European Journal of Prosthodontics and Restorative Dentistry

The Effect of Irradiation Distance on Light Transmittance and Vickers Hardness Ratio of Two Bulkfill Resin-based Composites

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Cover Date

December 2016

Print ISSN

0965-7452

Electronic ISSN

2396-8893

Vol

24

Issue

4

Abstract

ABSTRACT
This study evaluated the effect of cleaning protocols on the bond strength of resin cement to glass-ceramic. Ceramic specimens (N=120, n=12 per group) were etched with hydrofluoric acid and rinsed with water. After saliva contamination, specimens were cleaned as follows: water, 37% H3PO4, cleaning-paste (Ivoclean), or isopropanol. Noncontaminated specimens acted as the control. Resin cement was bonded to the specimens, and tested either after 24 h or x5000 thermocycling. Both the cleaning method (p=0.001) and the storage conditions (p=0.005) significantly affected the bond strength results. In dry conditions, the groups PA and IV showed no significant difference, being also similar to the non-saliva contaminated control group (p>0.05). In dry conditions, no significant difference was observed between the mean DW and IS being significantly lower than those of other groups (p<0.05). Except for the group IV, thermocycling decreased the results significantly in all groups (p<0.05). Predominantly mixed failure type was observed in both dry and aged conditions. SEM micrographs of ceramic surfaces after cleaning agents showed no major differences but on the specimens from the IV group, small, rounded-zirconia particles were observed. In case of saliva contamination of acid-etched glass-ceramics, mechanical cleaning can restore adhesion to the baseline situation.

Keywords
Bond Strength
Adhesion
Resin Cement
Ceramic
Hydrofluoric Acid
Cleaning Protocol