To make rheological and biological evaluation of dental materials, we measured the depth of cure D_c and the surviving fraction S_f of HeLa cells cultured in extracted culture media from four resins: Estio LC and Graft LC in GC Co., Silux Plus in 3M Co., and Palfique Light in Tokuyama Co. D_c was determined from the rigid depth of the resins (6mm∅ × 8mm) polymerized with a plane light source (λ=462~478nm, 20sec). S_f was defined as the ratio between active cell numbers in test and control media; active cell numbers were measured by OD at 570nm with MTT assay as a function of the resin surface concentration C in media and the irradiation distance L inside the resins. The results were as follows, 1) S_f versus L was represented by a logistic equation 2) S_f decreased with the increase of C and L 3) S_f most changed at L near D_c 4) D_c was greater for Estio and Graft LC's with the higher content and larger size of fillers than Silux Plus. It is suggested that cultured cells may be damaged by residual monomers.

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A dynamic tube law shows the dynamic elastic properties of an artery in the wide range of transmural pressure, and is represented in the form of relation between transmural pressure and intraarterial cross-section.
Dynamic tube laws of brachial arteries are non-invasively measured in patient with 13 hypertension, 15 cardiopathy and in 15 normal subjects. 6 characteristic variables of the dynamic tube law for all subjects are calculated and are compared. Intraarterial cross-section at 80 mmHg transmural pressure of normal group is positively correlated to subject's age. Dynamic elasticity at 80 mmHg transmural pressure is positively correlated to subject's age and its values in hypertensive group are slightly higher than other groups. And normalized intraarterial cross-section at 0 mmHg and transmural pressure where an artery shows maximum compliance are negatively correlated to age. The relation to age in dynamic elasticity at transmural pressure of maximum compliance is different from that at 80 mmHg. And on several variables some kind of differences are found in age groups before and after 40's.
It is concluded that some elastic properties of artery change with aging and hypertension can be found in non-invasively measured dynamic tube law.

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We measured the ultrasonic velocity V and the density ρ with varying the irradiation distance L at 37°C as well as the depth of cure D_c, and determined the longitudinal elastic modulus M (=ρV²) for four light-cured composite resins of Espio LC (EL) and Graft LC (GL) in GC Co., Silux Plus (SP) in 3M Co., and Palfique Light (PL) in Tokuyama Soda Co. ρ, V and M were most dependent upon L near D_c. Averaged ρ's were 2.16 for GL, 1.89 for EL, 1.72 for PL and 1.58g/cm³ for SP in order of filler contents. In the unpolymerized and polymerized resins, M's were roughly 5GPa and 20GPa, respectively.

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