• Corrosion Science and Technology
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• 제17권3호
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• pp.91-100
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• 2018

Development of biodegradable implants for treatment of complex bone fractures has recently become one of the priority areas in biomedical materials research. Multifunctional corrosion resistant and bioactive coatings containing hydroxyapatite $Ca_{10}(PO_4)_6(OH)_2$ and magnesium oxide MgO were obtained on Mg-Mn-Ce magnesium alloy by plasma electrolytic oxidation. The phase and elemental composition, morphology, and anticorrosion properties of the coatings were investigated by scanning electron microscopy, energy dispersive spectroscopy, potentiodynamic polarization, and electrochemical impedance spectroscopy. The PEO-layers were post-treated using superdispersed polytetrafluoroethylene powder. The duplex treatment considerably reduced the corrosion rate (>4 orders of magnitude) of the magnesium alloy. The use of composite coatings in inducing bioactivity and controlling the corrosion degradation of resorbable Mg implants are considered promising. We also applied the plasma electrolytic oxidation method for the formation of the composite bioinert coatings on the titanium nickelide surface in order to improve its electrochemical properties and to change the morphological structure. It was shown that formed coatings significantly reduced the quantity of nickel ions released into the organism.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제35권2호
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• pp.112-123
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• 2013

This study aims to investigate the clinical outcome following treatment of peri-implantitis lesions. Five subjects with 7 implants were treated with surgical approach. Four subjects with 6 implants were initially treated with non-surgical approach or hygiene control. However, inflammation was not resolved and more bone loss was found. Therefore, surgical treatment was performed. After surgical exposure of the defect, granulation tissue was removed and implant surface was treated using tetracycline and chlorhexidine. Then, the flaps were sutured. The wound healing was performed in a non-submerged mode. The present finding demonstrates stable results without progression of bone loss. In one subject, deep V shaped bone defect was filled with bone substitute (ICB, CanCellous Bone, Rockey Mountain Tissue Bank, USA), and resorbable membrane (Lyoplant$^{(R)}$, B.Braun Aesculap AG, Germany) was placed over the grafted defect and healing abutment was connected. However, the inflammation was not resolved and more bone loss was found. At one month after regenerative surgery, the implant was removed.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.203-204
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• 2006

Studies on some biodegradable polymers and other materials such as hydrogels have shown the promising potential for a variety of surgical applications. Postoperative adhesion caused by the natural consequence of surgical wound healing results in problems of the repeated surgery. Recently, scientists have developed absorbable anti-adhesion barriers that can protect a tissue from adhesion in case they are in use; however, they are dissolved when no longer needed. Although these approaches have been attempted to fulfill the criteria for adhesion prevention, none can perfectly prevent adhesions in all situations. Overall of this work, a new method to fabricate an anti-adhesion membrane using biodegradable polymer and hydrogel has been developed. The ideal barrier for preventing postoperative adhesion would have the following properties; it should be (i) resorbable (ii) non-reactive (iii) easy to apply (iv) capable of being fixed in position. In order to fulfill these properties, we adopted solid freeform fabrication method combined with surface modification which includes the hydrogel coating, therefore, inner or outer structure can be controlled and the property of anti adhesion can be improved.

• Journal of Periodontal and Implant Science
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• 제24권1호
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• pp.185-195
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• 1994

This study was conducted to evaluate the healing potential of hydroxyapatite and demineralized freeze dried bone in 5 dogs. Chronic periodontitis was induced by ligating elastic wire randomized as follows. The group in which only flap operation was performed was used as control. The group in which flap operation using nonresorbable nonporous hydroxyapatite (Orthomatrix)was performed was used as experimental I. The group which flap operation using resorbable porous hydroxyapatite (Biocoral) was performed as experimental II. The group in which flap operation using demineralized freeze-dried bone was performed was used as experimental III. Thereafter dogs serially sacrificed at the 1,2,4 and 8 weeks and the specimens were prepared, and stained with Hematoxilin-Eosin stain for the light microscopic evaluation. The results of the this study were as follows : 1. Control group : progressive inflammatory cell infiltration till 4 weeks and epithelial undergrowth. 2. Group I. : epithelial undergrowth and new bone formed with fibrous margin around HA granule. 3. Group II. : no epithelial undergrowth and direct bone formation at the porous granule 4. Group III. : could not see epithelial undergrowth but obviously new cementum formation.

• Journal of Periodontal and Implant Science
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• 제34권3호
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• pp.683-698
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• 2004

One of the bone substitutes now in routine use, deproteinized bovine bone mineral(DBBM), is regarded as resorbable and osteoconductive, but some studies refute this. The present study was performed to evaluate the effects of DBBM on guided bone regeneration using titanium membrane on the calvaria of rabbit. At 2 weeks, 4 weeks, 8 weeks, and 12 weeks after surgery, the animal was scrificed. Non-decalcified specimens were produced for histologic analysis. The results of this study were as follows : 1. Titanium membrane was biocompatible and capable of space-maintaining, but there was ingrowth of soft tissue through the pore of titanium membrane. 2. There was no resorption or reduction of DBBM with time. 3. Some of the DBBM particles were combined with newly formed bone. But, apart from host bone, a great part of the particles were surrounded by connective tissue. 4. The bone formation was slight vertically and restricted to superficial area of host bone. Whithin the above results, DBBM dose not appear to contribute to bone formation. DBBM may disturb the migration and proliferation of mesenchymal cell derived from host bone and increase the growth of connective tissue. Therefore, careful caution is needed on selection of bone graft material and surgical protocol at guided bone regeneration for implant placement.

• The Journal of Advanced Prosthodontics
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• 제5권2호
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• pp.172-178
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• 2013

PURPOSE. The purpose of this study was to assess the difference in efficacy between calcium metaphosphate (CMP)-coated implant fixtures and conventional resorbable blasted media (RBM) processed implant fixtures. MATERIALS AND METHODS. This study targeted 50 implants from 44 patients who visited Dankook University Dental Hospital. Implantations were done separately for RBM treated and CMP-coated implants, although their design was the same. Calcium metaphosphate has a quicker biodegradation process through hydrolysis compared to other phosphate calcium groups. For the first year of the implantation, the resorption volume of marginal bone analyzed via radiography and perio-test value were measured, under the check plan. Their analyses were composed of a non-inferiority trials test. A 95% level of reliability was used. RESULTS. In the comparative analysis of the resorption volume of marginal bone and the perio-test value, no statistically significant difference was found between the CMP-coated implants and RBM implants. CONCLUSION. One year after the implant placement, CMP-coated implants were found not to be inferior to the conventional RBM implants.

• Clinics in Shoulder and Elbow
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• 제25권3호
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• pp.240-243
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• 2022

Isolated deltoid paralysis is a rare pathology that can occur after axillary nerve injury due to shoulder trauma or infection. This condition leads to loss of deltoid function that can cause glenohumeral instability and inferior subluxation, resulting in rotator cuff muscle fatigue and pain. To establish dynamic glenohumeral stability, a novel technique was invented. Humeral suspension is achieved using a double button implant with non-resorbable high strength cords between the acromion and humeral head. This novel technique was used in two patients with isolated deltoid paralysis due to axillary nerve injury. The results indicate that the humeral suspension technique is a method that supports centralizing the humeral head and simultaneously dynamically stabilizes the glenohumeral joint. This approach yielded high patient satisfaction and reduced pain. Glenohumeral alignment was improved and remained intact 5 years postoperative. The humeral suspension technique is a promising surgical method for subluxated glenohumeral joint instability due to isolated deltoid paralysis.

• 대한두개안면성형외과학회지
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• 제10권2호
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• pp.71-75
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• 2009

Purpose: Recently, orbital wall fracture is common injuries in the face. Facial CT is essential for the accurate diagnosis and appropriate treatment to reconstruct of the orbital wall. The objective of this study was to report the method for accurate measurement of area and shape of the bony defect in the blow-out fractures using facial CT in prior to surgery. Methods: The authors experienced 46 cases of orbital wall fractures and examined for diplopia, sensory disturbance in the area of distribution of the infraorbital nerve, and enophthalmos in the preoperation and followed 1 months after surgery, from August 2007 to May 2008. Bony defect was predicted by measuring continuous defect size from 3 mm interval facial CT. Copying from the defect model (template), we reconstructed orbital wall with resorbable sheet (Inion $CPS^{(R)}$ Inion Oy, Tampere, Finland). Results: One months after surgery using this method, 26 (100%) of the 26 patients improved in the diplopia and sensory disturbance in the area of distribution of the infraorbital nerve. Also 8 (72.7%) of the 11 patients had enophthalmos took favorable turn. Conclusion: This accurate and time-saving method is practicable for determining the location, shape and size of the bony defect. Using this method, we can reconstruct orbital wall fracture fastly and precisely.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제27권4호
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• pp.307-314
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• 2005

After dental implant are planted into their bony site among the various growth factors associated with bone formation. BMP is expressed in the bone surrounding the implant fixture. By taking a close look at BMP2, BMP4 which are growth factors that take put in bone formation, its histologic features and radiographic bone healing patterns we would like to examine the mechanism of osseointegration. We randomly used 8 male and female house rabbit amd used diameter 5 mm height spiral shaped implants(Ostem, Korea) for animal use handled as a resorbable blast machined(RBM) surface and machined surface. 2group were formed and each group had RBM surface and machined surface implant or a simple bone cavity. After 3, 7, 14 and 28 days post surgery 2 objects were sacrificed from each group and histologic specimens were acquired. RT-PCR analysis was conducted and after H&E staining the extent of osseointegration was measured applying a histologic feature and histomorphometric analysis program. Quanitity one -4.41(Bio-Rad, USA) was used after scanning the PCR product image of the growth factors manifested in each group. According to the histomorphometric features the RBM, Machined surface group showed increased contact between bone and implant surface at 3, 7, 14 and 28 days after surgery. The BMP2 level increased in both experiment groups but remained unchanged in the contrast group. BMP4 levels stayed steady after the early post implantation period for RBM but showed decreased in the machined surface group and contrast group. The amount of contact between bone and implant surface increased with the passage of time. BMP2, BMP4 were expressed in both experimental group and contrast group. These growth factors play a role in osseointegration of implant.

• Journal of Periodontal and Implant Science
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• 제47권2호
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• pp.106-115
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• 2017

Purpose: The possibility of immediate or early loading has become popular in implant dentistry. A prerequisite for the immediate or early loading of an implant prosthesis is the achievement of initial stability in the implant. Moreover, in response to clinicians' interest in verifying clinical stability to determine the optimal time point for functional loading, a non-invasive method to assess implant stability has been developed on the basis of resonance frequency analysis (RFA). The primary objective of this study was to monitor the stability of sandblasted, large-grit, and acid-etched (SLA) implants with different diameters during the early phases of healing by RFA. The secondary objective was to evaluate how the initial stability of implants varied depending on different surface modifications and other contributing factors. Methods: Thirty-five implants (25 SLA implants and 10 resorbable blasting media [RBM] implants) placed in 20 subjects were included. To measure implant stability, RFA was performed at baseline and at 1, 2, 3, 4, 6, and 10 weeks after surgery. Results: The longitudinal changes in the implant stability quotient (ISQ) values were similar for the SLA implants with different diameters and for the RBM implants. During the initial healing period, the ISQ decreased after installation and reached its lowest values at 1 week and 2 weeks, respectively. The mean ISQ values in the SLA implants were significantly higher in ${\varnothing}5.0mm$ implants than in ${\varnothing}4.0mm$ implants. Men showed a higher ISQ than women. Mandibular sites showed a higher ISQ than maxillary sites. Conclusions: All implants used in this study are suitable for immediate or early loading under appropriate indications. A wider diameter and SLA surface treatment of implants could improve the stability, if the implant is fixed with at least 30 Ncm of insertion torque.