Clinical marginal and internal gaps of In-Ceram crowns fabricated using the GN-I system.

The marginal and internal gaps of ceramic crowns with alumina copings fabricated using a computer-aided design, computer-aided manufacturing system, were evaluated in vivo using silicone materials. Black and white silicone materials were used to record the marginal and internal gaps of 82 In-Ceram crowns before final cementation. The silicone materials were sectioned bucco-lingually and mesio-distally and viewed under a microscope to measure the thickness of the white silicone layer. Sixteen reference points were measured on each specimen. The mean marginal gaps were compared among the anterior, premolar and molar teeth, and the mean gaps at the reference points within the groups were compared by analysis of variance and the Dunnett T3 test. The mean marginal gap was 66.8 mum. There were no differences in marginal gaps among the three groups. In all the groups, the marginal gaps were the smallest, whereas the occlusal gaps were the largest. The mean marginal gaps of the In-Ceram crowns with the alumina copings fabricated using the GN-I system were within the range of clinically acceptable values.

Clinical marginal and internal gaps of Procera AllCeram crowns.

This study evaluated the marginal and internal gaps of Procera AllCeram crowns in vivo using silicone materials. Ninety Procera AllCeram crowns were evaluated before final cementation. White and black silicone materials were used to record the marginal and internal fit; then the crowns were sectioned bucco-lingually and mesio-distally to measure the thickness of the silicone layer using a microscope. Sixteen reference points were measured on each specimen. Mean marginal gaps among anterior, premolar and molar teeth, and mean gaps at the reference points within the groups were compared by analysis of variance and Dunnett T3 test. The mean values at the margins were the smallest in all tooth groups, whereas those at the rounded slope of the chamfer were the largest. There were significant differences (P < 0.001) in the mean gaps at the four reference points (margin, rounded slope of the chamfer, axial wall and occlusal surface) in each group, except for the molar teeth. The mean marginal gaps of the Procera AllCeram crowns were within the range of clinical acceptance.

Anti-pressor effect of a Chinese-Japanese herbal medicine, saiko-ka-ryukotsu-borei-to on hemodynamics in rabbits.

Saiko-ka-ryukotsu-borei-to (TJ-12) is a traditional Chinese-Japanese medicinal mixture clinically used for the treatment of hypertension and/or atherosclerosis concurrent with neurotic disorders. Study on the effect of TJ-12 on the vasoconstriction of cutaneous arterioles induced by nor-adrenaline (NA) was carried out using a rabbit ear chamber (REC) under conscious conditions. Before and after oral administration of TJ-12 everyday for 2 weeks, the same position of an arteriole within a REC was analyzed using an image shearing monitor every minute up to 15 min after varying doses (0.3, 1.0, 3.0 and 10.0 micrograms/kg i.v.) of NA. The changes of mean arteriolar diameter and vasomotion amplitude, before and after feeding of TJ-12 (1% w/w) supplemented diet were compared in the same position. Consequently, the pretreatment with TJ-12 significantly attenuated the changes of mean diameter of NA-induced vasoconstriction and also shortened its duration. In addition, concurrent with its cutaneous microcirculatory response, the pretreatment with TJ-12 systemically suppressed the increase of blood pressure under NA-induced vasoconstriction. These results suggest that the anti-pressor effect of TJ-12 might be apparently attributable to the inhibition of NA-induced vasoconstriction.

Vasodilator effects of cepharanthine, a biscoclaurine alkaloid, on cutaneous microcirculation in the rabbit.

Cutaneous microcirculatory responses to intravenous administration of cepharanthine (CT), a biscoclaurine alkaloid, isolated from Stephania cepharantha, were studied in a transparent round chamber installed in a rabbit ear, under conscious conditions. Vital-microscopic observations were made visually with a microscope-closed TV system and microphotoelectric plethysmography. Following the CT administration in doses of 1.0 and 3.0 mg/kg, an enhancement of rhythmic perfusion of microvascular blood due to vasomotion was developed for a period of 1 h or longer, although no appreciable change was observed following CT administration at 10.0 mg/kg. The microvascular dilator effect of CT appeared to have no direct association with systemic hemodynamics, based on the additional measurements of heart rate, blood pressure, carotid blood flow and auricular arterial blood flow.

Effects of acupuncture needle application upon cutaneous microcirculation of rabbit ear lobe.

Microcirculatory effects of the application of an acupuncture needle (32-gauge, silver) to the back, corresponding to Geshu (B17) in human beings, were studied in vivo by microscope, using a transparent ear chamber in conscious rabbits. Although no striking findings were obtained during the needle application for a period of 30 minutes, it was clearly observed that the microvascular blood flow increases gradually in parallel with augmenting spontaneous rhythmic fluctuation of the vessel diameter, namely vasomotion, throughout a continuous observation period longer than 2 hours following release from the needle application. Diameters of arterioles and venules at the full-dilating phases of vasomotion reached levels higher than 200% and 250% of the initial values just before application of the needle, respectively. The clinical efficacy of acupuncture was suggested to be explained at least in part by the increased rhythmic microvascular blood flow in parallel with vasomotion, from the physiological point of view based on the previous investigations.