• Restorative Dentistry and Endodontics
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• v.17 no.1
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• pp.206-213
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• 1992

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.

• Restorative Dentistry and Endodontics
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• v.18 no.1
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• pp.122-132
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• 1993

The aim of this study was to investigate the level of radiopacity of glass ionomer cements and to determine the optimum level of radiopacity that is the most compatible with the radiographic diagnosis of secondary caries. The experiments were performed in two parts. In the first part, the radiopacities of 9 glass ionomer cements (FI, FII, FI-LC, FII-LC, SI, SII, Vit, B-VLC, AC) and base materials(Ultra-Blend, Zinc phoaphate cements, Cavitec, Dycal) were measured by densitometer. Then all experimental materials were divided into 5 groups based on the level of radiopacity of enamel and dentin. In the second part, class III cavities with or without secondary caries were prepared in extracted anterior teeth. The representative materials of each group with different radiopacities were inserted into each cavity. The radiographs were interpreted by 15 dentists and seconsary caries were diagnosed according to a five-point confidence rating. Sensitivity and ROC analysis were used to compare observer performance. The following results were obtained : 1. The radipacity of glass ionomer cements varied between 1.111mm Al and 6.011mm Al equivalent. 2. Among experimental materials, three materials in group I had lower radiopacity than that of dentin. The radiopacity of two materials in group II slightly exeeded that of dentin. Three materials in group III had slightly lower radiopacity than that on enamel. The radiopacity of one material in group W was slightly higher than that of enamel. Four materals in group V had the radiopacity that exeeded over 2.0mm AI equivalent to that of enamel. 3. The group IV was the highest for sensitivity and the group V was the highest for ROC area. However, no significant differences were obtained among group II, III, IV and V (P<0.05) but only group I was significantly lower(P<0.01). 4. In comparison with the observer performance for the radiographic diagnosis of secondary caries, the group II, III, IV, and V were superior to the group I (P<0.01). And so the optimum level of radiopacity to detect the secondary caries was the radiopacity that is higher than that of dentin.

• Restorative Dentistry and Endodontics
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• v.6 no.1
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• pp.27-35
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• 1980

This study was to evaluate the effectiveness of a few disinfectant on amputated pulps of domestic dogs. The materials employed for the purpose were zinc oxide eugenol paste, calcium hydroxide as control groups and guaiacol (1%, 5%, 10% by weight) added zinc oxide eugenol paste and formaldehyde (1%, 5%, 10% by weight) added calcium hydroxide as experimental groups. Following were the results obtained throngh histo-pathological examination. 1) In calcium hydroxide-formaldehyde groups, secondary dentin formation was observed in the 2 weeks, but the remaining pulp tissue was severely atrophied according to the concentration of formaldehyde and the time increased. 2) In zinc oxide eugenol-guaiacol groups, the first evidence of secondary dentin formation was observed in the 3 weeks. It seems that the concentration variety of guaiacol influenced very little to the potential ability of dentin formation. 3) Except 1% formaldehyde containing calcium hydroxide group, every group showed severe pulp degeneration. In all groups of zinc oxide eugenol-guaiacol cases revealed the tendency of recovery.

• Restorative Dentistry and Endodontics
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• v.12 no.2
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• pp.73-80
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• 1987

The present study was designed to help elucidate the effect of glass ionomer cements on the exposed dental pulp by means of histologic examination. A total of 40 cavities of class V were prepared on the teeth of 4 dogs with exposure of 1mm in diameter on the bases of them. 20 cavities were filled with glass ionomer cement as the experimental group and the other 20 cavities were filled with zinc oxide eugenol cement as the control group. The dogs were sacrificed at one, two, three, and four weeks after filling, and the specimens were routinely prepared and stained with Hematoxylin-Eosin. The obtained microscopic findings were as follows: Inflammatory cell infiltrations were observed in control in 1 week, which decreased markedly with time. In all control groups, hemorrhage around exposed pulp tissue and coagulation change of pulp were observed. Secondary dentin formation and thickened predentin were observed in 4 week cases, and the recovery of pulp tissue was favorable on the whole. Inflammatory cell infiltration was observed in all GIC groups. Proliferation of blood vessel and congestion were observed with coagulation changes around the exposed pulp tissue. Secondary dentin formation and thickened predentin were observed in 3 weeks. In the experimental 4 week case, secondary dentin formation was evident. On the whole, pulpal irritation of glass ionomer cement was relatively severe. Recovery of pulp tissue in GIC groups was less favorable compared with that of ZOE groups.

• Journal of the korean academy of Pediatric Dentistry
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• v.49 no.4
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• pp.392-401
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• 2022

This study investigated the effects of silver diamine fluoride (SDF) and potassium iodide (KI) treatments on the acid resistance of dentin exposed to secondary caries. Sixteen bovine dentin specimens with artificially induced caries were assigned to the following four groups: untreated negative control, untreated positive control, SDF-treated (SDF), and SDF and KI-treated (SDFKI). Multispecies cariogenic biofilms containing Streptococcus mutans, Lactobacillus casei, and Candida albicans were cultured on the specimens for 28 days, except for the negative control group. Specimens from the negative control group were stored in phosphate-buffered saline for that period. After a cariogenic biofilm challenge, the degree of demineralization was evaluated using micro-computed tomography (micro-CT). As a result of data analysis using micro-CT, the demineralization depths of the negative control, positive control, SDF, and SDFKI groups were 149.0 ± 7 ㎛, 392.0 ± 11 ㎛, 206.0 ± 20 ㎛, and 230.0 ± 31 ㎛, respectively. The degree of demineralization was significantly reduced in the SDF and SDFKI groups compared with that in the untreated positive control group. There were no significant differences between the SDF and SDFKI groups. This study confirmed that SDF and SDFKI treatments increase the acid resistance of dentin to secondary caries. KI did not significantly affect the caries-arresting effect of the SDF.

• The Korean Journal of Legal Medicine
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• v.42 no.4
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• pp.141-145
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• 2018

There have been many radiographic studies on age estimation that evaluate reduction in size of dental pulp cavity with secondary dentin formation. The Paewinsky method reported high accuracy in estimating ages by measuring the width of the pulp cavity in panoramic radiographs. The aim of this study was to evaluate the application of the Paewinsky method to digital periapical radiographs. This study was conducted on 103 cases that reported to the Section of Human Identification of the National Forensic Service. The age was calculated by applying the Paewinsky method that measures the root and pulp canal width at three points in a tooth. The estimation results were compared with those calculated by the Johanson method. When the Paewinsky models were applied to digital periapical radiographs, the errors were significantly greater as compared to the original study. The errors of the maxillary second premolar and mandibular lateral incisor were greater than those of the maxillary central incisor, lateral incisor, mandibular canine, and first premolar. Furthermore, errors of the age estimation models in level C were greater than those in levels A and B. This study could be a reference for the application of the Paewinsky method to digital periapical radiographs.

• Restorative Dentistry and Endodontics
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• v.48 no.2
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• pp.13.1-13.11
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• 2023

Objectives: Natural extracts have been investigated as a biomimetic strategy to mechanically strengthen the collagen network and control the biodegradation of extracellular matrix. This study evaluated the effect of epigallocatechin-3-gallate (EGCG) on abfraction lesions prior to the composite resin. Materials and Methods: The sample consisted of 30 patients (aged between 28 and 60 years) with abfraction lesions located in 2 homologous premolars. The teeth were randomly assigned according to dentin treatment: 0.02% EGCG solution or distilled water (control). After enamel acid etching, the solutions were applied immediately for 1 minute. The teeth were restored with Universal Adhesive (3M) and Filtek Z350 XT (3M). Analyzes were done by 2 independent examiners using modified USPHS (retention, secondary caries, marginal adaptation, and postoperative sensitivity) and photographic (color, marginal pigmentation, and anatomical form) criteria at baseline (7 days) and final (18 months). The data analysis used Friedman and Wilcoxon signed-rank tests (α = 0.05). Results: At baseline, all restorations were evaluated as alpha for all criteria. After 18 months, restorations were evaluated as alpha for secondary caries, color, and marginal pigmentation. There was significant difference between baseline and 18 months (p = 0.009) for marginal adaptation and postoperative sensitivity (p = 0.029), but no significant difference were verified between treatments (p = 0.433). The EGCG group had a restoration retention rate of 93.3%, while the control group had 96.7%. Conclusions: The application of EGCG solution on abfraction lesions did not significantly influence the survival of the restorations based on clinical and photographic criteria.

• The Journal of Korean Academy of Prosthodontics
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• v.36 no.1
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• pp.133-149
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• 1998

Clinical application of composite resin recently draw great concerns in dentistry. Especially due to advantages such as esthetics, adhesiveness, simple clinical procedures, various shapes and kinds of composite resins are widely being applied to prosthodontics, conservative dentistry, and orthodontics. But, clinical problems attributable to the polymerization shrinkage of composite resin have been proposed, and we have to regard clinical problems such as secondary caries, loss of restoration, fracture of the surrounding tooth structure, marginal discoloration, and tooth sensitivity, and many portions are remained to be overcome. Therefore, this study attempts to analyze stress distribution between resin and tooth structure which is generated during polymerization shrinkage of composite resin using three dimensional finite element method. Three dimensional finite element models with conventional box-shape cavity and erosion/abrasion type V-shape lesion cavity in upper central incisor were developed. These cavities were filled with four different types of placement techniques. (bulk filling, horizontal increment filling, oblique occlusal increment filling, oblique gingival increment filling) The stresses generated by polymerization shrinkage of composite resin were calculated. The results analyzed with three dimensional finite element method were as follows : 1. The increment filling technique showed the highest maximum normal stress in both conventional box-shape and V-shape cavities and showed a tendency to decrease after complete polymerization. 2. The bulk filling technique resulted in increased stresses during the curing process in both conventional box-shape and V-shape cavities and the highest maximum normal stress occurred after complete polymerization. 3. The bulk filling resulted in the lowest maximum normal stress in both box-shape and V-shape cavities 4. Regardless of placement method, in conventional box-shape cavity, the maximum normal stress increased in dentin floor, enamel, dentin sequence and in V-shape cavity, the maximum normal stress increased in enamel, dentin sequence.

• Restorative Dentistry and Endodontics
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• v.6 no.1
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• pp.7-16
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• 1980

The author observed the periodontal tissue reactions to the root canal sealers after root perforations were made intentionally in dogs. The perforations were made on 74 teeth from 7 dogs. The experiments were performed in two different modes of procedure: In Group I, the perforations were made through the root canal to the alveolar bone. In Group II, the perforations were made from site of alveolar bone to the root canals. The perforated canals in Group I were filled with gutta-percha and root canal cements; Calxyl (Calcium Hydroxide in Ringer's solution), Zinc Oxide -Eugenol cement (Z.O.E.), Kerr sealer (Rickert's paste) and AH 26 (Epoxy Resin preparations). The perforated canals in Group II were sealed with Calxyl, Z.O.E, Kerr sealer and AH26. Histologic examinations of periodontal tissue reactions were observed at various time intervals. The results were as follows; l. Cementum deposition on the perforated root surface in Group II cases showed slightly earlier than that of Group I. Healing tendency of injured alveolar bone in Group II was greater than that of Group I. 2. According to the time increase after experiment, the cementum deposition on the site of perforated dentin in Group II with intact pulp was notably thickened. Secondary dentin deposition on the root canal surface where the dentinal tubles were cut was also found in similar pattern. 3. In the cases of perforated canals sealed with Calxyl both in Group I and Group II, It revealed the earliest cementum-deposition among 4 different root canal cements. In the cases of perforated canals sealed with Kerr sealer and AH26, the cementum-deposition on the root surface was not found. 4. Proliferation of epithelium around the perforated area was first seen at 5-week cases in Group I, and at 3-week cases in Group II. 5. In all cases, dentin resorption on the site of perforated root surface was always occured.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.4
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• pp.595-603
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• 2005

Incomplete removal of bacteria contaminated dentin or enamel associated with caries is a potential problem in restorative dentistry Secondary or residual caries, pulpal inflammation and hypersensitivity may result from bacteria left after the initial preparation, especially if an adequate seal against microleakage is not obtained. A possible solution to eliminate residual bacteria left in a cavity preparation would be to treat the cavity with cavity disinfectant wash. But a potential problem with using a cavity disinfectant with dentin bonding agents could be their interference with the ability of the resin to bond to the tooth micromechanically. The purpose of this study was to evaluate the effect of 2% chlorhexidine containing cavity disinfectant ($Consepsis^{(R)}$) on shear bond strength and microleakage of dentin bonding agents, $Adper ^{TM}$ $Scotchbond^{TM}$ Multi-Purpose, $Adper^{TM}$ Single Bond and $Adper^{TM}\;Prompt^{TM}\; L-Pop^{TM}$ Sixty and sixty sound human third molar teeth, respectively, were used for shear bond strength and microleakage test. For experimental group, cavity disinfectant was applied before dentin bonding agents, and was not applied for the control group. The result from the this study can be summarized as follows ; 1. Use of 2% chlorhexidine containing cavity disinfectant($Consepsis^{(R)}$) does not significantly affect the shear bond strength of dentin bonding agents. 2. Use of 2% chlorhexidine containing cavity disinfectant($Consepsis^{(R)}$) does not significantly affect the microleakage of dentin bonding agents.