• Restorative Dentistry and Endodontics
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• 제29권5호
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• pp.430-438
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• 2004

This study evaluated the influence of application time of self-etching primers on microtensile bond strength (${\mu}$TBS) to dentin using three self-etching primer adhesive systems. Dentin surfaces were exposed from forty-eight human molars. They were conditioned with three self-etching primers (Clearfil SE Bond [SE], Unifil Bond [UF], Tyrian SPE + One Step Plus [TY]) and different primining times (10s, 20s, 30s and 40s). Composite resins were bonded to dentin surfaces and specimens were made. ${\mu}TBS$ was tested and statistically compared using by one-way ANOVA and Tukey's Test. The results of this study presented that priming time for 10s in SE and UF groups and for 30s and 40s in TY group was highly decreased ${\mu}TBS$ to dentin.

• The Journal of Advanced Prosthodontics
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• 제10권3호
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• pp.177-183
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• 2018

PURPOSE. The purpose of the current study was to evaluate the effect of incorporating nanoparticles of silver (NAg) and amorphous calcium phosphate (NACP) into a self-etching primer of a resin cement on the microtensile bond strength of dentin, regarding the proven antibacterial feature of NAg and remineralizing effect of NACP. MATERIALS AND METHODS. Flat, mid-coronal dentin from 20 intact extracted human third molars were prepared for cementation using Panavia F2.0 cement. The teeth were randomly divided into the four test groups (n=5) according to the experimental cement primer composition: cement primer without change (control group), primer with 1% (wt) of NACP, primer with 1% (wt) of physical mixture of NACP+Nag, and primer with 1% (wt) of chemical mixture of NACP+Nag. The resin cement was used according to the manufacturer's instructions. After storage in distilled water at $37^{\circ}C$ for 24 h, the bonded samples were sectioned longitudinally to produce $1.0{\times}1.0mm$ beams for micro-tensile bond strength testing in a universal testing machine. Failure modes at the dentin-resin interface were observed using a stereomicroscope. The data were analyzed by one-way ANOVA and Tukey's post-hoc tests and the level of significance was set at 0.05. RESULTS. The lowest mean microtensile bond strength was obtained for the NACP group. Tukey's test showed that the bond strength of the control group was significantly higher than those of the other experimental groups, except for group 4 (chemical mixture of NACP and NAg; P=.67). CONCLUSION. Novel chemical incorporation of NAg-NACP into the self-etching primer of resin cement does not compromise the dentin bond strength.

• The Journal of Advanced Prosthodontics
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• 제9권1호
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• pp.38-44
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• 2017

PURPOSE. The objective of this study was to investigate the effect of surface treatments on microtensile bond strengths (MTBSs) of two types of indirect resin composites bonded to a conventional direct resin composite. MATERIALS AND METHODS. Indirect resin composite blocks of Ceramage and SR Nexco were prepared in a plastic mold having a dimension of $10{\times}10{\times}4\;mm$. These composite blocks were divided into three groups according to their surface treatments: Group1: Sandblast (SB); Group2: Sandblast and ultrasonically clean (SB+UL); Group3: Sandblast plus silane (SB+SI). After bonding with direct resin composite, indirect-direct resin composite blocks were kept in distilled water for 24 hours at $37^{\circ}C$ and cut into microbars with the dimension of $1{\times}1{\times}8\;mm$. Microbar specimens (n = 40 per group) were loaded using a universal testing machine. Failure modes and compositions were evaluated by SEM. The statistical analyses of MTBS were performed by two-way ANOVA and Dunnett's test at ${\alpha}=.05$. RESULTS. Surface treatments and brands had effects on the MTBS without an interaction between these two factors. For SR Nexco, the MTBSs of SB and SB+SI group were significantly higher than that of SB+UL. For Ceramage, the MTBSs of SB and SB+SI were significantly higher than that of SB+UL. The mean MTBS of the Ceramage specimens was significantly higher than that of SR Nexco for all surface treatments. CONCLUSION. Sandblasting with or without silane application could improve the bond strengths of repaired indirect resin composites to a conventional direct resin composite.

• The Journal of Advanced Prosthodontics
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• 제7권4호
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• pp.317-322
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• 2015

PURPOSE. The aim was to evaluate the effect of curing mode and different dentin surface pretreatment on microtensile bond strength (${\mu}TBS$) of self-adhesive resin cements. MATERIALS AND METHODS. Thirty-six extracted human permanent molars were sectioned horizontally exposing flat dentin surface. The teeth were divided into 12 groups (3 teeth/group) according to the dentin surface pretreatment methods (control, 18% EDTA, 10% Polyacrylic acid) and curing mode (self-curing vs. light-curing) of cement. After pretreatment, composite resin blocks were cemented with the following: (a) G-CEM LinkAce; (b) RelyX U200, followed by either self-curing or light-curing. After storage, the teeth were sectioned and ${\mu}TBS$ test was performed using a microtensile testing machine. The data was statistically analyzed using one-way ANOVA, Student T-test and Scheffe's post-hoc test at P<.05 level. RESULTS. For G-CEM LinkAce cement groups, polyacrylic acid pretreatment showed the highest ${\mu}TBS$ in the self-cured group. In the light-cured group, no significant improvements were observed according to the dentin surface pretreatment. There were no significant differences between curing modes. Both dentin surface pretreatment methods helped to increase the ${\mu}TBS$ of RelyX U200 resin cement significantly and degree of pretreatment effect was similar. No significant differences were found regarding curing modes except control groups. In the comparisons of two self-adhesive resin cements, all groups within the same pretreatment and curing mode were significantly different excluding self-cured control groups. CONCLUSION. Selecting RelyX U200 used in this study and application of dentin surface pretreatment with EDTA and polyacrylic acid might be recommended to enhance the bond strength of cement to dentin.

• The Journal of Advanced Prosthodontics
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• 제8권4호
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• pp.275-284
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• 2016

PURPOSE. The aim of this study was to evaluate the influence of different surface treatment methods on the microtensile bond strength of resin cement to resin nanoceramic (RNC). MATERIALS AND METHODS. RNC onlays (Lava Ultimate) (n=30) were treated using air abrasion with and without a universal adhesive, or HF etching followed by a universal adhesive with and without a silane coupling agent, or tribological silica coating with and without a universal adhesive, and divided into 6 groups. Onlays were luted with resin cement to dentin surfaces. A microtensile bond strength test was performed and evaluated by one-way ANOVA and Tukey HSD test (${\alpha}$=.05). A nanoscratch test, field emission scanning electron microscopy, and energy dispersive X-ray spectroscopy were used for micromorphologic analysis (${\alpha}$=.05). The roughness and elemental proportion were evaluated by Kruskal-Wallis test and Mann-Whitney U test. RESULTS. Tribological silica coating showed the highest roughness, followed by air abrasion and HF etching. After HF etching, the RNC surface presented a decrease in oxygen, silicon, and zirconium ratio with increasing carbon ratio. Air abrasion with universal adhesive showed the highest bond strength followed by tribological silica coating with universal adhesive. HF etching with universal adhesive showed the lowest bond strength. CONCLUSION. An improved understanding of the effect of surface treatment of RNC could enhance the durability of resin bonding when used for indirect restorations. When using RNC for restoration, effective and systemic surface roughening methods and an appropriate adhesive are required.

• Restorative Dentistry and Endodontics
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• 제37권1호
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• pp.9-15
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• 2012

Objectives: This study evaluated the effect of 2% chlorhexidine digluconate (CHX) with different application times on microtensile bonds strength (MTBS) to dentin in class I cavities and intended to search for ideal application time for a simplified bonding protocol. Materials and Methods: Flat dentinal surfaces with class I cavities ($4mm{\times}4mm{\times}2mm$) in 40 molar teeth were bonded with etch-and-rinse adhesive system, Adper Single Bond 2 (3M ESPE) after: (1) etching only as a control group; (2) etching + CHX 5 sec + rinsing; (3) etching + CHX 15 sec + rinsing; (4) etching + CHX 30 sec + rinsing; and (5) etching + CHX 60 sec + rinsing. Resin composite was builtup with Z-250 (3M ESPE) using a bulk method and polymerized for 40 sec. For each condition, half of the specimens were immediately submitted to MTBS test and the rest of them were assigned to thermocycling of 10,000 cycles between $5^{\circ}C$ and $55^{\circ}C$ before testing. The data were analyzed using two-way ANOVA, at a significance level of 95%. Results: There was no significant difference in bond strength between CHX pretreated group and control group at the immediate testing period. After thermocycling, all groups showed reduced bond strength irrespective of the CHX use. However, groups treated with CHX maintained significantly higher MTBS than control group (p < 0.05). In addition, CHX application time did not have any significant influence on the bond strength among groups treated with CHX. Conclusion: Application of 2% CHX for a short time period (5 sec) after etching with 37% phosphoric acid may be sufficient to preserve dentin bond strength.

• Restorative Dentistry and Endodontics
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• 제29권2호
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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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• 제28권6호
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• pp.491-497
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• 2003

The purpose of this study was to evaluate the correlation between hybrid layer thickness and bond strength using confocal laser scanning microscope and microtensile bond strength test of two adhesive systems. The dentin surface of human molars. sectioned to remove the enamel from the occlusal surface. Either Scotchbond Multi-Purpose(3M Dental Product, St. Paul, MN, U.S.A) or Clearfil SE Bond (Kuraray, Osaka, Japan) was bonded to the surface. and covered with resin-composite. The resin-bonded teeth were serially sliced perpendicular to the adhesive interface to measure the hybrid layer thickness by confocal laser scanning microscope. The specimen were trimmed to give a bonded cross-sectional surface area of $1\textrm{mm}^2$, then the micro-tensile bone test was performed at a cross head speed of 1.0 mm/min. All fractured surfaces were also observed by stereomicroscope. There was no significant differences in bond strengths the materials(p>0.05). However. the hybrid layers of three-step dentin adhesive system, SM, had significantly thicker than self-etching adhesive system. CS(p<0.05). Pearson's correlation coefficient showed no correlation between hybrid layer thickness and bond strengths(p>0.05). Bond strengths of dentin adhesive systems were not dependent on the thickness of hybrid layer.

• Restorative Dentistry and Endodontics
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• 제28권6호
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• pp.498-503
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• 2003

The purpose of this study was to evaluate the rewetting effect of water-based primer on the air-dried dentin. In this in vitro study, freshly extracted non-caries human molars and three-step adhesive system(SBMP) were used. Freshly extracted non-caries human molars and three-step adhesive system(SBMP) were used. Flat occlusal dentin surface were prepared using low-speed diamond saw, Prepared teeth were randomly divided into three groups. Group 1.(W): etched(35% phosphoric acid for 15s) and blot-dried, Group 2.(5D): 5s air-dried, Group 3.(30D): 30s ail-dried, To obtain color contrast in CLSM observation, primer was mixed with rhodamine B and bonding resin was mixed with fluorescein. Microscopic sample of each group were obtained after longitudinal section. Morphological investigation of resin-dentin interface and thickness of hybrid layer measurement using CLSM were done. Microtensile bond strength for each specimen was measured. Specimen were observed under microscope to examine the failure patterns of interface between resin and dentin. The results of this study were as follows: 1. The results(mean) of Thickness of hybrid layer were W:19.67, 5D:20.9, 30D:10$\mu\textrm{m}$. Only 30D had statistically significant differences to Wand 5D(P<0.05). 2. The results(mean) of Microtensile bond strength were W:16.02, 5D:14.69, 30D:11.14MPa. Only 30D had statistically significant differences to Wand 5D(P<0.05). 3. There were positive correlation between Thickness of hybrid layer and microtensile bond strength(P<0.05).

• Restorative Dentistry and Endodontics
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• 제29권3호
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• pp.233-238
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• 2004

The purpose of this study was to evaluate the effect of immediate or delayed composite resin filling on dentinal microtensile bond strength (${\mu}TBS$) after applied the adhesive. The coronal dentin of human third molars was exposed. Single-Bond or One-Step was applied on the dentin surfaces. and composite resin were constructed immediately (group 1) or 5min., 10min., 15min., 20min. and 30min. (groups 2-6) after an adhesive was applied. The specimens were sectioned and made bar-shaped. Each surface area of them was about $1\textrm{mm}^2$. The ${\mu}TBS$ test was performed by EZ test. The results were analysed by One-way ANOVA and Tukey's test at 95% significance level. The results suggested that the ${\mu}TBS$ of Single-Bond to dentin was decreased when the composite resin was constructed 20min. and 30min. after Single-Bond was applied. But the ${\mu}TBS$ of One-Step was not affected by delayed composite resin filling.