• Journal of Periodontal and Implant Science
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• 제44권5호
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• pp.242-250
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• 2014

Purpose: This study aimed to evaluate the effects of fibronectin and oxysterol immobilized on machined-surface dental implants for the enhancement of cell attachment and osteogenic differentiation, on peri-implant bone healing in the early healing phase using an experimental model in dogs. Methods: Five types of dental implants were installed at a healed alveolar ridge in five dogs: a machined-surface implant (MI), apatite-coated MI (AMI), fibronectin-loaded AMI (FAMI), oxysterol-loaded AMI (OAMI), and sand-blasted, large-grit, acid-etched surface implant (SLAI). A randomly selected unilateral ridge was observed for 2 weeks, and the contralateral ridge for a 4-week period. Histologic and histometric analyses were performed for the bone-to-implant contact proportion (BIC) and bone density around the dental implant surface. Results: Different bone healing patterns were observed according to the type of implant surface 2 weeks after installation; newly formed bone continuously lined the entire surfaces in specimens of the FAMI and SLAI groups, whereas bony trabecula from adjacent bone tissue appeared with minimal new bone lining onto the surface in the MI, AMI, and OAMI groups. Histometric results revealed a significant reduction in the BIC in MI, AMI, and OAMI compared to SLAI, but FAMI demonstrated a comparable BIC with SLAI. Although both the BIC and bone density increased from a 2- to 4-week healing period, bone density showed no significant difference among any of the experimental and control groups. Conclusions: A fibronectin-coated implant surface designed for cell adhesion could increase contact osteogenesis in the early bone healing phase, but an oxysterol-coated implant surface designed for osteoinductivity could not modify early bone healing around implants in normal bone physiology.

• Journal of Korean Dental Science
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• 제11권1호
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• pp.5-13
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• 2018

Purpose: Surface treatment with pH buffering agent has been developed to achieve higher and faster osseointegration. The aim of this study was to evaluate its influence by measuring removal torque and analyzing histological characteristics. Materials and Methods: Titanium implants with following surfaces were used in this study: sand-blasted acid-etched (SA) surface (SA group as control I group), SA surface in calcium chloride aqueous solution (CA group as control II group) and SA surface coated with pH buffering agent (pH group as test group). Removal torque test after 2 weeks and bone-to-implant contact and bone area analyses at 2 and 4 weeks were performed. Result: The rotational torque values at 2 weeks were significantly higher in pH group ($107.5{\pm}6.2Ncm$, P<0.05). The mean values of bone-to-implant contact at 2 and 4 weeks were both higher in pH group ($93.0%{\pm}6.4%$ at 2 weeks, $88.6%{\pm}5.5%$ at 4 weeks) than in SA group ($49.7%{\pm}9.7%$ at 2 weeks, $47.3%{\pm}20.1%$ at 4 weeks) and CA group ($73.7%{\pm}12.4%$ at 2 weeks, $72.5%{\pm}10.9%$ at 4 weeks) with significances (P<0.05). The means of bone area showed significantly higher numbers in pH group ($39.5%{\pm}11.3%$ at 2 weeks, $71.9%{\pm}10.9%$ at 4 weeks, P<0.05). Conclusion: Our findings demonstrated that surface modification with pH buffering agent improved early osseointegration with superior biomechanical property.

• Journal of Periodontal and Implant Science
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• 제24권1호
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• pp.131-143
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• 1994

구강내 노출된 임프란트를 건강한 상태로 유지하기 위해서는 임프란트 매식체 표면을 처치하여 주위조직과 잘 적합할 수 있는 표면구조를 만들어 주어야 한다. 실패한 임프란트의 처리방법으로 구연산이나 air-abrasive system과 같은 여러 가지 방법이 소개 되었으나 HA 피막 처치된 임프란트와 같은 거친 표면이 구강내로 노출된 경우에는 구연산이나 air-abrasive system을 이용한 표면 처리방법을 세균독소 제거에는 효과적이나 HA 피막 처리된 매식체의 거친 표면 제거는 어렵기 때문에 계속되는 치태침착을 방지하기에는 효과적이지 못하므로 세균독소를 제거하는 한편 표면성상을 변화시키지 않고 평활한 표면을 만들기 위한 처리방법들을 알아보고자 하였다. IMZ사에서 제작한 HA 피막 처리된 disc에 high speed diamond bur, low speed diamond bur, stone bur, rubber point, jetpolisher를 처치하고 표면평활도를 알아보기 위하여 표면조도측정 및 주사전자현미경으로 표면상태를 관찰하고 표면성분 변화 유무를 알아보기 위하여 EDX를 이용하여 표면성분을 분석한 결과 다음과 같은 결과를 얻었다. 각 시편에 대한 표면조도 측정 결과는 실험 I군 $2.11{\mu}m$, 실험 II군 $4.17{\mu}m$, 실험 III군 $7.28{\mu}m$, 실험 IV군 $8.61{\mu}m$, 실험 V군 $39.44{\mu}m$의 최대높이값을 나타내므로써, I, II, III, IV, V군 순으로 표면이 평활하게 나타났다. 주사전자현미경 관찰에서는 실험 I군은 비교적 평활한 면을 보였고, 실험 II군은 HA 입자가 거의 삭제되었으나 잔존하는 일부의 HA 입자로 인하여 I군보다 약간 거친 표면을 보였다. 실험 III군과 IV군은 삭제되지 않고 잔존하는 HA 입자가 많아 거친 양상을 보였으며 실험 V군인 HA 피막 처리된 면의 경우는 깊은 홈과 돌출된 부분을 가진 매우 불규칙한 표면 구조를 보였다. 시편의 단면 관찰에서는 실험 I군은 균일한 면을 보였으며 실험 III군과 IV군에서는 삭제되지 않고 잔존하는 다량의 HA 입자로 인해 거친 표면을 보였으나 HA 피막의 두께는 상당량 감소되어 나타났다. 또한 실험 II군과 I군과 유사한 양상을 보였다. 실험 V군의 경우는 일정하지는 않지만 약 $40{\mu}m$의 두께를 보였다. EDX에 의한 표면성분 분석 결과, 삭제가 가장 우수한 실험 II군에서는 calcium과 phosphorus가 소량 나타났고, 삭제가 완전하지 않은 실험 III, IV군에서는 calcium peak와 phosphorus peak를 보였다. 모든 군에 나타난 aluminum은 제조과정 중의 혼입으로 사료된다. 모든 실험군에서 titanium, aluminum, calcium, phosphorus 이외의 다른 성분은 나타나지 않았다.

• Journal of Periodontal and Implant Science
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• 제39권3호
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• pp.293-301
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• 2009

Purpose: The purpose of this study is to show the total survival rate of implants with maxillary sinus floor elevation and the effects that reach the survival rate by classifying types of graft materials, implant surface, operation method, bone height. Methods: In a total of 131 patients, 251 implants with sinus floor elevation were installed simultaneously or after regular healing. Various bone grafts (autograft, xonograft, allograft, alloplast) and implant surface (MTX-HA implant, chemical etching implant, Titanium oxide surface implant, resorbable blasting media implant, resorbable blast texturing implant, HA-coated implant) were used. All implants were investigated clinically and radiographically, being with 1 to 5 years follow-up period after installation. Results: The survival rate of 251 implants with maxillary sinus floor elevation was 94%. The types of implant, surface, graft material, bone height have no statistically signi-ficant differencies. Conclusions: It can be suggested that maxillary sinus floor elevation may have predictable result with various bone graft materials and implant surface.

• The Journal of Advanced Prosthodontics
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• 제7권5호
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• pp.375-379
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• 2015

PURPOSE. The purpose of this study was to evaluate the influence of tightening technique and the screw coating on the loosening torque of screws used for Universal Abutment fixation after cyclic loading. MATERIALS AND METHODS. Forty implants (Titamax Ti Cortical, HE, Neodent) (n=10) were submerged in acrylic resin and four tightening techniques for Universal Abutment fixation were evaluated: A - torque with 32 Ncm (control); B - torque with 32 Ncm holding the torque meter for 20 seconds; C - torque with 32 Ncm and retorque after 10 minutes; D - torque (32 Ncm) holding the torque meter for 20 seconds and retorque after 10 minutes as initially. Samples were divided into subgroups according to the screw used: conventional titanium screw or diamond like carbon-coated (DLC) screw. Metallic crowns were fabricated for each abutment. Samples were submitted to cyclic loading at $10^6$ cycles and 130 N of force. Data were analyzed by two-way ANOVA and Tukey's test (5%). RESULTS. The tightening technique did not show significant influence on the loosening torque of screws (P=.509). Conventional titanium screws showed significant higher loosening torque values than DLC (P=.000). CONCLUSION. The use of conventional titanium screw is more important than the tightening techniques employed in this study to provide long-term stability to Universal Abutment screws.

• Journal of Periodontal and Implant Science
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• 제49권6호
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• pp.366-381
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• 2019

Purpose: The purpose of this study was to evaluate the effectiveness of conventional sandblasted, large-grit, acid-etched (SLA) surface coated with a pH buffering solution based on surface wettability, blood protein adhesion, osteoblast affinity, and platelet adhesion and activation. Methods: Titanium discs and implants with conventional SLA surface (SA), SLA surface in an aqueous calcium chloride solution (CA), and SLA surface with a pH buffering agent (SOI) were prepared. The wetting velocity was measured by the number of threads wetted by blood over an interval of time. Serum albumin adsorption was tested using the bicinchoninic acid assay and by measuring fluorescence intensity. Osteoblast activity assays (osteoblast adhesion, proliferation, differentiation, mineralization, and migration) were also performed, and platelet adhesion and activation assays were conducted. Results: In both the wetting velocity test and the serum albumin adsorption assay, the SOI surface displayed a significantly higher wetting velocity than the SA surface (P=0.000 and P=0.000, respectively). In the osteoblast adhesion, proliferation, differentiation, and mineralization tests, the mean values for SOI were all higher than those for SA and CA. On the osteoblast migration, platelet adhesion, and activation tests, SOI also showed significantly higher values than SA (P=0.040, P=0.000, and P=0.000, respectively). Conclusions: SOI exhibited higher hydrophilicity and affinity for proteins, cells, and platelets than SA. Within the limits of this study, it may be concluded that coating an implant with a pH buffering agent can induce the attachment of platelets, proteins, and cells to the implant surface. Further studies should be conducted to directly compare SOI with other conventional surfaces with regard to its safety and effectiveness in clinical settings.

• 대한치과보철학회지
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• 제46권6호
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• pp.620-627
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• 2008

STATEMENT OF PROBLEM: A biochemical approach for surface modification has offered an alternative for physicochemical and morphological methods to obtain desirable bone-implant interfaces. PURPOSE: The purpose of the present study was to investigate cell responses to poly (D,L-lactide-co-glycolide) (PLGA)/$1{\alpha}$,25-(OH)$_2D_3$ coating with reference to cellular proliferation and differentiation in vitro. MATERIAL AND METHODS: 96 titanium discs were fabricated and divided into four groups. Group 1 was anodized under 300 V as control. Group 2, 3 and 4 were anodized then coated with 3 ml PLGA/$1{\alpha}$,25-(OH)$_2D_3$ solutions. Amount of the solutions were 2 ul, 20 ul and 200ul respectively. The osteoblast-like Human Osteogenic Sarcoma (HOS) cells were seeded and cultured for 1, 3 and 7 days. MTSbased cell proliferation assay and ALPase activity test were carried out. RESULTS: PLGA nanoparticles were observed as fine, smooth and round and HOS cells attached to the anodized surfaces through strand-like and sheet-like filopodia. After 3 days of culture, the dendritic filopodia were exaggerated and sheet-like cytoplasmic projections covered the coated titanium surfaces. After 3 days of culture, all of the groups showed increased cellular proliferation and the lowest proliferation rate was measured on group 2. Higher amount of incorporated $1{\alpha}$,25-(OH)$_2D_3$ (Group 3 and 4) improved cellular proliferation but the differences were not significant statistically (P > .05). But they increased the rate of ALP activities than the control group at day 3 (P < .05). CONCLUSION: Biodegradable PLGA nanoparticles incorporated with vitamin D metabolite positively affected proliferation and differentiation of cells on the anodized titanium surface.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제39권2호
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• pp.43-54
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• 2013

In an attempt to regain function and aesthetics in the craniofacial region, different biomaterials, including titanium, hydroxyapatite, biodegradable polymers and composites, have been widely used as a result of the loss of craniofacial bone. Although these materials presented favorable success rates, osseointegration and antibacterial properties are often hard to achieve. Although bone-implant interactions are highly dependent on the implant's surface characteristics, infections following traumatic craniofacial injuries are common. As such, poor osseointegration and infections are two of the many causes of implant failure. Further, as increasingly complex dental repairs are attempted, the likelihood of infection in these implants has also been on the rise. For these reasons, the treatment of craniofacial bone defects and dental repairs for long-term success remains a challenge. Various approaches to reduce the rate of infection and improve osseointegration have been investigated. Furthermore, recent and planned tissue engineering developments are aimed at improving the implants' physical and biological properties by improving their surfaces in order to develop craniofacial bone substitutes that will restore, maintain and improve tissue function. In this review, the commonly used biomaterials for craniofacial bone restoration and dental repair, as well as surface modification techniques, antibacterial surfaces and coatings are discussed.

• 대한치과보철학회지
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• 제47권4호
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• pp.376-384
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• 2009

연구목적: 본 연구에서는 양극산화 임플란트 표면에 서로 다른 두 가지 방법, Ion beam-assisted deposition (IBAD)법과 Sol-gel법으로 Ca-P 코팅한 임플란트 시편에 골모세포를 배양하였을 때 세포의 증식, 분화, 형태에 어떠한 영향을 미치는지 조사하고자 한다. 연구재료 및 방법: 지름 10 mm, 두께 2 mm 인 상업용 순수 titanium grade IV 재질의 디스크를 제작하였고, 모든 시편은 acetone, 70% ethanol, 증류수에서 각각 10분씩 세척 후 건조하였다. 모든 표면은 300 V의 constant voltage하에서 양극 산화 (anodized)시킨다. 실험군은 양극산화 임플란트 표면에 각각 IBAD법과 Solgel법으로 Ca-P 코팅하였다. 각 표면의 미세표면 거칠기(Ra)를 측정하였고, SEM을 통해 표면의 형상을 관찰하였다. 골모세포을 배양한 후 각 표면군의 세포 증식, ALP 활성도 및 RT-PCR를 통한 골세포 분화 능력 검증을 하였으며, SEM을 통해 세포의 형상도 확인하였다. 통계분석은 SPSS (version 12.0) 프로그램을 이용하여 Kruskal-Wallis Test로 각 군의 유의성을 검증하였다 ($\alpha$=0.05). 결과: IBAD법으로 Ca-P 코팅한 표면이 Sol-gel법으로 Ca-P 코팅한 표면보다 표면 거칠기 (Ra) 값이 더 크게 나타났다 (P<.05). IBAD법으로 Ca-P 코팅한 표면이 Sol-gel법으로 Ca-P 코팅한 표면 보다 세포 증식이 더 활발하고 골세포 조기 분화 정도를 확인 할 수 있는ALP 활성도 또한 더 높게 나타났다 (P<.05). SEM 관찰 결과IBAD법으로 Ca-P 코팅한 표면에 골모세포들이 친화성을 띄면서 안정적으로 부착되었다. 결론: IBAD법으로 Ca-P 코팅한 표면이 Sol-gel법으로 Ca-P 코팅한 표면보다 더 우수한 세포 반응을 보였다. IBAD법으로 Ca-P 코팅한 표면의 세포들은 증식이 잘 이루어지고 잘 분화된 골모세포 형상을 보이고 ALP 활성도 또한 높아 골 형성을 증가시켜 높은 골-임플란트 접촉을 보일 것이다.

• 대한치과보철학회지
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• 제41권2호
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• pp.128-135
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• 2003

Statement of problem : Implant screw loosening remains a problem in implant prosthodontics. Some abutment screws with treated surfaces were introduced to prevent screw loosening and to increase preload. DLC(Diamond Like Carbon) film has similar properties on hardness, wear resistance, chemical stability, biocompatibility as real diamond materials. Purpose : The purpose of this study was to investigate the effect of lubricant layer on abutment screw and to discriminate more effective method between soft lubricant and hard lubricant to prevent screw loosening. Material and method : In this study, $1{\mu}m$ thickness DLC was used as protective, lubricating layer of titanium screws and 3 times removal torque was measured on the abutment screws to investigate the difference in 10 coated and 10 non-coated abutment screws. Results : The results indicated that the implants with DLC coating group were not more resistant to the applied force in screw loosening. At 32Ncm, the 3 times removal torque in DLC group were $27.75{\pm}2.89,\;25.85{\pm}2.35$ and $26.2{\pm}2.57$. The removal torque in no-coated abutment screws were $27.85{\pm}4.23,\;27.35{\pm}2.81$ and $27.9{\pm}2.31$, respectively. Conclusion : The lubricant layer used in this study was Diamond Like Carbon(DLC) and it have a properties of hard and stable layer. The DLC coating layer was hard enough to prevent distortion of screws in the repeated unscrewing procedure in clinical situation. The reduced friction coefficient in hard DLC layer was not effective to prevent screw loosening.