• Restorative Dentistry and Endodontics
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• v.30 no.4
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• pp.319-326
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• 2005

This study compared the microtensile bond strength $({\mu}TBS)$ of single step adhesives to different dentin depths. Superficial or deep dentin was exposed in 30 molar teeth by sectioning immediately under the DEJ or 1.5mm area from central pit, respectively. After polishing with 600-grit SiC paper, the dentin surfaces were assigned to three groups: AQ group-AQ Bond, L-Pop group-Adper Prompt L-Pop, Xeno group-Xeno III. The bonded specimens were sectioned into sticks and subjected to ${\mu}TBS$ testing with a crosshead speed of 1mm/minute. The results of this study were as follows; The ${\mu}TBS$ to superficial dentin was higher than that to deep dentin in all group. The ${\mu}TBS$ of Xeno group was significantly higher than that of L-Pop group and AQ group in both superficial and deep dentin (p<0.05).

• Restorative Dentistry and Endodontics
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• v.30 no.4
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• pp.312-318
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• 2005

This study compared the microtensile bond strength $({\mu}TBS)$ of three single step adhesives to dentin. Occlusal superficial dentin was exposed in fifteen human molars. They were assigned to three groups by used adhesives: Xeno group (Xeno III). Prompt group (Adper Prompt L-Pop). AQ group (AQ Bond). Each adhesive was applied to dentin surface. and composite of same manufacturer was constructed. The bonded specimens were sectioned into sticks with an interface area approximately $1mm^2$, and subjected to $\mu$ TBS testing with a crosshead speed of 1mm/minute. The results of this study were as follows; 1. The ${\mu}TBS$ to dentin was $48.78\pm9.83MPa$ for Xeno III. $30.22\pm4.52MPa$ for Adper Prompt L-Pop. and $26.31\pm7.07MPa$ for AQ Bond. 2. The mean ${\mu}TBS$ of Xeno group was significantly higher than that of Prompt group and AQ group (p<0.05). 3. There was no significant difference between the ${\mu}TBS$ of Prompt group and AQ group.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.3
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• pp.348-357
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• 2009

The purpose of this study was to evaluate the micro-tensile bond strength (${\mu}TBS$) of four luting resin to regional dentin of human primary teeth. Dentin from non-carious primary molars were prepared from different regions (s, superficial dentin; d, deep dentin; c, cervical dentin), and divided into groups based on anatomical locations and types of luting resins (Scotchbond Multi-purpose : SB ; One-Step : OS ; AdheSE Bond : ASE ; G-Bond : GB) : SB-s, SB-d, SB-c; OS-s, OS-d, OS-c; ASE-s, ASE-d, ASE-c ; GB-s, GB-d, GB-c. Luting resins were used according to the manufacturers' instructions, to bond $Light-Core^{TM}$ Core Build-Up Composite) to the exposed dentin specimens in the light-curing mode. After storage for 1 day, ${\mu}TBS$ was tested at a cross-head speed of 1 mm/min. Data were analyzed with T-test and two-way ANOVA. The bonding interface and fractography analyses were performed with SEM. The results were as follows : 1. ${\mu}TBS$ to superficial dentin was significantly higher than to deep dentin for SB(p<0.05). But there were no significant differences in regional ${\mu}TBS$ among OS, ASE, GB(p>0.05). 2. There were no significant differences in ${\mu}TBS$ to superficial dentin among each groups. But, in deep dentin, ${\mu}TBS$ of SB-d was significantly lower than those of OS-d, ASE-d, and GB-d(p<0.05). ${\mu}TBS$ of OS-d was significantly higher than those of GB-d(p<0.05), but there were no significant differences in ${\mu}TBS$ of ASEd. There were no significant differences among ${\mu}TBS$ of ASE-d, OS-d, and GB-d.

• Restorative Dentistry and Endodontics
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• v.20 no.2
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• pp.856-868
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• 1995

The effect of collagen dissolution in acid conditioned dentin layer on resin - dentin adhesion was investigated. 160 freshly extracted human molars were divided into 4 groups randomly and dentin surfaces were exposed. 40 exposed dentin surfaces were not acid conditioned and each 10 of them were applied with bonding agents within dentin bonding systems of All Bond 2, Scotchbond Multipurpose, Clearfil Photobond and Superbond D - Liner respectively. Each 10 of another 40 exposed dentin surfaces were acid conditioned by the acid within the above four bonding systems respectively and applied with corresponding bonding systems. After acid conditioning of the other 40 exposed dentin surfaces as above, they were treated with 5% NaOCl for 2 minutes, and each 10 of them were applied with the above four dentin bonding systems respectively. The remaining 40 dentin surfaces were acid conditioned and treated with 10% NaOCl for 2 minutes, and each 10 of them were applied with corresponding bonding agents as the above. After the procedures were finished, composite resin (Z -100, 3M Dent. Prod., USA) were applied on the dentin surfaces and light cured. Shear bond strength values were measured. Surface changes of fractured dentin specimens were observed using SEM (Hitachi S-2350, Japan). The following results were obtained. 1. In all of dentin bonding systems, shear bond strengths of non - conditioned specimens were significantly lower than those of acid conditioned specimens (P<0.05). 2. A statistically significant difference of bond strengths did not exist between acid conditioned specimens and 5% NaGCI retreated specimens applied with All Bond 2, Scotchbond Multipurpose and Clearfil Photobond (P>0.05). However, strength values of 5% NaOCl retreated specimens applied with Superbond D - Liner were lower than those of acid conditioned specimens (P<0.05). 3. In all the applied dentin bonding systems except Clearfil Photobond, bond strengths of 10% NaOCl retreated specimens were lower than those of acid conditioned and 5% NaOCl retreated specimens (P<0.05). 4. The resin - dentin hybrid layer of 4 - $5{\mu}m$ thickness was formed in the acid conditioned specimens applied with All Bond 2, Scotchbond Multipurpose and Superbond D-Liner. 5. The resin - dentin hybrid layer of 3 - $4{\mu}m$ thickness was still formed in the 5% NaOCl retreated specimens applied with All Bond 2 and Scotchbond Multipurpose. In addition, this layer was not completely removed after the retreatment with 10% NaOCl. Above results indicate that the dissolution of collagen in acid conditioned dentin layer by NaOCl solution can not be achieved completely and the collagens contribute to the resin - dentin adhesion considerably.

• Restorative Dentistry and Endodontics
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• v.36 no.4
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• pp.290-299
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• 2011

Objectives: The usage of fluoride varnish for a moderate to low caries-risk group has not been well validated. This study aimed to evaluate the preventive and therapeutic efficacies of fluoride varnish on the initiated root caries. Materials and Methods: Ten premolars were sectioned into quarters, further divided into two windows, one of which was painted with Fluor Protector (1,000 ppm fluoride, Ivoclar Vivadent). An initial lesion with a well-preserved surface layer was produced by pH cycling. Scanned line analysis using energy dispersive spectrometry determined the weight percentages of Ca and P in the demineralized layer. Scanning Electron microscopy and confocal laser scanning microscopy (CLSM) evaluated the varnish-applied root surfaces. Results: The mean lesion depth (SD) was 12.3 (2.6) ${\mu}m$ (single cycling) and 19.6 (3.8) ${\mu}m$ (double cycling). Double cycling extended the lesion depth, but induced no more mineral loss than single cycling (p < 0.05). The mean weight percentages of Ca and P between groups with and without varnish were not significantly different (p < 0.05). A CLSM showed varnish remained within 15 ${\mu}m$ of the surface layer. Conclusions: When a mild acid challenge initiated root tissue demineralization, the application of low-concentration fluoride varnish did not influence the lesion depth or the mineral composition of the subsurface lesion.