• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.05a
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• pp.255-255
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• 2012

The interactions between cells and nanotopographies are increasingly interested as nanotopographies that may be more efficient in promoting cell functions and, titanium nanotubes have attracted much attention. Titanium nanotube can be fabricated easily with precisely controlled diameters and lengths. Titanium nanotubes with the suitable tube dimensions have been observed to enhance bone cell functions, whereas, there is still some controversy. These nanotubes can also serve as carriers for drugs such as growth factors, antibacterial agents and other drugs and show promise in bone implant applications.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.6
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• pp.575-580
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• 2005

Transitional implants were developed to support provisional restorations and to allow for load-free osseointegration of conventional implants while a patient was provided with immediate esthetics and function and are usually placed simultaneously at the time of definitive implant placement. Transitional implants are placed in a non-submerged fashion in a single-stage surgery and are designed to be immediately loaded. They generally are made of commercially pure titanium or titanium alloy and are designed as 1-piece implants composed of root and crown replacement segments. Transitional implants can be used in a wide range of indications, such as basic use as temporary implant, to support and protect the primary implants during the healing phase, single crown in the edentulous anterior region of mandibular, anchorage for orthodontic treatment, support a surgical and radiographic template, and primary implant to extremely atrophied alveolar crests of the mandible and maxilla. This article describes the clinical use of transitional implants to support the provisional complete denture and single crown in the restricted edenturous central incisor region of mandible.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.3
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• pp.379-392
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• 2005

Statement of problem. One of the common problems of dental implant prosthesis is the loosening of the screw that connects each component, and this problem is more common in single implant-supported prostheses with external connection, and in molars. Purpose. The purposes of this study were: (1) to compare the initial abutment screw detorque values of the six different implant-abutment interface designs, (2) to compare the detorque values of the six different implant-abutment interface designs after cyclic loading, (3) to compare the detorque values of regular and wide diameter implants and (4) to compare the initial detorque values with the detorque values after cyclic loading. Material and methods. Six different implant-abutment connection systems were used. The cement retained abutment and titanium screw of each system were assembled and tightened to 32Ncm with digital torque gauge. After 10 minutes, initial detorque values were measured. The custom titanium crown were cemented temporarily and a cyclic sine curve load(20 to 320N, 14Hz) was applied. The detorque values were measured after cyclic loading of one million times by loading machine. One-way ANOVA test, scheffe’s test and Mann-Whitney U test were used. Results. The results were as follows : 1. The initial detorque values of six different implant-abutment connections were not significantly different(p>0.05). 2. The detorque values after one million dynamic cyclic loading were significantly different (p<0.05). 3. The SS-II regular and wide implant both recorded the higher detorque values than other groups after cyclic loading(p<0.05). 4. Of the wide implants, the initial detorque values of Avana Self Tapping Implant, MIS and Tapered Screw Vent, and the detorque values of MIS implant after cyclic loading were higher than their regular counterparts(p<0.05). 5. After cyclic loading, SS-II regular and wide implants showed higher detorque values than before(p<0.05).

• The Journal of Korean Academy of Prosthodontics
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• v.36 no.1
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• pp.183-198
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• 1998

This study was designed to investigate the peri-implant tissue reaction in ovariectomized osteoporotic female rats, and to evaluate effects of estrogen, calcitonin, parathyroid hormone on the bone - implant interface in osteoporotic rats. 120 Sprague - Dawley rats were used in this experiments. Osteoporosis was induced by bilateral ovariectomy. They were divided 5 groups : sham-operated control group(Sham), ovariectomized group (OVX), OVX and estrogen treated group (OVX+E), OVX and PTH treated group (OVX+PTH), and OVX and calcitonin treated group (OVX+CT). Eight weeks after ovariectomy, two titanium screw implants were inserted into the left tibia of each rat. Eight weeks after the insertion of the implants, the periotest values (PTV) of implant were examined, and the rats were sacrificed, and examined the reaction of bone tissue surrounding the implant both histologically and histomorphometrically. The bone density and ash weight of opposite right tibia were examined. Over 40 rats were fractured on left tibia that was implant inserted. On histologically finding, all groups were osseointegrated well, especially in OVX+PTH group. In OVX group, tibial cortical bone showed many large harversian canal and microfracture lines. The OVX+PTH group showed the lowest mean PTV (-2.33) (p<0.05), and the hightest mean bone - implant contact percentage (89%) (p>0.05). But the OVX+CT group showed the highest mean bone density ($5.45mg/cm^3$) and ash weight (56.12%) (p<0.05). The results indicate that PTH treatment enhances osseointegration of implant in OVX rats, and CT treatment depresses bone turnover and prevent the development of osteopenia in OVX rats.

• Journal of Periodontal and Implant Science
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• v.33 no.4
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• pp.651-671
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• 2003

The influence of calcium phosphate (Ca-P) coating on the bone response of titanium implants was investigated two types of titanium implants, i.e. as -machined ,as -machined with Ca-P coating, were prepared. The Ca-P coating produced by OCT Inc technique. These implants were inserted into the left and right femur of beagle dog, After implantation periods of 3 days, 1weeks, weeks, 4weeks, 8weeks, 12weeks. 24weeks, the bone-implant interface was evaluated histologically, histomorphometrically , and removal torque. Histological evaluation revealed no new bone formation around different implant materials after 2weeks of implantation. After 4 weeks, Ca-P coated implants showed a higher amount of bone contact than either of the non coated implants. After 12weeks, bone healing was almost completed. And implant were removed by reverse torque rotation with torque-measuring device. Mean torque values for 4weeks control were 2.375Kgf.cm and experimental were 2.725Kgf.cm. And mean torque values for 8weeks control were 1.25Kgf.cm and experimental were 1.0Kgf.cm On the basis of these findings, we concluded that deposition of a Ca-P coating on an implant has a beneficial effect on the bone response to this implant during the healing phase. Besides implant surface conditions the bone response is also determined by local implant site condition.

• Journal of Periodontal and Implant Science
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• v.29 no.1
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• pp.209-231
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• 1999

Even though titanium(Ti) and its alloys are the most used dental implant materials, there are some problems that Ti wears easily and interferes normal osteogenesis due to the metal ions. Ti coated with bioactive ceramics such as hydroxyapatite has also such problems as the exfoliation or resorption of the coated layer, Recent studies on implant materials have been proceeding to improve physical properties of the implant substrate and biocompatibility of the implant surfaces. The purpose of the present study was to examine the physical property and bone tissue compatibility of bioinert nitrides ion plated Ti, Button type specimens(14mm in diameter, 2.32rrun in height) for the abrasion test and cytotoxicity test and thread type implants(3.75mm in diameter, 6mm in length) for the animal experiments were made from Ti(grade 2) and 316LVM stainless steel. Ti specimens were ion plated with TiN, ZrN by the low temperature arc vapor deposition, and the depth profile of the TiN/Ti, ZrN/Ti ion plated surface was examined by Auger Electron Spectroscopy. Three kind of button type specimens .of TiN/Ti, ZrN/Ti and Ti were used for abrasion test, and HEPAlClC7 cells and CCD cells were cultivated for 4 days with the specimens for cytotoxicity test. Thread type implants of TiN/Ti, ZrN/Ti, Ti, 316LVM were implanted on the femur of 6 adult dogs weighing 10kg-13kg. Two dogs were sacrified for histological examination after 45 days and 90 days, and four dogs were sacrified for the removal torque test of the implant') after 90 days. The removal torque force was measured by Autograph (Shimadzu Co., AGS-1000D series, Japan). Abrasion resistance of TiN/Ti was the highest, and that of ZrN/Ti and Ti were followed. The bioinert nitride ion plated Ti had much better abrasion resistance, compared with Ti, In the cytotoxicity test, the number of both cells were increased in all specimens, and there were no significant difference in cytotoxic reaction among all groups (p>0.1), In histological examination, 316LVM showed the soft tissue engagement in interface between the implant and bone, but the other materials after 45 days noted immature new bone formation in the medullary portion along the implant surface, and those after 90 days showed implant support by new bone formation in both the cortical and the medullary portion, The removal torque force of Tilv/Ti showed significantly higher than that of Ti(p(O,05). The difference in removal torque force between TiN/Ti and ZrN/Ti was not significant(p>0.05), and that of 316LVM was lowest among all groups(p<0.05). These results suggest that bioinert nitrides ion plated Ti can resolve the existing problems of Ti and bioactive ceramics, and it may be clinically applicable to human.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.37
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• pp.1.1-1.6
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• 2015

The restoration of extensive zygomatic complex defects is a surgical challenge owing to the difficulty of accurately restoring the normal anatomy, symmetry, proper facial projection and facial width. In the present study, an extensive post-traumatic zygomatic bone defect was reconstructed using a custom-made implant that was made with a selective laser melting (SLM) technique. The computer-designed implant had the proper geometry and fit perfectly into the defect without requiring any intraoperative adjustments. A one-year follow-up revealed a stable outcome with no complications.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.6
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• pp.747-761
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• 2003

Statement of problem. The proper materials of attachments for implant retained overdenture are unknown, such as the correlation between retention and abrasion, as well as the types of materials that are suitable for patrix and for matrix individually. Purpose of this study. The aim of this study was to select a proper clinical attachment system for a successful treatment as well as patient satisfaction. Methods. Retention and abrasion of 14 commercial attachments were measured during 15,000 removes. Results. A retentive part (matrix) which requires elasticity has to be made of gold while the patrix part which does not require elasticity has to be made of titanium. This gold matrix / titanium patrix combination showed the most retentive force and the least retention loss.

• Journal of Periodontal and Implant Science
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• v.42 no.3
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• pp.88-94
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• 2012

Purpose: The use of appropriate instruments to clean surfaces with minimal change, is critical for the successful maintenance of a dental implant. However, there is no consensus about the type and methodology for such instruments. The aim of this study was to characterize changes in the roughness of titanium surfaces treated by various scaling instruments. Methods: Thirty-seven identical disks (5 mm in diameter) were investigated in this study. The specimens were divided into eight groups according to the types of instrumentation and the angle of application. Ultrasonic scaling systems were applied on a titanium disk to simulate standard clinical conditions. The equipment included a piezoelectric ultrasonic scaler with a newly developed metallic tip (NS group), a piezoelectric ultrasonic scaler with a conventional tip (CS group), a piezoelectric root planer ultrasonic scaler with a conventional tip (PR group), and a plastic hand curette (PH group). In addition, the sites treated using piezoelectric ultrasonic scaler systems were divided two sub-groups: 15 and 45 degrees. The treated titanium surfaces were observed by scanning electron microscopy (SEM), and the average surface roughness (Ra) and mean roughness profile depth (Rz) were measured with a profilometer. Results: SEM no significant changes in the titanium surfaces in the NS group, regardless of the angle of application. The PH group also showed no marked changes to the titanium surface, although some smoothening was observed. All CS and PR sites lost their original texture and showed irregular surfaces in SEM analysis. The profilometer analysis demonstrated that the roughness values (Ra and Rz) of the titanium surfaces increased in all, except the PH and NS groups, which showed roughness decreases relative to the untreated control group. The Ra value differed significantly between the NS and PR groups (P<0.05). Conclusions: The results of this study indicated that changes in or damage to titanium surfaces might be more affected by the hardness of the scaler tip than by the application method. Within the limitations of this study, the newly developed metallic scaler tip might be especially suitable for peri-implant surface decontamination, due to its limited effects on the titanium surface.

• 대한치과보철학회:학술대회논문집
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• 2004.11a
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• pp.75-75
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• 2004