• Restorative Dentistry and Endodontics
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• v.36 no.3
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• pp.203-210
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• 2011

Objectives: The purpose of this study was to evaluate the effect of various application methods of one-step self-etch adhesives to microtensile resin-dentin bond strength. Materials and Methods: Thirty-six extracted human molars were used. The teeth were assigned randomly to twelve groups (n = 15), according to the three different adhesive systems (Clearfil Tri-S Bond, Adper Prompt L-Pop, G-Bond) and application methods. The adhesive systems were applied on the dentin as follows: 1) The single coating, 2) The double coating, 3) Manual agitation, 4) Ultrasonic agitation. Following the adhesive application, light-cure composite resin was constructed. The restored teeth were stored in distilled water at room temperature for 24 hours, and prepared 15 specimens per groups. Then microtensile bond strength was measured and the failure mode was examined. Results: Manual agitation and ultrasonic agitation of adhesive significantly increased the microtensile bond strength than single coating and double coating did. Double coating of adhesive significantly increased the microtensile bond strength than single coating did and there was no significant difference between the manual agitation and ultrasonic agitation group. There was significant difference in microtensile bonding strength among all adhesives and Clearfil Tri-S Bond showed the highest bond strength. Conclusions: In one-step self-etching adhesives, there was significant difference according to application methods and type of adhesives. No matter of the material, the manual or ultrasonic agitation of the adhesive showed significantly higher microtensile bond strength.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.4
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• pp.653-660
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• 2006

Fuji VII is a glass-ionomer cement specially targeted for early protection in erupting first and second molars. Properties of Fuji VII such as very high level of fluoride release, low viscosity and no need to preliminarily etch the substrate would be useful to erupting molars with primary pit and fissure caries or hypoplastic area for preventive goal or remineralization. The purpose of this study were to evaluate remineralization of Fuji VII glass ionomer cement and to compare with one of other restorative materials such as conventional glass ionomer cement, resin-modified glass ionomer cement, compomer and composite resin. Forty-two extracted human molars were used for this study. All teeth were immersed in demineralizing solution for 48 hours after Class V cavity preparation was made on sound proximal surface. The teeth were randomly divided into six groups and restored with Fuji VII, Fuji II, Fuji II LC improved, F2000, $Filtek^{TM}$ Z250 and control group was unrestored. The middle area with $130{\pm}20{\mu}m$ thickness was separated from specimen using microtome and demineralized area was photographed under polarized microscope. Separated area was relocated to specimen and stored in artificial saliva, After four weeks, changes of demineralized area were observed and compared to them restorated immediately. The results from the this study can be summarized as follows ; 1. Fuji VII, Fuji II, Fuji II LC improved have more prominent remineralization effect than F2000, $Filtek^{TM}$ Z250, control group. 2. No significant differences in remineralization effect are seen between Fuji VII and Fuji II, Fuji II LC improved.

• Restorative Dentistry and Endodontics
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• v.30 no.2
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• pp.112-120
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• 2005

This study was done to evaluate whether there were any differences in microleakage of class V composite restorations according to restoration site and cavity size. Total sixty-four restorations were made in molar teeth using Esthet-X. Small ($2\;{\times}\;2\;{\times}\;1.5\;mm$) and large ($4{\times}2{\times}1.5\;mm$) restorations were made at the buccal/lingual surface and the proximal surface each. After 1,000 times of thermocycling ($5^{\circ}\;-\;55^{\circ}C$), resin replica was made and the percentage of marginal gap to the whole periphery of the restoration was estimated from SEM evaluation. Thermocycled tooth was dye penetrated with $50\%$ silver nitrate solution. After imbedding in an auto-curing resin, it was serially ground with a thickness of 0.25 mm. Volumetric microleakage was estimated after reconstructing three dimensionally. Two-way ANOVA and independent T-test for dye volume, Mann-Whitney U test for the percentage of marginal gap, Spearman's rho test for the relationship between two techniques were used, The results were as follows : 1. The site and size of the restoration affected on the microleakage of restoration. Namely, much more leakage was seen in the proximal and the large restorations rather than the buccal/lingual and the small restorations. 2. Close relationship was found between two techniques (Correlation coefficient = 0.614/ P = 0.000). Within the limits of this study, it was noted that proximal and the large restorations leaked more than buccal/lingual and the small restorations. Therefore, it should be strictly recommended large exposure of margins should be avoided by reducing unnecessary tooth reduction.

• Restorative Dentistry and Endodontics
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• v.20 no.2
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• pp.699-720
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• 1995

This study was conducted to evaluate the effect of benzalkonium chloride solution as a wetting agent instead of water on dentin bonding with NTG-GMA/BPDM system (All-bond 2, Bisco.) and DSDM system (Aelitebond, Bisco.). Benzalkonium chloride solution is a chemical disinfectant widely used in medical and dental clinics for preoperative preparation of skin and mucosa due to its strong effect of cationic surface active detergent. Eighty freshly extracted bovine lower incisor were grinded labially to expose flat dentin surface, and then were acid-etched with 10 % phosphoric acid for 15 second, water-rinsed, and dried for 10 second with air syringe. The specimens were randomly divided into 8 groups of 10 teeth. The specimens of control group were remoistured with water and the specimens of experimental groups were remoistured with 0.1 %, 0.5 %, and 1.0 % benzalkonium chloride solution respectively. And then, the Aelitefil composite resin was bonded to the pretreated surface of the specimens by use of All-bond 2 dentin bonding system or Aelitebond dentin bonding system in equal number of the specimens. The bonded specimens were stored in $37^{\circ}C$ distilled water for 24 hours, then the tensile bond strength was measured, the mode of failure was observed, the fractured dentin surface were examined under scanning electron microscopy, and FT-IR spectroscopy was taken for the purpose of investigating the changes of the dentin surface pretreated with benzal konium chloride solution followed by each primer of the dentin bonding systems. The results were as follows : In the group of bonding with NTG-GMA/BPDM dentin bonding agent(All-bond 2), higher tensile bond strength was only seen in the experimental group remoistured with 0.1 % benzal konium chloride solution than that in water-remoistured control group(p<0.05). In the group of bonding with DSDM dentin bonding agent (Aelitebond), no significant differences were seen between the control and each one of the experimental group(p<0.05). Higher tensile bond strength were seen in NTG-GMAIBPDM dentin bonding agent group than in DSDM dentin bonding agent group regardless of remoistur ization with benzal konium chloride solution. On the examination of failure mode, cohesive and mixed failure were predominantly seen in the group of bonding with NTG-GMAIBPDM dentin bonding agent, while adhesive failure was predominantly seen in the group of bonding with DSDM dentin bonding agent. On SEM examination of fractured surfaces, no differences of findings of primed dentin surface between the groups with and without remoisturization with benzal konium chloride solution. FT-IR spectroscopy taken from the control and the experimental group reve::.led that some higher absorbance derived from the primers binding to dentin surface was seen at the group pretreated with 0.1 % benzal konium chloride solution than at the control group of remoisturizing with water.

• 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.2
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• pp.148-161
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• 2008

The purpose of this study was to evaluate the effect of chlorhexidine (CHX) on microtensile bond strength (${\mu}TBS$) of dentin bonding systems. Dentin collagenolytic and gelatinolytic activities can be suppressed by protease inhibitors, indicating that MMPs (Matrix metalloproteinases) inhibition could be beneficial in the preservation of hybrid layers. Chlorhexidine (CHX) is known as an inhibitor of MMPs activity in vitro. The experiment was proceeded as follows: At first, flat occlusal surfaces were prepared on mid-coronal dentin of extracted third molars. GI (Glass Ionomer) group was treated with dentin conditioner, and then, applied with 2 % CHX. Both SM (Scotchbond Multipurpose) and SB (Single Bond) group were applied with CHX after acid-etched with 37% phosphoric acid. TS (Clearfil Tri-S) group was applied with CHX, and then, with adhesives. Hybrid composite Z-250 and resin-modified glass ionomer Fuji-II LC was built up on experimental dentin surfaces. Half of them were subjected to 10,000 thermocycle, while the others were tested immediately. With the resulting data, statistically two-way ANOVA was performed to assess the ${\mu}TBS$ before and after thermo cycling and the effect of CHX. All statistical tests were carried out at the 95 % level of confidence. The failure mode of the testing samples was observed under a scanning electron microscopy (SEM). Within limited results, the results of this study were as follows; 1. In all experimental groups applied with 2 % chlorhexidine, the microtensile bond strength increased, and thermo cycling decreased the micro tensile bond strength (P > 0.05). 2. Compared to the thermocycling groups without chlorhexidine, those with both thermocycling and chlorhexidine showed higher microtensile bond strength, and there was significant difference especially in GI and TS groups. 3. SEM analysis of failure mode distribution revealed the adhesive failure at hybrid layer in most of the specimen. and the shift of the failure site from bottom to top of the hybrid layer with chlorhexidine groups. 2 % chlorhexidine application after acid-etching proved to preserve the durability of the hybrid layer and microtensile bond strength of dentin bonding systems.

• Restorative Dentistry and Endodontics
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• v.20 no.1
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• pp.328-341
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• 1995

I. Shear Bond Strength to Air-dried and Remoistened Dentin.. The effect of air-drying and remoistening of acid-conditioned dentin before priming with the primer of All-Bond 2(BISCO. INC., U. S. A.) on shear bond strength(SBS) was investigated. Ninty freshly extracted sound human molars were divided at random into 9 groups of 10 teeth each. SBSs were meaured for acid-conditioned and non-conditioned dentin to which the primer and bonding agent of All-Bond 2 and composite resin(Z-100, 3M Dental Products, U. S. A.) were applied. The following values(Mean${\pm}$ SD, MPa) were obtained for the groups conditioned with 10% phosphoric acid for 15 seconds: Group l(blot dried) $6.7{\pm}4.1$ ; Group 2(10 seconds dried) $16.1{\pm}5.3$ ; Group 3(20 seconds dried) $15.4{\pm}4.8$ ; Group 4(30 seconds dried) $15.2{\pm}6.3$ ; Group 5(10 seconds dried/remoistened) $26.4{\pm}2.6$ ; Group 6(20 seconds dired/remositened) $22.2{\pm}2.7$ ; Group 7(30 seconds dried/remoistened) $21.5{\pm}4.1$. For the non-conditioned groups the values were: Group 8 (blot dried) $13.3{\pm}2.6$ ; Group 9(10 seconds dried) $12.9{\pm}3.5$. The data were analyzed using ANOVA. In the acid-conditioned groups, mean values of SBS for the air-dried specimens(Grps. 2, 3 and 4) and the 20 and 30 seconds dried/remoistened specimens (Grps. 6 and 7) were significantly lower than that of blot dried specimens.(p<0.05) The value for 10 seconds dried/remoistened specimens (Grp. 5), however, was not statistically different compared to that of blot dried specimens.(p>0.05) In the non-conditined groups, there was no statistical difference between blot dried and 10 seconds dried specimens.(p>0.05) The results suggest that the acid-conditioned dentin surface is more vulnerable to dentin bonding when it is air-dried or even remoistened after long period of drying. II. Shear bond stengh to the moistened and primed enamel. The effect of moistening and priming of enamel compared to the air-drying of enamel on the shear bond strength of enamel bonding agent was investigated. The experiment was divided into 4 groups each containing 10 caries-free maxillary incisor teeth. Shear bond strength values were measured for the primed and non-primed enamel to which All-Bond 2 and Z-100 were applied. The following values(MPa) were obtained for the primed groups pretreated with 32 % phosphoric acid for 15 seconds. : Group 1 (10 seconds dried) $29.8{\pm}2.2$ ; Group 2(moistened) $26.8{\pm}5.4$. For the non-primed groups the values were: Group 3(10 seconds dried/primed) $27.6{\pm}5.0$ ; Group 4(mostened/primed) $28.2{\pm}3.5$. The data were subjected to statistical analysis using ANOVA. The results showed that mean shear bond strengths among the experimental groups were not statistically different. (p>0.05) Conclusively, It is suggested that the bonding ability to enamel is not decreased by the moistening and priming of the enamel.

• Restorative Dentistry and Endodontics
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• v.34 no.1
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• pp.51-60
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• 2009

The purpose of this study was to perform quantitative comparisons of water permeable zones in both the adhesive and the hybrid layer before and after thermo cycling in order to assess the integrity of the bonding interface. Twenty eight flat dentin surfaces were bonded with a light-cured composite resin using one of four commercial adhesives [OptiBond FL (OP), AdheSE (AD), Clearfil SE Bond (CL). and Xeno III (XE)]. These were sectioned into halves and subsequently cut to yield 2-mm thick specimens; one specimen for control and the other subjected to thermocycling for 10,000 cycles. After specimens were immersed in ammoniacal silver nitrate for 24 h and exposed to a photo developing solution for 8 h, the bonded interface was analyzed by scanning electron microscopy (SEM) and wavelength dispersive spectrometry (WDS) at five locations per specimen. Immediately after bonding. the adhesive layer of OP showed the lowest silver uptake, followed by CL, AD. and XE in ascending order (p < 0.0001); the hybrid layer of CL had the lowest silver content among the groups (p = 0.0039). After thermocycling, none of the adhesives manifested a significant increase of silver in either the adhesive or the hybrid layer. SEM demonstrated the characteristic silver penetrated patterns within the interface. It was observed that integrity of bonding was well maintained in OP and CL throughout the thermocycling process. Adhesive-tooth interfaces are vulnerable to hydrolytic degradation and its permeability varies in different adhesive systems, which may be clinically related to the restoration longevity.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.3
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• pp.376-381
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• 2002

The purpose of this study was to analyse the color of natural deciduous teeth in Korean children and to compare with that of composite resin specimens. The subjects were 148 children (80 boys and 68 girls) with good general condition and normal teeth color, aged between 3 and 6 years. The color of middle third of maxillary central incisor in deciduous teeth was examined with shade guide and then measured by means of the colorimeter CV300 which can be measured by CIELAB system. The data were analyzed statistically by SPSS program. The results were summerized as follows; 1. Over 90% of the color for the deciduous anterior teeth was in A1, A2, B1, B2 and P shade. 2. The means of deciduous teeth color were $L^*=58.72,\;a^*=-1.18,\;b^*=-0.63$ by colorimeter CV300. 3. $L^*,\;a^*\;and\;b^*$ prices for A1, A2, B1, B2, P were $L^*=52.52,\;a^*=-1.90,\;b^*=1.18$ in A1 specimen, $L^*=54.90,\;a^*=-1.87,\;b^*=1.60$ in A2 specimen, $L^*=59.80,\;a^*=-2.70,\;b^*=-0.63$ in B1 specimen, $L^*=56.90,\;a^*=-1.70,\;b^*=1.63$ in B2 specimen, $L^*=52.93,\;a^*=-2.33,\;b^*=1.10$ in P specimen. The means of B1 color specimen were most similar to those of deciduous teeth color. The A1 color values were similar to the P color values. 4. The standard deviation of $L^*,\;a^*$ was small among colors, but that of $b^*$, in the yellowish color, was large.

• Restorative Dentistry and Endodontics
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• v.32 no.3
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• pp.222-235
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• 2007

The objectives of this study was to evaluate the effect of thermocycling on the ${\mu}TBS$ (microtensile bond strength) to dentin with four different adhesive systems to examine the bonding durability. Freshly extracted $3^{rd}$ molar teeth were exposed occlusal dentin surfaces, and randomly distributed into 8 adhesive groups 3-steps total-etching (Scotchbond Multi-Purpose Plus; SM, All Bond-2; AB), 2-steps total-etching (Single Bond; SB, One Step plus; OS), 2-steps self-etching (Clearfil SE Bond; SE, AdheSE AD) and single-step self-etching systems (Promp L-Pop; PL, Xeno III; XE) Each adhesive system in 8 adhesives groups was applied on prepared dentin surface as an instruction and resin composite (Z250) was placed incrementally and light-cured. The bonded specimens were sectioned with low-speed diamond saw to obtain $1\times1mm$ sticks after 24 hours of storage at $37^{\circ}C$ distilled water and proceeded thermocycling at the pre-determined cycles of 0, 1,000 and 2,000. The ${\mu}TBS$ test was carried out with EZ-tester at 1mm/min. The results of bond strength test were statistically analyzed using one-way ANOVA/ Duncan's test at the a < 0.05 confidence level. Also, the fracture mode of debonded surface and the interface were examined under SEM. The results of this study were as follows ; 1. 3-step total etching adhesives showed stable, but bond strength of 2-step adhesives were decreased as thermocycling stress. 2. SE showed the highest bond strength, but single step adhesives (PL, XE) had the lowest value both before and after thermocycling. 3 Most of adhesives showed adhesive failure. The total-etching systems were prone to adhesive failure and the single-step systems were mixed failure after thermocycling. Within limited results of this study, the bond strength of adhesive system was material specific and the bonding durability was affected by the bonding step/ procedure of adhesive Simplified bonding procedures do not necessarily imply improved bonding performance.