• Journal of Korean Neurosurgical Society
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• v.30 no.10
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• pp.1170-1176
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• 2001

Objective : The purpose of the study was to evaluate the clinical and radiological results after discectomy and Lubboc bone graft in the surgical management of the cervical diseases with a new titanium interbody implant and integrated screw fixation(PCB) by anterior approach. Methods : The authors retrospectively analyzed 28 cases of anterior cervical fusion with PCB system and Lubboc bone(xeno graft) from september 1998 to december 2000. Twenty-eight patients with cervical diseases underwent decompression cervical lesion and followed from 5 to 27 months with a mean follow-up of 14 months. There patients were evaluated with clinically and radiologically at immediate postoperative period and at 3, 6, 9, and 12 months. Result : The authors investigated the pre- and postoperative intervertebral disc space, clinical outcomes, radiography fusion rate, and Cobb angle in the fixed segments by anterior approach. The lordotic angles and height of disc space were increased after the operation. The clinical outcome of patients follow-up was good or excellent result based on Odom's criteria with improvement of clinical symptom in about 92.9% of the cervical diseases. Two patients showed loosening of the lower and upper cervical screw of PCB instruments, and two patients showed swallowing difficulty and wound infection Conclusion : The PCB system is a new implant for anterior cervical interbody fusion in the degenerative cervical disease and disc herniations. It provides immediate stability and segment distraction. The results of this study indicate that the PCB system is safe, easy handling of hardware, less complications, high fusion rate, and has provide the keeping the intervertebral disc space height and lordotic angles.

• The Journal of Korean Academy of Prosthodontics
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• v.37 no.2
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• pp.256-268
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• 1999

Submerged implants require secondary surgical uncovering of implants after healing period of 3-6 months. In surgical methods, there are surgical scalpel, tissue punch, electro-surgical, and laser-used uncovering, and so forth The objectives of this study are investigation and assessment of 1) thermal change in clinical application for uncovering of HA-coated implant and pure titanium implant irradiated by pulsed Nd-YAG, $CO_2$, and Er-YAG laser. 2) surface change of cover screws aaer irradiation using laser energy. The temperature of apex & side wall of implants were recorded at 10sec, 20sec, 30sec after 30sec irradiation to implant healing screw; 1) pulsed Nd-YAG laser; 2W, 20pps, contact mode 2) $CO_2$ laser; water-infused & non-water infused state, 2.5-3.5W, contibuous mode, noncontact mode 3) $CO_2$ laser ; non-water infused state, 3W, superpulse, noncontact. mode 4) Er-YAG laser; (1) non-water infused state, 10pps, 60mj, contact mode (2) water-infused state, 10pps, 60mj, 80mj, 101mj, contact mode. According to the results of this study, pulsed Nd-YAG laser is not indicated because of increased thermal change and pitting of metal surface of implant cover screw. By contrast, $CO_2$ laser & Er-YAG laser are presumed to indicate because of narrow range of thermal change & near abscence of thermal damage of metal surface. Dental laser is thought to be much helpful to surgical procedure when it is used as optimal power and time condition considering characteristics and indications of each laser. Further research is needed to verify that these techniques are safe and beneficial to implant success.

• 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.717-728
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• 2003

This study was performed to evaluate the difference of the bone-to-implant contact according to the surface roughness of the implants. Two beagles were used in the experiment. Extraction of the all premolars was performed in the mandible. In 3 months of healing, screw-shaped pure titanium machined surface implants (Implantium(R), Dentium Co. Korea), implants blasted with 45${\mu}m$ $TiO_2$ particles, (Implantium(R), Dentium Co. Korea) and implants blasted with 100${\mu}m$ $TiO_2$ particles (Implantium(R), Dentium Co. Korea) in diameter 3.4mm and length 6mm were installed in the edentulous mandible. Each dog was sacrificed at 4, 12 weeks after placement and then nondecalcified specimens were prepared for histologic analysis. The results of this study were as follows. 1. At 4 , 12 weeks after the surgery, bone-to-implant contact in the surface blasted with $TiO_2$ particles was higher than that in the pure titanium machined surface respectively. 2. Osseointegration in the surface blasted with 45${\mu}m$ $TiO_2$ particles was more increased than that in the surface blasted with 100${\mu}m$ $TiO_2$ particles. 3. Bone-to-implant contact was increased with time independent of surface roughness. 4. Bone formation was in the outfolded area more than inside the threads independent of surface roughness. From the above results, we were able t o find the most bone-to-implant contact in 45${\mu}m$ $TiO_2$ blasted implant.

• Archives of Plastic Surgery
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• v.33 no.6
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• pp.792-796
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• 2006

Purpose: After exposure of fracture site, the proximal segment must be reduced to their preinjury position for open reduction of fractured mandibular condyle. We examined the use of inter-maxillary fixation screws or titanium screws tied with stainless steel wire to assist in positioning of proximal segment. Since it enables to make a relatively small preauricular incision by not disturbing the operative field like Moule pin, we can reduce the danger of injury to the facial nerve. Methods: A preauricular approach was used for exposure, reduction, and rigid fixation in 4 cases of mandibular condylar fractures. Inter-maxillary fixation screws or titanium screws tied with stainless steel wire were used to assist in aligning proximal segment. The joints were submitted to functional exercises and postoperative radiologic and clinical follow-ups were performed. Results: No facial nerve lesions were found in all 4 cases. Radiologic follow-up showed correct reduction and fixation in all 4 cases. Clinical follow-up showed an initial limitation, but normal morbility of the condyle was achieved within 4 months after the operation, with a maximum mouth opening of $34.1{\pm}5.2mm$ after 12 months. There found no occlusal disturbances, no trismus, no lateral deviations of the mandible. Conclusion: By using Inter-maxillary fixation screws tied with stainless steel wire, it was shown that reducing the proximal segment to their preinjury position is easy to perform and it enables us to make a minimal dissection below preauricular skin incision to avoid facial nerve injury.

• Journal of Dental Rehabilitation and Applied Science
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• v.19 no.1
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• pp.27-33
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• 2003

Excessive heat generation at the implant-bone interface may cause irreversible bone damage and loss of osseointegration. The effect of heat generation in vitro at the implant surface caused by abutment reduction with high-speed dental turbine was examined. Titanium-alloy abutments connected to a titanium alloy screw-implant embedded in an acrylic-resin block in a $37^{\circ}C$ water bath were prepared. Temperature changes were recorded via embedded thermocouples at the cervix and apex of the implant surface. Analysis of variance for repeated measures was used to compare seven treatment groups. Fifty seconds of continuous cutting with air and water coolant caused a mean temperature increase of $1.24^{\circ}C$ at apex and $5.77^{\circ}C$ at cervix. Similar intermittent cutting caused increase of $2.50^{\circ}C$ at apex and $1.64^{\circ}C$ at cervix. But, continuous cutting with air coolant caused a mean temperature increase of $6.47^{\circ}C$ at apex and $5.77^{\circ}C$ at cervix. Similar intermittent cutting caused increase of $6.47^{\circ}C$ at apex and $5.77^{\circ}C$ at cervix. Preparation of implant abutment does not lead to detrimental effect on peri-implant tissues provided that adequate cooling. However, without water cooling, extreme overheating could be provoked, reaching the critical temperature that would lead to irreversible bone damage within only a few seconds.

• The korean journal of orthodontics
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• v.48 no.5
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• pp.339-345
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• 2018

Objective: The purpose of this study was to clarify the effects of continuous force application for extrusive tipping movement and occlusal interference on periapical root resorption in the rat mandibular first molar. Methods: We constructed an appliance comprising a titanium screw implant with a cobalt-chromium post as the anchorage unit and a nickel-titanium closed coil spring (50 cN) as the active unit. Force was applied on the mandibular left first molar of rats for 8 (n = 10) and 15 days (n = 10; experimental groups), with the tooth in occlusion. Five rats were included as a non-treated control group to examine the body effect of the appliance. Active root resorption lacunae, identified using tartrate-resistant acid phosphatase, were evaluated in terms of the length, depth, and area. Results: The rat mandibular first molars were mesially tipped and extruded in the occlusal direction. This mesio-occlusal tipping movement and occlusion resulted in the formation of a compression zone and active root resorption lacunae in the distoapical third of the distal roots. However, there was no significant difference in the amount of root resorption between the two experimental groups. The control group did not exhibit any active root resorption lacunae. Conclusions: Periapical root resorption was induced by continuous extrusive tipping force and occlusal interference in rat mandibular molars. These data suggest that we orthodontists had better take care not to induce occlusal interference during our orthodontic treatment.

• Journal of Korean Neurosurgical Society
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• v.56 no.4
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• pp.323-329
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• 2014

Objective : Vertebral body replacement following corpectomy in thoracic or lumbar spine is performed with titanium mesh cage (TMC) containing any grafts. Radiological changes often occur on follow-up. This study investigated the relationship between the radiological stability and clinical symptoms. Methods : The subjects of this study were 28 patients who underwent corpectomy on the thoracic or lumbar spine. Their medical records and radiological data were retrospectively analyzed. There were 23 cases of tumor, 2 cases of trauma, and 3 cases of infection. During operation, spinal reconstruction was done with TMC and additional screw fixation. We measured TMC settlement in sagittal plane and spinal angular change in coronal and sagittal plane at postoperative one month and last follow-up. Pain score was also checked. We investigated the correlation between radiologic change and pain status. Whether factors, such as the kind of graft material, surgical approach, and fusion can affect the radiological stability or not was analyzed as well. Results : Mean follow-up was 23.6 months. During follow-up, $2.08{\pm}1.65^{\circ}$ and $6.96{\pm}2.08^{\circ}$ of angular change was observed in coronal and sagittal plane, respectively. A mean of cage settlement was $4.02{\pm}2.83mm$. Pain aggravation was observed in 4 cases. However, no significant relationship was found between spinal angular change and pain status (p=0.518, 0.458). Cage settlement was seen not to be related with pain status, either (p=0.644). No factors were found to affect the radiological stability. Conclusion : TMC settlement and spinal angular change were often observed in reconstructed spine. However, these changes did not always cause postoperative axial pain.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.1
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• pp.119-147
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• 1999

The purpose of this study was to investigate the effects of the Co-60 γ irradiation on the osseointegration. 2.0 mm titanium alloy screw implants(Sankin Industry Co. Ltd., Japan) were placed in the tibial metaphysis of the rabbits, bilaterally. The mean length of the implants was 6.0 mm. The right tibia was irradiated with a single dose of 15Gy from 60Co teletherapic machine at 5th postoperative day. The experimental group was irradiated tibia. The control group was non­irradiated tibia. To observe the phase of bone formation, the bone labeling by intramuscular injection of 20mg/Kg of Tetracycline, Calcein, Alizarin red S, was performed. The rabbits were sacrificed on the 1st, 2nd, 4th, 6th, 8th week and the tibia including implants were taken, and then the specimens were examined by the microradiography, light microscopy, and fluorescent microscopy. The obtained results were as follows: 1. There were connective tissue between bone and titanium at 1st week, in both group. Especially, the many empty lacunae without nucleus and obscure cytoplasm in experimental group, were observed. 2. The osteons were observed at 4th week in control group, and at 6th week in experimental group. The bone formation in experimental group was retarded as compared to the control group. 3. In fluorescent microscopy, bone labelling band was observed as linear, arc or concentric shape. Occasionary interrupted labelling band was observed, which is demonstrated bone remodeling. 4. In microradiographic examination, the radiolucent image was found between bone and implant with widening of bone marrow spaces as compared to the control group.

• The Journal of Advanced Prosthodontics
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• v.6 no.6
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• pp.491-497
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• 2014

PURPOSE. This study evaluated the influence of abutment materials on the stability of the implant-abutment joint in internal conical connection type implant systems. MATERIALS AND METHODS. Internal conical connection type implants, cement-retained abutments, and tungsten carbide-coated abutment screws were used. The abutments were fabricated with commercially pure grade 3 titanium (group T3), commercially pure grade 4 titanium (group T4), or Ti-6Al-4V (group TA) (n=5, each). In order to assess the amount of settlement after abutment fixation, a 30-Ncm tightening torque was applied, then the change in length before and after tightening the abutment screw was measured, and the preload exerted was recorded. The compressive bending strength was measured under the ISO14801 conditions. In order to determine whether there were significant changes in settlement, preload, and compressive bending strength before and after abutment fixation depending on abutment materials, one-way ANOVA and Tukey's HSD post-hoc test was performed. RESULTS. Group TA exhibited the smallest mean change in the combined length of the implant and abutment before and after fixation, and no difference was observed between groups T3 and T4 (P>.05). Group TA exhibited the highest preload and compressive bending strength values, followed by T4, then T3 (P<.001). CONCLUSION. The abutment material can influence the stability of the interface in internal conical connection type implant systems. The strength of the abutment material was inversely correlated with settlement, and positively correlated with compressive bending strength. Preload was inversely proportional to the frictional coefficient of the abutment material.