Cytotoxicity study of plasma-sprayed hydroxyapatite coating on high nitrogen austenitic stainless steels

In Vitro Cytotoxicity Test and Surface Characterization of CoCrW Alloy in Artificial Saliva Solution for Dental Applications

In order to evaluate its application as a dental prosthesis material, a CoCrW alloy was subjected to in vitro cytotoxicity test, surface characterization and electrochemical studies performed in artificial saliva and 0.15 mol.L-1 NaCl medium. The used techniques were: anodic polarization curves, chronoamperometric measurements, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) analysis and X-ray photoelectron spectroscopy (XPS). Cytotoxicity test was also performed. The electrochemical behavior of CoCrW alloy was compared in both studied media, from corrosion potential (Ecorr) to a 600 mV anodic overvoltage. From the electrochemical measurements it was observed that the CoCrW alloy in both media presents only generalized corrosion. SEM and EDS analysis showed that the alloy presents carbide niobium and silicon and manganese oxides as nonmetallic inclusions. XPS results indicated that cobalt does not significantly contribute to the passivating film formation. Cytotoxicity test showed no cytotoxic character of CoCrW alloy. These results suggest that the CoCrW alloy can be used as biomaterial to be applied as prosthesis in dental implants.

An alternative to nerve repair using an antioxidant compound: a histological study in rats

The fascicular composition and organisation of the inferior alveolar nerve (IAN) were determined to confirm the microarchitecture of the IAN bundles into each of the mandibular teeth, including the composition of the mental nerve. The aim of this study was to evaluate peripheral nerve repair after the application of an antioxidant compound to the damaged nerve tissue to elevate the concentration and bioavailability of elements capable of favouring tissue repair. Twenty-five Wistar rats were divided into groups: The Control 1 (Ctl 1) (n = 5) animals had the ischiatic nerve exposed with no suture injury and were sacrificed at 30 days post-operatively. The Control 2 (Ctl 2) (n = 10) animals had the ischiatic nerve exposed, and the nerve was injured using suture in three distinct regions. In the experimental (Exp) animals (n = 10), an antioxidant organic compound was applied to the nerve injury site. The animals with nerve injury (Ctl2 and Exp group) were sacrificed at 15 and 30 days post-operatively. The histological analysis showed less degeneration in the Exp group at 15 and 30 days post-operatively. Nerve neoformation forming a connection between the distal and proximal suture sites was observed in the experimental group. This study presented an alternative to nerve repair using an antioxidant compound.