Effect of cementation on the mechanical behavior of a nanoceramic resin

Efeito da cimentação no comportamento mecânico de uma resina nanocerâmica

Abstract

Conventional flexural strength tests of restorative materials neglect the effect of essential variables that can affect their mechanical behavior. The purpose of this study was to evaluate the effect of cementation on the mechanical behavior of a nanoceramic resin. A nanoceramic resin (LU) and a leucite-reinforced glass-ceramic (IE) were evaluated. Non-cemented specimens of the materials were produced and subjected to biaxial flexural strength test $({\mathrm{\sigma }}_{\mathrm{f}},\mathrm{n}=30)$. Cemented specimens were constituted of the restorative material bonded with resin cement onto a dentin analog substrate. Cemented specimens were subjected to the monotonic compressive load test $({\mathrm{L}}_{\mathrm{f}},\mathrm{n}=20)$. Vickers microhardness (HV) and translucency parameter (TP) of the materials were characterized. Data were analyzed using t-test (σ_f and TP), Mann-Whitney test (L_f and HV), and Weibull analysis (σ_f and L_f, $\mathrm{\alpha }=0.05$). Non-cemented LU showed higher σ_f and Weibull modulus (m) than IE. When cemented to the substrate, LU showed higher L_f than IE; however, the m-value was similar among groups. LU showed lower HV than IE and higher TP values. Cementation influenced the mechanical behavior and failure mode of the nanoceramic resin.

Keywords:
ceramics; dental prosthesis; mechanics