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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Restorative Dentistry and Endodontics
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Journal DOI :
The Korean Academy of Conservative Dentistry
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Volume & Issues
Volume 18, Issue 2 - Sep 1993
Volume 18, Issue 1 - Apr 1993
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THE CYTOTOXIC EFFECTS OF GLASS-IONOMER CEMENT LINERS ON FIBROBLASTS IN HUMAN PULP
Na, Young-Min ; Min, Byung-Soon ; Choi, Ho-Young ; Park, Sang-Jin ; Choi, Gi-Woon ;
Restorative Dentistry and Endodontics, volume 18, issue 2, 1993, Pages 261~276
The purpose of this study was to evaluate for the cytotoxicity of glass-ionomer cement liners(GC liningcement, Ketac-bond, Vitrebond and Fuji lining LC) on the fibroblasts cultured from human pulp. The fibroblasts were cultured in DMEM-10% FBS medium. The measurement of pH, succinate dehydrogenase (SDH) activity test and
release test were performed. Viable cell count and
-leucine incorporation rate were evaluated following culture time of 2, 4 and 6 days. The results of this study were as follows : 1. The pH in all cements was to be neutralized as time elapsed, and Fuji lining LC was the lowest pH value among them. 2. SDH activity was more inhibited in GC lining cement and Vitrebond than Ketac-bond and Fuji lining LC with the setting process, and GC lining cement and Ketac-bond were reduced after 5 minute's setting and then elevated as time elapsed. 3. In SDH activity test following exposure time, the activity in Vitrebond, GC lining cement and Fuji lining LC was inhibited with increased exposure time, but it was fairly constant in Ketac-bond. 4. Overall the liquid component was more inhibited than the powder component of glass-ionomer cement in SDH activity test. 5. In
-release test, Fuji lining LC was the most released of all the cements tested and followed by : Vitrebond, Ketac-bond, GC lining cement. 6. In viable cell count, the number of cells increased as the culture day proceeded in Ketac-bond, but they decreased in GC lining cement. Fuji lining LC was only observed after 2 days culture and there was not observed the whole culture days in Vitrebond. 7. In
-leucine incorporation rate test, protein synthesis was decreased with the number of culture days in GC lining cement, Vitrebond and Fuji lining LC, but it was followed that of control in Ketacbond.
THE EFFECT OF ACID CONCENTRATION AND pH OF LACTATE BUFFER SOLUTION ON THE PROGRESS OF ARTIFICIAL CARIES LESION IN HUMAN TOOTH ENAMEL
Park, Seong-Ho ; Lee, Chan-Young ; Lee, Chung-Suck ;
Restorative Dentistry and Endodontics, volume 18, issue 2, 1993, Pages 277~290
Dental caries is considered to be caused by demineralization by organic acid produced by microorganism. But the formation of subsurface lesion in initial caries make it diffcult to explain by simple demineralization. This study is carried out on the basis of thermodynamic concept proposed by Margolis and Moreno. The purpose of this study is to evaluate the effects of acid concentration and pH of lactate buffer system on the artificial caries lesion progress. 160 teeth without any crack, defect or opaque enamel were used and coated with nail varnish except the window (
mm). Under the constant degree of saturation(D.S.). The teeth were divided into 8 groups according to acid concentration(10mM, 25mM, 50mM, 100mM) and pH(4.3, 5.0, 6.0). Each group was immersed in buffer solution for 3, 6, 9, 18 days under controlled temperature(
). After cutting through the window and grinding, the specimens, 100-150 um in thickness, were imbibed in water or air and examined using polarilizing microscope. The depth of the surface and subsurface surface lesion were measured. 1. In the constant pH and D. S. value, the subsurface lesion progresses more rapidly as the concentration of lactic acid increases. (0.01, 0.025, 0.05, 0.1) 2. In the constant acid concentration and DS value, the subsurface lesion progresses more slowly as the pH increases. (4.3, 5.0, 5.5, 6.0) 3. The width of surface lesion seems to be constant independant of pH and acid concentration.
A STUDY ON TOOTH FRACTURE WITH THREE DIMENSIONAL FINITE ELEMENT METHOD
Cho, Byeong-Hoon ; Um, Chung-Moon ;
Restorative Dentistry and Endodontics, volume 18, issue 2, 1993, Pages 291~316
Restorative procedures can lead to tooth fracture due to the relatively small amount of the remaining tooth structure. It is essential to prevent fractures by having a clear concept of the designs for cavity preparations. Among the several parameters in cavity designs, profound understanding of isthmus width factor would facilitate selection of the appropriate cavity preparation for a specific clinical situation. In this study, MO amalgam cavity were prepared on maxillary first premolar and filled with amalgam. Three dimensional, model with 1365 8-node brick elements was made by serial photographic method. In this model, isthmus was varied in width at 1/4, 1/3, 1/2 and 2/3 of intercuspal width and material properties were given for three element groups, i.e., enamel, dentin and amalgam. A load of 500 N was applied vertically on amalgam and enamel. In case of enamel loading, 2 model (with and without amalgam) was compared to consider the possibility of play at the interface between tooth material and amalgam. These models were analyzed with three dimensional finite element method. The results were as follows: 1. The stress was concentrated on the facio-pulpal line angle and distal marginal ridge of the cavity. 2. With the increase of the isthmus width, the stress spread around the facio-pulpal line angle and the area of stress concentration moved toward the proximal box. 3. In case of narrow isthmus width, the initiation point of crack would be in the area of isthmus corner of the cavity, and with the increase of the isthmus width, it would move toward the proximal box and at the same time the possibility of crack increase at the distal marginal ridge. 4. The direction of crack progressed outward and downward from the facio-pulpal line angle, and with the increase of the isthmus width, it approximated vertical direction. At the marginal ridge, it occurred in vertical direction. 5. It would be favorable to make the isthmus width narrower than a third of the intercuspal width, and to cover the cusp if isthmus width were wider than half of the intercuspal width. 6. It is necessary to apply the possibility of play to the finite element analysis.
FLOW CYTOMETRIC ANALYSIS OF LYMPHOCYTE AND CYCLING CELL DISTRIBUTION IN PERIAPICAL LESIONS
Oh, Tae-Seok ; Lim, Sung-Sam ;
Restorative Dentistry and Endodontics, volume 18, issue 2, 1993, Pages 317~340
This study was designed 1) to compare the distributions of periapical inflammatory cells and 2) to identify lymphocytes and compare the lymphocyte distribution with T lymphocyte subpopulation and then 3) to examine the distribution of cycling cell in human dental periapical lesions. From each of the twenty-five human dental periapical lesions observed one small portion was fixed, embeded in paraffin, sectioned serially and stained with HE. The periapical inflammatory cells were counted to obtain the relative concentration of lymphocyte, plasma cell, macrophage and neutrophil. The large part of each lesion was analysed using Flow cytometer and monoclonal antibodies to obtain the relative concentration of T lymphocyte, B lymphocyte, T'helper cell and T suppressor/cytotoxic cell. In addition to that, seven human dental periapical lesions were examined with DNA analysis to observe the distribution of cycling cell. Following results were obtained: 1. 24 cases of the 32 periapical lesions examined were diagnosed as periapical granuloma and the remaining 8 cases as periapical cyst. Lymphocytes comprised 42.1% of total inflammatory cells in periapical granuloma and 41.8% in periapical cyst. Corresponding percentages for macrophages were 33.8% and 30.3%; for plasma cells, 15.9% and 19.0%; for neutrophils, 8.2% and 8.8%. 2. All of the periapical lesions examined had T lymphocyte, B lymphocyte, T helper cell, T suppressor/cytotoxic cell. And in all cases, T lymphocytes were observed predominantly more than B lymphocytes. 3. In 2 cases of the control group only T lymphocytes were found, and in the remaining 2 cases T lymphocytes were observed predominantly. 4. T helper cells were observed predominantly more than T suppressor/cytotoxic cells in all cases of perapical granulomas. 5. T suppressor/cytotoxic cells were observed predominantly more than T helper cells in 4 cases of periapical cysts (total 5 cases were examined) and only in one case T helper cells were more than T suppressor/cytotoxic cells. 6. In control group, T helper cells were predominant in 2 cases and T helper cells were equivalent to T suppressor/cytotoxic cells in one case. In remaining one case T suppressor/cytotoxic cells were predominant. 7. As the result of DNA analysis, the average proliferating indices of the various groups examined were measured as follows: in the control group 5.45%, in periapical granuloma 6.64%, in periapical cyst 10.1%. The highest index was observed in periapical cyst.
A STUDY ON THE CHANGES OF THE ROOT SURFACE PLAQUE FLORA AND GINGIVAL CREVICULAR FLUID ANTIBODY TITERS AFTER ANTIMICROBIAL VARNISH TREATMENT
Do, Jeong-Wook ; Kwon, Hyuk-Choon ;
Restorative Dentistry and Endodontics, volume 18, issue 2, 1993, Pages 341~356
In the prevention of root surface caries, antimicrobial therapy for the control of subgingival and supragingival plaque is seriously considered as a long term suppression of pathogenic microflora. Recently, varnishes containing antimicrobial agents have been developed to control the supragingival microflora. The purpose of this study was to determine the antimicrobial effects of 20% chlorhexidine varnish and 2.6% silane fluoride varnish with sealant. In clinical experiments, 12 subjects were selected from the periodontally treated patient and divided into 3 groups. After a dental prophylaxis, the subjects were treated with single application of placebo varnish (group I), 20% chlorhexidine varnish (group II), and 2.6% silane fluoride varnish (group III). Root surface plaque samples were taken before (baseline) and one, two, four, and 8 weeks after the treatments. Microbiological examinations of root surface plaque were performed with culture study and indirect immunoflorescence (I.I.F.) study, and immunological examination of gingival crevicular fluid antibody titers was performed with ELISA study. The results were as follows: 1. Pathogenic microflora on the root surface including S. mutans, S. sanguis, S. mitis, A. naeslundii, A. viscosus were 24 - 37% on I.I.F. study. 2. S. mutans, S. sanguis, S. mitis, A. naeslundii, A. viscosus of the root surface plaque was significantly reduced from 1 week to 8 weeks after antimicrobial varnish treatment, but showed generally increasing tendency in control group. 3. Gingival crevicular fluid antibody titers were significantly reduced from 1 or 2 weeks to 4 weeks after antimicrobial varnish treatment.
AN EXPERIMENTAL STUDY ON THE FRACTURE STRENGTH OF CLASS II POSTERIOR RESTORATIONS
Lee, Kye-Hyuck ; Hur, Seung-Myun ; Cho, Young-Gon ;
Restorative Dentistry and Endodontics, volume 18, issue 2, 1993, Pages 357~367
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
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
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(
) than other groups and Group 4 had the lowest fracture strength(
). 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).
A STUDY ON THE CYTOTOXICITY OF THE INCUBATED RESIN SOLUTION
Im, Mi-Kyung ; Kim, Eun-Chul ; Yoo, Soo-Kyung ; Kim, Kang-Ju ;
Restorative Dentistry and Endodontics, volume 18, issue 2, 1993, Pages 369~376
To know the in vitro and the in vivo cytotoicity of resin solution, resin solution was applied to cultured fibroblast and was injected into the mouse. The cytotoxic effect of resin solution was measured by MIT assay and in vivo cytotoxicity was examined after Hematoxylin and Eosin staining. The cell activity of resin solution in the concentration of 50% was significantly decreased compared to control group and 5 % group. In histopathologic study of resin solution, there were severe inflammatory cell infiltration, mild interstitial edema, trace hemorrhage, and moderate or severe muscle destruction in resin injected group. These results suggested that there might be some differences between the cell viability of fibroblast and in vivo cell cytotoxicity. Further study is needed to clarify the cytotoxicity by direct implanting of resin mass.
AN EXPERIMENTAL STUDY ON THE EFFICACY OF DIFFERENT IRRIGATION METHODS AND IRRIGATION SOLUTIONS IN INFECTED ROOT CANALS
Kang, In-Ho ; Im, Mi-Kyung ;
Restorative Dentistry and Endodontics, volume 18, issue 2, 1993, Pages 377~386
The purpose of this study was to evaluate the disinfection efficacy of root canal irrigation method and irrigation solution in infected root canals. Access cavity were prepared in single-rooted extracted human teeth and each canals were prepared with step-back method and sterilized with ethylene oxide gas. Prepared teeth were experimentally inoculated in the canals for 30 minutes with four aerobes(Streptococcus mutans, Stapylococcus aures, Streptococcus sanguis, and E. coli) and two anaerobes(Streptoccus intermedius, and Clostrium perfringens). Normal saline, 3%
, and 3% NaOCl were used as irrgation solutions. And root canals were irrigated with each irrigation solutions manually with disposible syringe or ultrasonic instument. (Apoza Uitrasonc, Taiwan). The irrigation effect on the eradication of S. aures and S. intermedius with normal saline was not similar between manual method and ultrasonic method. No significant differences were observed in the eradication of E. coli and C. perfringens among the irrigation solution and irrespective of the irrigation methods. In S. aurues and S. mutans, there was somewhat different eradication effect according to irrigation solutions, but there was no significant difference between manual method and ultrasonic methods. These results suggest that ultrasonic irrigation method with saline is more effective in some strains than manual irrigation.
REMINERALIZATION OF ARTIFICIAL ENAMEL CARIOUS LESIONS
Hur, Bock ; Kim, Shin ;
Restorative Dentistry and Endodontics, volume 18, issue 2, 1993, Pages 387~394
In order to investigate the effects of continuous and pH cyclic remineralization, artificial enamel carious lesions were produced on sections of about 2mm thickness of bovine incisor. 0.1M lactic acid solution adjusted to a pH of 4.3 and saturity of
was used as demineralizing solution. The lesions were remineralized with the solution of pH 7.0 containing 1.5mM
, 0.9 mM
and 20mM Hepes. In continuous remineralization procedure, the specimens were immersed in remineralizing solution continuously for 72 hours. In pH cyclic remineralization procedure, the sections were immersed in remineralizing solution for 6 hours and in dermineralizing solution for 20 minutes alternately during 72 hours. The effect of remineralization was determined by polarizing microscopy and electron microprobe analysis. The obtained results were as follows. 1. In case of continuous remineralization, the lesion depth was reduced partially or unchanged. 2. In pH cyclic condition, the thichness of surface layer and the lesion depth were increased simultaneously. 3. The mineral content of lesion was recovered to the level of sound enamel by remineraiization.
A FINITE ELEMENT ANALYSIS ON STRESS AND DISPLACEMENT ACCORDING TO ISTHMUS WIDTH OF GOLD INLAY CAVITY
Shin, Gang-Suk ; Cho, Young-Gon ; Hwang, Ho-Keel ;
Restorative Dentistry and Endodontics, volume 18, issue 2, 1993, Pages 395~411
The purpose of this study was to examine the clear concept of the designs for cavity preparations. Among the several parameters in cavity designs, profound understanding of isthmus width factor would facilitate selection of the appropriate cavity preparation for a specific clinical situation. In this study, the cavities were prepared on maxillary first premolar and filled with gold inaly. A two - dimensional model was composed of 1037 - node triangle elements. In this model, isthmus was varied in width at 1/4, 1/3 and 1/2 of intercuspal width and material properties were given for four element groups, i.e., enamel, dentin, pulp and gold. The 500N occlusal load varied in direction and it was examined using three types of load : concentrated load, divided load and distributed load. The models were also examined with empty cavities using the devided load and distributed load. These models were analyzed the displacement and strees distribution by the two - dimensional Finite Element Method. The results were as follows : 1. All experimental models which filled with gold inlay after cavity preparation were similar direction of displacement with control model under same load type. But in the models with empty cavities, as isthmus width was wider, the degree of displacement was increased at same load type. 2. Among the experimental models which were filled with gold inaly after cavity preparation, the model II showed the least stress concentration under concentrated load and divided load. But in the models with empty cavities, the model III showed the largest stress concentration and tooth fracture is expected regardless isthmus width. 3. All experimental models showed similar displacement pattern beneath restorative material under a concentrated load. In the models with empty cavities, a divided load resulted in a lingual displacement of the lingual cusp, but a distributed load resulted in a buccal displacement of the lingual cusp. In regard to the above results, the restored models were stronger than empty models in respect to the bending moment and tensile stress. The empty models are expected to fracture regardless isthmus width. The safest isthmus width was 1/3 of intercuspal distance, which showed the least stress concentration in respect to the effect of stress distribution.
A SEM STUDY ON THE ADAPTATION OF ESTHETIC RESTORATIVE MATERIALS TO TOOTH STRUCTURE IN CLASS V CAVITIES
Cho, Young-Gon ; Gho, Chang-Hyun ;
Restorative Dentistry and Endodontics, volume 18, issue 2, 1993, Pages 413~422
The purpose of this study was to evaluate the adaptation of light cured glass ionomer cement and composite resin using all- etch technique to tooth structure. In this study, class V cavities were prepared on the buccal surfaces of 10 extracted human premolar teeth with cementum margin and teeth were randomly assigned 2 groups of 5 teeth each. The cavities of glass ionomer cement group were filled with the light cured glass ionomer cement(Fuji II LC) and the cavities of composite resin group were filled with the light cured composite resion(P - 50) using all- etch technique with All- Bond 2. The restored teeth were stored in 100 % relative humidity at
for 48 hours. And then, the roots of the teeth were removed with the tapered fissure bur and the remaining crowns were sectioned occlusogingivally through the center of restorations. Adaptation at tooth - restoration interface were assessed occlusally, gingivally, and axially by scanning electron microscope. The results were as follows : 1. The adaptation to enamel walls of composite resin restorations using All - Bond 2 showed better than glass ionomer restorations. 2. The adaptation to gingival and axial walls of glass ionomer restorations showed better than composite resin restorations using All - Bond 2. 3. In both groups, occlusal margins of restorations showed better adaptation than gingival margins of restorations.
EFFECT OF CUPRIC AND FERRIC IONS ON BONDING OF MMA/TBBO RESIN TO DENTIN
Park, Jin-Hoon ;
Restorative Dentistry and Endodontics, volume 18, issue 2, 1993, Pages 423~430
The purpose of this study was to investigate the effect of ferric and ferric ions contained in phosphoric acid solution as a pretreatment solution on bonding of MMA/TBBO resin to dentin. Each of 1 % and 3 % ferric chloride. cupric chloride. cupric sulfate. and cupric nitrate was mixed into 10% phosphoric acid solution and pretreated dentin surface of bovine anterior teeth for 30 seconds followed- by water rinse and dry. Tensile bond strength was determined after bonding of pretreated dentin with MMA/TBBO resin by use of brush-on ;technique and storing for 24 hours in 3it distilled water. The amount of cupric ions adsorbed on pretreated dentin surface was detected by Wave-Dispersion X-ray microanalyzer for different groups of each pretreatment solution containing cupric salts. The pretreatment with cupric ions contained in 10% phosphoric acid solution was effective to increase bonding strength of MMA/TBBO resin to dentin but not in case of ferric ions. The pretreatment with 3 % cupric chloride and cupric nitrate both enhanced significant increase in bonding strength compared to the control group of 10% phosphoric acid solution(p<0.05). Cupric ions measured in pretreated dentin surface was higher in 3 % cupric chloride group than in 1% cupric chloride group, but couldn't find distinct relationship from the results of this experiment between the amount of adsorbed cupric ions according to the kind of cupric salts and the bonding strength value.
AN ELECTROCHEMICAL STUDY ON THE OXIDATION' AND REDUCTION OF DENTAL AMALGAM
Yi, In-Bog ; Lee, Myong-Jong ;
Restorative Dentistry and Endodontics, volume 18, issue 2, 1993, Pages 431~445
The purpose of this study was to observe corrosion characteristics of six dental amalgams and was to analyse corrosion products electrochemically. After each amalgam alloy and Hg was triturated as the direction of the manufacturer by using mechanical amalgamator, the triturated mass was inserted into the cylinderical metal mold (
) and was condensed with 160kg/
by using the hydrolic press. The specimen was removed from the mold and was stored at room temperature for 1 week, and was polished with amalgam polishing kit. The anodic and cathodic polarization curve was obtained by using cyclic voltammetric method with 3-electrode potentiostat in saline for each amalgam and Ag, Sn, Cu plate specimen at
. The potential sweep range was -1.7V~0. 4V(vs SCE) in working electrode and scan rate was 50mV/s and the exposed surface area of each specimen to the electrolytic solution was
. The results were as follows. 1. In anodic-cathodic polarization curve of amalgam specimens, two anodic current rising areas and two cathodic current peaks were obtained at the low Cu amalgam(CF, CS) specimen and three anodic current rising areas and three cathodic current peaks were obtained at the high Cu amalgam (TY, DS, HV) specimen. 2. As this compared with the anodic and cathodic current peak potentials of Sn, Cu and Ag specimen, the first cathodic current peak I c was caused by the reduction of divalent tin salt, second cathodic current peak IIIc results from the reduction of quadravalent tin salt, and third cathodic current peak me results from the reduction of copper salt. 3. As reverse potential sweeping was done repeatedly, anodic current was decreased slightly in all amalgam specimens.
AN EXPERIMENTAL STUDY FOR THE EFFECT OF SANDWICH TECHNIQUE ON MICROLEAKAGE IN CLASS V CAVITY
Shin, Chang-Seung ; Lee, Chung-Suck ;
Restorative Dentistry and Endodontics, volume 18, issue 2, 1993, Pages 447~462
To evaluate the marginal leakage in Class V cavity this study has been undertaken to compare the sandwich technique with the conventional method, and find out the effect of lining material, lining method, and polishing time on sandwich technique. Ninty extracted teeth were divided into eight test groups and a control group, and were prepared with a buccal Class V cavity. Four test groups were lined with Dentin Cement whereas the other four test groups were lined with Vitrabond. Half of the either group were lined 0.5mm short of the carvosurface margin and the rest were lined completely to the carvosurface margin. The four subgroups were further divided into specimens which were polished immediately and 24 hours after resin filling. The polished specimens were immersed in
, 0.5% methylene blue solution for 24 hous after thermocycling at
, 200 times and buccolingually sectioned. The sectioned specimens were examined dye penetration under the light microscope. The following results were obtained, 1. At the enamel margin, the conventional method showed a lower microleakage than the sandwich technique. The difference between the control and Vitrabond group was statistically significant(P<0.05), but no difference between the control and Dentin Cement group, and between the lining materials was observed. 2. At the dentinal margin, the sandwich technique showed a significant lower amount of microleakage (P<0.05), but there was no significant difference between the lining materials. 3. Regardless of the lining material, lining method, and polishing time used, values of microleakage were significantly higher at the dentinal margin compared to the enamel margin(P<0.05). 4. In specimens till the cavosurface margin, microleakage at the dentinal margin was less with the light-cured base than with the chemically-cured base, but there was no siginificantly difference between the lining materials regarding the lining method and polishing time. 5. The lining material, lining method, and polishing time did not affect the amount of micro leakage in the sandwich technique(P<0.05).
CLINICAL STUDY ON THE EFFECT OF VITAPEX UPON THE PERIAPICAL TISSUE
Kim, Min-Kyum ; Yoon, Soo-Han ;
Restorative Dentistry and Endodontics, volume 18, issue 2, 1993, Pages 463~468
The purpose of this study was to evaluate the effects of Vitapex on the periapical lesions. Thirteen single-rooted teeth from ten patients who visited the SNU hospital were endodontically treated with Vitapex and Gutta percha cone, and radiographically and clinically evaluated for a period of 1 to 6 months. The results were as follows : 1. The loss of clinical symtoms was observed in all 13 teeth. 2. The reduction of size of periapical lesions in radiographs was observed in 10 teeth. The periapical lesions of remaining 3 teeth also look better in the radiographs. 3. All 13 teeth showed the reduction of radiolucency. 4. The gradual resorption of Vitapex over the root apex was observed.
A STUDY ON THE REDUCTION OF GALVANIC CURRENT BETWEEN AMALGAM AND GOLD ALLOY WITH VARIOUS CHEMICAL AGENTS
Kim, Seung-Soo ; Um, Chung-Moon ;
Restorative Dentistry and Endodontics, volume 18, issue 2, 1993, Pages 469~481
The purpose of this study was to achieve the reduction of the galvanic current between the dental amalgam alloy and gold alloy. In order to measure the galvanic current between these two metals a prep in the size of
which was filled with amalgam and another prep of
was filled with gold alloy was made in the acrylic resin. These two preps were then connected to a 2mm diameter copper wire. Using an ammeter to measure the galvanic current, six different kinds of amalgam and gold alloy were immersed in saline solution with approximately 10mm distance between the two alloys. Chemical agents that are thought to reduce the galvanic current such as hydrazine. silver nitrate, potassium chromate, and bonding agents such as Scotch bond 2(3M) and All bond 2(Bisco) were applied to the alloy surface. Cathodic inhibitor such as hydrazine was applied to gold alloy where as anodic inhibitor such as silver nitrate and potassium chromate were applied to amalgam. Both bonding agents, Scotch bond 2(3M) and All bond 2 (Bisco), were applied to amalgam. The following results were obtained when the currency on the coated alloy surface was compared to the uncoated surface. 1. The galvanic currency went down as the time elapsed and after 30 minutes no change was detected. 2. Initial currency was higher in low copper amalgam compared to high copper amalgam. Intitial currency was the highest in low copper lathe-cut amalgam. 3. Group of gold coated with hydrazine had the most reduction in galvanic currency. 4. Group of amalgam coated with silver nitrate or potassium chromate also showed significant reduction in galvanic currency. 5. The bonding agents also helped reduce galvanic currency. 6. Of all the agents used to reduce galvanic currency, silver nitrate showed the best result.
STUDY ON DENTINAL TUBULES SEALING EFFECTS OF DENTIN BONDING AGENTS
Kown, O-Teak ; Park, Dong-Soo ;
Restorative Dentistry and Endodontics, volume 18, issue 2, 1993, Pages 483~496
Dentin hypersensitivity medicaments such as Gluma, Scotchbond 2, All-Bond 2, which are resin adhesives, were used to compare the sealing effects of dentinal tubule under mechanical stress. Topical application of above medicaments on the dentin surfaces of extracted teeth followed by artificial tooth brushing for 6 weeks was performed for the comparison. The following conclusions on the degree of dentinal tubule exposure versus time by were reached by using polyvinyl siloxane impression material for taking the impression, epoxy resin for the duplication and SEM for observing the surface. 1. SEM was used to compare the accuracy of the duplicated surface, but no differences were found when teeth samples and the duplicated surfaces were observed. 2. After comparing the degree of dentinal tubules exposure with varnish applied contrast group, resin adhesive materials showed much less exposure as time went by. 3. The results indicated that AU-Bond 2 adhesive, under mechanical stress, showed lesser exposure of dentinal tubules comparing with Gluma and Scotchbond 2 adhesives After the results were put together, it was demonstrated that resin replica method is an useful way to evaluate the treatment effects of the dentinal tubule hypersensitivity medicaments. Also, it was noticed that under mechanical stress, All-Bond 2, classified as fourth generation, illustrated the best dentinal tubules sealing effects.
LONG TERM SEALING ABILITY OF SEALAPEX
Yoon, Soo-Han ;
Restorative Dentistry and Endodontics, volume 18, issue 2, 1993, Pages 497~500
Sealapex was compaired with a zinc oxide eugenol sealer over a 24 - wk interval to examine solubility in an in vitro situation. After obturation with gutta percha and the appropriate sealer, speciemens were immediately immersed in a saline solution to challenge the solubility of the sealers. The solutions were changed weekly to allow for a continued dissolution of the sealers. After immersed in methylene blue solution for 3 days, the speciemens were made transparent by a clearing process. Microscopic examination was used to determine the linear penetration of dye for each speciemen. Result revealed that sealapex had no greater dissolution than ZOE(P<0.05).
THE STUDY ON LONGEVITY OF AMALGAM AND COMPOSITE RESIN
Um, Chung-Moon ; Kim, Seung-Soo ; Bae, Kwang-Shik ;
Restorative Dentistry and Endodontics, volume 18, issue 2, 1993, Pages 501~506
The purpose of this study was to observe the longevity of amalgam and composite resin fillings in Korea. The number of placement of restorations was 760 amalgams and 415 composite resins. The amalgam restorations inserted because of primary caries were 61 % and replacement of amalgam restorations were 39%, and composite restorations inserted because of primary caries were 62 % and replacement of composite restorations were 38 %. The median longevity of failed amalgam restorations was 3 years and the madian longevity of failed composite restorations was 2 years. The main reason of replacement of amalgam and composite resin restorations was secondary caries.
THE EFFECT OF EARLY WATER CONTACT ON GLASS-IONOMER CEMENTS
Um, Chung-Moon ; Oilo, Gudbrand ;
Restorative Dentistry and Endodontics, volume 18, issue 2, 1993, Pages 507~513
The purpose of this study was to observe the effect of immersion in water at 3, 5, 7, and 10 minutes after mixing on the surface of three regular and one light-curing glass-ionomer cement by measuring penetration of a methylene blue solution. Early solubility of these cements was also measured and compared with that of a zinc phosphate and a polycarboxylate cement. A blue-stained zone was observed in all glass-ionomer cement, but an inner, opaque zone was observed in only two of the regular glass-ionomer cements. Extending the time between start of mixing and immersion on water decreased the width of both zones in all cements and markedly lowered the loss of substance from the surface of regular glass-ionomer cements. However, time after mixing had no or only a limited effect on the loss of substance from the light-curing glass-ionomer cement, the zine phosphate cement, or the polycarboxylate cement.
ANTIMICROBIAL EFFECT OF ANTIBIOTICS AND ROOT CANAL CEMENTS ON THE PREDOMINANT PATHOGENIC ANAEROBIC MICROFLORA IN ROOT CANALS
Bae, Kwang-Shik ;
Restorative Dentistry and Endodontics, volume 18, issue 2, 1993, Pages 515~525
The purpose of this study was to evaluate the susceptibility of anaerobic microorganisms to certain antibiotics and root canal cements. Prevotella intermedia(Bacteroides intermedius) ATCC 25611(serotype A), Fusobacterium nucleatum ATCC 25586, Actinomyces viscosus ATCC 15987 which are the predominant pathogenic anaerobes in dental root canals were cultured in BHI for 48 hours(Fig.1). After each
of those broths with microorganisms was streaked on each surface of blood agar plate, 2 to 5 antibiotic discs which are impregnated with Tetrncycline, Erythromycin, Ampicillin, Clindamycin, or Vancomycin were applied on each surface of blood agar plate and cultured for 5 days anaerobically in the anaerobic chamber
(Fig.2). 15 antibiotic discs for each kind of antibiotics and each species of microorganisms were tested. Also each kind of root canal cement tubes which include Zinc oxide eugenol cement, Zinc phosphate cement, Calcium hydroxide powder+DD.W., Calcium hydroxide paste(Pulpdent Tempcanal), or Vitapex(Table 1) were applied on the inoculated BAPs after
of each experimental species of microorganisms was streaked on the surface of blood agar plates, and they were cultured for 5 days anaerobically in the anaerobic chamber(Fig.3). The sensitivity(antimicrobial effect) was determined by the diameter of the inhibition zone. The results are as follows: 1. The results of antibiotic susceptibility test(Table 2) 1) All of the tested antibiotics had antimicrobial activity with various degrees. 2) In Prevotella intermedia (old Bacteroides intermedius), the diameter of inhibition zone to Erythromycin(
) was largest, those to Tetracycline(
) was smaller than former orderly, and That to Ampicillin (
) was smallest. 3) In Actinomyces viscosus, the diameter of inhibition zone to Erythromycin(
) was largest, those to Ampicillin(
) was similarly next order, that to Vancomycin(
) was smaller than Clindamycin, and that to Tetracycline(
) was smallest. 4) In Fusobacterium nucleatum, the diameter of inhibition zone to Ampicillin(
) was largest, that to Erythromycin(
), Vancomycin (
), Tetracycline (
) are smaller than former orderly. 2. The results of root canal cements and pastes(Table 3) 1) The external diameter of tube is 4mm, so 4mm of the inhibition zone diameter means non-susceptable. Prevotella intermedia (old Bacteroides intermedius) was non-susceptable to Calcium hydroxide powder+D.D.W., Calcium hydroxide paste(pulpdent Tempcanal), and Actinomyces viscosus was non-susceptable to Zinc phosphate cement, Calcium hydroxide powder + D.D.W., Calcium hydroxide paste(pulpdent Tempcanal). 2) In Prevotella intermedia (old Bacteroides intermedius), the diameter of inhibition zone to Zinc oxide eugenol cement(
) was largest, that to Vitapex(
), Zinc phosphate cement(
) was smaller than former. 3) In Actinomyces viscosus, the diameter of inhibition zone to Zinc oxide eugenol cement(
) was largest and that to Vitapex(
) was next order. 4) In Fusobacterium nucleatum, the diameter of inhibition zone to Vitapex(
) was largest and those to Calcium hydroxide paste(Pulpdent Tempcanal)(
) and Zinc oxide eugenol cement(
), Zinc phosphate cement(
), Calcium hydroxide powder+D.D.W.(
)was next orderly. And then In Zinc oxide eugenol cement and Zinc phosphate cement group, two of fifteen samples showed no inhibition zone, in Calcium hydroxide powder + D.D.W. group, 8 of 15 samples showed no inhibition zone.