• 구강회복응용과학지
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• 제22권3호
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• pp.231-242
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• 2006

Statement of problem: The sealing of the opened dentinal tubules that follows the tooth preparation for the prosthodontic restoration is considered as clinical process to reduce postoperative sensitivity. Purpose: This study investigated the effect of desensitization treatment on shear bond strength of luting cements. Materials and Method: Total 80 dentin specimens were divided into two groups according to the kinds of luting cements. Each groups was further divided into 4 subgroups with AQ $bond^{(R)}$, $Saforide^{(R)}$, Diode laser $MDL-10^{(R)}$ application and without desensitization treatment. After desensitization treatment application, Ni-Cr specimens were luted to dentin surface with Fuji $CEM^{(R)}$ and $Panavia-F^{(R)}$. Specimens were placed in distilled water at $37^{\circ}C$ for 24 hours and shear bond strength between metal and dentin was measured by a universal testing machine. Results: 1. In Fuji $CEM^{(R)}$ cemented groups, the combination of AQ $bond^{(R)}$ showed the greatest strength, followed by diode laser, no desensitizer treatment, and $Saforide^{(R)}$. Both AQ $bond^{(R)}$ and Diode laser groups had a significant difference than no desensitization treatment group and $Saforide^{(R)}$ group(p<0.05). 2. In $Panavia-F^{(R)}$ cemented groups, the combination of Diode laser showed the greatest strength, followed by AQ $bond^{(R)}$, $Saforide^{(R)}$, and No desensitization treatment. All desensitization treatment groups had a significant difference than no desensitization treatment group(p<0.05). 3. All $Panavia-F^{(R)}$ groups showed a significant higher shear bond strength than all Fuji $CEM^{(R)}$ groups(p<0.05). Conclusion: The results of this study showed possibility of bond strength increase after desensitization treatment. The application of desensitization treatments like AQ $bond^{(R)}$, $Saforide^{(R)}$, and Diode laser $MDL-10^{(R)}$ have advantages in exposed dentin surface after tooth prep.

• Restorative Dentistry and Endodontics
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• 제24권1호
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• pp.240-250
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• 1999

The purpose of this study was to evaluate the effect of different etching time on the shear bond strength and adaptibility of composite to enamel and dentin when used one-bottle adhesive Prime & Bond$^{TM}$ 2.0. The proximal and occlusal surfaces of 88 extracted human molars were ground to expose enamel(n=44) and dentin (=44) using diamond wheel saw. Teeth were randomly assigned to four test groups(n=11) and received the following treatments : Control group were conditioned with 36% phosphoric acid for 20 sec. according to the manufacturer's directions. Experimental 10 sec. group, 30 sec. group and 60 sec. group were conditioned with 36% phosphoric acid for 10 sec., 30 sec. and 60 sec., respectively. Teeth were rinsed and dried for 2 sec. Prime & Bond$^{TM}$ 2.0 were applied according to the manufacturer's directions and Spectrum$^{TM}$ TPH composite resins were bonded to enamel and dentin surfaces. All specimens were stored in distilled water for 24 hours. Eighty specimens were sheared in a Universal Testing Machine with a crosshead speed of 5mm/minute. One way ANOVA and LSD test were used for statistical analysis of the data. Failure modes of all specimens after shear bond strength test were examined and listed. Also, representive postfracture modes and eight specimens were examined under scanning electron microscope. The results of this study were as follows: 1. The shear bond strength to enamel was the highest value in 30 sec. group (20.68${\pm}$8.54MPa) and the lowest value in 10 sec. group (14.92${\pm}$6.07MPa), so there was significant difference of shear bond strength between two groups (p<0.05). But there was no significant difference among other groups (p>0.05). With longer etching time to enamel from 10 sec. to 30 sec., higher the shear bond strength was obtained, but the shear bond strength was decreased at 60 sec. etching time. 2. The shear bond strength to dentin was the highest value in control group (13.08${\pm}$6.25MPa) and the lowest value in 60 sec. group (9.47${\pm}$3.35MPa), but there was no significant difference among the all groups (p>0.05). The eching time over 20 sec. decreased the shear bond strength to dentin. 3. In SEM observation, the enamel and resin interfaces were showed close adaptation with no relation to etching time of enamel. And the dentin and resin interfaces were showed close adaptation at 20 sec. and 30 sec. etching time, but showed some gaps at 10 sec. and 60 sec. etching time. Accordingly, these results indicated that a appropriate etching time in Prime & Bond$^{TM}$ 2.0 was required to be 30 sec. in enamel and 20 sec. in dentin for the high shear bond strength and good adaptation between the composite resin and tooth substance.