Effect of Saliva on Candidal Adherence to Polymethyl Methacrylate Resin

The adherence of Candida species to saliva-coated plates of polymethyl methacrylate resin was studied physico-chemically. Saliva-coating of the resin plate caused increasing adherence of C. albicans, whereas it caused decreasing adherence of C. tropicalis. The hydrophobicities of the surfaces of the resin plate and the candidal cells were evaluated by a contact angle method, and surface free energies of these surfaces were calculated. The candidal cell adherence to the saliva-coated plates was highly correlated with the free energy change in hydrophobic interaction

Preoperative Computed Tomography-Derived Bone Densities in Hounsfield Units at Implant Sites Acquired Primary Stability

The purpose of this study was to evaluate preoperative CT-derived bone densities in Hounsfield units (HU) at implant sites that acquired primary stability, and to compare these values to the optimal bone densities proposed in the literature. Fifty-one patients, 18 males (37 implant sites) and 33 females (67 implant sites) between 2003 and 2010 were assessed. CT data for different jaw sections, regions, and operating procedures were compared using the Kruskal-Wallis test and Scheffe's test for multiple comparisons (P < 0.05). The mean bone density in the maxilla was significantly lower than that in the mandible (P < 0.05); the mean bone densities in the 4 jaw regions decreased in the following order: anterior mandible > anterior maxilla > posterior mandible > posterior maxilla. The bone densities assessed by HU fell into the range of optimal bone densities associated with acquired primary implant stability proposed in the literature

Real time assessment of surface interactions with a titanium passivation layer by surface plasmon resonance

Due to the high corrosion resistance and strength to density ratio titanium is widely used in industry, and also in a gamut of medical applications. Here we report for the first time on our development of a titanium passivation layer sensor that makes use of surface plasmon resonance (SPR). The deposited titanium metal layer on the sensor was passivated in air, similarly to titanium medical devices. Our "Ti-SPR sensor" enables analysis of biomolecule interactions with the passivated surface of titanium in real time. As a proof of concept, corrosion of a titanium passivation layer exposed to acid was monitored in real time. The Ti-SPR sensor can also accurately measure the time-dependence of protein adsorption onto the titanium passivation layer at sub-nanogram per square millimeter accuracy. Besides such SPR analyses, SPR imaging (SPRI) enables real time assessment of chemical surface processes that occur simultaneously at "multiple independent spots" on the Ti-SPR sensor, such as acid corrosion or adhesion of cells. Our Ti-SPR sensor will therefore be very useful to study titanium corrosion phenomena and biomolecular titanium-surface interactions with application in a broad range of industrial and biomedical fields