Shear Bond Strength of a Multi-Mode Universal Adhesive Containing Hydroxy-Apatite Nanoparticles to Dentin (In Vitro Study).
Aim: To evaluate the effect of addition of Hydroxyl-Apatite nanoparticles to a commercial
universal adhesive on sheer-bond-strength to dentin using two application modes, immediately and
Methods: A-commercial UA was used for bonding composite-resin to dentin and considered
as control. 10% of HAp were prepared and added to the commercial UA and considered as
experimental. 88-freshly extracted sound human premolar teeth were sectioned to expose midcoronal-
dentin. Samples were y divided into: control and experimental group. Each group was
further divided based on the application protocol. Half of the samples were stored in distilled water
for 24h at 37°C for immediate SBS testing whereas the other half was subjected to thermocycling
for 20,000 cycles. SBS was measured one-day post polymerization and after thermocycling using
universal testing machine. SBS values and failure modes were recorded and statistically analyzed.
Results: the experimental group presented significantly lower resin-dentin SBS than the control
group. Thermocycling significantly lowered SBS values for both groups. When using SE mode,
the experimental group reported lower resin-dentin SBS than the control group before and after
thermocyclying. When using ER mode before thermocycling, no significant difference was found
between the two groups, while after thermocycling, the experimental group reported significantly
higher resin-dentin SBS than the control group. For both adhesive groups, mixed failure dominated
with ER mode while adhesive failure dominated with SE mode.
Conclusions: Addition of HA may provide resistance to degradation and offer a potential to
improve resin-dentin bond stability against thermal changes when ER protocol is applied.
KEYWORDS: hydroxyapatite, dentin-bonding, universal-adhesive, etch&rinse
Egyptian Dental Journal,DOI: 00000000000, ISSN: https://edj.journals.ekb.eg/, Volume: 67, Issue: 3, Pages Range: 1-10,