Publication: Evaluation of physical and mechanical properties of zirconia and alumina reinforced experimental nanohybrid dental luting composite cement using silica from rice husk
Date
2022-03
Authors
Islam, Md. Saiful
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Aims: This study aimed to extract silica from the rice husk, then characterised
the synthesised silica and commercial zirconia and alumina fillers to fabricate
experimental nanohybrid dental luting composite cement (NHDLCC). The zirconia
and alumina reinforced experimental NHDLCC were subjected for the evaluation of
compressive strength, flexural strength, viscosity, water sorption and solubility
testings. Materials and methods: The unsilanated nano silica from rice husk was
characterized using a scanning electron microscope (SEM) equipped with energy
dispersive X-ray (EDX). Silica, zirconia and alumina fillers were subjected to a surface
treatment using silane coupling agents. All the silanated and unsilanated fillers were
then characterized using Fourier transform infrared spectroscopy (FTIR). Three groups
were fabricated based on different types of filler reinforcement: Group 1 (3 wt.%
zirconia); Group 2 (3 wt.% alumina); Group 3 (3 wt.% zirconia and 2 wt.% alumina)
whereas experimental NHDLCC without zirconia and alumina reinforcement was used
as a negative control and a commercial nanohybrid dental luting composite, Rely-XTM
U200 luting cement (3M ESPE; USA) was used as a positive control. All the
experimental groups were then characterized using (SEM) equipped with (EDX) and
subjected to its mechanical and physical properties evaluation that included
compressive strength, flexural strength, viscosity, water sorption and solubility. Oneway
ANOVA was used for multiple group comparison followed by post-hoc (Bonferroni) A statistically significant level was set at p = 0.05. Results: SEM and
EDX confirmed the homogenously distributed spherical-shaped filler and the presence
of filler particles in each group of expermental NHDLCC. The compressive strength
of 3 wt.% zirconia reinforced filler group was found significantly higher when
compared to the negative control (p < 0.05). Meanwhile, for the flexural strength, the
water sorption and solubility, 3 wt.% zirconia and 2 wt.% alumina reinforced filler
group showed significantly higher compared to the negative control (p < 0.05). For the
viscosity testing, 3 wt.% alumina reinforced filler group showed statistically
significant increase of viscosity compared to control at the oscillation frequency (ω)
of 1 rad/s (p < 0.05). However, the difference was found not statistically significant at
the oscillation frequency (ω) of 10 rad/s (p > 0.05) of NHDLCC. Conclusion: The
silica was successfully extracted from the rice husk and all three fillers were
characterised before and after surface treatment with the silane coupling agent. The
reinforcement of different percentages of zirconia and alumina filler particles in the
experimental NHDLCC improved compressive strength, flexural strength, viscosity
properties, and decreased water sorption and solubility.