• Restorative Dentistry and Endodontics
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• v.21 no.1
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• pp.242-253
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• 1996

Penetration degree of several dyes into dentinal tubules in vivo was compared with in vitro, and experimental sensitivity of those dyes was investigated in 64 canines of 16 cats. Dentin 1mm below cusp tip was exposed by cross-sectioning with diamond disc. Pulp of 32 canines were extirpated through cervical cavities. In the presence of smear layer or after add-etching with 37% phosphoric acid to the exposed dentin surface, acrylic collar and resin cap was attached to keep dyes. 52 mmol/$\ell$ Evans' blue, 2% Methylene blue, 10 % Silver nitrate and 5% Fluorescene were then applicated on each 4 canines respectively for 30 minutes. After rinsing, the canines were ground-sectioned longitudinally and linear dye penetration was measured under microscope. The results obtained were as follows ; 1. Evans' blue and Methylene blue penetrated significantly(P<0.05) more in vitro than in vivo only in the cases that exposed dentin surfaces were not etched with acid. 2. Silver nitrate penetrated significantly(P<0.05) more in vitro than in vivo in both cases that exposed dentin surfaces remained intact and were etched with acid. 3. The penetration degree of Fluorescene did not show statistical significance between in vivo and in vitro or in acid-etched and in not acid-etched cases.

• 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.

• Journal of Periodontal and Implant Science
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• v.43 no.6
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• pp.269-275
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• 2013

Purpose: In this study, the effect of calcium sodium phosphosilicate (NovaMin) desensitizing agent, which is a powder-based system, and hydroxyethyl methacrylate and glutaraldehyde (Gluma desensitizer), which is liquid-based system, on dentinal tubule occlusion was analyzed by scanning electron microscope. The effects of the above two along with one control group were compared to determine the more effective method of sealing the dentinal tubules after initial application. Methods: Twenty specimens were allocated to each of 3 groups: Control, Gluma desensitizer, and NovaMin. Two additional samples were also prepared and treated with Gluma and NovaMin; these samples were longitudinally fractured. The specimens were prepared from extracted sound human premolars and were stored in 10% formalin at room temperature. The teeth were cleaned of gross debris and then sectioned to provide one to two dentin specimens. The dentin specimens were etched with 6% citric acid for 2 minutes and rinsed in distilled water. Control discs were dried, and the test discs were treated with the desensitizing agents as per the manufacturer's instructions. The discs as well as longitudinal sections were later analyzed under the scanning electron microscope. The proportions of completely occluded, partially occluded, and open tubules within each group were calculated. The ratios of completely and partially occluded tubules to the total tubules for all the groups was determined, and the data was statistically analyzed using nonparametric tests and statistical significance was calculated. Results: NovaMin showed more completely occluded tubules ($0.545{\pm}0.051$) while Gluma desensitizer showed more partially occluded tubules ($0.532{\pm}0.075$). The differences among all the groups were statistically significant ($P{\leq}0.05$). Conclusion: Both materials were effective in occluding dentinal tubules but NovaMin appeared more promising in occluding tubules completely after initial application.

• International Journal of Oral Biology
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• v.43 no.2
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• pp.83-91
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• 2018

Nonthermal atmospheric plasma has been studied for its many biomedical effects, such as tooth bleaching, wound healing, and coagulation. In this study, the effects of dentinal tubules occlusion were investigated using fluoride-carboxymethyl cellulose (F-CMC) gel, nano-sized hydroxyapatite (n-HA), and nonthermal atmospheric plasma. Human dentin specimens were divided to 5 groups (group C, HA, HAF, HAP, and HAFP). Group HA was treated with n-HA, group HAF was treated with n-HA after a F-CMC gel application, group HAP was treated with n-HA after a plasma treatment and group HAFP was treated with n-HA after a plasma and F-CMC gel treatment. The occlusion of dentinal tubules was investigated using scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS), which shows Ca/P ratio. In the EDS results, a higher Ca/P ratio was shown in the groups including n-HA than in the control group. The specimens of group HAP and HAFP had a higher Ca/P ratio in retentivity. In the SEM results, there was not a significant difference in the amount of times applied. Therefore, this study suggests F-CMC gel and n-HA treatment using nonthermal atmospheric plasma will be a new treatment method for decreasing hypersensitivity.

• Restorative Dentistry and Endodontics
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• v.26 no.1
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• pp.64-76
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• 2001

Despite the improvements in bond strengths of dentin adhesives and resin-modified glass ionomers, the marginal seal of cervical restorations remains a concern. Microleakage at poorly sealed margins can result in staining, post-operative sensitivity, pulpal irritation, and recurrent caries. The objective of this study was to evaluate the effect of surface penetrating sealant(SPS) on the microleakage of cervical restorations. 45 extracted human teeth were selected, and Class V preparations were prepared on the both buccal and lingual surface of the teeth to the following dimensions : 1.5mm axially, 3mm mesiodistally, and 3mm incisogingivally. After cervical restoration with composite resin, compomer, glass ionomer each restoration was treated as three methods: No Tx., Scotchbond Multipurpose Adhesive$^{\circledR}$, Fortify$^{\circledR}$. The sections were examined with a stereomicroscope to determine the extent of microleakage at enamel and dentin margins. The results of this study were as follows. 1. All groups showed some microleakage. 2. Gingival cavity wall with cementum margin showed significantly higher leakage value than occlusal cavity wall with enamel margin. 3. The group treated with SPS showed significantly lower leakage value than no treated group(p<0.05). But there is no difference between Fortify$^{\circledR}$ and Scotchbond Multipurpose adhesive$^{\circledR}$. The results of this study suggest that SPS are effective in reducing microleakage of class V restorations. But it is certain that some microleakage still occurred despite the application of SPS.

• The Journal of the Korean dental association
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• v.46 no.11
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• pp.683-688
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• 2008

Purpose : The aim of this study was to evaluate the clinical efficacy of two commercially available desensitizing agents over 3 weeks on patients with dentin hypersensitivity. Materials and Methods : An oxalate-based solution, Sensblok (NIBEC Inc. Seoul, Korea) & Superseal (Pheonix Inc. Michigan, USA), and a distilled water placebo were compared in a clinical setting. Seven volunteers exhibiting three or more teeth that were sensitive to tactile & air were enrolled in the study (35 teeth total). A visual analog scale (VAS) was used for recording each patient s level of sensitivity to tactile & air stimuli. A Florida probe was rubbed across the exposed dentin three times with a constant pressure 20 grams to measure the tactile stimulus. The air stimulus was generated by dental unit air syringe for 1-second blast from 1/2 inch distance. The desensitizing agents were applied according manufacture s guideline. VAS scores were recorded at baseline, 1 minute after treatment, at 1 week, 2weeks, 3weeks. VAS score were analyzed using a repeated measures ANOVA ( =0.05). Results : The Sensblok, Superseal, and distilled water placebo all decreased dentin sensitivity. A statistically significant difference existed between Sensblok and placebo when tactile stimulus was applied (P<0.05), but no significant difference was found among other desensitizing agents and tactile and air stimuli.

• The Journal of Korean Academy of Prosthodontics
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• v.52 no.3
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• pp.165-176
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• 2014

Purpose: The effects of desensitizing agent are often for a short duration. One of the reasons is believed to be wear of desensitizing agent by tooth brushing. To reduce the wear and make the duration longer, dental bonding resin was applied and the changes of dentin permeability after toothbrushing were measured. Materials and methods: Extracted teeth free from caries were chosen. Coronal dentin discs with thickness of 1 mm were prepared. Using the split chamber device developed by Pashely, hydraulic conductance and scanning electron microscope images (SEM) were compared and contrasted before and immediately after the application of desensitizing agent and bonding resin and then after equivalent tooth brushing of 1 week, 2 weeks, and 6 weeks. Four commercially available desensitizing agents were used in this study; they were All-Bond 2, Seal & Protect, Gluma, and MS Coat. And Dentin/Enamel Bonding resin (Bisco Inc.) was used. The results of this study are as follows. Results: On all specimens, the hydraulic conductance decreased after the application of tooth desensitizing agent and bonding resin. Compared with the specimens treated only with desensitizer, the specimens treated with All-Bond 2, Gluma, MS Coat and plus D/E bonding resin had a little increase in hydraulic conductance after 1, 2 and 6-week tooth brushing. In case of Seal & Protect, the specimens showed the same result only after 6-week tooth brushing. On examination of SEM, the dentinal tubule diameter had decreased after treatment of desensitizing agents and bonding resin. And the specimens treated with All-Bond2, Seal&Protect, Gluma, MS Coat and plus D/E bonding resin had an significant decrease in diameter of dentinal tubule after 6-week tooth brushing. Conclusion: According to the results of this study, it is effective to use bonding resin after application of desensitizer in reducing the wear by tooth brushing and making the duration longer. In this study, just 6-week tooth brushing was performed, and it is not enough to regard it as a long-term data. So further study is needed and more perfect method for treating dentin hypersensitivity should be developed.

• Imaging Science in Dentistry
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• v.32 no.4
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• pp.187-194
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• 2002

Purpose: To evaluate the performance of the LOGICON Caries Detector using RVG-4 and RVG-ui sensors, by comparing results of each detector to the results of clinical and histological examinations. Materials and Methods : Pairs of extracted teeth were radiographed, and a total of 57 proximal surfaces, which included both carious and non-carious situations, were analyzed. The RVG-4 produced 8-bit images, while the RVG-ui unit produced 12-bit images, which were taken in the high sensitivity mode. The images produced by the LOGICON were evaluated by a trained observer using both automated and manual caries detection software modes. Ground sections of the teeth established the actual absence or existence of caries. Results: LOGIC ON-aided caries detection and depth discrimination of the RVG-4 and RVG-ui sensors were equally inconsistent irrespective of whether the LOGIC ON software was set to the automated or manual mode. Sensitivity ranged from 50% to 57% for caries penetration of the enamel-dentin junction. Conclusion: Care needs to be taken when using LOGIC ON in conjunction with RVG images as an adjunct for treatment planning dental caries. Even when applied by a trained observer, substantial discrepancies exist between the results of the LOGIC ON software-guided evalutations using RVG images and histologic examination.

• Journal of Dental Anesthesia and Pain Medicine
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• v.21 no.2
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• pp.173-178
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• 2021

Inferior alveolar nerve (IAN) injury is usually caused by stretching or crushing of the neurovascular structures and postoperative intra-alveolar hematoma or edema after dental procedures. This results in paresthesia in the ipsilateral chin, lip (vermilion border, skin, and mucosa), and labial or buccal alveolar mucosa of the mandibular anterior teeth. However, there are no reports of sensory alterations in the teeth, especially tooth hypersensitivity, after IAN injury. I report a case in which paresthesia of the lower lip and hypersensitivity of the lower anterior teeth occurred simultaneously after the removal of the third molar that was located close to the IAN. In addition, I discuss the reasons for the different sensory changes between the tooth and chin (skin) after nerve injury from a neurophysiological point of view. Since the dental pulp and periodontal apparatus are highly innervated by the inferior alveolar sensory neurons, it seems necessary to pay attention to the changes in tooth sensitivity if IAN injury occurs during dental procedures.