• Restorative Dentistry and Endodontics
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• v.35 no.1
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• pp.5-12
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• 2010

The purpose of this study was to evaluate the pulp tissue reaction to direct pulp capping of mechanically exposed beagle dogs' pulp with several capping materials. A total of 36 teeth of 2 healthy beagle dongs were used. The mechanically exposed pulps were capped with one of the followings: (1) Mineral Trioxide Aggregate (MTA: $ProRoot^{(R)}$ MTA. Dentsply, Tulsa, USA), (2) Clearfil SE Bond (Dentin adhesive system: Kuraray, Osaka, Japan), (3) Ultra-Blend (Photo-polymerized Calcium hydroxide: Ultradent, South Jordan, USA), (4) Dycal (Quick setting Calcium hydroxide: LD Caulk Co., Milford, USA) at 7, 30, and 90 days before sacrificing. The cavities were restored with Z350 flowable composite resin (3M ESPE, St. Paul. MN, USA). After the beagle dogs were sacrificed, the extracted teeth were fixed, decalcified, prepared for histological examination and stained with HE stain. The pulpal tissue responses to direct pulp capping materials were assessed. In MTA calcium hydroxide, and photo-polymerized calcium hydroxide groups, initial mild inflammatory cell infiltration, newly formed odontoblast-like cell layer and hard tissue bridge formation were observed. Compared with dentin adhesive system, these materials were biocompatible and good for pulp tissue regeneration. In dentin adhesive system group, severe inflammatory cell infiltration, pulp tissue degeneration and pulp tissue necrosis were observed. It seemed evident that application of dentin adhesive system in direct pulp capping of beagle dog teeth cannot lead to acceptable repair of the pulp tissue with dentine bridge formation.

• Restorative Dentistry and Endodontics
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• v.33 no.6
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• pp.545-552
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• 2008

The purpose of this study was to evaluate the influence of sodium ascorbate on microtensile bond strengths of total-etching adhesive system to pulp chamber dentin treated with NaOCl. Pulp chambers of extracted human non-caries permanent molars were treated as follows: group 1, with 0.9% NaCl; group 2, with 5.25% NaOCl; group 3, with 5.25% NaOCl and 10% sodium ascorbate for 1min; group 4, with 5.25% NaOCl and 10% sodium ascorbate for 1 min and 10ml of water; group 5, with 5.25% NaOCl and 10% sodium ascorbate for 5 min; group 6, with 5.25% NaOCl and 10% sodium ascorbate for 5 min and 10ml of water; group 7, with 5.25% NaOCl and 10% sodium ascorbate for 10 min; group 8, with 5.25% NaOCl and 10% sodium ascorbate for 10 min and 10ml of water. Treated specimens were dried, bonded with a total-etching adhesive system (Single bond), restored with a composite resin(Z250) and kept for 24h at 100% humidity to measure the microtensile bond strength. NaOCl-treated group (group 2) demonstrated significantly lower strength than the other groups. No significant difference in microtensile bond strengths was found between NaCl-treated group (group 1) and sodium ascorbatetreated groups (group 3-8). The results of this study indicated that dentin treated with NaOCl reduced the microtensile bond strength of Single bond. Application of 10% sodium ascorbate restored the bond strength of Single bond on NaOCl-treated dentin. Application time of sodium ascorbate did not have a significant effect.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.4
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• pp.579-589
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• 2007

The objective of this study was to compare the shear bond strengths of five adhesive systems to the enamel and dentin of primary and permanent teeth. Fifty noncarious primary and fifty permanent teeth were collected and stored in an 0.1% thymol solution at room temperature after extraction. The tested adhesives were: Adper Scotchbond Multi-purpose Plus Adhesive (SM) Adper Single bond 2 (SB), Clearfil SE Bond (SE), Adper Prompt L-Pop (PL), GBond (GB). For the shear bonding test, the labial and lingual surfaces of primary and permanent teeth were used. To obtain a flat surface, the labial and lingual surfaces of the teeth were sanded on $SiO_2$ with number 600 grit and then divided into 20 groups of 10 surfaces each. All samples were theromocycled in water $5^{\circ}C$ and $55^{\circ}C$ for 1000 cycles. The results were as follows: 1. For primary enamel, shear bond strengths of SM and SB were significantly higher than that of SE and also SM, SB, and PL were higher than GB(p<0.05). 2. For primary dentin, there were no significant differences among the shear bond strengths of any other bonding systems except difference between SE and GB. 3. For permanent enamel, SB showed significantly higher mean shear bond strength than those of any other bonding systems(p<0.05). 4. For permanent dentin, SM showed significantly higher mean shear bond strength than that of PL and GB(p<0.05). 5. Between the primary enamel and dentin, there were significant differences in SM, SB, and GB, whereas there was statistically significant difference in PL between the permanent enamel and dentin(p<0.05). 6. Between the primary and permanent teeth on enamel, there were no significant differences among all bonding systems, whereas there were statistically significant differences in SM and SB between the primary and permanent teeth on dentin(p<0.05).

• Restorative Dentistry and Endodontics
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• v.20 no.1
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• pp.1-16
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• 1995

The purpose of this study was to investigate the effect of dentin bonding agents on the bond strength of composite resin restorations in case of applying the dentin bonding agents to acid etched enamel surfaces. Freshly extracted 364 bovine anterior teeth were selected as a adherents. 320 enamel specimens were divided into two groups(unetched group (1) and etched group (2) for testing the shear bond strength, 40 specimens were used for the hardness testing, and 4 specimens of rest were to observe the resin-tag formation into etched enamel surfaces. All surfaces of enamel specimens were polished with 320~1500 SiC paper under continuous running water. In Group (1), 100 enamel specimens were polished and unetched. 220 polished enamel specimens in Group (2) were etched with 37 % phosphoric acid solution for 60 seconds, washed with water for 20 seconds, and dried with a light air pressure for 60 seconds. Three kinds of dentin bonding agents(Gluma, Prisma, Scotchbond 2) were evaluated the effect on the bond strength to conditioned enamel surfaces. Shear bond strengths were measured on the three cases such as a coating of primer only, a coating of sealer only, and a sequential coating of primer and sealer to acid etched enamel surfaces were compared with the bond strengths measured by the coating of enamel bonding agent followed by the bonding of composite resin (Photo clearfil bright, Kuraray, Japan) to unetched and acid etched enamel surfaces. In addition, the hardness tested on the adhesive fractured surface between composite resin enamel as a mean of evaluation of a factor whether the mechanical bond strengths were affected and the penetration of dentin bonding agents into etched enamel surfaces was also observed. Bond strengths were measured using the method of shear bond strength by a universal testing machine (Instron-4467, USA), statistical test were applied to the results using a one way analysis variance(ANOVA), and hardness was measured by the Vicker's Hardness Tester(MHT-i, Matsuzawa, Japan) and the penetration of the resins were observed by the SEM (Hitachi, S-2300, Japan). The following conclusions were drawn; 1. Enamel bonding agent showed to affect the improvement of bond strength of composite resin to enamel surface both unetched and etched. 2. Dentin bonding agents could be resulted in increase of bond strength to unetched enamel surface, but there were no statistical significances. 3. Bond strengths to etched enamel surface were significantly decreased with a coating of dentin primer only. 4. Coating of sealer only and coating of primer and sealer noticed the similar bond strengths of composite resin to etched enamel using the enamel bonding agents. 5. The applying method proved to be more effective than the kinds of dentin bonding agents on the bond strength of composite resin to etched enamel than the kind of dentin. 6. Vicker's hardness numbers of dentin bonding agents were lower than that of composite resin, but the degree of penetration of dentin bonding agents into etched enamel surfaces was excellent.

• Restorative Dentistry and Endodontics
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• v.28 no.1
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• pp.11-22
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• 2003

This study compared the dentin adhesion to composite resin according to air-dry, blot dry, application of rewetting agent on air-dry or blot dry dentin surface by microleakag test and SEM observation. For microleakage test, class V cavity preparations with dentinal margins were prepared on both buccal and lingual surfaces of 40 extracted human molars. For SEM observation, occlusal dentin of 20 extracted human molars were exposed. After etched the dentin, prepared teeth were randomly divided into four groups; D group: air dry for 10-15 sec., B group: blot dry with moist cotton pellet, D-R group: air dry and rewet with Aqua-Prep F for 20 sec., B-R group: blot dry and rewet with Aqua-Prep F for 20 sec. Treated cavities and surfaces were filled or constructed using One-Step adhesives and Aelitefil composite resins. Specimens were stored in distilled water for 24 hours. For microleakage test, the specimens were thermocycled and soaked into 2% methylene blue. The specimens were sectioned longitudinally and evaluated for microleakage under steromicroscope. The data were statistically analysed by Kuskal-Wallis Test, Mann-Whitney and Wilcoxon signed ranked tests. For SEM observation, the specimens were bisectioned mesiodiatally. After decalcified and deproteinized, specimens were observed under SEM. The results of this study were as follows; 1. The microleakges on dentinal margin were the highest in D group compared with B group, D-R group, and B-R group(p<0.05). But there was no significant difference between B group, D-R group and B-R group. 2. D group showed gap and a few resin tags between dentin and composite resin. 3 B group, D-R group, and B-R groups showed close adaptation between dentin and composite resin. It showed that resin rags in B group were numerous and long, in D-R group were few and short, in B-R group were numerous and short or long. 4. Adhesive layer showed in D-R group ($10{\;}\mu\textrm{m}$) and B-R group ($3{\;}\mu\textrm{m}$) In conclusion, use of rewetting agent to dry dentin was efficient to dentin adhesion, also it did not provide reverse effect on blot dry dentin.

• Restorative Dentistry and Endodontics
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• v.22 no.1
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• pp.61-75
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• 1997

The bond strengths of composite resin to tooth dentin vary with the methods of cavity preparation and surface treatment. Recent developments in techniques of dentinal surface treatment have renewed interest in microabrasive as a means of tooth preparation, The purpose of this study was to determine the effects of a new method of cavity preparation on the bond of composite resin to dentin. Freshly extracted 144 healthy human third molars were used in this study. The dentin surfaces prepared with #600 SiC abrasive paper were divided into control and air abrasion groups according to the method of dentin surface preparation using different combinations of delivery pressure, time, and acid etching. The shear bond strengths were measured after the composite resin (Clearfil Photo Bright) was bonded to prepared dentin surfaces by light-curing using a dentin bonding system (All-bond 2), In addition, the average surface roughness was measured to investigate the effect of differently prepared dentin surfaces on the shear bond strengths. The surface changes of prepared dentin and the debonded dentin surfaces were observed with SEM (S-2300, Hitachi Co., Japan). The following results from this-study were obtained ; 1. There was no significant difference of shear bond strengths according to the changes of delivery pressure and time. 2. The shear bond strengths were lower than the control in the air abraded-only groups, but those of the additional acid-etched groups were higher than the control. 3. The shear bond strengths to all air-abraded surfaces were increased by acid etching. 4. The correlation between shear bond strengths and surface roughness was not certain, although the mean surface roughness of all air-abraded surfaces has increased evidently while it has slightly decreased for additional acid etching. 5. On SEM examination, the dentinal tubules were almost occluded in the air abraded-only groups, but those were opened in the additional acid-etched groups. 6. The debonded surfaces were showed adhesive failure mode in the air abraded- only groups, while those were showed mainly the mixed and cohesive failure mode in the additional acid-etched groups. These results suggest that the layer produced during cavity preparation or surface treatment with air abrasion must be removed for maximum bond strength of composite resin to dentin.

• Restorative Dentistry and Endodontics
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• v.29 no.2
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• pp.153-161
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• 2004

This study investigated that the effect of rewetting agent on dentinal microtensile bond strength(${\mu}TBS$). Human molars were sectioned to expose the superficial dentin surfaces. Samples were divided into two groups according to type of adhesives-Single Bond (S) and One-Step (0)], and again subdivided into five groups by different dentin surface treatment-dry for 15s (D), blot dry (BD) or dry for 15s, and rewet with different rewetting agents [distilled water (DW), Gluma Desensitizer (GD) and Aqua-Prep (AP)] for 30s. After application of adhesive, composite resin was built up on the bonding surface. Each tooth was sectioned to obtain stick with $1\textrm{mm}^2$ cross sectional area and the ${\mu}TBS$ was determined by EZ test. In the S group, the mean ${\mu}TBS$ of GD, AP, and BD group was significantly higher than that of DW and D group (p < 0.05), In the O group, the mean, ${\mu}TBS$ of AP, GD, BD and DW group was significantly higher than that of D group (p < 0.05). The data suggested that Gluma Desensitizer and Aqua-Prep could be successfully used as rewetting agents, and Distilled water could be acceptable in aceton based adhesive system only.

• Restorative Dentistry and Endodontics
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• v.20 no.2
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• pp.685-698
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• 1995

This study was conducted to the effect of temporary cement on the adhesiveness of dentin bonding agent to dentin surface. One hundred freshly extracted bovine mandibular incisors were grinded to expose flat labial dentin surface. The dentin surfaces were temporarized with either eugenol-containing temporary cement(TemBond and Zinc Oxide Eugenol cement) or non-eugenol temporary cement(Nogenol and TempBond NE) for 7days, and then the temporarization was removed with surgical currette and the exposed dentin surfaces were water-rinsed. Bonding specimens were made by use of All-Bond 2 and Super-Bond C&B dentin bonding agent, and stored in $37^{\circ}C$ distilled water for 24hours. The tensile bond strenth and the cohesive failure rate were measured, and then the pretreated dentin surfaces which the temporary cement had been applied to and removed from and the fractured dentin surfaces after bonding test were examined under scanning electron microscope. The results were as follows : In case of bonding with All-Bond 2, tensile bond strength of each experimental group was lower than that of the control group(p<0.05), but there was no significant difference between the bond strengths of the control group and each experimental group in case of bonding with Super-Bond C&B(p>0.05). No significant difference between tensile bond strength of experimental group, whether temporary cement contains eugenol or not, was seen(p>0.05). In case of bonding with All-Bond 2, the control group showed cohesive-adhesive mixed failure mode and the experimental groups mainly showed adhesive failure mode, but in case of bonding with Super-Bond C&B, almost of the control and the experimental groups mainly showed cohesive failure mode. On SEM examination, all of the dentin specimens pretreated with either 10 % phosphoric acid or 10% citric acid after application of the temporary cements demonstrated remnants of temporary cement attached to dentin surface.

• Restorative Dentistry and Endodontics
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• v.33 no.1
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• pp.45-53
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• 2008

The purpose of this study was to determine the effects on the elastic moduli of the adhesive and the hybrid layer from thermocycling. Twenty one human molars were used to create flat dentin surfaces. Each specimen was bonded with a light-cured composite using one of three commercial adhesives (OptiBond FL [OP], Clearfil SE Bond [CL], and Xeno III [XE]). These were sectioned into two halves and subsequently cut to yield 2-mm thickness specimens; one specimen for immediate bonding test without thermocycling and the other subjected to 10,000 times of thermocycling. Nanoindentation test was performed to measure the modulus of elasticity of the adhesive and the hybrid layer, respectively, using an atomic force microscope. After thermocycling, XE showed a significant decrease of the modulus in the adhesive layer (p < 0.05). Adhesives containing hydrophilic monomers are prone to hydrolytic degradation. It may result in the reduced modulus of elasticity, which leads to the mechanically weakened bonding interface.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.4
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• pp.619-627
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• 2008

The objective of this study was to compare the microleakage of five adhesive systems in the enamel and dentin of permanent teeth. Class V cavity preparations with occlusal margins in enamel and gingival margins in dentin were prepared on both buccal and lingual surfaces of 25 extracted human molar teeth. The tested adhesives were: Adper Scotchbond Multi-purpose Plus Adhesive (SM), Adper Single bond 2 (SB), Clearfil SE Bond (SE), Adper Prompt L-Pop (PL) and G-Bond (GB). The results were as follows: 1. At the enamel margins, PL showed the highest leakage value(0.85), and others showed values of SB(0.55), GB(0.50), SM(0.35) and SE(0.25) in decreasing order. There were statistically significant differences in PL vs. SM and PL vs. SE(p<0.05). 2. At the dentin margins, GB showed the highest leakage value(2.10), and others showed values of SE(1.45), PL(1.40), SB(1.05), SM(0.70) in decreasing order. There were statistically significant differences in GB vs. SB and GB vs. SM(p<0.05). 3. Dentin margins showed high dye penetration rate than enamel margins in all material tested groups and there were statistically significant differences for SE, PL and GB.