Influence of the fabrication process and fluoride content on the tribocorrosion behaviour of Ti6Al4V biomedical alloy in artificial saliva.

Titanium and its alloys are widely used as dental implants due to their low density, excellent biocompatibility, mechanical properties and corrosion resistance. However, during their lifetime Ti6Al4V biomedical alloys are subjected to different mechanical actions (i.e., sliding or fretting), thus resulting in a tribocorrosion system, which is an irreversible material degradation process due to the combined effect of corrosion and wear. In this study, the tribo-electrochemical behavior of cast and sintered (by powder metallurgy) Ti6Al4V alloy in artificial human saliva solution without and with fluoride additions of 100ppm and 1000ppm and in an average industrial mouth wash solution with a 112ppm fluoride content have been investigated by different electrochemical techniques. The same tribocorrosion mechanisms were found in the cast and sintered titanium alloys, although slightly different wear debris behavior was observed. At low applied passive potentials, wear rates are similar to those obtained under equilibrium conditions (Open Circuit Potential). There exists a critical fluoride concentration above which corrosion and tribocorrosion rates increase.

Introducing ultrasound-guided vein catheterization into clinical practice: A step-by-step guide for organizing a hands-on training program with inexpensive handmade models.

INTRODUCTION: Central vein catheterization (CVC) plays a central role in hospital patient management. Compared with the use of traditional anatomical landmarks, ultrasound-guidance is associated with higher CVC success rates, fewer complications, and more rapid central venous access. The use of US-guided CVC in clinical practice has not become widespread, largely because anesthesiology and general surgery residents receive limited training in this technique. To increase the use of US-guided CVC in our surgical department, we organized a hands-on training program based on the use of handmade models. METHODS: Three different models were constructed using plastic food-storage containers, segments of rubber tourniquet and silastic tubing (to simulate vessels), and agar gelatin. RESULTS: The hands-on training course allowed progressive acquisition of the basic hand-eye coordination skills necessary for performing US-guided venipuncture. The overall cost for each model was less than €5.00. DISCUSSION: The models described in this report are useful tools for teaching US-guided CVC. Thanks to their low-cost, they can be widely used to facilitate the introduction of this technique in clinical practice.