Effect of Sintering Technique on Shade and Shear Bond Strength of CAD/CAM Monolithic Translucent Zirconia

Document Type : Original Article

Authors

1 Post Graduate student in Crown and bridge, Faculty of Dentistry Suez Canal University.

2 Lecturer of Crown and Bridge. Department of Crown and Bridge. Faculty of dentistry. Suez Canal University

3 Prof. of Crown and bridge, Faculty of Dentistry Suez Canal University

Abstract

Introduction: The fabrication of zirconia dental restoration is a time-consuming
process due to traditional slow sintering schemes. A speed sintering protocol has
been developed to meet the demand for time and cost-effective chair-side CAD/
CAM-produced restorations, as well as to control ceramic microstructures for better
translucency. Fast heating and cooling rates, as well as shorter sintering dwell times
are known to affect the microstructure and properties of zirconia. Aim of study: This
study aimed to investigate and compare between three types of monolithic translucent
zirconia in terms of the shade and the shear bond strength of the zirconia samples to
adhesive resin cement after conventional and speed sintering. Material and Methods:
Three types of zirconia discs were cut into 20 square shaped samples, 10 large square
shaped and 10 small square shaped and bonded to each other. Bonded samples were
divided according to type of zirconia into 3 groups: Group 1: Dental direct ZX2,
Group 2: Dental Direct ZW iso, Group 3: Zolid HT+. Each group was subdivided
according to sintering technique into 2 subgroups. Shade and shear bond test were
measured. Results: The speed sintering of the three types of zirconia showed a lower
ΔE values than that showed with the conventional sintering, and among the speed and
conventional sintering subgroups Dental Direkt Bio ZX2 showed the lowest ΔE value
and highest shear bond strength value followed by Dental Direct Bio ZW iso and Zolid
Ht+. Conclusion: The speed sintering technique of the monolithic translucent zirconia
gave better color shade reproduction and higher shear bond strength to resin cement
than that of the conventional sintering technique. Dental Direkt ZX2 produced better
color shade reproduction and higher shear bond strength to resin cement than that of
the Dental Direkt ZW iso and Zolid Ht+ in speed and conventional sintering technique.

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