• Journal of Periodontal and Implant Science
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• 제29권3호
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• pp.621-636
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• 1999

When mucoperiosteal flaps are positioned and sutured to desirable position, the wound contains several interface between tissues which differ fundamentally in composition & biological reaction. Thus the C-T surface of the flap will, on one hand, oppose another vascularized surface, and on the other, the avascular dental material for example, when root resoptions, fractured root, endodontic perforation, deep root carious lesions were filled with amalgam, glass ionomer, resin etc. Recently, a number of case report described the successful treatment of a subgingival root lesion with restorative material & free gingival graft, open flap surgery, but more objective research was needed . Most of study on restorative materials were concerned for cytotoxicity not for actual healing event on that materials and its influencing factors such as biocompatibility, surface wettability, surface topography . The aim of this in vitro study was to evaluate the effect of amalgam, resin modified glass ionomer, composite resin per se, and their surface roughness on the growth of human gingival fibroblast. The cells were obtained and placed on culture flask and incubated for 3 days with the prepared test materials. Then count the attached cell number with hemocytometer,(n=12) and 2 samples were examined with SEM about attachment cell morphology . Another 4 samples were evaluated on their surface roughness with Talysurf and average surface roughness value(Ra) were obtained. Statistical difference in attached cell number, roughness value were analyzed using ANOVA. The number of attached cell was as follows, for root dentin specimen 16.7${\pm}$4.41, resin modified glass ionomer 14.0${\pm}$4.15, resin 8.13${\pm}$3.63, amalgam 0.72${\pm}$3.33(${\times}10^3$). Between root dentin and resin-modified glass ionomer, no significant difference was observed, but resin, amalgam showed a significant less cell numbers than for root dentin, resin modified glass ionomer cement. SEM examination expressed many cell surface attachment apparatus in root dentin and resin modified glass ionomer specimens. For resin specimen, cell attachment was observed but exposed less appratus. The average surface roughness value are following results. Dentin specimen 0.6972${\pm}$ 0.104, resin modified glass ionomer 0.0822${\pm}$0.009, resin 0.0875${\pm}$0.005, amalgam 4.2145${\pm}$0.985(${\mu}m$). Between root dentin, resin-modified glass ionomer, and resin, no significant difference was observed, but amalgam showed a significant more rough surface than other groups. When evlauated the interrelationship between cell attachment and surface roughness, therefore, there was weak reverse correlation.(pearson correlation : - 0.593) These results suggest that resin modified glass ionomer have the favorable healing potential when used for subgingival restoration. And for relationship between cell attachment and surface characteristics, further investigations were needed.

• 보존과학회지
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• 제33권2호
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• pp.107-120
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• 2017

경주 월지에서 출토된 금동삼존판불을 복원하고자 고문헌에 공통적으로 기록되어 있는 매실산을 도금 실험에 적용하였으며 도금 결과를 색도, SEM-EDS, XPS 등의 분석을 통해 알아보았다. 색도 분석결과 전체적으로 황색도가 높았으며 10분 이상 매실산 처리를 한 시편이 명도가 높았다. SEM으로 표면을 관찰한 결과 아말감을 도포하고 바로 소성한 경우 도금이 거의 되지 않았으며 36시간 방치 후 소성한 경우 도금층이 불균일하게 관찰되었으므로 도금시간은 12시간~24시간 이내가 적절함을 확인할 수 있었다. EDS로 도금층의 성분을 분석한 결과 산처리 시간이 20분인 시료의 경우 5 wt.% 내외로 수은의 비율이 다른 시료에 비해 낮았다. 또한 XPS로 표면상태를 분석한 결과 산처리시간은 20분이고 24시간동안 아말감을 도포한 시료가 Au의 XPS peak 분해능이 높으며, Hg가 다른 시편들에 비해 거의 남아 있지 않음을 확인할 수 있었다. 즉, 매실산을 이용한 실험 및 분석결과 산처리 시간이 20분이고 아말감 도포시간이 24시간일 때 도금이 잘 되는 것으로 확인하였고, 이 결과를 토대로 금동삼존판불을 복원하였다.

• Restorative Dentistry and Endodontics
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• 제18권2호
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• pp.357-367
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• 1993

The purpose of this study was to evaluate the fracture strength of class II restored premolars with amalgam, posterior composite, amalgam - Ketac silver, resin - Ketac silver restorations at marginal ridge. Fifty extacted maxillary and mandibular premolar teeth that were caries free, fracture free, and restoration free were selected and randomly divided into five groups : Group 1 : 10 intact teeth, Group 2 : 10 teeth with class II cavities and restored with, amalgam, Group 3: 10 teeth with class II cavities and restored with posterior resin, Group 4 : 10 teeth with class II cavities and restored with amalgam - ketac silver, Group 5 : 10 teeth with class II cavities and restored with resin - Ketac silver. All teeth were mounted in base of dental stone within metal rings of 2cm diameter, exposing only the crown portion. Class II mesio - occlusal or disto - occlusal cavities were prepared into specimens of Group 2 through 5 by using a No. 710 fissure bur. The occlusal portion was prepared to a faciolingual width of 1.5mm and a pulpal depth of 1.5mm. The proximal protion was prepared to a faciolingual width of 4mm, a occlusogingival height of 4mm, and a gingival floor of 1.5mm. The teeth in Group 2 and 3 were resotored with silver amalgam apd posterior resin respectively. In Group 4 and 5, proximal portions were first filled with Ketac silver 1.5mm gingivally and remaining cavities were restored with amalgam and posterior resin respectively. All specimens were stored in 100 % relative humidity at $37^{\circ}C$ for 48 hours before testing. All teeth were subjected to a compressive load in a Universal Instron Testing Machine at marginal ridges. The loads required to fracture the restorations were recorded in killograms and the data obtained were subjected to statisticall analysis. The results were all follows : 1. The fracture strength of Group 1 which were unprepared were $100{\pm}10.1\;kg$ and the higher values than Group 2, 3, 4, 5 which were prepared and resotred. 2. In restored groups, Group 2 had the higher fracture strength($81.8{\pm}12.4\;kg$) than other groups and Group 4 had the lowest fracture strength($66.8{\pm}9.2kg$). 3. There were significant differences between fracture strength of between Group 1 and Group 3, 4, 5(P<0.05), but not significant difference between fracture strength of Group 2, 3, 4, 5(P>0.05).

• 대한치과교정학회지
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• 제44권5호
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• pp.229-235
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• 2014

Objective: The aim of this study was to assess artifacts induced by metallic restorations in three-dimensional (3D) dental surface models derived by cone-beam computed tomography (CBCT). Methods: Fifteen specimens, each with four extracted human premolars and molars embedded in a plaster block, were scanned by CBCT before and after the cavitated second premolars were restored with dental amalgam. Five consecutive surface models of each specimen were created according to increasing restoration size: no restoration (control) and small occlusal, large occlusal, disto-occlusal, and mesio-occluso-distal restorations. After registering each restored model with the control model, maximum linear discrepancy, area, and intensity of the artifacts were measured and compared. Results: Artifacts developed mostly on the buccal and lingual surfaces. They occurred not only on the second premolar but also on the first premolar and first molar. The parametric values increased significantly with increasing restoration size. Conclusions: Metallic restorations induce considerable artifacts in 3D dental surface models. Artifact reduction should be taken into consideration for a proper diagnosis and treatment planning when using 3D surface model derived by CBCT in dentofacial deformity patients.

• 대한치과의사협회지
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• 제16권12호통권115호
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• pp.935-940
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• 1978

The purpose of this study was to evaluate the marginal sealing ability of 'Hi-Pol' Enamel Bond system. Using freshly extracted human teeth and 2% acquous methylene blue, the marginal leakage of dye in restorative materials such as 'Hi-Pol' Enamel Bond system, Hi-Pol, Adaptic, Nuva system, Epolite and Amalgam were investigated at 37℃ and under temperature cycling in range of 4℃-60℃. the results as follows; 1. All filling materials showed some degree of marginal penetration by 2% methylene blue dye. 2. 'Hi-Pol' Enamel Bond system revealed the least marginal penetration by 2% methylene blue as Nuva did at 37℃, but under temperature cycling in range of 4℃-60℃ it showed the greatest marginal penetration. 3. Hi-Pol restoration showed a tendency the similar to the other composite restoration. 4. Nuva system had the most effective marginal sealing ability either at 37℃ and under temperature cycling.

• The Journal of Advanced Prosthodontics
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• 제3권4호
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• pp.186-189
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• 2011

PURPOSE. Porcelain fused to metal (PFM) crowns provide the best treatment option for teeth that have a large or defective restoration. More than 20% of teeth with PFM crowns or bridges require non-surgical root canal treatment (NSRCT). This may be due to the effect of restorative procedures and the possible leakage of bacteria and or their by-products, which leads to the demise of the tooth pulp. Thus, this study was planned to compare the ability of the restorative materials to seal perforated PFM specimens. MATERIALS AND METHODS. The study evaluates the ability of amalgam, composite or compomer restorative materials to close perforated PFM specimen's in-vitro. Ninety PFM specimens were constructed using Ni-Cr alloys and feldspathic porcelain, and then they were divided into 3 groups: amalgam (A), composite + Exite adhesive bond (B) and compomer + Syntac adhesive bond (C). All the PFM samples were embedded in an acrylic block to provide complete sealing of the hole from the bottom side. After the aging period, each group was further divided into 3 equal subgroups according to the thermocycling period (one week for 70 cycles, one month for 300 cycles and three months for 900 cycles). Each subgroup was put into containers containing dye (Pelikan INK), one maintained at $5^{\circ}C$ and the other at $55^{\circ}C$, each cycle for 30 sec time. The data obtained was analyzed by SPSS, 2006 using one way ANOVA test and student t-test and significant difference level at (P<.01). RESULTS. The depth of dye penetration was measured at the interfaces of PFM and filling materials using Co-ordinate Vernier Microscope. The lowest levels of the dye penetration for the three groups, as well as subgroups were during the first week. The values of dye leakage had significantly increased by time intervals in subgroups A and C. CONCLUSION. It was seen that amalgam showed higher leakage than composite while compomer showed the lowest level of leakage.

• 대한치과보철학회지
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• 제33권4호
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• pp.634-644
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• 1995

The purpose of this study is to evaluate the color differences in the In-Ceram according to coping thickness and various abutment core materials ; amalgam, precious alloy, composite resin, non-precious alloy. After the porcelain was built up on the In-Ceram coping at the thicknes of 0.3mm and 0.5mm then it was cemented with glass ionomer cement to the post & core materials. The following results were obtained. 1. There were significant differences in the $L^*$ values $a^*$ and $b^*$ values in the cementation of different cores, to the In-Ceram(P<0.01). $L^*$ values were not significantly different between the composite resin to the In-Ceram and the $a^*\;b^*$ values were not significantly different between the amalgam and the non-precious alloy. 2. All of cementations of In-Ceram to the core materisal had color difference(${\Delta}E^*ab$) compared to the In-Ceram. In the 0.3mm thickness of the In-Ceram copping non-precious alloy indicated the greatest value, while the composite resin core showed the lowest value with a thickness of 0.5mm In-Ceram copping. 3. By controlloing the In-Ceram coping thickness $L^*$ value was significatly different(P<0.01), but not in $a^*$ and $b^*$ values. 4. In an amalgam, precious & non-prcious alloys there was a 1,74 to 3.06 range color difference in the controlled thickness of In-Ceram coping at the thickness of 0.3mm and 0.5mm. The above results suggest that the requirement of the sufficient thickness of In-Ceram coping and the suitable core material in order to get an estheti restoration by In-Ceram and also to intercept the original core color.

• Restorative Dentistry and Endodontics
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• 제20권2호
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• pp.655-669
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• 1995

Restorative procedures can lead to weakening tooth due to reduction and alteration of tooth structure. It is essential to prevent fractures to conserve tooth. Among the several parameters in cavity designs, cavity isthmus is very important. In this study, amalgam 0 cavity was prepared on maxillary first premolar. Two dimensional finite element models were made by serial photographic method and isthmus(1/4, 1/3, 1/2, 2/3 of intercuspal distance) were varied. Three or four-nodal mesh were used for the two dimensional finite element models. The periodontal ligament and alveolar bone surrounding the tooth were excluded in these models. 1S model was sound tooth with no amalgam cavity. B model was assumed perfect bonding between the restoration and cavity wall. Both compressive and tensile forces were distributed directly to the adjacent regions. A load of 500N was applied vertically at the first node from the lingual slope of the buccal cusp tip. This study analysed von Mises stress, 1 and 2 directional normal stress and Y and Z axis translation with FEM software Super SAPII Version 5.2 (Algor Interactive System Co.) and hardware 486 DX2 PC. The results were as :follows : 1. 1S model was slightly different with 1B model in stress distibution. 1S, 2B, 3B, 4B models showed similiar stress distribution. 2. 1S model and four B models showed similiar pattern in Y axis and Z axis translation. 3. 1S model and four B models showed the bending phenomenon in the translation. 4. As increasing of the width of the cavity, experimental group was similiar with the control group in stress distribution. 5. As increasing of the width of the cavity, experimental group was similiar with the control group in Y and Z axis tranlation.

• Restorative Dentistry and Endodontics
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• 제35권2호
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• pp.65-68
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• 2010

복합레진의 개발 및 환자의 심미적 욕구로 인해 기존의 아말감을 복합레진 수복이 빠른 속도로 대체하고 있다. 하지만 복합레진의 경우 술식의 어려움, 중합수축으로 인한 응력의 발생, 재료의 파절, 이차우식등의 문제를 가지고 있으며 아직까지 복합레진 수복을 위해서는 치과용 접착제의 사용이 필수적이다. 이에 본 글에서는 현재 복합레진이 가지고 있는 문제점을 극복하기 위해 복합레진 수복의 가장 많은 실패 원인으로 알려진 이차우식을 억제할 수 있는 재광화 물질을 방출할 수 있는 복합레진의 개발이 어디까지 이루어지고 있는지 살펴보고 앞으로의 임상적용 가능성에 대해 생각해보고자 한다.

• Restorative Dentistry and Endodontics
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• 제46권3호
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• pp.34.1-34.9
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• 2021

Objectives: This study aimed to assess the presence of pulp stones through an examination of cone beam computed tomography images and correlate their prevalence with age, sex, dental arch and side, tooth type, and restoration type and depth. Materials and Methods: Cone beam computed tomography images obtained from 673 patients and archival data on 11,494 teeth were evaluated. The associations of pulp stones with age, sex, dental arch and side, tooth type, and restoration type and depth were noted. All the measurements were subjected to a χ² test and one sample χ² test (p < 0.05). Results: In the study group, 163 (24.2%) patients and 379 (3.3%) teeth had at least one pulp stone. The pulp stone frequency in those aged 30-39 years was significantly greater than in those aged 18-29 and ≥ 60 years, and the frequency was higher in females than in males (p < 0.05). The highest prevalence of pulp stones was found in maxillary dental arches and molar teeth (p < 0.05). Pulp stones were significantly more common in medium-depth restorations (p < 0.05). Conclusions: Maxillary molar teeth, medium-depth restorations, individuals aged 30-39 years and females had a greater percentage of pulp stones.