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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 8, Issue 1 - Dec 1982
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THE FINE STRUCTURE OF THE FIBROBLAST IN INFLAMED HUMAN PULP TISSUE
Bae, Kwang-Shik ;
Restorative Dentistry and Endodontics, volume 8, issue 1, 1982, Pages 7~17
The purpose of this study was to investigate the fine structural modifications of fibroblasts in the coronal region of inflamed human pulps from carious teeth. Six untreated human teeth with large carious lesions and two normal teeth as control were selected from male and female patients between the ages of 20 and 39. The teeth were divided into 4 groups by light microscopic findings: the normal control group, the chronic inflammatory cell-appeared group, the acute and chronic inflammatory cell-appeared group, and the total necrosis group. All tissues were fixed in 2.5% glutaraldehyde in 0.1M sodium cacodylate buffer at pH 7.4 and 1% osmic acid in same buffer. They were embedded in Epon 812. The ultrathin sections were stained conventionally and examined with a AEI Corynth 500 electron microscope. The results were as follows; 1. The fibroblasts of the normal pulps were almost in a quiescent state. 2. The active and the quiescent fibroblasts were found in the pulps of the chronic inflammatory cell-appeared group. Lymphocytes and plasma cells were also seen scattered among these fibroblasts. 3. In the pulps of the acute and chronic inflammatory cell-appeared group, active, degenerative and necrotic fibroblasts were found in the PMN appeared area. And all the fibroblasts in the fibrosis area were active. In the area of chronic inflammatory cellular infiltration, almost all the fibroblasts were active, but seldom were quiescent fibroblasts observed. Some fibroblasts in the pulps of two teeth had large vacuoles that contained banded collagen fibrils. The phagosomes had small beaded vesicles or large lysosome-like varicosity. In two of the teeth, microorganisms were present and two morphological shapes were identified, a rod and a coccus. 4. Vacuolar, vesicular, lamellar, fibrous and myelin structures were observed in the pulp of the total necrosis group, and cocci were also seen.
IMMUNOHISTOPATHOLOGIC STUDY OF PERIAPICAL LESIONS
Cho, Hyo-Sun ;
Restorative Dentistry and Endodontics, volume 8, issue 1, 1982, Pages 19~30
This study was performed to elucidate the histopathologic distribution of immunoglobulins, particularly IgA, IgG and IgM in the periapical lesions, including 22 periapical granulomas and 18 periapical cysts. The immunoperoxidase staining method using reagents manufactured and supplied by Danish DAKO company was employed in this study. In comparison with the immunohistochemical methods, this method was proved to be reliable and convinient one to detect immunoglobulins in the tissue. The following results were obtained: 1. In the 22 periapical granulomas, IgG was found in 20 cases (90.9%), IgA in 16 cases (72.7%) and IgM in 19 cases (86.3%). 2. In the 18 periapical cysts, IgG was found in 16 cases (88.8%), IgA in 13 cases (72.2%) and IgM in 15 cases (83.3%). 3. The distribution of immunoglobulins both in periapical granulomas and periapical cysts was in great diversity according to the lesion and area. 4. More immunoglobulins were found in the exudative area with moderate or severe infiltrations of plasma cells and lymphocytes and less concentration of immunoglobulins were seen in the area with leukocytes infiltration and tissue destruction. 5. The area with collagenolysis and reparative activity contained more abundant IgG and IgM than IgA in periapical granulomas. 6. IgG was dominant in the granulomatous connective tissue and immunoglobulins were not easily found in the fibrous capsule in periapical cysts.
A STUDY ON THE ISOLATION AND SEROTYPING OF STREPTOCOCCUS MUTANS FROM DENTAL PLAQUE OF CARIOUS LESION
Lee, Chae-Dong ; Choi, Ho-Young ; Park, Sang-Jin ;
Restorative Dentistry and Endodontics, volume 8, issue 1, 1982, Pages 31~44
Streptococcus mutans strains were isolated from dental plaques of carious lesions of 53 patients on mitis-salivarius-bacitracin (MSB) and mitis-salivarius(MS) medium as a supplement. The epidemiological investigation was carried out to determine the biotypes and serotypes of S. mutans isolates. For the serotyping, autoclaved extract antigens from the isolates and serotype-specific antisera against seven known serotypes of S. mutans were prepared. The serotypes of the isolates were demonstrated in immunodiffusion test. In addtition, the prevalence of
-hemolysis on 5% sheep blood agar plate in restricted anaerobic condition and yellow pigment production on 5% sucrose agar plate in less anaerobic condition among the isolates were investigated. The results were as follows: 1. Forty-eight S. mutans strains were isolated from dental plaque samples of 33 patients (62.3%) among 53 patients. 2. Of the isolates, some strains were not grown on MSB medium. 3. Serotype c S. mutans was found in 60.6%, serotype d was found in 30.3% of the patients who were known to harbor S. mutans. 4. Of. the isolates, serotype c isolates were most prevalent (43.8%), serotype d isolates were 25.0%, and serotype b, e, f and g isolates were also found but in lower frequencies. Serotype a S. mutans were not detected. 5. The correlation between serotype and biotype of the isolates was found in 78.6% of the typing cases. 6. Strains revealed
-hemolysis were in 52.1% of the isolates, strains produced yellow pigment were in 47.9% of the isolates, and with one exception, all the strains were belong to serotype c, e and f. 7. The majority of the isolates which revealed
-hemolysis appeared to be yellow pigmented, these isolates were belong to serotype c, e and f.
A STUDY ON THE FRACTURE MODES AND FAILURE LOADS OF THE VARIOUS TYPES OF RESTORATION FOR THE ENDODONTICALLY TREATED ANTERIOR TEETH
Park, Young-Sook ; Choi, Sung-Keun ;
Restorative Dentistry and Endodontics, volume 8, issue 1, 1982, Pages 45~51
An endodontically treated tooth is likely to be brittle than a vital tooth. Internal structure of the tooth has been weakened due to a significant removal of dentin by coronal access, canal preparation. There are many controversies concerning with various methods of reinforcing an intact anterior tooth that has endodontic treatment. In this experiment, 128 extracted maxillary anterior teeth were endodontically treated, and prepared with 4 methods of restorations; Composite resin filling with zinc phosphate cement, composite resin filling without zinc phosphate cement, composite resin filling with post, and metal crown with post. An Instron testing machine was used to measure the fracture loads of the specimens. The means of the failure loads for the 4 groups were compared by F-test statistically and the failure modes were observed. The results were as follows; 1. There were no statistically significant difference between the failure loads of the four methods of restoration. 2. Teeth without post were fractured in a horizontal or oblique plane through upper or middle third of the root. 3. In the posted teeth, fractures were occurred around the post. 4. In the metal crowned teeth with post, the fracture were occurred around the post or coronal area.
A EXPERIMENTAL STUDY OF RESTORATIVE TECHNIQUES FOR ENDODONTICALLY TREATED POSTERIOR TEETH
Ahn, Jong-Gill ; Choi, Sung-Keun ;
Restorative Dentistry and Endodontics, volume 8, issue 1, 1982, Pages 53~59
An in vitro study was performed in order to evaluate the restoring methods in the endodontically treated molar teeth. 68 extracted teeth were divided into 4 groups according to the restoring techniques. The teeth of first group were restored by amalgam. Those of second group were restored by the stainless steel post and amalgam. The teeth of the third group were restored by the amalgam with crown. The teeth of the fourth group were restored by the stainless steel post and amalgam core with crown. All the specimens were tested and measured for the fracture load by means of the Instron (UTM-111-500 Toyo Baldwin Co., LTD. Japan) and the Pressure Instrument (Yonsei University, Department of Metal Engineering.) The results were as follows; 1. There were no statistical differences in the fracture loads between the amalgam restoration and post-amalgam core restorative techniques. 2. The techniques of amalgam core with crown showed lower fracture loads those of post and amalgam core with crown. 3. In the crowned teeth, they presented higher fracture loads than those without crown.
AN EXPERMENTAL STUDY ON THE EFFECTS OF COBALT-60 RADIATION OF THE TEETH OF THE RAT
Lee, Chan-Young ;
Restorative Dentistry and Endodontics, volume 8, issue 1, 1982, Pages 61~68
This study was undertaken to compare the histopathological effects of the fractionated doses of 2,400, 4,800 and 7,200 rads of Cobalt-60 irradiation on the teeth of the sixty eight rats (Wester strain), weighing approximately 130gm. They were devided into four groups; no irradiation as a control (Group I) and others (Group II, III, and IV) which received different doses of radiation using 1.25 Mev RAC-120 Cobalt-60 Teletherapy Unit with exposure dose rate 69 rads/min, TSD 80cm. Experimental animals received 600 rads every three days until the total dosage of their groups were reached. Experimental animals were sacrified at the 1st day, 1st, 2nd, 3rd, 4th, 5th and 6th week irradiation. The following histopathologic findings were obtained: 1. The Group II, received 2,400 rads, showed no histopamologic changes essentially same as those of the control Group. 2. In the Groups III and IV, received 4,800 rads and 7,200 rads, disarray of the normal palasading arrangement of the odontoblastic cells, vacuolar degeneration in the odontoblastic layer, osteodentin and dentinal niches in the anterior teeth were observed. 3. There were no distinct changes in the posterior teeth in the Groups III and IV. 4. The ameloblast cells seemed to be less sensitive to radiation damage than the odontoblast cells.
A STUDY ON THE COLOUR PENETRATION OF KOREAN FOODS SUBSTANCE TO CAVITY MARGIN OF COMPOSITE RESIN RESTORATION
Ahn, Sang-Hun ;
Restorative Dentistry and Endodontics, volume 8, issue 1, 1982, Pages 69~76
The purpose of this study was to evaluate the color penetration of cavity margin with composite resin restorations in some Korean foods substance-soy sauce and hot bean paste. Fifty specimans which were extracted caries free third molar of young adults recently. All of the prepared 100 cavities were filled with two kinds of composite resin (Hipol
). The experimental specimans were divided into five groups by the following procedures. Group I : Filling of composite resin and polishing. Group II : Filling, polishing, etching of cavity and sealing. Group III : Etching, sealing, filling and polishing. Group IV : Etching, sealing, filling, polishing, and repeated of etching of cavity margin and sealing. Group V : Etching, sealing, filling, polishing, and sealing again without etching. Before examination, the restorated teeth were subjected to thermal cycling (
). All the specimens were immersed in soy and 30% hot bean paste solution under
incubator during six weeks. Then, the specimens were sectioned bucco-lingually through the center of two restorations with diamond disk and examined under a. metallographic microscope. (Union 6617 U.S.A.) Thereafter, the degree of color penetration was calculated and analyzed. The obtained results were as follows: 1. The color penetration was the lowest in the procedure of Group III which was acid etching, sealing, composite resing filling, and polishing. 2. The color penetration occured in soy and hot bean paste, but the degree of penetration was not so significant statistically between them. 3. The degree of color penetration was not so significant statistically between Hipol
HISTOPATHOLOGIC STUDY ON THE RAT SUBCUTANEOUS TISSUE FOLLOWING EXPOSURE TO VARIOUS CONCENTRATIONS OF CANAL IRRIGANT AND CANAL MEDICAMENTS
Suh, Woonn-Suk ; Yoon, Soo-Han ;
Restorative Dentistry and Endodontics, volume 8, issue 1, 1982, Pages 77~87
The purpose of this study is to estimate the reaction of rat subcutaneous tissues following exposure to the various concentrations of formocresol (100, 50, 20%), eugenol (100, 75, 50%), and sodium hypochlorite. (5, 3.5, 0.5%) The results were as follows: 1. As the concentration of formocresol was decreased, the inflammatory reaction was decreased conspicuously. 2. The inflammatory reaction of 100% eugenol was appeared to be similar to that of 75% eugenol. The inflammatory reaction of 50% eugenol was decreased conspicuously. 3. No significant differences were found in inflammatory response between 3.5% and 5% sodium hypochlorite. 4. The inflammatory reaction of 0.5% sodium hypochlorite was mild and appeared to be similar to that of saline solution in 7 days.
AN EXPERIMENTAL STUDY ON THE MICROHARDNESS OF DENTAL AMALGAMS
Shin, Dong-Hoon ;
Restorative Dentistry and Endodontics, volume 8, issue 1, 1982, Pages 89~96
The purpose of this study is to identify the phases of four different types, low-copper lathe cut (Type II, class 1) and spherical (Type II, class 2) amalgam alloys which are made by Caulk company and high copper Dispersalloy (Type II, class 3) made by Johnson & Johnson and Tytin (Type I, class 2) made by S.S. White and to determine the Vickers hardness number on the individual phase and four different types of dental amalgam. After each amalgam alloy and Hg measured exactly by the balance was triturated by the mechanical amalgamator (De Trey), the triturated mass was inserted into the cylindrical metal mold which was 4 mm in diameter and 12mm in height and was pressed by the Instron Universal Testing machine (Model 1125) at the speed of 1mm/minute with 143
according to the A.D.A. Specification No. 1. The Specimen removed from the mold, mounted and stored in the room temperature for 7 days. The speciman was polished with the emery paper from #220 to #1200 and finally on the polishing cloth with 0.3 and 0.05 um
powder suspended in water. And then each specimen was etched by Allan's method and washed with Sodium Bisulfinite for 30 seconds. Finally differentiation and metallography on each phase were obtained by using metallographical microscope (Versamet, Union) and microhardness was obtained by using microhardness tester (MVH-2, Torsee). The results were as follows: 1. In the low-copper amalgam, the
phase were observed and in the high-copper amalgam, the
phases were observed but
phase was not observed. 2. Among the microhardness of each amalgam phase measured under pressing a vickers diamond indenter with 2.0gm load for 30 seconds, e phase has the highest V.H.N (314
20), and in low-copper amalgam 12 phase has the lowest V.H.N. (29
phase which was observed in high-copper amalgam has 230
13 V.H.N and this phase is considerd to contribute to strengthen the handness in amalgam. 3. The V.H.N. measured under pressing a Vickers diamond indenter with 300.0gm load for 30 seconds in low-copper amalgam was lower than that of high-copper amalgam.
EXPERIMENTAL STUDY OF THE SURFACE FINISHINGS ON THE COMPOSITE RESIN SURFACES
Kim, Boo-Rang ; Choi, Ho-Young ; Park, Sang-Jin ;
Restorative Dentistry and Endodontics, volume 8, issue 1, 1982, Pages 97~106
The purpose of this study was to evaluate the effect of different polishing procedures on the surfaces of composite resins. Two-paste type comosite restorative resin (Hipol) was selected for this study. 70 cavities prepared on the plaster-stone dies, 6mm in diameter and 2mm in depth, was filled with composite resin according to the manufacturer's specifications and by polymerizing against mylar strips. The polymerized composite resin specimens were polished (surface finished) by using 6 polishing devices; white stones, diamond finishing points, 12-fluted carbide finishing burs, green stones, sand paper disks, and Quasite rubber disk after polished with sand paper disks and green stones. A profilometer (Bendix type) was used to record in microinches the surface roughness of each surface finished composite resin specimens. The results were as follows. 1. The best finished surface that can be obtained is a surface formed by the mylar matrix strip 2. The white stones produced the smoothest surface in the experimental group. 3. The green stones produced the roughest surface in the experimental group. 4. It was proved that the gradual use of finishing instruments from a rough one to fine ones reduced the surface roughness.
AN EXPERIMENTAL STUDY ON THE TENSILE STRENGTH OF COMPOSITE RESIN TO ETCHED DENTIN SURFACE
Pak, Sun-Jae ; Choi, Ho-Young ; Park, Sang-Jin ;
Restorative Dentistry and Endodontics, volume 8, issue 1, 1982, Pages 107~113
The purpose of this study was to observe the tensile strength of composite resins to etched dentin surface with the various methods of placing bonding agent before composite resin or placing composite resin alone. Recently extracted 60 maxillary incisors were chosen. These were divided into 6 groups: Group I : Immediate Silar adaptation to the etched dentin surface with 37% phosphoric acid for 60 seconds without bonding agent. Group II : Immediate Silar adaptation to the etched dentin surface with 37% phosphoric acid for 60 seconds with bonding agent. Group III : Silar adaptation to the etched dentin surface with 37% phosphoric acid for 60 seconds after 5 minutes of bonding agent. Group IV : Immediate Enamelite adaptation to the etched dentin surfaces with 50% phosphoric acid for 120 seconds without bonding agent. Group V : Immediate Enamelite adaptation to the etched dentin surface with 50% phosphoric acid for 120 second s with bonding again. Group VI : Enamelite adaptation to the etched dentin surface with 50% phosphoric acid for 120 seconds after 5 minutes of bonding agent. All specimens were immersed in water at
for 24 hours before testing. The results were as follows: 1. The tensile strength of powder/liquid composite resin system was higher than that of pastel paste composite resin system. 2. The tensile strength of the composite resin group II, III, V, & VI with bonding agent was higher than that of the composite resin group I & IV without bonding agent. 3. The tensile strength of the composite resin group III & VI after 5 minutes added to bonding agent was higher than that of the composite resin group II & V immediately added to bonding agent.
THE EFFECT OF SOLVENT ACTION OF SODIUM HYPOCHLORITE SOLUTION ON PULP TISSUE
Park, Jin-Hoon ;
Restorative Dentistry and Endodontics, volume 8, issue 1, 1982, Pages 115~121
Sodium hypochlorite solution has been widely used as endodontic irrigant due to its ability to dissolve pulp tissue debris and its antimicrobial action. This in vitro study was conducted to evaluate the solvent action of sodium hypochlorite solution on vital pulp tissue under various conditions include concentration, exposure time, and temperature. The percentage of weight loss due to pulp tissue dissolution was calculated with weight difference of lyophilized specimens before and after the exposure to test solutions. The results were as follows; Statistical analysis indicated that the ability of both 5.0% and 2.5% sodium hypochlorite solutions to dissolve pulp tissue was significantly greater than that of distilled water, but no significant difference was found between 5.0% and 2.5% sodium hypochlorite solutions. There was no significant increase in the pulp tissue dissolving ability of sodium hypochlorite solutions; as exposure time increased 2 minutes, 5 minutes, and 10 minutes. Of the given temperatures, no significant difference was found in the solvent aciton of sodium hypochlorite solution on pulp tissue between
(room temperature) and
AN EXPERIMENTAL STUDY ON THE EFFECT OF Ca(OH)
UPON THE HEALING PROCESS OF THE PULP AND PERIAPICAL TISSUE IN THE DOGS' TEETH
Lim, S.S. ; Yoon, S.H. ; Lee, C.S. ; Lee, M.J. ; Kim, Y.H. ; Kwon, H.C. ; Um, C.M. ;
Restorative Dentistry and Endodontics, volume 8, issue 1, 1982, Pages 123~131
The purpose of this study was to observe the responses of the remaining pulp tissue after pulpotomy upon the several kinds of
products and the responses of periapical tissue upon some root canal filling materials after extirpation. For pulpotomy, the class V cavities were prepared on the premolars, molars and upper canines, and the pulp was amputated. Each drug was placed over the amputated tissue and cavity was sealed with zinc oxide eugenol cement. The drugs which were used for the study were Dycal (Caulk Co. U.S.A.), Cavitec (Kerr Co. U.S.A.), Calvital, Nobudyne and Neodyne (Neo Dental Chemical Products). For extirpation, the endodontic cavities were prepared on the lingual surfaces of anterior teeth, and the pulp tissues were extirpated as routine method. After enlarging, irrigation, and measuring of root length by taking X-ray, each root canal filling material was filled in the canal with gutta percha cone, and endodontic cavity was sealed with zinc oxide eugenol cement. Zinc oxide eugenol,
(Eli Lilly Co. U.S.A.) and Vitapex (Neo Dental Chemical Products) were used as root canal filling materials. Animals were sacrificed after 1, 3 and 6 weeks following the operation. The teeth were decalcified in formic acid, sectioned and stained with hematoxylin eosin. Microscopic examination revealed as follows. 1. Dycal: The dentin bridge formation was observed at the 3rd week after pulpotomy. Inflammatory conditions which were infiltration of inflammatory cells and dilatation of blood vessels were kept in remaining pulp tissue at the 6th week. 2. Calvital: The dentin bridge was observed at the 1st week after pulpotomy. As the time clasped, the pulp tended to be the fibrous degeneration. 3. Cavitec, Nobudyne and Neodyne: In the case of Cavitec and Nobudyne, the incompleted and irregular dentin bridge was observed at the 6th week, and in Neodyne, was observed at the 3rd week. The severe inflammatory changes were seen in the remaining pulp tissue. As the time clasped, the fibrous degeneration tended to spread in the remaining pulp tissue. 4.
: Osteocementum was formed at the 3rd week, the matrix of cementum and dentin were resorted, and infiltration of lymphocytes was seen in periapical tissue when
was used as canal-filling materials. S. ZOE and Vitapex The cementum like substance was seen in periapical portion at the 1st week, when ZOE and Vitapex were used as root canal filling materials. As the time elapsed, the matrix of cementum and dentin tended to be resorted. At the 6th week, the inflammatory condition of periapical tissue was continued in the case of ZOE, but was reduced in the case of Vitapex.
A STUDY ON TRANSFERENCE OF A CONTRAST MEDIA IN PULPAL CHAMBER
Kim, Yung-Hai ;
Restorative Dentistry and Endodontics, volume 8, issue 1, 1982, Pages 133~137
Radiography is one of the important tool adopted in daily dental practice and medical diagnosis. To visualize soft tissuechange various contrast media has Been introduced. Any cavity or space can be easily determined by increasing the X-ray absorption of the cavity using the radiopaque contrast media which widely employed in medical radiography to show much of the digestive, cardiovascular, pulmonary, and renal system. The essential part of any radiopaque medium is a heavy element that can absoarb most of the X-ray beam. The element must be noninjurious and easily eliminated. Both aqueous and oil suspensions of iodine containing compounds' are available to the dental profession, for example Lipiodol and Dionosil. The study was designed to determine toxic effect of Lipiodol to the vital pulp and to confirm visualization ioprovement in pulp canal. 1. Thin mixture of Calcium hydroxide and Lipiodol was applied to 19 deep vital cavities for 24 hours. Only one case complained slight pain for short time. 2. Cotton pellet over-saturated in Lipiodol was inserted in coronal chamber of which 6 were non vital and 5 were vital. The transference of Lipiodol was not noticed in every case after 24 hours. 5 cases with vital pulp tissue in the canals showed no clinical symptome. 3. Extracted 20 teeth were routinely prepared for endodontic treatment and applied Lipiodol in conjunction with cotton fiber as deep as midportion of the roots. After 24, hours the medicament reached to nearly the end of apex, but there were no evidence of penetration in dentine layer and migrate into ramified canal.
A STUDY ON THE ROOT CANAL MORPHOLOGY OF HUMAN MAXILLARY SECOND PREMOLAR WITH TRANSPARENT SPECIMENS
Lee, Chung-Sik ;
Restorative Dentistry and Endodontics, volume 8, issue 1, 1982, Pages 139~145
Eighty four human maxillary second premolars were injected with china. ink, decalcified, cleared and used in study, in vitro, to determine the number of root canals, the frequency and location of lateral canals, the frequency and location of transverse ansatomoses, the curvature of root canals, the location of apical foramens, and the frequency of apical deltas. The results were as follows: 1. Most of the teeth demonstrated one canals, but the only tooth was found to have two canal. 2. Of the 101 canals studied, 85.1% of the canals were found to have lateral canals and these ramifications were usually located in the apical third of the root. 3. Of the two root canals in one root, 25.4% of the canals were found to have transverse anastomoses and were usually located in the middle third of the root 4. 33.3% of apical foramens were located directly on the root apex and 66.7% of them laterally, and 46.5% of canals showed distal curvature.
A SCANNING ELECTRON MICROSCOPIC STUDY OF THE EFFICACY OF ROOT CANAL IRRIGATION
Lee, Myung-Jong ;
Restorative Dentistry and Endodontics, volume 8, issue 1, 1982, Pages 147~153
The purpose of this study is to observe the effect of cleansing action of irrigation solutions which are 3% hydrogen peroxide, 5% sodium hypochlorite and 15% EDTA solution on the root canal wall. After the root canal wall is enlarged with K-file in distilled water, the canal wall which is irrigated with each irrigant for 2 minutes, is compared with the. control group without using any irrigants. Each sample is dehydrated, and coated with 200-250
of gold, and observations are made with the use of scanning electron microscope. The results are as follows: 1. The canal walls irrigated with 3% hydrogen peroxide, 5% sodium hypochlorite and 15% EDTA solution are cleaner than the walls without using irrigants. 2. There are no significant difference of cleansing effect among 3% hydrogen peroxide, 5% sodium hypochlorite and 15% EDTA. 3. After using 3% hydrogen peroxide and 5% sodium hypochlorite solution, large debris are removed on root canal walls, but micro debris remain on the canal walls. 4. The root canal walls irrigated with 15% EDTA solution are decalcifed slightly and show clean surfaces.
AN EXPERIMENTAL STUDY ON THE MARGINAL LEAKAGE OF SEVERAL CANAL FILLING MATERIALS
Yoon, Soo-Han ;
Restorative Dentistry and Endodontics, volume 8, issue 1, 1982, Pages 155~159
The author has studied comparatively the sealing quality of conventional Z.O.E. cement, chloropercha and FR cement by means of penetration of 2% methylene blue solution through the apex of human teeth in 112 cases as the time elapsed. The results were as follows; 1. All the specimen, of which dye immersion time is three days, showed dye penetration of low degree unrelated to the kinds of root canal cement and the degree of dye penetration was increased as the time elapsed. 2. Of all the experimental group, the Z.O.E. cement group showed the lowest degree of dye penetration and the FR filling group showed the highest degree of dye penetration. 3. The degree of dye penetration of FR cement group was higher than that of the Z.O.E. cement group but lower than that of the chloropercha group.
THE EFFECT OF THE METHOD OF CANAL PREPARATION ON THE QUALITY OF CANAL OBTURATION
Lim, Sung-Sam ;
Restorative Dentistry and Endodontics, volume 8, issue 1, 1982, Pages 161~166
The purpose of this study was to examine the influence of canal preparation on the property of apical seal. Seventy canals from extracted human maxillary and mandibular teeth were randomly selected and divided into two groups: conventional group and step-back group. Thirty five canals in one group were enlarged with a, conventional preparation method and thirty five canals in the other group were instrumented in a step-back method with K-file. After instrumentation sixty canals were obturated by lateral condensation of gutta percha and zinc oxide eugenol cement, and five canals in each group were not filled and used as control. All the specimens were immersed in 2% methylene blue dye solution and the depth of dye penetration into the canals were observed by macroscope at the intervals of 1 day, 2 days, and 7 days. The following results were obtained. 1. All the canals experimented showed varying degrees of dye penetration. 2. There was no significant difference between conventional method and step-back method in the depth of dye penetration and the degree of dye penetration tended to increase with time passage in both groups. 3, In conventional preparation group the mean dye penetration was 3.6mm at 1 day, 4.8mm at 2 days. and 6.5mm at 7 days. 4. In step-back prepareation group, the specimens exposed to the dye for 1 day showed mean dye penetration of 4.1mm, and the specimens immersed in the dye for 2 days and 7 days revealed mean dye penetration of 4.6mm and 6.2mm respectively.
MARGINAL LEAKAGE TEST ON "SILAR" COMPOSITE RESIN
Kwon, Hyuk-Choon ;
Restorative Dentistry and Endodontics, volume 8, issue 1, 1982, Pages 167~172
The purpose of this study was to evaluate the marginal sealing ability of "Silar". Using freshly extracted human teeth and 2% acquous methylene blue, the marginal leakage of dye in restorative materials such as Silar, Silar with acid etching technique, Hi-Pol, Hi-Pol Enamel Bond system, Adaptic and Amalgam were investigated at
and under temperature cycling in range of
. The results as follows; 1. All filling materials showed some degree of marginal penetration by 2% methylene blue dye. 2. Silar with acid etching technique revealed effective marginal sealing ability, but under temperature cycling it showed increased marginal leakage. 3. All composite resins showed greater marginal leakage than amalgam restoration. 4. Silar had the most effective marginal sealing ability in experimented composite resins.