Early tissue response to modified implant surfaces using back scattered imaging.

PURPOSE: It is now well known that implant surface properties affect osseointegration. Grit-blasting with abrasives and coating by plasma are methods to modify implant surfaces. This study aimed to compare the direction of new bone formation associated with three types of surfaces. MATERIALS AND METHODS: Titanium (Ti) alloy rods grit-blasted with alumina abrasive (Group 1, G1), with apatitic abrasive (Group 2, G2), and with apatitic abrasive and plasma-sprayed with hydroxyapatite (Group 3, G3) were implanted in surgically created defects in tibias of New Zealand white rabbits for 2 and 4 weeks. After sacrifice, the implants and surrounding bones were obtained and analyzed using back scattered imaging. RESULTS: Differences in patterns of bone formation among the groups were observed: originating from the cortical bone towards the implant surface (Type A), surrounding the implant (Type B) and originating from the medullary cavity (Type C). G1 and G3 showed Types A and B while G2 exhibited Types A, B and C. After 4 weeks, greater amount of new bone was observed in G2 group compared with those in G1 and G3 groups. CONCLUSIONS: This study demonstrated that patterns of bone formation are influenced by methods of surface modification.

Thermal ablation of FEL irradiation using gypsum as an indicator.

Thermal effects produced in a laser-irradiated sample were studied by micro-X-ray diffraction and micro-Fourier transform infrared spectroscopy (FTIR). Gypsum, transformed into bassanite at 124 degrees C and into anhydrite at 147 degrees C, was used as a thermal indicator. Pit formation by a wavelength-tunable free electron laser (FEL) irradiation on the gypsum pellet maximized at a wavelength of 3.0 microm, 2 mJ/shot, and pits were not detected in those irradiated at 2.6 or 3.8 microm compared with the maximum at 3.0 microm and diminished at 2.0 or 4.0 microm in the human tooth case. Micro-X-ray diffraction and micro-FTIR did not reveal any appreciable bassanite or anhydrite in the irradiated regions. From the laser ablation viewpoint, these results allow the FEL ablation to be considered as plasma or evaporative ones. This study indicated that the micro-pulse of laser was effective to prevent thermal damages of laser irradiation.

Distribution of care information packages for the support of patients with cancer and their families during disaster situations and their evaluation via the internet.

With the aim of preparing for disasters, care information packages for the support of patients with cancer and their families during disaster situations were developed in our previous study, and were provided via the internet with a questionnaire asking the face validity and the usefulness of such information. Thirty replies were received. Most subjects thought the care packages were appropriate and useful in the actual settings, however 43.3% of them thought the amount of information was excessive. Many comments and suggestions on the care information packages also could be obtained via the internet.