• 한국지반환경공학회 논문집
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• 제11권1호
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• pp.45-51
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• 2010

본 연구는 hydroxyapatite(HAP) 첨가 활성탄(HAP sorbent)의 카드뮴에 대한 흡착특성을 조사하였다. HAP 첨가량의 변화에 따른 카드뮴의 제거특성은 HAP 첨가량이 증가 할수록 카드뮴의 제거량은 흡착에 의한 영향으로 증가하는 것으로 나타났다. 이러한 결과는 HAP에 의한 이온교환능력의 증가에 의한 것으로 사료된다. 동역학적 흡착과 흡착평형에 관한 연구는 연속적인 회분식 실험을 통하여 조사하였다. 조사된 흡착평형 데이터는 Langmuir와 Freundlich isotherm mode을 사용하여 살펴보았으며, 초기 흡착질의 농도 변화에 따른 HAP 첨가 활성탄의 카드뮴의 흡착은 Freundlich isotherm model에 적합한 것으로 나타났다. Cd의 흡착반응의 동역학적 연구를 위하여 유사 1차 반응속도와 유사 2차 반응속도 모델을 사용하 Cd 흡착반응의 흡착 메커니즘을 조사하였다. 유사 2차 반응속도를 따르며, 유사 2차 반응속도 상수는 활성탄에 HAP의 첨가량이 증가할수록 증가하는 것을 확인할 수 있었다. 또한, intraparticle diffusion model을 사용하여 수용액상의 흡착질과 흡착매질과의 흡착 메커니즘을 조사하였다. 수용액상 카드뮴의 흡착 메커니즘은 흡착질과 흡착매질에서 표면흡착반응과 입자내 확산이 동시에 일어나는 것으로 확인되었다.

• Journal of Periodontal and Implant Science
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• 제29권2호
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• pp.415-433
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• 1999

Implant stability is the key to long-term successful outcome for osseointegrated implants. To evaluate the initial healing response of bone around HA-coated implants without primary bone contact. 21 HA-coated thread type implants(STERI-OSS?) were placed in the femurs of 5 mongrel dogs, about 1-year old. Implants, 8 mm in length and 3.8mm(experimental 1group), 5.0mm(experimental 2group) and 6.0mm(control group) in diameter, were inserted after 3 holes of 6.0mm in diameter and 10mm in depth were prepared in the surgical sites each dog. Implants were supported by only nonresorbable membrane($Teflon^{(R)}$), in order to prevent the ingrowth of upper soft tissue into the gap between bone and implant, and to maintain each implant to be positioned in the center of the drilled hole. 9 implants with different diameters were inserted in 3 dogs for histologic observation, and 12 implants were inserted in 2 dogs for mobility test and removal torque test. Fluorescent dyes were injected for the observation of new bone formation in order of $Terramycin^{(R)}$, Arizarin $Red^{(R)}$, and $Calcein^{(R)}$ at an interval of 2 weeks. 3 dogs were sacrificed for histologic observation at 4, 8, and 12-week after placement. Light microscopy and confocal laser scanning microscopy were used to qualitatively characterize the bone around HA-coated implant. 2 dogs were sacrificed for mobility test($Periotest^{(R)}$, Simens AG, Bensheim, Germany) and removal torque test($Autograph^{(R)}$ AGS-1000D series, Japan) at 8 and 12-week after placement The results were as follows: 1. Histologic observation showed that osseointegration occurred to both control and experimental groups as time lapse, but delayed bone healing was revealed in 3.8mm group (experimental 1group), compared to contrtol group and 5.0mm group (experimental 2group). 2. The mobility test showed that the experimental groups had no distinguishable movement during experimental periods of 8 and 12-week, and there was no difference in mobility depending on the gap between bone and implant, and time lapse. 3. The removal torque forces were increased depended on the gaps decreasing between bone and implant, and time lapse. The results suggest that HA-coated implant without primary bone contact, based on guided bone regeneration could obtain its stability in all experimental groups as time lapse, but bone healing was delayed in experimental group of 3.8mm. And the results suggested that studies on correlationship between mobility test and removal torque test for implant stability would be necessary.

• 대한치과보철학회지
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• 제38권5호
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• pp.659-674
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• 2000

A large increase in the use of thin film coating of hydroxyapatite(HA) in implant dentistry is driven by the desire to take advantage of the excellent biocompatibility and high strength of HA coating. The purpose of this study was to evaluate the effects of HA-coated implants by ion Beam Assisted Deposition(IBAD) method in comparison to the sand-blasted and machined surfaces. Osteoblast culture test, removal torque test and histomorphometric analysis were performed and the following results obtained; 1. Examination of the osteoblast cultures displayed no difference in the secretion of alkaline phosphatase between the various specimen, but IBAD with pure HA specimen showed low alkaline phosphatase secretion(p<0.05). 2. Removal torque tests showed HA-coated implants by IBAD method to be similar in high value to the implants with sand-blasted surface than the implants with machined surface. And the ovariectomized group showed low mechanical test value than the normal group(p<0.05). 3. Histomorphometrical comparisons were performed on undecalcified ground sections. HA-coated implants by IBAD method demonstrated the highest mean bone-to-metal contact ratio on all threads and 3-best consecutive threads, and the implants with sand-blasted surface and implants with machined surface was in the next consecutive order(p<0.05). HA-coated implants showed slightly higher bone-to- metal contact ratio than sand-blasted implants, but no statistically significant difference was obtained between the two materials. The ovariectomized group showed lower value of bone-to-metal contact ratio than the normal group, but no statistically significant difference was obtained between the two groups. 4. Evaluation of bone volume on all threads and 3-best consecutive threads showed no statistically significant difference among the different surface treatment groups, but showed lower bone volume in ovariectomized group than in the normal group(p<0.05). According tn these results, thin film coated implants with HA showed high bone contact ratio, bone volume and removal torque strength in the short term, but long term observation is needed.

• 대한소아치과학회지
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• 제31권3호
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• pp.506-515
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• 2004

치아 우식증을 조기에 발견하여 기존의 외과적 와동 형성을 피하고 건전한 치질을 최대한 보존하고자하는 예방적 시술 개념에 대한 관심과 연구가 최근 유럽을 중심으로 확산되고 있다. 치아 우식증의 임상적 조기 진단을 위해 새로운 장비들이 개발되고 있으며, 이미 실험실 연구를 통해 성능의 우수성이 입증된 바 있다. 본 연구의 목적은 치아 우식증의 조기 진단을 목적으로 새로 개발된 quantitative light induced fluorescence analysis (QLF) 시스템을 이용하여 우치, 사람의 유치 및 영구치의 법랑질 탈회 속도를 비교 평가하고자 하였다. 각 군당 25개씩 배정된 실험 대상 치아들은 표면을 약 $50{\sim}100{\mu}m$정도 제거한 후 활택하여 탈회 용액(0.1mol/L 젖산, 0.2% 카보폴 907 그리고 50%로 농축된 수산화 인회석으로 제조)에서 1, 2, 4 그리고 8일 동안 탈회시켰다. 모든 시편들은 QLF분석을 시행하였으며 실험 일정에 따라 5개의 시편들을 선택하여 gold standard로 사용하기 위해 Transverse Microradiography analysis (TMR)를 시행하였다. TMR 분석을 통하여 무기질의 탈회량(IML)과 병소 깊이(LD)를 측정하였다. QLF 분석에서 측정된 정상 법랑질의 fluorescence radiance (FRs) 값에 대한 탈회 법랑질의 fluorescence radiance $(FR_D)$의 비율인 FR ratio $(FR_D/FR_s)$를 산출하였다. 우치에서는 FR Ratio와 병소 깊이 간에 통계적 유의성이 있었으며(p<0.05), 유치에서는 FR Ratio와 광물질 소실 및 병소 깊이 간에는 유의성이 없었다(p>0.05). 영구치에서는 FR Ratio와 광물질 소실 및 병소 깊이 간에 통계적 유의성이 있었다(p<0.05). 탈회 시간에 대한 FR Ratio의 회귀 분석 결과에서 얻은 회귀 계수 값은 우치에서는 -4.643(p<0.05), 유치에서는 -5.421(p<0,05), 영구치에서 -4.435(p<0.05)로 나타났다.