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Dentistry and Craniofacial Research
ISSN: 2576-392X
3 rd Euroscicon Conference on
M a r c h 2 5 - 2 6 , 2 0 1 9
B u d a p e s t , H u n g a r y
Dental Hygiene 2019
Dental & Dental Hygiene
Introduction: Dental zirconia restorations present long-term clinical survival
and be in service within the oral environment for many years. However, low
temperature degradation could affect their mechanical properties and survival.
Objectives: Was to investigate the effect of two aging methods on the flexural
strength and crystal structure of yttrium-stabilized zirconia (Y-TZP).
Material and methods: Thirty bar specimens were prepared from a yettria
stabilized zirconia polycrystals and were divided into 3 groups (control, aged
for 720,000 mechanical loads of 50N and 3600 thermal cycles, aged for 1 hour
using autoclave). The aging procedures represent 3 years of clinical use. The
specimens were loaded until fracture and the crystalline phase polymorphs
of the material (tetragonal, t, and monoclinic, m, zirconia) were investigated
by x-ray diffraction (XRD). Further investigations were done using scanning
electron microscope (SEM). Data was statistically analysed using ANOVA test.
Results: Group B and C showed no statistical significance in their flexural
strength with means of their break force (793.23±164.03) and (780.97 ±
257.25) respectively but statistically significant and higher than group A
with mean (549.7 ± 54.14). The XRD showed nearly no change in the crystal
structure between group A and B but an increase in the percent of monoclinic
phase in group C. The SEM demonstrated a relatively homogenous size with
particle size ranged between 400 to 570 µm for group A, while Group B and C
showed an increase in particle size between 768 to 1150 µm respectively.
Conclusions: Both aging methods caused changes in the flexural strength and
structure of the zirconia specimens with no significant difference between
them.
Biography
Amr Elsheemy has completed his Msc at the age of 28 years
from Alexandria University and is currently conducting his Phd
studies at the same university. He is an assistant lecturer at the
faculty of dentistry Alexandria university and a board member
at Alexandria dental syndicate.
THE EFFECT OF TWO AGING METHODS ON THE FLEXURAL STRENGTH AND
CRYSTAL STRUCTURE OF YETTRIA STABILISED ZIRCONIA POLYCRYSTALS
(IN VITRO STUDY)
Amr A Elsheemy
Alexandria University, Egypt
Amr A Elsheemy, Dent Craniofac Res 2019, Volume:4
DOI: 10.21767/2576-392X-C2-017