Radiopacity, pH and antimicrobial activity of Portland cement associated with micro- and nanoparticles of zirconium oxide and niobium oxide

Abstract

The aim of this study was to evaluate some properties of the calcium silicate materials Mineral Trioxide Aggregate (MTA) and Portland cement (PC) with microparticulated (micro) and nanoparticulated (nano) zirconium oxide (ZrO 2 ) or niobium oxide (Nb 2 O 5 ). The experimental materials: White PC (PC), MTA-Angelus ® (MTA), PC+ZrO 2 micro, PC+ZrO 2 nano, PC+Nb 2 O 5 micro and PC+Nb 2 O 5 nano were submitted to radiopacity and pH evaluations. Furthermore, the antimicrobial activity against different microorganisms was assessed by agar diffusion test. MTA presented higher radiopacity than other materials. However, all materials except PC presented higher radiopacity than recommended by ISO/ADA. MTA promoted higher pH values in all analyzed periods (p≤0.05). At the initial periods, PC and PC+ZrO 2 micro showed pH similar to MTA. All materials showed antimicrobial activity against the evaluated microorganisms. In conclusion, ZrO 2 and Nb 2 O 5 could be alternative radiopacifiers to be added to calcium silicate materials.

Hydration kinetics, ion-release and antimicrobial properties of white Portland cement blended with zirconium oxide nanoparticles

“…This finding confirms those of Guerreiro-Tanomaru et al 11,21) , who report little difference in pH values in distilled water for pure Portland cements and those blended with 30 wt% ZrO 2 micro-and nanoparticles.…”

“…For example, soluble calcium and silicate species are acknowledged to stimulate bone tissue regeneration 18,19) . The release of hydroxide ions is associated with antimicrobial activity and also the ability to induce bone mineralisation 11,20,21) . The reaction between released calcium ions and physiological carbonate ions forms insoluble calcite which precipitates in the cracks, pores, voids and margins of the cement and is conjectured to improve the sealing ability of the material 20) .…”

“…Alternative radiopacifying agents with superior physicochemical properties and biocompatibility are currently under consideration. Zirconium oxide, ZrO 2, is among these candidate radiopacifiers as it is bioinert, biocompatible and is currently used in the reconstruction of skeletal and dental tissues [8][9][10][11] . In particular, zirconium oxide nanoparticles, nano-ZrO2, have recently been shown to accelerate the hydration of WPC and to improve its biocompatibility with respect to human osteosarcoma cells in vitro 12) .…”

Bioactivity of MTA Plus, Biodentine and an experimental calcium silicate‐based cement on human osteoblast‐like cells

“…Niobium oxide as a radiopacifier of calcium silicate cement, at the proportion of 30% Nb 2 O 5 micro‐ and nanoparticles in association with CP, provided adequate radiopacity according to ANSI/ADA (Guerreiro Tanomaru et al . ). The bioactive potential of Nb 2 O 5 and ZrO 2 in association with CSC in an endodontic sealer formulation was demonstrated by hydroxyapatite crystal deposition (Viapiana et al .…”

Zirconium oxide and niobium oxide used as radiopacifiers in a calcium silicate‐based material stimulate fibroblast proliferation and collagen formation

“…), and when added to CS, it has an adequate radiopacity (Guerreiro‐Tanomaru et al . , Silva et al . ).…”