• Journal of Industrial and Engineering Chemistry
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• v.68
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• pp.229-237
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• 2018

Medical silicone tubes are generally used as implants for the treatment of nasolacrimal duct stenosis. However, side effects such as allergic reactions and bacterial infections have been reported following the silicone tube insertion, which cause surgical failure. These drawbacks can be overcome by modifying the silicone tube surface using a functional coating. Here, we report a biocompatible and superhydrophilic surface coating based on a polysaccharide multilayer nanofilm, which can load and release antibacterial and anti-inflammatory agents. The nanofilm is composed of carboxymethylcellulose (CMC) and chitosan (CHI), and fabricated by layer-by-layer (LbL) assembly. The LbL-assembled CMC/CHI multilayer films exhibited superhydrophilic properties, owing to the rough and porous structure obtained by a crosslinking process. The surface coated with the superhydrophilic CMC/CHI multilayer film initially exhibited antibacterial activity by preventing the adhesion of bacteria, followed by further enhanced antibacterial effects upon releasing the loaded antibacterial agent. In addition, inflammatory cytokine assays demonstrated the ability of the coating to deliver anti-inflammatory agents. The versatile nanocoating endows the surface with anti-adhesion and drug-delivery capabilities, with potential applications in the biomedical field. Therefore, we attempted to coat the nanofilm on the surface of an ophthalmic silicone tube to produce a multifunctional tube suitable for patient-specific treatment.

• Journal of Periodontal and Implant Science
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• v.34 no.1
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• pp.71-81
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• 2004

Peri-implantitis could be the result of biomechanical and occlusal overload as well as microbiologic invasion. The dental implant may be more susceptible to dental plaque than the natural tooth, as the predictability of a stable soft tissue attachment complex has not yet been confirmed. With the development of peri-implantitis, the implant surface would be exposed to the oral environment and becomes coated with bacteria. The objective of therapy for this condition is to regain integration of the implant with bone. Since fibroblast adherence to surfaces is impeded by endotoxin, it would seem that decontamination would be desirable to obtain maximum osseointegration. The purpose of this study was to determine whether various chemotherapeutic and mechanical treatments(distilled water, air-powder abrasive, hypersaturated citric acid, tetracycline) can detoxify contaminated titanium implant surface by means of kinetic LAL test. Experimental rough surface titanium disks were fabricated. All of them were divided into two groups(A.a group and P.g group) and each contaminated by A. actinomycetemcomitans and P. gingivalis suspension. Contaminated disks were treated with distilled water, air-powder abrasive, citric acid and tetracycline, and then all disks were placed into LPS-free water for elution. The results were as follows : 1. In A.a group, LPS elute level of all test groups were significantly lower than control group(p<0.05). 2. In A.a group, LPS elute level of test 2, test 3 and test4 groups were significantly lower than that of control group(p<0.05). But, among the test 2, test 3, test4 groups, the significant differences were not detected. 3. In P.g group, LPS elute level of test 2, test 3 and test 4 groups were lower than that of control group(p<0.05). But, among the test groups, the significant differences were not detected. From the result of this study, it would be concluded that air-powder abrasive, hypersaturated citric acid and tetracycline treatments may be effective at reducing endotoxin level on rough titanium implant surfaces, and can be clinically used. But the treatments in peri-implantitis differentially impact osseointegration making one method clinically superior. To gain this knowledges, further molecular biologic and histopathologic studies should be developed.

• The Journal of Korean Academy of Prosthodontics
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• v.42 no.3
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• pp.307-326
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• 2004

Statement of problem. The long-term success of implants is the development of a stable direct connection between bone and implant surface, which must be structural and functional. To improve a direct implant fixation to the bone, various strategies have been developed focusing on the surface of materials. Among them, altering the surface properties can modify cellular responses such as cell adhesion, cell motility and bone deposition. Purpose. This study was to evaluate the cellular behaviors on the surface-modified titanium by morphological observation, cellular proliferation and differentiation. Material and methods. Specimens were divided into five groups, depending on their surface treatment: electropolishing(EP) anoclizing(AN), machining(MA), blasting with hydroxyapatite particle(RBM) and electrical discharge machining(EDM). Physicochemical properties and microstructures of the specimens were examined and the responses of osteoblast-like cells were investigated. The microtopography of specimens was observed by scanning electron microscopy(SEM). Surface roughness was measured by a three-dimensional roughness measuring system. The microstructure was analyzed by X-ray diffractometer(XRD) and scanning auger electron microscopy(AES). To evaluate cellular responses to modified titanium surfaces, osteoblasts isolated from neonatal rat were cultured. The cellular morphology and total protein amounts of osteoblast-like cell were taken as the marker for cellular proliferation, while the expression of alkaline phosphatase was used as the early differentiation marker for osteoblast. In addition, the type I collagen production was determined to be a reliable indicator of bone matrix synthesis. Results. 1. Each prepared specimen showed specific microtopography at SEM examination. The RBM group had a rough and irregular pattern with reticulated appearance. The EDM-treated surface had evident cracks and was heterogeneous consisting of broad sheet or plate with smooth edges and clusters of small grains, deep pores or craters. 2. Surface roughness values were, from the lowest to the highest, electropolished group, anodized group, machined group, RBM group and EDM group. 3. All groups showed amorphous structures. Especially anodized group was found to have increased surface oxide thickness and EDM group had titaniumcarbide(TiC) structure. 4. Cells on electropolished, anodized and machined surfaces developed flattened cell shape and cells on RBM appeared spherical and EDM showed both. After 14 days, the cells cultured from all groups were formed to be confluent and exhibited multilayer proliferation, often overlapped or stratified. 5. Total protein amounts were formed to be quite similar among all the group at 48 hours. At 14 days, the electropolished group and the anodized group induced more total protein amount than the RBM group(P<.05). 6. There was no significant difference among five groups for alkaline phosphatase(ALP) activity at 48 hours. The AN group showed significantly higher ALP activity than any other groups at 14 days(P<.05). 7. All the groups showed similar collagen synthesis except the EDM group. The amount of collagen on the electropolished and anodized surfaces were higher than that on the EDM surface(P<.05).

• Journal of Periodontal and Implant Science
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• v.39 no.1
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• pp.71-76
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• 2009

Purpose: Many researches showed loss of alveolar bone in fresh extraction socket and even in case of immediate implant placement. The aim of this study was to evaluate the effect of non-resorbable barrier membrane on the change of buccal and lingual alveolar bone in immediate implant placement into periapically infected extraction sockets. Materials and methods: Immediate implants were placed into artificially induced periapical lesion of mandibular premolars after complete debridement using buccal bone defect made by a 6mm trephine bur in 4 mongrel dogs. Before flap repositioning, a non-resorbable barrier membrane was placed on the buccal defect in the experimental group. No membrane was placed in the control group. In 12 weeks after placement, the dogs were sacrificed and undecalcified histologic specimens were prepared. The vertical distance from the smooth-rough surface interface(SRI) to gingiva, 1st bone contact and bone crest were measured in buccal and lingual side. The horizontal thicknesses of gingiva and bone at 0, 1, 2 and 3mm below SRI were measured. Results: The buccal bone was resorbed more than lingual bone in both groups and there was statistical significance(p<0.05). The distances from SRI to 1st bone contact were $2.45{\pm}2.35\;mm$ in experimental group and $4.49{\pm}3.10\;mm$ in control group. In all vertical level, lingual bone was thicker than buccal bone(p<0.05). Conclusion: Buccal bone was reduced more than lingual bone in immediate implant placement into periapically infected extraction sockets. Placement of non-resorbable barrier membrane reduced the buccal bone resorption. However there was no statistical significance.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.3
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• pp.325-341
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• 2003

Statement of problem: In cases where bony defects were present, guided bone regenerations have been performed to aid the placement of implants. Nowadays, the accepted concept is to isolate bone from soft tissue by using barrier membranes to allow room for generation of new bone. Nonresorbable membranes have been used extensively since the 1980's. However, this material has exhibited major shortcomings. To overcome these faults, efforts were made to develop resorbable membranes. Guided bone regenerations utilizing resorbable membranes were tried by a number of clinicians. $Bio-Gide^{(R)}$ is such a bioresorbable collagen that is easy to use and has shown fine clinical results. Purpose: The aim of this study was to evaluate the histological results of guided bone regenerations performed using resorbable collagen membrane($Bio-Gide^{(R)}$) with autogenous bone, bovine drived xenograft and combination of the two. Surface morphology and chemical composition was analyzed to understand the physical and chemical characteristics of bioresorbable collagen membrane and their effects on guided bone regeneration. Material and methods: Bioresorbable collagen membrane ($Bio-Gide^{(R)}$), Xenograft Bone(Bio-Oss), Two healthy, adult mongrel dogs were used. Results : 1. Bioresorbable collagen membrane is pure collagen containing large amounts of Glysine, Alanine, Proline and Hydroxyproline. 2. Bioresorbable collagen membrane is a membrane with collagen fibers arranged more loosely and porously compared to the inner surface of canine mucosa: This allows for easier attachment by bone-forming cells. Blood can seep into these spaces between fibers and form clots that help stabilize the membrane. The result is improved healing. 3. Bioresorbable collagen membrane has a bilayered structure: The side to come in contact with soft tissue is smooth and compact. This prevents soft tissue penetration into bony defects. As the side in contact with bone is rough and porous, it serves as a stabilizing structure for bone regeneration by allowing attachment of bone-forming cells. 4. Regardless of whether a membrane had been used or not, the group with autogenous bone and $Bio-Oss^{(R)}$ filling showed the greatest amount of bone fill inside a hole, followed by the group with autogenous bone filling, the group with blood and the group with $Bio-Oss^{(R)}$ Filling in order. 5. When a membrane was inserted, regardless of the type of bone substitute used, a lesser amount of resorption occurred compared to when a membrane was not inserted. 6. The border between bone substitute and surrounding bone was the most indistinct with the group with autogenous bone filling, followed by the group with autogenous bone and $Bio-Oss^{(R)}$ filling, the group with blood, and the group with $Bio-Oss^{(R)}$ filling. 7. Three months after surgery, $Bio-Gide^{(R)}$ and $Bio-Oss^{(R)}$ were distinguishable. Conclusion: The best results were obtained with the group with autogenous bone and $Bio-Oss^{(R)}$ filling used in conjunction with a membrane.