• Restorative Dentistry and Endodontics
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• 제20권1호
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• pp.183-192
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• 1995

The purpose of this study was to evaluate the effect of smear layer management on the interfacial morphology between dentin bonding system and dentin. Clearfil New Bond, Scotchbond Multipurpose, Prisma Universal Bond 3 and X-R Bond were used on the cervical dentinal surfaces of bovine incisor teeth. All of the dentin bonding systems were labeled with fluorescene in primer and rhodamine B in adhesive. Specimens of 2~3mm thichness were prepared by longitudinal and labiolingual sectioning. The interface between dentin bonding system and dentin was observed by flouresence imaging with a confocal laser scanning microscope. Following results were obtained. 1. In the specimen of Clearfil New Bond, dentinal tubules were widened by destruction of peritubular dentin in the course of treatment with phosphoric acid of high concentration. 2. Hybrid layer was observed in the specimen of Scotchbond Multipurpose and X-R Bond. 3. In the specimen of Prisma Universal Bond 3, the penetraton of adhesive was not observed clearly.

• Journal of Periodontal and Implant Science
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• 제30권1호
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• pp.145-157
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• 2000

Cytotoxic substances in dental calculus and root cementum of periodontally diseased teeth inhibit new attachment and regeneration. The purpose of scaling and root planing is to remove pathologic structures harboring these cytotoxic substances in order to create a biologically acceptable root surface. However, these procedures inevitably leave a non-biocompatible smear layer. Conventionally, the smear layer has been removed with low pH etching agents such as citric acid, phosphoric acid and tetracycline hydrochloride(TC). Lately, a supersaturated neutral pH etching solution of ethylene diamine tetraacetic acid(EDTA) has been found to be as effective as low pH etchants with respect to smear removal and to be superior in exposing root surfaceassociated collagen. The aim of the present study was to determine the effect of root surface treatment using EDTA on the initial attachment of human gingival fibroblasts. 27 human teeth, extracted due to severe periodontitis, were cut into dentin slices after root planing. The specimens were divided into TC group(treated with $50㎎/m{\ell}$ tetracycline-HCl, pH 1.52), EDTA group(treated with 17% EDTA, pH 7.4), and non-treated control group. After sterilization, 5th subcultured human gingival fibroblasts were seeded in each culture well containing a prepared root slice and incubated for 15 min., 60 min., and 4 hours in 5% $CO_2$ incubator at $37^{\circ}C$. At each incubation time, the number of attached fibroblasts were counted on the microphotographs taken at a magnification of x100. The difference of the number of attached cells between groups was statistically analyzed by the ANOVA followed by Duncan test in SPSS/PC＋programs. The results were as follows : 1. After incubation for 15 min, the attached cells were significantly more in EDTA group and TC group than non-treated control group(p<0.05), but there was no significance in the difference between EDTA group and TC group(p>0.1). 2. After incubation for 60 min and 4 hours, there was no significant difference in the number of attached cells between all groups(p>0.1). 3. In both EDTA group and TC group, there was no significant difference in the number of attached cells between different incubation(p>0.1). But in control group, the number of attached cells was significantly increased after incubation for 60 min, compared with incubation for 15 min(p<0.05). The above results suggest that root surface treatment using EDTA could enhance the initial attachment of gingival fibroblasts to root surface as effective as tetracycline-HCl.

• 대한치과보철학회지
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• 제39권2호
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• pp.208-219
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• 2001

To study the effect of dentin permeability on a tooth with wear from tooth brushing after application of desensitizing agent, extracted teeth free from caries were chosen. Coronal dentin discs with thickness of 1mm were prepared. Using the split chamber device developed by Pashely, hydraulic conductance, scanning electron microscope images(SEM) and atomic force microscope images(AFM) were compared and contrasted before and immediately after the application of desensitizing agent and after equivalent tooth brushing of 1 week, 2 weeks, and 6 weeks. Four commercially available desensitizing agents were used in this study ; they were Gluma, Seal & Protect, All-Bond 2 and MS Coat. The results of this study are as follows. 1. On all specimens, the hydraulic conductance decreased after the application of tooth desensitizing agent. 2. Except the specimens treated with MS Coat, the remaining specimens had an increase in dentin permeability after tooth brushing for 1 and 2 weeks but a decrease after 6 weeks. 3. The specimens treated with MS Coat had statistically significant increase in the dentin permeability regardless with the duration of tooth brushing. 4. On examination of SEM and AFM, the dentinal tubule diameter had decreased after treatment of desensitizing agents. The specimens other than those treated with MS Coat, smear layers were noted after tooth brushing. It is not always consistant but the hydraulic conductance correlated with the images from SEM and AFM.

• 한국동물위생학회지
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• 제34권1호
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• pp.55-61
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• 2011

Dermatopathologic findings on cutaneous streptothricosis (bovine dermatophilosis) were conducted in Dinajpur of Bangladesh for one year. The animals were examined clinically at hospital during the physical visit of the affected animals and clinical manifestations and patients' history were recorded. The gross lesions were systematically examined, noted and categorized. An impression smear was made by the skin scraps, stained with Gram's stain and examined microscopically for the presence of causative bacteria. The suitable sizes of skins of 3 animals typically affected with dermatophilosis were collected surgically from the animals, and prepared for the histopathological study. The cardinal clinical features and gross lesions were characterized as paint-brush cutaneous surface with matted hairs, scab and crust formation, roughened coat; istopathologically as hyperkeratosis, parakeratosis, typical "palisading encrustations", extensive proliferation of coccoid shaped, bluish coloured bacteria (zoospores) in the cells of the outer rootsheath of the hair follicles, separation of keratinized layer from the epidermal epithelium, epidermal hyperplasia, densely cellular dermis with moderate destruction of glandular structures. Coccoid shaped gram positive organisms which form multidimensional arrangement were also observed by impression smear. The clinical signs, gross lesions, morphology of the organisms, staining properties, and histopathological features of the affected skin were diagnostic criteria for the bovine cutaneous streptothricosis.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1999년도 봄 학술발표회 논문집
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• pp.365-372
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• 1999

The plane deformation and spatial seepage(PDSS) analysis was developed to consider 3D flow of excess pore water as well as plane deformation of ground. Here is newly developed an equivalent model for PDSS analysis, which was the purpose to reduce number of finite elements and to take the effects of smear and well resistance into consideration. As the result of PDSS analysis with applying the new model, it is showed that the settlement-tin e relationship by PDSS agrees well with those of Plane strain(PS) and axisymmetric analyses, irrespective of existence of untreated layer. And the excess pore pressure distribution by PDSS is relatively agreed with that of axisymmetric analysis, not with that of PS.

• 대한치과의사협회지
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• 제56권10호
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• pp.556-566
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• 2018

Whether you use a hand file or an engine-driven file, you cannot remove bacteria completely from the root canal by mechanical work alone. If the root canal is well cleaned, endodontic irrigants will well penetrate into these areas that will not be mechanically accessible. It will decompose and remove the biofilm and also remove the smear layer to reach the dentinal tubule. Clinicians who are not yet using NaOCl as their primary irrigant, should be aware that there are no other irrigants that offer all the benefits of NaOCl and are inexpensive. Clinicians may be reluctant to use it because of concern about NaOCl accident, but this possibility is extremely low if used with caution.

• 대한치과보존학회:학술대회논문집
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• 대한치과보존학회 2001년도 추계학술대회(제116회) 및 13회 Workshop 제3회 한ㆍ일 치과보존학회 공동학술대회 초록집
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• pp.565.1-565
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• 2001

This study aimed to compare the efficiency of propylene glycol (PG) and distilled water (DW) as vehicles that would allow diffusion of dye through the root canal system. Human maxillary central incisors were chosen and de-crowned. After enlarging the upper part of the root canal with a Peeso reamer, cementum covering the upper third of the root was removed. The roots were ultrasonically irrigated with 5% NaOCI to remove smear layer.(omitted)

• 대한치과보존학회:학술대회논문집
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• 대한치과보존학회 2003년도 제120회 추계학술대회 제 5차 한ㆍ일 치과보존학회 공동학술대회
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• pp.585-585
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• 2003

I. Objectives 17% EDTA is known as an effective solution to remove smear layer. When it's applicated for more than 1 minute, it shows dentinal erosion of intertubular and peritubular dentin. This study is to investigate the effect of dentinal tubule erosion with different time application of 17% EDTA solution on the apical leakage. II. Materials and Methods 35 recently extracted human teeth with single canal, straight root, and closed apex were used in this study. Crowns were removed and the pulp tissue remnants were removed with a barbed broach.(omitted)

• 대한치과보존학회:학술대회논문집
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• 대한치과보존학회 2003년도 제120회 추계학술대회 제 5차 한ㆍ일 치과보존학회 공동학술대회
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• pp.603-603
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• 2003

I. Objectives The purpose of this study is to evaluate the effect of immediate or delayed composite placement on dentinal micro-tensile bond strength. Caries-free human third molars were used in this study. At first, the occlusal enamel was removed so that the middle dentin was exposed. And then the exposed dentin was polished with 1200-grit silicon carbide paper for the formation of smear layer. The polished dentin was etched with 32% phosphoric acid, dried with gentle air and applicated by dentin adhesives. The specimens were divided into 12 groups.(omitted)

• 대한치과보존학회:학술대회논문집
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• 대한치과보존학회 2003년도 제120회 추계학술대회 제 5차 한ㆍ일 치과보존학회 공동학술대회
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• pp.587-589
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• 2003

I. Objectives The purpose of this study was to evaluate the effects of EDTA on microhardness of roor canal dentine according to different working time. II. Materials and Methods Forty recently extracted, intact single root teeth were used. Debris and soft tissue remnants on the root surface were cleaned with scaler and stored in saline at $4^{\circ}C$ until used. All selected roots were similar in size and shape. 1. Preparation of teeth. The crown of the teeth were removed at the level of the CEJ, using a water-cooled diamond bur.(omitted)