pm}\;0.28$) at 12-months respectively. No statistically significant difference was found between baseline and 3-, 6-, 12-months re-examinations (p > 0.05). The mean bone level reduction in maxilla was 0.33(${\pm}0.25$) at 3-months, 0.36(${\pm}0.33$) at 6-months, 0.56(${\pm}0.26$) at 12-months. And the mean bone level reduction in mandible was 0.35(${\pm}0.27$) at 3-months, 0,49(${\pm}0.27$) at 6-months, 0.68(${\pm}0.30$) at 12-months. No statistical difference in bone level reduction between implants placed in the maxilla and mandible. Histologically, the height of the junctional epithelium was about 2.09 mm. And the width was about 0.51 mm. Scattered fibroblasts and inflammatory cells, and dense collagen network with few vascular structures characterized the portion of connective tissue. The inflammatory cell infiltration was observed just beneath the apical end of junctional epithelium and the area of direct in contact with zirconia/alumina abutment. These results suggest the zirconia/alumina composite abutment can be used in variable intraoral condition, in posterior segment as well as anterior segment without adverse effects.

• The korean journal of orthodontics
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• v.43 no.5
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• pp.218-224
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• 2013

Objective: To examine the effect of bite force on the displacement and stress distribution of orthodontic mini-implants (OMIs) in the molar region according to placement site, insertion angle, and loading direction. Methods: Five finite element models were created using micro-computed tomography (microCT) images of the maxilla and mandible. OMIs were placed at one maxillary and two mandibular positions: between the maxillary second premolar and first molar, between the mandibular second premolar and first molar, and between the mandibular first and second molars. The OMIs were inserted at angles of $45^{\circ}$ and $90^{\circ}$ to the buccal surface of the cortical bone. A bite force of 25 kg was applied to the 10 occlusal contact points of the second premolar, first molar, and second molar. The loading directions were $0^{\circ}$, $5^{\circ}$, and $10^{\circ}$ to the long axis of the tooth. Results: With regard to placement site, the displacement and stress were greatest for the OMI placed between the mandibular first molar and second molar, and smallest for the OMI placed between the maxillary second premolar and first molar. In the mandibular molar region, the angled OMI showed slightly less displacement than the OMI placed at $90^{\circ}$. The maximum Von Mises stress increased with the inclination of the loading direction. Conclusions: These results suggest that placement of OMIs between the second premolar and first molar at $45^{\circ}$ to the cortical bone reduces the effect of bite force on OMIs.

• Journal of Periodontal and Implant Science
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• v.33 no.2
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• pp.301-310
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• 2003

The purpose of this study is to evaluate the biocompatibility and the biorsorbability of several types of calcium polyphosphate made through change of manufacturing process for 12 month. To solve limitation of calcium phosphate, we developed a new ceramic, Calcium Polyphosphate(CPP), and report the biologic response to CPP in extraction sites of beagle dog. Porous CPP blocks were prepared by condensation of anhydrous $Ca(H_2PO_4)_2$ to form non-crystalline $Ca(PO_3)_2$ and then milled to produce CPP powder. CPP powder, CPP block, and CPP granules added with $Na_2O$ were implanted in extraction sockets and histologic observation were performed at 12 months later. Like 3 months results, histologic observation at 12 months revealed that CPP matrix were mingled with and directly apposed to new bone without any adverse tissue reaction, CPP powder show direct bony contact, but new bone formation and fibrous tissue encapsulation showed in CPP block. 10% $Na_2O$ CPP granules show more inflammatory cells infiltration around graft materials compared at 3 month, but 15% $Na_2O$ CPP granules show less. This result revealed that regardless of addition of $Na_2O$, CPP had a high affinity for bone and had been resorbed slowly. From this results, it was suggested that CPP is promising ceramic as a bone substitute and addition of $Na_2O$ help biodegradation but optimal concentration of $Na_2O$ and other additive component to increase degradation rate should be determined in further study.

• The Journal of Korean Academy of Prosthodontics
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• v.58 no.2
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• pp.77-85
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• 2020

Purpose: The aim of the present study was to investigate the effects of N-acetyl cysteine (NAC) loading on the bone formation surrounding sandblasted, large-grit and acid-etched (SLA) implants. Materials and methods: Implantation of NAC loaded SLA implants (NSI group) and SLA implants (SI group) was performed bilaterally in the mandible of 4 adult beagle dogs (each group, n = 8). The animals were sacrificed after a healing period of 3 and 6 weeks, respectively (n = 2 animal each). Dissected blocks were processed for histomorphometrical analysis. Bone to implant contact percentage (BIC%) and bone volume (BV%) were assessed histomorphometrically. Results: BIC% of NAC loaded SLA implants were about 50% higher than that of SLA implants at 3 weeks of bone healing, but not significantly (51.79 vs 35.43%; P=.185). BV% of NAC loaded SLA implants were significantly higher than that of SLA implants at 3 weeks of bone healing (45.09 vs 37.57 %; P=.044). At 6 weeks of bone healing, BIC% and BV% of two experimental groups were similar (P>.05). Conclusion: Within the limits of the present study, NAC loading have a positive effects on the early bone formation surrounding SLA implants. So, it might be concluded that NAC loading enhance the osseointegration and shorten the healing time after implantation of the SLA implants.

• Journal of Periodontal and Implant Science
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• v.34 no.1
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• pp.223-241
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• 2004

The purpose of this present study evaluated the osseous response around Ca-P coated xenogenic bone and compared osteogenic potential of Ca-P coated xenogenic bone to that of combination with type I collagen derived from bovine tendon as a biocompatible binder to prevent migration of bone particle on the repair of calvarial defects in rabbits. To study the effects of Ca-P coated xenogenic bone and collagen on bone healing, four 5-mm-diameter skull defect were made in calvaria with trephine filled with an autogenous bone chip or Ca-P coated xenogenic bone or Ca-P coated xenogenic bone and type I collagen (1:1 mixture by volume) or left empty. The defects were evaluated histologically at 1, 2, 4 and 8 weeks following implantation. Ca-P coated xenogenic bone at the calvarial defects of rabbits showed osteoconductivity at the margin of defect in the early stage of bony healing, but no direct contact with new bone was observed. With time passed by, it was resorbed slowly and showed consistent inflammatory reaction. An additional use of type I collagen derived from bovine tendon improved clinical handling, but no new bone formation was observed histologically. Above all, autogenous bone graft showed most prominent healing in quantity and density of new bone formation. According to this study, the use of Ca-P coated xenogenic bone alone and combination with type I collagen did not showed effective healing in quantity and density of new bone formation.

• The korean journal of orthodontics
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• v.33 no.4 s.99
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• pp.307-317
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• 2003

Conventional osseointegrated titanium implants have many limitations; large size, limited location for placement of the implant, severity of the surgery, discomfort of initial healing, difficulty of oral hygiene and uncontrollable force direction. Recently titanium miniscrew and miniplate have been used for an alternative to conventional dental implant. But in relation to miniplate, miniscrew has disadvantages in that more potential inflammation, light orthodontic force application and limited orthodontic application. This study was conducted to evaluate the effectiveness of miniplate by observing the reactions of peri-implant tissues to early orthodontic and orthopedic loading of titanium miniplate. In four adult beagle dogs 10 miniplates were inserted into the alveolar bone using 20 osseointegrated titanium screws. 4 miniplates were placed in two dogs(dogA, B) and 6 miniplates in two dogs(dogC, D). In dogA, B miniplates were loaded with 200gm of force immediately after placement for 15 weeks. In dogc, D, miniplates were loaded with 400gm of force immediately after placement for 8 weeks. Miniplates of dogA were removed, dogA was healed for 4 weeks, and the area which was removed of miniscrew was examined. Following an observation period, the miniplates including miniscrews and the surrounding bone of dogB and dogC, D were removed, respectively. Undecalcified section along the long axis of miniscrews were made and the degree of osseointegration was examined under the light microscope. The results were as follows. 1. In the histologic features there was direct contact between bone and miniscrew in all groups except one, dogC control group. The loaded miniscrew demonstrated only a slight increase of the osseous proximaty when compared with unloaded miniscrew 2. There was no significant difference of the osseointegration of Peri-miniscrew surface between dogB and dogC, D. But dogB showed slightly more increased bone apposition than dogC, D 3. The gingiva overlapping the miniplate and miniscrew showed no inflammatory sign in clinical and histological aspects. 4. The impaled hard and soft tissues at the area which was removed of miniscrews showed good healing without inflammatory reaction. 5. The mobility showed slight increase in un-loaded miniplate but that was insignificant. Based on the results of this study, miniplate(C-tube) can be used as a firm osseous orthodontic and orthopedic anchorage unit immediately after insertion.

• Clinics in Shoulder and Elbow
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• v.16 no.2
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• pp.163-169
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• 2013

Designs of total elbow arthroplasty have been evolving with clinical experiences. Newer implants are expected to resolve current limitations and improve long term outcomes. This review article focuses on the basic knowledge of unlinked and convertible total elbow arthroplasty. There have been a variety of designs of unlinked total elbow prostheses. Some implants are still used in the market, while others are no longer commercially available. Modified and newer designs include more congruent contact surface, stemmed implant, and radiocapitellar arthroplasty. Two convertible elbow prostheses have been developed, and one implant is currently available in Korea. Conversion from an unlinked to a linked mode is performed by adding a linking cap. Unlinked total elbow arthroplasty, which restores native elbow kinematics, has a biomechanical rationale of lowering polyethylene wear and loosening of implants. It can be indicated in younger and higher demand patients, who have adequate bone stock and soft tissues. Convertible total elbow arthroplasty broadens implant selection and simplifies revision surgery. These newer prostheses possibly improve the long term outcomes and resolve disadvantages of linked prostheses in total elbow arthroplasty.

• Journal of Periodontal and Implant Science
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• v.46 no.4
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• pp.277-287
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• 2016

Purpose: The purpose of this study was to evaluate the clinical efficacy of enhancing deficient interdental papilla with hyaluronic acid gel injection by assessing the radiographic anatomical factors affecting the reconstruction of the interdental papilla. Methods: Fifty-seven treated sites from 13 patients (6 males and 7 females) were included. Patients had papillary deficiency in the upper anterior area. Prior to treatment, photographic and periapical radiographic standardization devices were designed for each patient. A 30-gauge needle was used with an injection-assistance device to inject a hyaluronic acid gel to the involved papilla. This treatment was repeated up to 5 times every 3 weeks. Patients were followed up for 6 months after the initial gel application. Clinical photographic measurements of the black triangle area (BTA), height (BTH), and width (BTW) and periapical radiographic measurements of the contact point and the bone crest (CP-BC) and the interproximal distance between roots (IDR) were undertaken using computer software. The interdental papilla reconstruction rate (IPRR) was calculated to determine the percentage change of BTA between the initial and final examination and the association between radiographic factors and the reconstruction of the interdental papilla by means of injectable hyaluronic acid gel were evaluated. Results: All sites showed improvement between treatment examinations. Thirty-six sites had complete interdental papilla reconstruction and 21 sites showed improvement ranging from 19% to 96%. The CP-BC correlated with the IPRR. More specifically, when the CP-BC reached 6 mm, virtually complete interdental papilla reconstruction via injectable hyaluronic acid gel was achieved. Conclusions: These results suggest that the CP-BC is closely related to the efficacy of hyaluronic acid gel injection for interdental papilla reconstruction.

• Journal of Periodontal and Implant Science
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• v.41 no.6
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• pp.273-278
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• 2011

Purpose: To analyze the dimensions of the embrasure space between the maxillary central incisors as potential factors influencing interdental papilla fill and height. Methods: The embrasure dimensions between the maxillary central incisors of 100 subjects (40 females/60 males) were assessed with clinical, study model, and radiographic examinations. Variables of the complete and deficient papilla fill groups were compared. Multiple regression analyses were performed to investigate potential influence of the distance between the contact point and bone crest (CP_BC), horizontal interdental distance (HID), and facio-lingual thickness (FLT) at the papilla base on complete/deficient papilla fill and papilla height (PH). Results: CP_BC was the only variable that showed a significant difference between the complete and deficient papilla groups (P<0.05). When the CP_BC was less than 5 mm, the embrasure spaces between the maxillary central incisors were completely filled with interdental papilla. Multiple regression analyses revealed that a significant predictor for complete/deficient papilla fill was CP_BC, and significant predictors for PH were CP_BC and HID (P<0.05). Conclusions: The chances of complete papilla fill increased as CP_BC decreased, while PH increased as CP_BC and HID increased. However, the FLT of the papilla base did not appear to affect papilla fill or PH. From an esthetic perspective, CP_BC as well as HID should be considered as factors influencing the topography of interdental papilla.