Development of Portland cement for orthopedic applications, establishing injectability and decreasing setting times

Abstract

The injectability of Portland cement (PC) with calcium chloride and calcium nitrate additives was investigated using a syringe with a 2 mm aperture for potential clinical applications such as vertebroplasty. Addition of either additive at 10 wt % increased the quantity of cement extruded through the syringe from approximately 25 wt % for the PC standard, to over 95 wt %. 10 wt % additions of either additive also decreased setting times from over 2 h to below 25 min. The compressive strength of the modified cements was all greater than the compressive strength of a human vertebral body. Decreasing either additive to 5 wt % generated compressive strengths after 24 h setting equal to polymethylmethacrylate, the cement used for the majority of vertebroplasty procedures. An initial early exotherm in the chloride cements was coupled with an X-ray diffraction (XRD) peak that indicated the early formation of the ettringite cement phase. In contrast, Fourier transform infrared (FTIR) spectroscopy and XRD data indicated that calcium nitrate may have stimulated early calcium silicate hydrate (CASAH) production (the main strength producing phase of PC). Combining the two additives produced a synergistic effect with cements having increased injectabilities and compressive strengths compared with either addition used individually. This study has demonstrated that by modifying PC with nonproprietary chemicals it was possible to significantly increase cement injectability and reduce setting times whilst maintaining compressive strengths, making PC suitable for potential orthopedic applications.

Microparticulated and nanoparticulated zirconium oxide added to calcium silicate cement: Evaluation of physicochemical and biological properties

“…This material is basically composed by Portland cement (PC), a calcium silicate‐based material (CS) added to a radiopacifying agent, bismuth oxide (BO), in a 4:1 proportion . It has been reported that PC exhibits biocompatibility and high compressive strength allowing that this material may be also suitable for medical indications, such as in orthopedic applications …”

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

“…MTA is basically composed by Portland cement (PC) which has physicochemical, antimicrobial and biological properties similar to commercially available MTA [3][4][5] . PC shows biocompatibility and high compressive strength allowing that this material may be suitable for medical indications, such as orthopedic applications 6) .…”

Characterization and antimicrobial efficacy of Portland cement impregnated with silver nanoparticles

“…PC is characterized by stable biocompatibility, high compressive strength, rapid set-up, and low solubility to blood. This allows PC to be useful in providing initial graft stability in medical orthopedic applications 34. Concerning dental applications, PC is a main component of mineral trioxide aggregate (MTA), which is already widely used in endodontic surgery including root end filling, root repair, and pulp capping due to its biological and physicochemical properties 56.…”