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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 17, Issue 2 - Oct 1992
Volume 17, Issue 1 - Mar 1992
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EFFECT OF POTASSIUM ION ON INTRADENTAL NERVE ACITIVITY
Son, Ho-Hyun ; Park, Soo-Joung ; Lee, Kwang-Won ;
Restorative Dentistry and Endodontics, volume 17, issue 1, 1992, Pages 1~9
The intradental nerve activity was recorded from single pulp nerve unit dissected from the inferior alveolar nerve in canine teeth of anesthetized cats. The effects of various test solutions on intradental nerve activity evoked by 4M NaCl applied to the deep dentinal cavities were investigated. 1. Total 15 single pulp nerve units were recorded. Of these 9 were Mi - fibers and 6 were C -fibers. The mean conduction velocity and electrical threshold of
- fiber were
and those of C - fiber were
, respectively. The response to cold stimuli of
- fiber began immediately and that of C - fiber began after a latency. 2. When applied to deep dentinal cavity, 4M NaCl induced irregular bursts of action potential in 4
- fibers and 3 C - fibers, which continued until the solution was washed away. 3. In the
- fiber, histamine failed to induce any nerve acitivity and did not produce an increase in intradental nerve activity evoked by 4M NaCl. However following the application of 1M KCl, the response to 4M NaCl was eliminated. 4. In the C - fiber, histamine generated some nerve activity and produced a significant increase in intradental nerve activity evoked by 4M NaCl, but 5M
did not abolish this enhandced response.
EFFECTS OF EUGENOL, CAPSAICIN AND DEMETHOXY-NE ON THE PAIN RESPONSE OF DENTAL PULP
Lee, Eun-Goo ; Lee, Chung-Sik ;
Restorative Dentistry and Endodontics, volume 17, issue 1, 1992, Pages 10~21
The purpose of this study was to investigate the analgesic effect of eugenol, capsaicin and demethoxy-NE. Young adult cats, weighing 2.0 to 3.0kg, were used. Each animal was anesthetized (
-chloralose 60mg per kg body weight) and divided into four groups; control, eugenol, capsaicin and demethoxy-NE group. The anterior digastric muscles were exposed and a pair of electrodes was inserted to record the electromyograms. To expose the pulp, each canine teeth was prepared with a low speed bur under cooling and used for recording anterior digastric muscular EMGs evoked by noxious stimulation of dental pulp. To observe effects on jaw opening reflex, inferior alveolar nerve of both sides were exposed for drug application and wire electrodes were inserted in anterior digstric muscle for recording the EMGs. To observe effects on action potential, saphenous nerves of both sides were exposed and three tissue pools were made from surrounding tissue. The most distal pool was used for applying stimulation, the most proximal one for recording of action potential, and the other one for drug application. One side of inferior alveolar nerve and saphenous nerve were used for eugenol, capsaicin, or demethoxy-NE application, the other side of nerve for control experiments(only vehicle application). Anterior digastric muscular EMGs evoked by noxious stimulation of dental pulp were recorded before drug application, immediate after drug application, at 60 and 120 minutes, and 5 days after drug application. Action potentials were recorded before drug application, immediate after 30 minutes drug application, at 30, 60 and 120 minutes after drug had been washed out. The results were as follows; 1. Eugenol had a continuous blocking effect on the anterior digastric muscular EMGs evoked by noxious pulp stimulation and after 5 days, showed completely blocking effect. 2. After 5 days, demethoxy-NE applied to dental pulp had a considerable blocking effect on the jaw opening retlex evoked by noxious stimulation but capsaicin had no significant effect. 3. After 5 days, eugenol group showed the strongest blocking effect among the all experimental groups on the jaw opening reflex evoked by noxious stimulation of dental pulp and capsaicin group showed the weakest blocking effect. 4. Eugenol had a completely blocking effect on the action potential conductivity of peripheral nerve. Capsaicin and demethoxy-NE had the blocking effect on the action potential conductivity of
-and C-nerve fibers. 5. Capsaicin, demethoxy-NE and eugenol applied to inferior alveolar nerve surppressed the jaw opening reflex evoked by noxious stimulation of dental pulp.
EFFECT OF ZINGIBERIS RHIZOMA AND ASIASARI RADIX EXTRACTS ON THE JAW OPENING REFLEX PROVOKED BY NOXIOUS STIMULI AND THE PERIPHERAL NERVE CONDUCTION
Choi, Han-Seok ; Yoon, Soo-Han ;
Restorative Dentistry and Endodontics, volume 17, issue 1, 1992, Pages 22~35
The aim of this study was to investigate the effect of herbal organic extracts on the pain response provoked by noxious stimuli on dental nerve and the peripheral nerve conduction. Cats (2-2.5Kg regardless of sex) that were chosen as experimental animals were classified into control group, Asiasari radix application group and Zingiberis rhizoma application group. They were anesthetized with
-chloralose, then anterior belly of digastric muscle of both sides were exposed and wire electrodes were inserted for recording of Electromyogram (EMG). Cavities were prepared on canines until pulp of the teeth were exposed. And after the drugs solubilized for 2% and 4% concentration (W/V) in vehicle were applied, their effects were compared through the recording of EMG immediately after drug application, 30 minutes, 60 minutes, 120 minutes and 5 days after, respectively. And after both inferior alveolar nerves were exposed, 4% organic extracts of Zingiberis rhizoma and Asiasari radix were applied for 30 minutes then the change of jaw opening reflex provoked by noxious stimuli on pulpal nerves were observed immediately after washing out, at 30, 60 and 90 minutes after drug had been washed out. After saphenous nerve of both sides were exposed, one side of nerve was used for vehicle application and the other side was used for drug application for 30 minutes. Then conduction of action potential of A-
and C-fiders of saphenous nerves, which have changed with time, was recorded. With analysis of these records, the following results were obtained: 1. Organic extract of Zingiberis rhizoma (2% or 4% concentration) greatly suppressed EMG of digastric muscle provoked by noxious stimuli on pulpal nerve at five days after application, the suppressive: effect was greater than that of organic extract of Asiasari radix. 2. Organic extract of Asiasari radix (2% or 4% concentration) suppressed jaw opening reflex provoked by noxious stimuli on pulpal nerve, at 5 days after drug application. 3. Organic extract of Zingiberis rhizoma and Asiasari radix (immediately after 30 minutes application) suppressed neural conduction of A-
and C-fibers, the suppressive effect was greater on A-
fibers than on C-fibers. 4. Jaw opening reflex provoked by noxious stimuli on pulpal nerve in inferior alveolar nerve was greatly suppressed 30 minutes after drug application, this effect was greater by Zingiberis rhizoma than by Asiasari radix.
STUDIES ON THE BOND BETWEEN COMPOSITE RESIN AND DENTIN TREATED BY DENTIN BONDING AGENTS
Youn, Dong-Ho ; Park, Sang-Jin ;
Restorative Dentistry and Endodontics, volume 17, issue 1, 1992, Pages 36~54
The purpose of this study was to compare the shear bond strengths to ground dentin surfaces of four dentinal bonding agents in 193 teeth. Various dentin surfaces treated with four dentin bonding agents were attached with two restorative composite resins. The effectiveness of the bonding were tested by the monitoring the shear bond strength. The shear bond strengths were measured after 2 hours and 24 hours after surface conditioning with four dentin bonding agents. Effects of EDTA, the additive illumination, and sealer treatments without primer on bond strength to dentin surfaces were assessed. In addition the effects of the thickness of specimens ranging from 0.65 mm to 1.95 mm and the ratio of catalyst and base paste on the bond strength of chemical cure composite resin were estimated. The shear bond strength was determined by testing specimens in the Instron universal testing machine (Model No. 1122) at a crosshead speed of 1.0 mm/min. Following condusions were drawn: 1. The highest mean shear bond strengths of chemical cure composite resin to dentin conditioning with dentin bonding agents aged 2 hours were obtained, and then that was decreased with time followed by EDTA treatment. 2. In light cure composite resin, the shear bond strength was increased following dentin conditioning with bonding agents with time, irradiation time and EDTA treatment except in SB group. 3. The thicker the composite resin specimen was, the less the shear bond strength in chemical cure composite resin was. 4. In light cure composite resin, there was a little change in shear bond strength following dentin conditioning with bonding agents. 5. In chemical cure composite resin, the shear bond strength was the highest in the ratio of 1/1 of catalyst and base part. 6. Without a dentin primer, shear bond strength to dentin conditioned only with UB sealer was the highest among four sealers in light cure composite resin.
A QUANTITATIVE ANALYSIS OF THE IMMUNOCOMPETENT CELLS IN PERIAPICAL LESIONS OF THE HUMAN TEETH
Yoon, Tai-Cheol ; Kim, Jin ; Park, Dong-Soo ;
Restorative Dentistry and Endodontics, volume 17, issue 1, 1992, Pages 55~68
Periapical lesions are developed as a result of inflammatory response to irritants from root canal system. Clinicians remove these irritants from root canal system and seal the root canal space to induce healing of the periapical lesions. Immunopathologic responses may play an important role in development and progression of periapical lesions and periapical lesions contain immunocompetent cells. The purposes of the present study were to analys and to compare the distribution of the immunocompetent cells in the human periapical lesions according to the stage of endodontic treatment using indirect immunoperoxdase technique. Obtained 94 human periapical lesions were devided into four groups: Group 1 : no endodontic treatment(28 samples) Group 2 : root canal enlarged and irrigated(28 samples) Group 3 : root canal filled(29 samples) Group 4: unknown(9 samples) Monoclonal antibodies to examine target cells were UCHL-1 for T lymphocytes(1 : 200, Dakopatt, Denmark), L26 for B lymphocytes(1 : 200, Dakopatt, Denmark), OPD4 for helper T lymphocytes(l : 200, Dakopatt, Denmark) and alpha-1-antichymotrypsin for macrophages(l : 2000, Dakopatt, Denmark). The following results were obtained : 1. All the periapical lesions studied were infiltrated by T lymphocytes, plasma cells, B lymphocytes, and macrophages. T lymphocytes were more infiltrated than B lymphocytes, and B lymphocytes and macrophages were less infiltrated than T lymphocytes and plasma cells(P<0.05 : Oneway ANOVA test). 2. In untreated group and canal irrigated and enlarged group of all the periapical lesions, helper T lymphocytes were predominently infiltrated(P>0.05 : Oneway ANOVA test). 3. In canal filled groups of all lesions except periapical cyst, plasma cells were predominently infiltrated. But, in canal filled group of periapical cyst, helper T lymphocytes were the predominent cells(P>0.05 : Oneway ANOVA test). The above results shows that the immunologic responses play important role in pathogenesis of periapical lesions and the immunologic response involved undergoes certain changes after endodontic therapy.
AN INVESTIGATION ON THE CHARACTERIZATION OF COMPOSITE RESIN POLYMERIZED BY THE USE OF AN ARGON ION LASER
Cho, Hyung-Kyung ; Lee, Chung-Suck ;
Restorative Dentistry and Endodontics, volume 17, issue 1, 1992, Pages 69~82
An experimental investigation of the physical properties of light curing composite resin P-50 was performed, in which an argon ion laser beam was irradiated. The physical and mechanical properties of laser polymerized composite resin were determined by measuring the compressive strength, diametral tensile strength, curing depth and microhardness depending upon the experimental conditions such as the laser irradiation time(10sec, 20sec, 30sec) and laser power(300mW, 500mW, 1000mW). These observations were compared with a conventional visible light curing technique. In addition, to evaluate the marginal adaptation, Class V cavity was prepared on the buccal or lingual surface of the extracted premolar and filled with P-50 light curing resin. The test samples were irradiated with both light sources so that the interface between the restoration and the tooth structure were observed under scanning electron microscope. The most of physical and mechanical properties of the laser cured resin showed a remarkable improvement than those treated with the conventional light source, while the observations with the scanning electron microscope provided no significant difference for two polymerized sources. From the results in the experiment it appears that the potential of an argon ion laser is of important value of the use in the polymerization of composite resin.
A STUDY ON ARACHIDONIC ACID METABOLISM OF CHRONIC PERIAPICAL LESIONS
Park, Keum-Soon ; Son, Ho-Hyun ;
Restorative Dentistry and Endodontics, volume 17, issue 1, 1992, Pages 83~94
This study was executed to measure the biosynthesis of arachidonic acid metabolic products in chronic periapical lesions, to compare the products among periapical granuloma, periapical cyst and chronic periapical abscess, and to understand the pathogensis of chronic periapical lesions. Tissues from 33 chronic periapical lesions of human teeth were enucleated during endodontic surgery. large part of each tissue was contained in liquid nitrogen immediately and the other was examined histologically. In histologically diagnosed 8 cases of periapical granuloma, 9 cases of periapical cyst and 8 cases of chronic periapical abscess. the tissues were homogenatecl and incubated with
-arachidonic acid. Lipid solvent extracts were separated by thin layer chromatography to be analyzed by autoradiography and TLC analyzer. 1.
, HETEs, and unidentified product which are metabolic products of arachidonic acid were measured in the tissues of chronic peripaical lesions. 2. In all of periapical granuloma, cyst and abscess, the conversion rate of HETEs among all products was the highest(P<0.05), and the percentage of HETEs in total converted products was also the highest(P<0.05). 3. The concentration of each arachidonic acid product was higher in chronic periapical absecss than in periapical granuloma and cyst(P<0.05). The concentration of
and HETEs in periapical cyst were hight than in periapical granuloma. 4. The relative amounts of total products from lipoxygenase pathway to those from cyclo-oxygenase pathway were about 7 fold in chronic periapical lesions. There was no difference among periapical granuloma, cyst and abscess(P<0.05). The total amount of products from each pathway were higher in chronic periapical abscess than in periapical cyst and granuloma.
THE EFFECT OF THE DENTINE PRETREATMENT ON THE MARGINAL LEAKAGE OF A GLASS IONOMER CEMENT
Cho, Jung-Hee ; Hong, Chan-Ui ; Shin, Dong-Hoon ;
Restorative Dentistry and Endodontics, volume 17, issue 1, 1992, Pages 95~103
The purpose of this study was to evaluate the effect of the dentin pretreatment on the marginal leakage of a glassionomer cement. 1n this study, 60 molars with sound and healthy crown portion were used. The dentin surface of these teeth were exposed and polished with 600 grit silicon carbide paper. Square - shaped cavities were prepared on the flattened dentin surfaces and these were divided into 4 groups according to the dentin pretreatment procedures. Group I : Dentin pretreatment with distilled water as a control group. Group II : Dentin pretreatment with 5% sodium hypochlorite solution. Group III : Dentin pretreatment with Ketac conditioner. Group IV : Dentin pretreatment with 40% polyacrylic acid. The degrees of dye penetration in the cavity walls were assessed using a stereoscope at
magnification according to the maximum dye penetration. The results were analyzed by using Mann - Whitney U test. The results were as follows : 1. All groups showed varying depth of dye penetration. 2. Distilled water group showed the most severe marginal leakage when compared with the other groups(P<0.05). 3. 40% polyacrylic acid group showed the least amount of marginal leakage compared with the other groups (P<0.05). 4. There were significant differences between Goup I(distilled water) and Group IV (40% polyacrylic acid)(P<0.05), but there were no significant differences among Group I(distilled water), Group II(sodium hypochlorite), Group III(Ketac conditioner) (P>0.05).
AN EXPERIMENTAL STUDY ON SHEAR BOND STRENGTH OF GLASS IONOMER CEMENT TO DENTIN SURFACE FOLLOWING SURFACE CONTIONING
Lee, Kwang-Woo ; Hong, Chan-Ui ; Shin, Dong-Hoon ;
Restorative Dentistry and Endodontics, volume 17, issue 1, 1992, Pages 104~114
The purpose of this study was to evaluate the shear bond strength of glass ionomer cement(Ketacfil, ESPE, Co.) against dentin surface which had been treated with surface conditioning agents(distilled water, 5% sodium hypochlorite solution, Ketac - conditioner, 40% polyacrylic acid). In this study, 60 human molars with sound and healthy crown portion which were previously extracted for orthodontic or periodontal problem. The dentin surfaces of these teeth were exposed with wet trimmer and polished with 150 - grit and 600 - grit silicon carbide paper and the teeth were divided into four groups(15 teeth per group) according to the following surface conditioning methods. Group I : Surface treatment with distilled water as control group. Group II : Surface conditioning with 5% sodium hypochlorite solution. Group III : Surface conditioning with Ketac conditioner. Group IV : Surface conditioning with 40% polyacrylic acid. The shear bond strengths were measured by Autograph(Shimatzu Co. Japan). The result of the evaluations were then subjected to statistical analysis using one - way analysis of variance and Duncan test and the results were as follows : 1. The shear bond strength accrding to the dentin surface conditioning conditions was highest in Ketac conditioner group, with measurements of
and lowest in the distilled water group, with measurements of
. 2. Statistically significant differences were found between surface conditioning with 5% sodium hypochlorite solution group or Ketac conditioner group and distilled water group(P<0.01). 3. Also, statistically significant difference was found between surface conditioning with distilled water group and 40% polyacrylic acid group(P<0.05). 4. Overall difference in statistical significance between the groups was not found (P<0.05). 5. Fractured dentin surface treated with conditioning solutions showed cohesive fracture. 6. Distilled water group and 5% sodium hypochlorite solution group removed the smear layer less effectively. 7. Conditioning dentin with Ketac conditioner and 40% polyacrylic acid resulted in the removal of a significant amount of the smear layer without removing the tubular plugs and dissolving the peritubular dentin.
A STUDY ON THE ANTIBACTERIAL EFFECT OF IRRIGATION SOLUTIONS TO STREPTOCOCCI
Shim, Jae-Han ; Im, Mi-Kyung ; Han, Du-Seok ;
Restorative Dentistry and Endodontics, volume 17, issue 1, 1992, Pages 115~125
It is advisable to use irrigation solutions which have strong antibacterial effect and weak cytotoxic effect on treating root infections. Streptococci are ones of the most frequently isolated microorganisms in infected root canals. The antibacterial effect of ten irrigation solutions were investigated on S. mutans (19449), S. sanguis. )10556) and 4 streptococci isolated from saliva of healthy persons. These streptococci were exposured to irrigation solutions during 10 sec, 30 sec,. 1 min, 3 min, 5 min, 10 min, 30 min and 2hrs respectively. Four irrigation solutions which showed strong antibacterial activity were diluted to 1 : 1 to 1 : 10,000. Then they were subcultured on blood agar plate an observed after 1 day. 5.25% NaOC1 had the strongest antibacterial effect. 30% urea and normal saline showed no antibacterial effect. 50 % citric acid and 3%
showed relatively weak antibacterial effect. 15 % EDTA had very weak antibacterial effect.
A STUDY ON THE COLOR STABILITY AND MICROHARDENSS OF LIGHT CURING RESINS
Oh, Se-Hong ; Im, Mi-Kyung ; Cho, Hye-Won ; Lee, Kwang-Hee ;
Restorative Dentistry and Endodontics, volume 17, issue 1, 1992, Pages 126~133
Tooth colored resin restorative materials are widely used in anterior teeth restorations. The color instability of resin was the main cause of failure in resin restorations. The purpose of this study was to investigate color stability and microhardness of serval visible light curing resins. Colorimetric measurements(Tokyo Denshoku Co., Japan) and microhardness tests(Matusuzawa, MXT 70, Japan) were made on six composite resins before and after controlled immersion treatments. The six composite resins were BIS - FILM(BISCO, USA), Durafill(Kulzer, Germany), Helioprogess(VIVADENT, Germany), Palfique(TOKUYAMA SODA, Japan), Silux(3M, USA), Photoclearfil(KURARAY, Japen). Six light curing resins showed significant color change after 2 weeks. Palfique exhibited the hightest
values and Helio progress presented the lowest
values. Photoclearfil showed the highest microhardness value. Durafill and Helio progress showed lower microhardness values. Microhardness values were decreased after 8 weeks in Bisfil, Palfique light, and Photoclearfil.
A STUDY ON THE ANTIBACTERIAL EFFECT OF RESTORATIVE MATERIALS
Jeong, Hee-Il ; Im, Mi-Kyung ; Choi, La-Young ; Han, Du-Seok ;
Restorative Dentistry and Endodontics, volume 17, issue 1, 1992, Pages 134~140
The purpose of this study was to investigate the antibacterial effect of zinc oxide eugenol(ZOE), zinc phosphate cement(ZPC), glass ionomer cement, resin, and Vitapex to S. muntans, S. sanguis, S. fecalis and E. coli by agar diffusion method. Four wells were punctured in mitis-salivarius agar plate per each group and each wells were filled with restorative matetials. The width of inhibition zones produced in mitis - salivarius agar were measured as the parameter of the antibacterial effect after 16 hours and 40 hours. In S. mutans and S. sanguis, the largest inhibition zone was produced on ZOE, followed by glass ionomer cement, and ZPC. Inhibition zones was not observed in resin and Vitapex. In S. fecalis, ZOE and glass ionomer cement showed wider inhibition zone than ZPC. In E. coli, ZOE showed wider inhibition zone than ZPC, but no inhibition zone was observed on glass ionomer cement.
SHAPING ABILITY OF ROOT CANAL INSTRUMENTS ON CURVED ROOT CANALS
Kim, Myeong-Su ; Son, Ho-Hyun ;
Restorative Dentistry and Endodontics, volume 17, issue 1, 1992, Pages 141~152
Four endodontic instruments from different manufacturers(K - file, Hedstrom - file, K - flex - file, Cavi - Endo) were used to shape 80 mesial canals of extracted posterior teeth. The instrument's ability to enlarge and shape the canals as the original canal shape was assessed by superimposing radiographs of canals obtained before and after canal shaping. The results were as follows 1. Hedstrom - file enlarged canals greater than K - file, K - flex - file, and Cavi - Endo(P<0.05). There are no differences in canal enlargement among K - flex, K - flex - file, and Cavi - Endo(P<0.05). 2. All the instruments showed no difference in canal enlargement between convex side and concave side of B point in proximal and clinical radiographic views, but at the concave side of C point canals were enlarged greater than at the convex side(proximal view of K - file: P<0.05, the others: P<0.01). 3. There was no difference m canal enlargement between convex side and concave side in proximal view of A and D points of K - file and K - flex - file(P<0.05). But in clinical view, canal enlargement at convex side of A point and concave side of D point was greater than that at concave side of A point and convex side of D point respectively. 4. Hedstrom - files showed greater canal enlargement at convex side of A points and concave side of D points (P<0.05 or P<0.01). Cavi - Endo showed no difference in canal enlargement between convex side and concave side at A and D points in proximal view(P<0.05). Bur canal enlargement was greater at concave side than at convex side of D point in clinical view. 5. K - file and Cavi - Endo showed no differences in canal enlargement between convex and concave side in proximal and clinical view (P<0.05). K - flex - file showed greater canal enlargement at concave side in proximal and clinical view(P<0.0:5). Hedstrom file showed no difference in canal enlargement between convex side and concave side in proximal view, but showed greater canal enlargement at concave side in clinical view(P<0.05).
ACOUSTIC EMISSION ANALYSIS FOR FRACTURE CHARACTERISTICS OF DENTAL POSTERIOR COMPOSITES
Park, Jin-Hoon ; Kim, Kyo-Han ;
Restorative Dentistry and Endodontics, volume 17, issue 1, 1992, Pages 153~165
Dental composite resin is a kind of the particle - reinforced composite material, and is widely used in recent dental restoration of anterior and posterior tooth region. The purpose of this study was to investigate the fracture behaviour according to volume fractions and external findings of the filler particles for better interpretation of the fracture characteristics of posterior dental composite resins by analytic method of fracture mechanics. The plane strain fracture toughness(
) and Acoustic Emission were determined with three - point bending test using the single edge notch specimen according to the ASTM - E399, and its analyzed data was compared with filler volume fractions derived from the standard ashing test and scanning electron fractographs of each specimen including the unfilled experimental resin as a control. The results were that the value of fracture toughness of the composite resin material was in the range from 0.85 MPa
to 1.60 MPa
and was higher than the value of the unfilled experimental resin, and the fracture behaviours dervied from Acoustic Emission analysis show prominent differences according to the volume fraction and the size of filler particles used in each composite resin. The degree of resistance against crack propagation seems to be increase and the fractographs demonstrate the high degree of surface roughness and irregularity according with the increase of fracture toughness value.
EXPERIMENTAL STUDIES ON THE SURFACE ROUGHNESS OF GLASS IONOMER CEMENT RESTORATIONS
Kim, Kwang-Soon ; Lee, Seung-Jong ; Lee, Chung-Suck ;
Restorative Dentistry and Endodontics, volume 17, issue 1, 1992, Pages 166~180
One disadvantage of Glass Ionomer Cement Restoration is the difficulty in polishing. To find the appropriate polishing method, we polished the surface of Glass Ionomer Cement Restorations by 11 combination methods serially using disks shared with large-small particles and evaluated the polishing process in terms of surface roughness, surface roughness curve, and SEM findings. In addition, a visible light curing type bonding material was applied to evaluate the possible improvement in surface properties. The following results were obtained. 1. The disk surface of Glass Ionomer Cement was polished serially by disks with superfine particles, but it didn't become smooth. 2. The surface of Microfilled Composite resin became smoother as using a disk with finer particles. 3. When a visible light curing type bonding material was applied in finishing process, the surface of Glass Ionomer Cement became smooth as much as the applied matrix.
QUANTITATIVE ANALYSIS OF RESIDUAL MONOMERS IN VISIBLE LIGHT-CURED RESINS
Choi, Kyoung-Kyu ; Min, Byung-Soon ;
Restorative Dentistry and Endodontics, volume 17, issue 1, 1992, Pages 181~190
The purpose of this study was to estimate the contents of the residual monomers, such as Bis-GMA and TEGDMA. In this study, materials used were six kinds of anterior and posterior visible light-cured resins. Resins were placed in disk-shaped Teflon mold (8.5mm in diameter, 2.0mm in thickness), and cured for 20 seconds with visible light source attached wide diameter lightguide. The specimens were immersed in 10ml ethanol and stored for 5 days at
. The concentration of residual monomers in eluate solution was analysed by HPLC, and the following results are obtained. 1. The residual Bis-GMA and TEGDMA were detected in all materials used, and the ranges of quantity of the residual Bis-GMA was 0.101-1.236 wt% and that of TEGDMA was 0.230-5.794 wt%.2. The contents of residual TEGDMA was detected higher than that of residual Bis-GMA (P < 0.01). 3. The content of residual monomers was detected to be highest in Bis-Fil M as microfilled type. 4. In most of the materials used, there was no significant difference in the contents of residual monomers between anterior and posterior light-cured resins.
A STUDY ON THE MARGINAL LEAKAGE OF CLASS II COMPOSITE RESIN INLAY
Kang, Hyun-Sook ; Choi, Ho-Young ;
Restorative Dentistry and Endodontics, volume 17, issue 1, 1992, Pages 191~205
The purpose of this study was to evaluate the microleakage of class II composite resin inlays and compare them with the conventional light-cured resin filling restorations. Class II cavities were prepared in 60 extracted human molars with which cervical margins were located below 1.0mm at the cemento-enamel junction using No. 701 tapered fissure carbide bur. All of the prepared cavities were restored as follows and divided into 6 groups. Group I and 2 were restored using direct filling technique and group 3,4,5 and 6 were restored using direct inlay technique that was cemented with dual-cured resin cements. group I: Cavities were restored with light-curing composite resin, Brilliant Lux. group 2. Cavities were restored with light-curing composite resin, Clearfil PhotoPosterior. group 3: Cavities were restored with Clearfil CR Inlay and heat treated at
for 7 minutes. group 4: Cavities were restored with same material as group 3 and heat treated at
for 15 minutes. group 5: Cavities were restored with Brilliant (Indirect esthetic system) and heat treated at
for 7 minutes. group 6: Cavities were restored with same material as group 5 and heat treated at
for 15 minutes. All specimens were polished with same method and thermocycled between
, then immersed in a bath of 2.0% aqueous solution of basic fuchsin dye for 24 hours. Dyed specimens were sectioned longitudinally and dye penetration degree was read on a scale of 0 to 4 by Tani and Buonocore's method 45). The results were as follows: 1. Microleakage was observed rather at the cervical margins than at the occlusal margins in all groups. 2. Composite resin inlay groups showed significantly less leakage than direct filling groups at the cervical margins (p < 0.001). 3. In composite resin inlay groups, there was no significant difference in microleakage between specimens by heat treating temperature and time (p > 0.05). 4. There was no significant difference in leakage between each groups at the occlusal margins (p > 0.05).
A STUDY ON THE OPTIMAL RADIOPACITY OF POSTERIOR COMPOSITE RESINS
Kim, Byung-Hyun ; Lee, Chung-Sik ; Um, Chung-Moon ;
Restorative Dentistry and Endodontics, volume 17, issue 1, 1992, Pages 206~213
The aim of this study was to compare the accuracy of radiographic diagnosis of secondary carious lesions adjacent to composite filling materials with different radiopacity. The level of radiopacity that is most compatible with the radiographic diagnosis of secondary caries was studied in a two part experiment. In the first part, the radiopacity of 6 posterior composites CBP, CF, HM, LF, PQ, P50), enamel and dentin were measured by desitometer and 6 posterior composites divided into 3 groups based on their level of radiopacity compared with enamel and dentin. In the seocnd part, class II composite fillings with or without secondary caries were made in extracted premolar and radiographs of the teeth were examined by 10 dentists to diagnose simulated carious lesion. The following results were obtained: 1. The radiopacity of 6 posterior composites varied between 1.76(PQ) and 6.78(P50)mm Al equivalent. 2. For 4 composites the radiopacity exeeded that of an equal thickness of enamel, and for two the radiopacity was lower than that of dentin. 3. The detection of secondary caries was facillitated when the radiopacity of a composite resin was similar to or slightly greater than that of enamel.
A STUDY ON THE EFFECTS OF BACTERIA ON THE SIZE OF THE LESION AND THE DISCOLORATION IN THE TRAUMATIZED NONVITAL TEETH
Youn, Jung-Hye ; Lee, Myung-Jong ;
Restorative Dentistry and Endodontics, volume 17, issue 1, 1992, Pages 214~221
The five different types of bacteria, Bacteroides, Actinomyces, Capnocytophaga, Streptococcus, Fusobacterium which had frequently been recovered in infected canals, were investigated. The purpose of this study was to investigate the bacteriologic status in the traumatized nonvital teeth, and to investigate the effects of bacteria on the size of the le8ion and on the discoloration of teeth. The canal contents of sxiteen traumatized nonvital teeth were sampled and cultured aerobically and anaerobically for growth in five selective agar plates for five bacterial species. The sizes of the radiolucent areas in periapical films were measured and according to the sizes, the samples were divided into two groups. The discoloration of the teeth was checked and according to the existence of the discoloration, the samples were divided into two groups, also. The difference of bacterial colonial numbers in each group was investigated and the following results were obtained. 1. In traumatized nonvital teeth, all of the samples gave bacterial growth except one case. 2. Streptococcus was isolated in four cases but Bacteroides, Actinomyces, Fusobacterium and Capnocytophaga were not isolated. 3. The number of bacterial colonies was not found to be related the size of the lesion periapical films. 4. The number of bacterial colonies was not found to be related the discoloration of teeth.
A STUDY ON SYSTEMIC AND LOCAL PRODUCTION OF IMMUNOGLOBULINS IN HUMAN PERIAPICAL CYSTS
Park, Kye-Yang ; Lim, Sung-Sam ;
Restorative Dentistry and Endodontics, volume 17, issue 1, 1992, Pages 222~234
The purpose of this study was to evaluate the systemic and local production of immunoglobulins and their levels in patients with periapical cysts using Enzyme - Linked Immunosorbent Assay. Streptococcus sanguis, Bacteroides gingivalis, and Bacteroides intermedius were grown for use as antigen and they were harvested by centrifugation. The patients were divided into two groups: patients of periapical cysts and normal control. 5 patients of each group were selected and their blood were obtained via intravenous puncture prior to surgical operation. Sera were prepared by centrifugation of each blood samples. Cyst fluid were aspirated from cystic cavity and cyst wall were excised at operation. Control tissue were also excised at extraction site of impacted wisdom teeth from normal control. Each tissue was prepared by homogenization and centrifugation. Then antibodies of each sample were measured by modified ELISA. The following results were obtained: 1. Serum IgG and IgM levels were not significantly different between patients with periapical cyst and normal control. 2. IgG and IgM levels of cyst fluid to Bacteroides gingivalis and Bacteroides intermedius were significantly higher than those of serum of patients with periapical cyst, but there was no significant difference to Streptococcus sanguis. 3. IgG and IgM levels of cyst wall to Bacteroides gingivalis and Bacteroides intermedius were significantly higher than those of control tissue, but there was no significant difference to Streptococcus sanguis. 4. IgG and IgM levels in cyst fluid and IgG levels in cyst wall were highest to Bacteroides gingivalis, and IgM levels in cyst wall were highest to Bacteroides intermedius.
EVALUATION OF THE ACCURACY OF THE ELECTRONIC APEX LOCATOR USING THE POLARIZING MICROSCOPE
Park, Han-Soo ; Yoon, Soo-Han ;
Restorative Dentistry and Endodontics, volume 17, issue 1, 1992, Pages 235~243
The purpose of this study was to evaluate the accuracy of an electronic apex locator, the Neosono - M, in determining the location of the cementodentinal junction. A total of 26 teeth with 46 canals were evaluated. The apex locator was used to locate the file and the teeth extracted. The specimen were prepared with highspeed burs and sandpaper discs to a thickness of
. Distances were measured from the cementodentinal junction with the use of polarizing microscope. Measurements made by the apex locator were also compared with those by the X - ray. The results were as follows. 1. The apex locator and X - ray were to measure a mean value of 0.17, 0.45mm coronal to the CDJ respectively. There was no significant difference between the accuracy of the apex locator and that of X - ray. 2. There was no significant difference between the accuracy of apex locator in vital and in nonvital teeth, and between in narrow and in wide canals. 3. The files in nonvital and narrow group were apical to the CDJ significantly than those of vital and narrow, vital and wide, and non vital and wide groups.