No abstract

This present study investigated the effects of the addition of hydroxyapatite (HA) on the flexural strength and microstructure of conventional GIC, and its effect on the cement's initial flexural strength at different storage conditions. Specimens were fabricated by mixing HA in whisker or granule form into commercially prepared GIC, and these were subjected to a threepoint bending test and SEM observations. Some specimens were stored in different conditions from dry to wet for 15 minutes to an hour prior to testing. When compared to the control, specimens with 16-25% HA whiskers added at P/L 1.75 showed a significant increase in the flexural strength (p<0.05), and as well with 19% HA whiskers at P/L 1.75 (p<0.001) and 2.33 (p<0.05). A significant increase was also noted for those with 8-25% HA granules added at P/L's 1.75 (p<0.05), 2.5 (p<0.05) and 3.60 (p<0.01). The addition of HA hastens the development of early (15min, 1 hour) flexural strength of GIC in moist or wet conditions. These results indicate that the addition of HA, regardless of form, improve the flexural and microstructural properties of GIC.

The aim of this study was to modify acrylic resin (PMMA) with fluorine (F) and silver (Ag) dual ions by a hybrid process of plasma-based ion implantation & deposition (PBII-D), and to enable the surface of the devices inhibition of bacterial adhesion. The surface characteristics, hydrophobic property and brushing abrasion resistance were evaluated by XPS analysis, contact angle measurement and brushing abrasion test. F and Ag were implanted-deposited and have formed carbon-fluoride and Ag-deposited layer on the surface of the PMMA plate. The contact angle of F+Ag implanted-deposited PMMA was increased compared with non-treated control and F only deposited PMMA. After 60,000 brushing strokes, the contact angle of modified PMMA remained to be higher than that of the control PMMA. This study indicated that F+Ag implantation-deposition has improved the hydrophobic property of acrylic resin and was sustained even after routine tooth brushing.