Effect Of The Desensitizers Using On Abutment Tooth Of The Fixed Dental Prosthetic Restoration On The Bonding Performance Of Cements

Objective To observe the microscopic characteristic of the dentinal surface and crosssection after using dental desensitizer, and evaluate the effect of the dental desensitizer onthe shear strength and microleakage of the cements.Methods Used the dental desensitizer (Gluma, SingleBond2, Bisblock) individuallyon the prepared human bicuspid teeth. Observed the microscopic characteristic of thedentinal surface and cross section with SEM. Bonded the adhered posts to the teethpretreated with desensitizer with 5 cements individually—Zinc phosphate cements(ZPC),Zinc polycarboxylate cements(ZPCC), Glass ionomer cements(GIC), Resin-modifiedglass ionomer cements(RMGIC), Resin cements(RC). Measured the shear strength andmicroleakage, and analyzed by SPSS 13.0 statistics software.Results 1. The seal capability of the desensitizer: the orifices of dentinal tubule weremostly occluded in Gluma samples under SEM and partly occluded in Bisblock samples.Resin layer were observed in SingleBond2 samples. 2. The result of shear strengthexperiment: SingleBond2+ZPC group gathered the lowest shear strength value(0.41±0.09MPa). SingleBond2 degraded the shear strength of ZPCC and GIC notably,but enhanced the shear strength of RMGIC. The shear strength were lower but statisticdifference were not found when Gtuma combined with ZPC, ZPCC, GIC. Then the shearstrength of Gluma+RMGIC was enhanced (5.88±1.37MPa). The value of shear strengthof the ZPC was degraded when combined with Bisblock and statistic difference wasfound. Bisblock enhanced the value of shear strength of the RMGIC and RC (13.04±2.76MPa) and statistic difference was found. ZPCC control gained the biggest value of shearstrength (16.71±4.02MPa). 3. Microleakage experiment: SingleBond2+GIC groupgathered the lowest microleakage value (0.16±0.08mm)and differed from the GIC control(P＜0.01). RC control gained the biggest microleakage value (2.51±0.20mm). Bisblockaggravated the microleakage of GIC and RC group, but Gluma gained the contrary values,and notable statistic difference were found.Conclusions 1. The effect of desensitizers on the bonding performance of cementsassociates with both component and bonding mechanisms. 2. The abutment tooth pretreated with Gluma can be bonded with one of these cements: ZPCC, GIC, RMGIC,RC. 3. The abutment tooth pretreated with SingleBond2 can be bonded with resin-basedcements. 4. The abutment tooth pretreated with Bisblock can be bonded with ZPCCcements.