• Proceedings of the KACD Conference
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• 2001.11a
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• pp.566.1-566
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• 2001

The most desirable healing process for endodontic therapy is apical closure by hard tissue such as dentine or cementum. Then, we estimated hard tissue conductivity of tetracalcium phosphate (4CP)/dicalcium phosphate (2CP) compound using mandibular first molars of SD rats. Residual pulp responses to the calcium phosphate compound were examined at several amputation levels of pulp. 2CP was purchased and passed through a $32-\mu\textrm{m}$ sieve. 4CP was obtained from a stoichiometric mixture of 2CP and calcium carbonate (Mol ratio: Ca/P=2.0) by the dry synthetic method at 1, 400(C for 8 hours.(omitted)

• Proceedings of the KACD Conference
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• 2003.11a
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• pp.601-601
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• 2003

AQ Bond Plus has the function of self-etching priming adhesive, which can be applied by single coating without second coating, being different from conventional AQ bonds. Moreover, because the absorption range of light became wider, the bond can comply with any visible light curing units. Thus, the bond can produce an unified form between the dentine layer with impregnated resin of good quality and the thin and hard film characteristically. In this study, we investigated the junctional conditions of AQ Bond Plus, using a scanning electron microscope (SEM).(omitted)

• The Journal of the Korean dental association
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• v.57 no.10
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• pp.588-594
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• 2019

The fusion is an anomalous union of two or more tooth germ at some stage in the development process resulting in a decreased number of teeth in the dental arch. Fusion is common odontogenic anomaly but triplication of primary teeth is a rare phenomenon. We report a case of a 3 - year - old girl who visited our clinic for the pain on maxillary anterior tooth. The patient was diagnosed by the fusion of a the maxillary primary right central and lateral incisor with a supernumerary tooth and caries of dentine. And then, Endodontic treatment and composite resin restoration were performed on the triple teeth. After follow-up of 6 months period, there was no marked complications.

• Journal of Dental Rehabilitation and Applied Science
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• v.27 no.1
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• pp.1-13
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• 2011

The aim of this study was to evaluate shear bond strength of pressed reinforced composite resin ($TESCERA^{TM}$ ATL) veneering to zirconia with various surface treatments. Forty sintered zirconia specimens and forty pockmarked zirconia specimens were fabricated. All the materials were categorized as Group 1 (Control : porcelain veneering on zirconia surface), Group 2 ( $TESCERA^{TM}$ ATL dentine veneering after bonding agent application on zirconia surface), Group 3 ($TESCERA^{TM}$ ATL dentine veneering on pockmarked zirconia surface), Group 4 ($TESCERA^{TM}$ ATL dentine veneering after bonding agent application on pockmarked zirconia surface), Group 5 (Thermocycling on Group 1), Group 6 (Thermocycling on Group 2), Group 7 (Thermocycling on Group 3), and Group 8 (Thermocycling on Group 4). SBS(Shear bond strength) of 8 groups was determined with an Instron Universal Testing Machine. Also fractured surface of specimens were observed with a scanning electron microscope. There were no significant differences in the initial SBS between Group 1(control group), Group 3, and Group 4. (p>0.05) Group 2 presented the lowest SBS values. There was a no significant difference between just as 24hour water storage and simulated aging on pockmarked zirconia groups. (p>0.05) A formation of pockmarked irregularities on zirconia surface as mechanically pitted surface was reliable method for establishing a stronger bond between $TESCERA^{TM}$ ATL and zirconia-based material.

• 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.

• Restorative Dentistry and Endodontics
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• v.28 no.1
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• pp.89-99
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• 2003

The purpose of this study was to investigate the bonding of resin- based root canal sealer, AH26 when the sealer was applied as a thin layer between dentine and gutta-percha surface. In this study forty non-caries extracted human molars and resin-based root canal sealer(AH 26, DeTrey/Dentsply, Germany) were used. Disks of gutta-percha, 6mm in diameter.6mm thick (Diadent/Dentsply, Korea) for thermoplastic obturation were used and dentin surfaces were treated with 2% NaOCl(Group 1) or 2%NaOCl+17% EDTA(Group 3). Disks of gutta-Percha, 6mm in diameter.6mm thick (Diadent/Dentsply, Korea) for conventional obturation were used and dentin surface were treated with 2% NaOCl(Group 2) or 2%NaOCl+17% EDTA(Group 4). Enamel was removed by a horizontal section 1mm below the deepest portion of the central occlusal groove by using a watercooled low speed diamond saw. A second horizontal section was done around cementoenamel junction. Exposed dentin surface was cut to approximately $8{\times}8{\;}mm$ rectangular shape and was ground against 320, 400, 600 grade silicon carbide abrasive paper serially. After grinding, the dentine surface were soaked in a solution of 2% NaOCl for 30 minutes and twenty of specimens were treated with 17% EDTA solution for 1 minute. The treated specimens were washed and dried, Root canal sealer, AH26 was prepared according to the manufacture's instructions The Gutta-percha and dentin surface were coated with a thin layer of the freshly mixed seal or. The specimens were left overnight at room temperature. After their initial set, they were transferred to an incubator at $37$^{\circ}C$ for 72 h. After 72 hours, resin blocks were made. The resin block was serially sectioned vertically into stick of $1{\cdot}1mm$. Twenty sticks were prepared from each group. After that, tensile bond strength f3r each stick was measured with Microtensile Tester Failure patterns of the specimens at the interface between gutta-percha and dentin were observed under the SEM(x1000) and Stereomicroscope (LEICA M42O, Meyer Inst., TX U.S.A) at 1.25 x25 magnification. The results were statistically analysed by using a One-way ANOVA and Tukey's test. The results were as follows; 1. Tensile bond strengths($mean{\pm}SD$) were expressed with ascending order as follows: Group 1, $3.09{\pm}$ 1.05Mpa : Group 2, $6.23{\pm}1.16MPa$ : Group 3, $7.12{\pm}1.07MPa$ : Group 4, $10.32{\pm}2.06MPa$. 2. Tensile bond strengths of the group 2 and 4 used disks of gutta-percha for conventional obturation were significantly higher than that of the group 1 and 3 used fir thermoplastic obturation. (p < 0.05). 3. Tensile bond strengths of the group 3 and 4 treated with 2% NaOC1+17% EDTA were significantly higher than that of the group 1 and 2 treated with 2% NaOCl. (p < 0.05). 4. In analysis of failure patterns at the interface between sealer and gutta-percha, there were observed 49 (61%)cases of adhesive failure patterns and 31 (39%) cases of mixed failures patterns.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.2
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• pp.416-426
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• 1999

The objective of this study is to confirm the effect of dentine bonding primer application on penetration of sealant. Extracted permanent molars were used to compare penetration success rate of control group (sealant application only) and experimental groups (sealant application after applying the primers of $Scotchbond^{TM}$ Multi-Purpose system and $All-Bond^{(R)}$ 2 system). The following results were obtained: 1. The experimental groups using the primers showed increased sealant penetration success rate to the base of fissure when compared to control group but there was no statistically significant differences(p>0.05). 2. The depth, width and 'depth/width' value of fissure had statistically significant effect on sealant penetration success rate(p<0.05). 3. The penetration success rate decreased about 0.9 times as the depth of fissure increased every $25{\mu}m$, and increased about 1.1 times as the width of the fissure orifice increased every $25{\mu}m$ and decreased about 0.6 times as the 'depth/width' value increased every 1. From the above results, it can be concluded that assure morphology had a great effect on sealant penetration and for better penetration, use of dentine bonding primer can be helpful but it needs more study in clinical bases.

• Journal of Dental Rehabilitation and Applied Science
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• v.33 no.2
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• pp.97-105
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• 2017

Purpose: The purpose of this study was comparing the efficacy of passive irrigation (PI) and passive ultrasonic irrigation (PUI) for ability to remove debriment of canals. Materials and Methods: Mandibular premolars were decoronated and standardized to 16 mm length. After root canal enlargement and half separating longitudinally, standardized groove of 4 mm length, 0.2 mm width and 0.5 mm depth were formed on the dentin wall of one half. Three depressions in the canal wall of the opposite half, 0.3 mm in diameter and 0.5 mm in depth, were formed. After each groove and depression was filled with dentin debris, two sections of each half were reassembled using impression putty material. In group 1 the canals were irrigated with 2.5% NaOCl by PI. In group 2 the canals were irrigated with 2.5% NaOCl by PUI. Before and after root canal irrigation, the root canal wall of the section was taken with a microscope and a digital camera as images. The amount of dentin debris remaining in grooves and depressions was assessed using a scoring system. Results: There was no significant difference between PI and PUI except for the middle 1/3 of the root canal (P = 0.004). Conclusion: At the middle 1/3 of the root canal, PUI removed more dentine debris than PI. But the removal efficiency of dentin debris is not significantly different between the PUI and PI at the apical area of root canal in mandibular premolars.

• Journal of Oral Medicine and Pain
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• v.36 no.4
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• pp.215-224
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• 2011

The aim of the study was to investigate the effects of 904 nm GaAs laser irradiation for patients with hypersensitive teeth and to find the possibility of clinical use of this Low Level Laser Therapy (LLLT) for the control of hypersensitive teeth. Eleven patients visited Dept. of Oral Medicine, Dankook University participated in this study. Each patient contributed at least two or more contralateral pairs of hypersensitive teeth with exposed dentine at cervical surfaces. Total number of teeth used from subjects participated in this study was 50: 25 experimental and control teeth respectively. All participants were treated with 904 nm GaAs diode laser every week during 4 weeks. Tactile and cold (ice stick) tests were carried out before LLLT every week during 4 weeks and 1 week later after the last LLLT by measuring visual analogue scale (VAS) of patients and by measuring a score of electrical pulp tester (EPT) simultaneously. The VAS score in tactile test decreased significantly with time, but there was not statistically difference between those of groups. The score of EPT in the experimental group was significantly higher than that of control group, although there was no change with time. In cold test, there was significant difference between two groups and cold sensitivity of the experimental group significantly decreased with time after every LLL irradiation, compared with that of control group. Based on the results, it is suggested that the 904 nm GaAs laser irradiation could be positively used as an effective, reversible method in treating cervical dentine hypersensitivity.

• 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.