• The Journal of Korean Academy of Prosthodontics
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• v.51 no.3
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• pp.167-174
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• 2013

Purpose: This study was conducted to evaluate the roughness and surface alternations of three differently blasted titanium discs treated by $Nd:YVO_4$ Laser irradiation in different conditions. Materials and methods: Thirty commercially pure titanium discs were prepared and divided into three groups. Each group was consisted of 10 samples and blasted by $ZrO_2$ (zirconium dioxide), $Al_2O_3$ (aluminum oxide), and RBM (resorbable blasted media). All the samples were degreased by ultrasonic cleaner afterward. Nine different conditions were established by changing scanning speed (100, 300, 500 mm/s) and repetition rate (5, 15, 35 kHz) of $Nd:YVO_4$ Laser (Laser Pro D-20, Laserval $Korea^{(R)}$, Seoul, South Korea). After laser irradiation, a scanning electron microscope, X-ray diffraction analysis, energy dispersive X-ray spectroscopic analysis, and surface roughness analysis were used to assess the roughness and surface alternations of the samples. Results: According to a scanning electron microscope (SEM), titanium discs treated with laser irradiation showed characteristic patterns in contrast to the control which showed irregular patterns. According to the X-ray diffraction analysis, only $Al_2O_3$ group showed its own peak. The oxidation tendency and surface roughness of titanium were similar to the control in the energy dispersive X-ray spectroscopic analysis. The surface roughness was inversely proportional to the scanning speed, whereas proportional to the repetition rate of $Nd:YVO_4$. Conclusion: The surface microstructures and roughness of the test discs were modified by the radiation of $Nd:YVO_4$ laser. Therefore, laser irradiation could be considered one of the methods to modify implant surfaces for the enhancement of osseointegration.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.197-197
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• 2019

총인처리시설에서는 응집제를 주입하여 인이나 오염물질을 침전시켜 처리하고 있으며 PAC(poly aluminum chloride)나 $FeCl_3$, $Al_2(SO_4)_3$, 등 다양한 종류의 응집제가 사용되어지고 있다. 하지만 기존에 사용되어 지고 있는 알루미늄계열의 응집제는 처리수에 잔류이온이 존재하게 되어 인체에 축적돼 알츠하이머 병 등 신체질환을 유발할 수 있는 단점이 있다. 따라서 이러한 단점을 사전에 예방하기 위해 $TiCl_4$와 같은 티타늄계열 응집제에 대한 연구가 진행되고 있다. $TiCl_4$ 응집제는 인 제거에 효과적으로 적용할 수 있으며 수중에 잔류이온을 유발하지 않으며 Ti이온은 치과임플란트나 의료장비로 사용될 만큼 인체에 무해하다고 알려져 있다. 응집제 사용에 따라 생성된 응집슬러지의 처리방안에 있어서 기존 응집제의 경우 생성된 슬러지의 대부분은 하수슬러지 위탁처리업체를 통해 소각 및 매립, 재활용 되고 있으나, $TiCl_4$를 응집제로 사용할 경우 생성된 슬러지를 인발하여 건조 및 소성을 통해 이산화티타늄으로 재활용할 수 있어 슬러지를 친환경적으로 처리가 가능해 기존 슬러지 처리방안의 경제적, 환경적 부담을 줄일 수 있는 장점이 있다. 따라서 본 연구에서는 $TiCl_4$를 하수처리장 방류수에 주입하여 수중의 총인(T-P)을 처리한 후 생성된 슬러지를 인발하여 건조와 소성과정을 거쳐 이산화티타늄을 제조하였다. 방류수를 취수해 2.5mg/L의 초기 총인 농도를 가진 원수를 제조하였으며 제조된 원수에 $TiCl_4$를 0.6mL 주입하였을 때 99.93%의 총인제거효율을 얻을 수 있었다. 응집 실험 후 생성된 슬러지를 인발하여 건조 후 $300{\sim}1000^{\circ}C$의 각각 다른 온도조건에서 소성하여 이산화티타늄을 제조하였으며, SEM과 XRD를 통해 제조된 이산화티타늄의 표면특성과 결정성 분석을 실시하였다. 제조된 이산화티타늄은 $500{\sim}800^{\circ}C$에서는 아나타제, $900{\sim}1000^{\circ}C$에서는 루타일 결정구조가 나타났다. 또한, $TiCl_4$ 주입량에 따른 이산화티타늄의 최종 생산량과 제조 시 사용되는 건조로 및 소성로의 경제적 비용 등을 고려하여 이산화티타늄 1Ton을 제조하기 위해 필요한 단가를 산출하였다. 본 연구에서 제조된 이산화티타늄 1kg의 생산단가는 약 5,400원으로 나타났으며, 가장 많이 사용되는 P-25 광촉매 보다 저렴한 가격으로 제조 및 판매를 기대할 수 있다. 따라서 하수처리장에 적용 시 기존 응집제 보다 비싼 $TiCl_4$ 비용을 보완하고 친환경적인 슬러지 처리로 제조된 이산화티타늄의 유통 및 현장적용을 통해 경제적, 환경적으로 우수하다고 판단된다.

• The Journal of Engineering Research
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• v.6 no.2
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• pp.23-32
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• 2004

Metals, ceramics and polymers are widely used as bioimplant materials. However, Ti and Ti alloys are widely used because of its high strength to weight ratio and good biocompatibility when implanted in the body. In this experiment, Ti alloys of Grade-4 (gr4), 0.2 wt % Fe, 0.5 wt % Fe and 2 wt % Fe were studied for their surface morphology and HAp forming ability on the metal substrate for different treatments. Intially, the samples were mechanically polished on silicone carbide paper (No.-2000). The polished samples were treated with 5M NaOH solution at $60^{\circ}C$ for 24 hours. The NaOH treated samples were washed gently with distill water and dried at $40^{\circ}C$ for 1 day. The dried samples were heated in air at $600^{\circ}C$ for 1 hour. The surface morphology of these samples were studied using SEM. The SEM studies showed network of pores in all samples. These samples were immersed in stimulated body fluids (SBF) kept at $36.5^{\circ}C$ for different periods over the length of 1 to 14 days. The apatite formation was confirmed on all Ti-alloys using EDAX.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.3
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• pp.258-265
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• 2008

Purpose. This multicenter retrospective study was performed to evaluate the survival and success rates of immediate placement of USII and SSII Osstem implant (Osstem implant Co, Korea) on the maxillary and mandibular anterior and premolar areas. Materials and methods. Dental records were obtained in 37 patients who were treated with immediate implantation on the maxillary and mandibular anterior and premolar areas in 6 different clinics. The 98 implants were evaluated both clinically and radiographically using predefined success criteria. Results. There was no failed implant in all patients. The mean follow up period was 24.7 months (ranged from 12 to 58 months), and 25.1 months (ranged from 16 to 35 months) in USII and SSII implants, respectively. The crestal bone loss was 3 mm in 3 USII implants during 41 months, and in 1 SSII implant during 22 months. The overall success rate was 94.2% and 97.7% in USII and SSII implants, respectively. The age, gender, diameter, or length of implants, and type of surgery were not influenced to the success rate of immediate implantation. Conclusion. These results suggest that USII and SSII Osstem implant can be used successfully in immediate implantation on the maxillary and mandibular anterior and premolar areas.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.3
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• pp.285-292
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• 2008

Purpose: The present study was performed to evaluate the effect of surface treatment of the cervical area of implant on bone regeneration in fresh extraction socket following implant installation. Materials and methods: The four minipigs, 18 months old and 30 kg weighted, were used. Four premolars of the left side of both the mandible and maxilla were extracted. ${\phi}$3.3 mm and 11.5 mm long US II plus implants (Osstem Implant co., Korea) with resorbable blasting media (RBM) treated surface and US II implants (Osstem Implant co., Korea) with machined surface at the top and RBM surface at lower portion were installed in the socket. Stability of the implant was measured with $Osstell^{TM}$ (Model 6 Resonance Frequency Analyser: Integration Diagnostics Ltd., Sweden). After 2 months of healing, the procedures and measurement of implant stability were repeated in the right side by same method of left side. At four months after first experiment, the animals were sacrificed after measurement of stability of all implants, and biopsies were obtained. Results: Well healed soft tissue and no mobility of the implants were observed in both groups. Histologically satisfactory osseointegration of implants was observed with RBM surface, and no foreign body reaction as well as inflammatory infiltration around implant were found. Furthermore, substantial bone formation and high degree of osseointegration were exhibited at the marginal defects around the cervical area of US II plus implants. However, healing of US II implants was characterized by the incomplete bone substitution and the presence of the connective tissue zone between the implant and newly formed bone. The distance between the implant platform (P) and the most coronal level of bone-to-implant contact (B) after 2 months of healing was $2.66{\pm}0.11$ mm at US II implants group and $1.80{\pm}0.13$mm at US II plus implant group. The P-B distance after 4 months of healing was $2.29{\pm}0.13$mm at US II implants group and $1.25{\pm}0.10$mm at US II plus implants group. The difference between both groups regarding the length of P-B distance was statistically significant(p<0.05). Concerning the resonance frequency analysis (RFA) value, the stability of US II plus implants group showed relatively higher RFA value than US II implants group. Conclusion: The current results suggest that implants with rough surface at the cervical area have an advantage in process of bone regeneration on defect around implant placed in a fresh extraction socket.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.3
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• pp.237-242
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• 2009

Implant-supported fixed and removable prostheses provide a proper treatment modality with reliable success. The SS $II^{(R)}$ Implants is a one-stage nonsubmerged threaded titanium implants with Resorbable Blasting Media (RBM) surface developed by Osstem company (Busan, Korea) in October of 2002. This study is to evaluate the survival rate of the SS $II^{(R)}$ Implants for 4 years using radiographic parameters and to review the retrieved implants by the cytotoxicity tests. Since September 2003, 439 SS $II^{(R)}$ implants had been used for 173 patients at Ewha Womans University Medical Center in Korea. Patients consisted of 91 females (52.6 %) and 82 males (47.4 %). The patients' mean age was $42\;{\pm}16$ years, ranging from 21 to 83 years. The follow-up period ranged from 9 to 46 months (mean F/U $24.2\;{\pm}\;10.2$ months). The results are as follows; 1. Of 439 implants, 17 implants were removed and 4-year cumulative survival rate was 96.1%. 2. 82.3% of 17 failed implants were founded during healing phase, and 94.1% of failed fixtures were removed within 5 months after implantation. 3. Crestal bone around the implants was resorbed to 1 mm in 89.0%, to 1 - 2 mm loss of the marginal bone in 8.3%, and the bone loss over 2 mm was occurred in 2.7%. 4. Microscopic examination of the retrieved implants disclosed Grade 0 cytotoxicity in 4 and Grade 1 cytotoxicity in 2 of 6 groups divided according to LOT numbers. Inhibition rate with optical density was acceptable as low as ISO standard.

• Journal of Periodontal and Implant Science
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• v.31 no.1
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• pp.41-57
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• 2001

It is well known that the apposition of bone at implant surface would be influenced by the microstructure of titanium implants. The purpose of this study was to compare bone healing around the screw-shaped titanium implant with three different surface topographies in the canine mandibles by histological and biomechanical evaluation. All mandibular premolars of six mongrel dogs were extracted and implants were placed one month later. The pure titanium implants had different surface topographies: smooth and machined ($Steri-OSS^{(R)}$: Group II); sandblasted and acid-etched ($ITI^{(R)}$, SLA: Group III) surface. The fluorescent dyes were injected on the 2nd (calcein), 4th (oxytetracycline HCI) and 12th (alizarin red) weeks of healing. Dogs were sacrificed at 4 and 12 weeks after implantation. The decalcified and undecalcified specimens were prepared for histological and histo-metrical evaluation of implant-bone contact. Some specimens at 12 weeks after implantation were used for removal torque testing. Histologically, direct bone apposition to implant surface was found in all of the treated groups. More mature and dense bone was observed at the implant-bone interface at 12 weeks than that at 4 weeks after implantation. Under the fluorescent microscope, thick regular green fluorescent lines which mean early bone apposition were observed at the implant-bone interface in Group III, while yellow and red fluorescent areas were found at the implant-bone interface in Group I and II. The average implant-bone contact ratios at 4 weeks of healing were 54.3% in Group I, 57.7% in Group II and 66.2% in Group III. In Group I, implant-bone contact ratio was significantly lower than Group II and III(p<0.05). The average implant-to-bone contact ratios at 12 weeks after implantation were 64.3% in Group I, 66.7% in Group II and 71.2% in Group III. There was no significant difference among the three groups. In Group I and II, the implant-bone contact ratio at 12 weeks increased significantly in comparison to ratio at 4 weeks(p<0.05). The removal torque values at 12 weeks after implantation were 90.9 Ncm in Group I, 81.6 Ncm in Group II and 77.1 Ncm in Group III, which were significantly different(p<0.05). These results suggest that bone healing begin earlier and be better around the surface-treated implants compared to the smooth surface implants. The sandblasted and acid-etched implants showed the most favorable bone response among the three groups during the early healing stage and could reduce the waiting period prior to implant loading.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.1
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• pp.16-21
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• 2011

Purpose: The purpose of this study was to investigate the bioactivity of precalcified nanotubular $TiO_2$ layer on Ti-6Al-7Nb alloy. Materials and methods: Anodic oxidation was carried out at a potential of 20 V and current density of 20 mA/$cm^2$ for 1 hour. The glycerol solution containing 1 wt% $NH_4F$ and 20 wt% deionized water was used as an electrolyte. Precalcification treatment was obtained by soaking in $Na_2HPO_4$ solution at $80^{\circ}C$ for 30 minutes followed by soaking in saturated $Ca(OH)_2$ solution at $100^{\circ}C$ for 30 minutes, followed by heat treatment at $500^{\circ}C$ for 2 hours. To evaluate the activity of precalcified nanotubular $TiO_2$ layer, specimens were immersed in a simulated body fluid with pH 7.4 at $36.5^{\circ}C$ for 10 days. Results: 1. Nanotubular $TiO_2$ layer showed the highly ordered dense structure by interposing small diameter nanotubes between large ones, the shape of nanotubes was enlarged as going down. 2. The mean length of nanotubes was $517.0{\pm}23.2\;nm$ innm glycerol solution containing 1 wt% $NH_4F$ and 20 wt% $H_2O$ at 20 V for 1 hour. 3. The bioactivity of Ti-6Al-7Nb alloy was improved with formation of nanotubular $TiO_2$ layer and precalcification treatment in $80^{\circ}C$ 0.5 M $Na_2HPO_4$ and saturated $100^{\circ}C$ $Ca(OH)_2$ solution. Conclusion: Bioactivity of precalcified nanotubular $TiO_2$ layer on Ti-6Al-7Nb alloy was improved.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.4
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• pp.309-320
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• 2007

Purpose: This study was to evaluate the removal effect on artificial plaque from RBM treated implant surfaces that are exposed due to peri-implantitis. Materials and methods: Artificial plaque with Streptococcus mutans and acquired pellicle adhered to RBM treated implant discs. Study materials divided into one control and six test groups. In test groups, physical and chemical methods used to remove plaques. Prophyflex, Professional Mechanical Tooth Cleaning (PMTC) and interdental brush as mechanical treatments and 0.1% Chlorhexidine, Citric acid, HCl tetracycline as a chemical treatment were used. To analyses the study, disc weight was measured for remaining plaque quantities and SEM(Scanning Electronic Microscope) findings was taken for evaluation of surfaces. Results: 1. In weight changes, there was significant difference between each treatment group and the control group (p<0.05). Therefore all treatment methods using this study have good ability for remove plaques. 2. In weight changes, there was no significant difference between mechanical and chemical group, and there were no significant differences between each groups (p>0.05). 3. SEM findings after mechanical treatment disclosed as follows; Prophyflex group looked like sound implant surface, and there were some paste on implant surface at PMTC group, and there were some artificial plaque at interdental brush group. 4. SEM findings after chemical treatment disclosed as follows; there were some dark lesions which were supposed as the product from Streptococcus mutans at Chlorhexidine, Citric acid and HCl tetracycline groups. Conclusion: All six methods using in this study have good ability to remove artificial plaque on RBM treated implant. According to SEM findings, prophyflex is a superior method for removing of dental plaque among test groups.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.1
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• pp.31-41
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• 2008

Statement of problem: It has been proved that Pleurotus eryngii Quel and Eleutherococcus senticosus have antiinflammatory action and not only stimulates the proliferation and activity of osteoblast but inhibits the generation and activity of osteoclast in vitro. Pleurotus eryngii Quel and Eleutherococcus senticosus are the main component of $OPB-K^{(R)}$. Purpose: The purpose of this study was to evaluate $OPB-K^{(R)}$ which enhances the healing rate of peri-implant bone and the bone mineral density. Materials and methods: Thirty six specially designed implants were installed in the tibia of rats. The group medicated with $OPB-K^{(R)}$ was the experimental group, and that without was the control group. hen the implant stability was measured by $Periotest^{(R)}$. Bone mineral density and histological measurement were conducted at the 2nd, 4th and 6th week $Periotest^{(R)}$ and bone mineral density values were analyzed statistically with independent t-test at 95% confidence level(p<0.05). Results: The results of this study were as follows : 1. There was no statistically significant difference in $Periotest^{(R)}$. values between the experimental group and control group at the 2nd week, however, on the 4th and 6th week there was significant difference(p<0.05). 2. There was no statistically significant difference in bone mineral density between the experimental group and control group at the 2nd and 4th week, however on the 6th week there was significant difference(p<0.05). 3. Histological analysis showed difference in osseointegration on the 4th and 6th week between the groups. Conclusion: From the results, it is concluded that the $OPB-K^{(R)}$ medicated group showed statistically better results in bone density and stability than the control group. Clinically it would be better to medicate $OPB-K^{(R)}$ to patients for a long period of time after implantation to get superior results.