EFFECT OF YTTRIA STABILISED ZIRCONIA ADDITION IN NATURAL HYDROXYAPATITE COMPOSITES FOR DENTAL RESTORATION

Abstract

Resin based composite (RBC) resembles the color of teeth has been used as a popular 
dental materials to repair or restore damaged teeth. In this study, the RBC were 
prepared using a hydroxyapatite from fish scales and yttria stabilised Zirconia as 
reinforcement fillers, while the organic resin are the blended monomers of Bis-GMA, 
TEGDMA and UDMA. The aim of this study is to assess the effect of addition of yttria 
stabilised Zirconia (YSZ) on the mechanical properties of natural hydroxyapatite resin
based composites for dental restoration. The composites were prepared in ratio 30:70 
wt% of organic resin and inorganic filler, respectively. For inorganic filler, different 
ration of YSZ (0, 10, 25, 50 and 75 wt%) was added to the natural hydroxyapatite 
(HAp) powder and mixed with the blended resin. The RBC was inserted into mould and 
light cured with LED polymerization unit for 60 s on the both sides. The flexural 
strength, compression strength, Vickers hardness and surface roughness of composites 
were measured. The HAp-YSZ composite with 10 wt% YSZ filler content exhibited 
satisfactory mechanical strength with a flexural strength, compression strength, Vickers 
hardness and surface roughness of 65.61 MPa, 158.20 MPa, 50.80 HV and 120.00 nm, 
respectively. These results suggested that the strong mechanical properties of RBCs are 
important for the long-term clinical application of dental restorative materials.