In situ effect of sodium fluoride or titanium tetrafluoride varnish and solution on carious demineralization of enamel

This study evaluated the effect of titanium tetrafluoride (TiF4) formulations on enamel carious demineralization in situ. Thirteen subjects took part in this cross-over, split-mouth, double-blind study performed in three phases of 14 d each. In each subject, two sound and two predemineralized specimens of bovine enamel were worn intra-orally and plaque accumulation was allowed. One sound and one predemineralized specimen in each subject was treated once with sodium fluoride (NaF) varnish or solution (Treatment A); TiF4 varnish or solution (Treatment B); or placebo varnish or no treatment (Treatment C). The initially sound enamel specimens were exposed to severe cariogenic challenge (20% sucrose, eight times daily for 5 min each time), whereas the predemineralized specimens were not. Eleven subjects were able to finish all experimental phases. The enamel alterations were quantified by surface hardness and transversal microradiography. Demineralization of previously sound enamel was reduced by all test formulations except for the NaF solution, while both TiF4 formulations were as effective as NaF varnish. For the predemineralized specimens, enamel surface hardness was increased only by TiF4 formulations, while subsurface mineral remineralization could not be seen in any group. Within the experimental protocol, TiF4 was able to decrease enamel demineralization to a similar degree as NaF varnish under severe cariogenic challenges, while only TiF4 formulations remineralized the enamel surface.

MAXIMAL PSEUDOCOMPACT AND MAXIMAL R-CLOSED SPACES

In this paper a space X is pseudocompact if it is Tychonoff and every real-valued continuous function on X is bounded. We obtain conditions under which a Tychonoff space is maximal pseudocompact and study conditions under which a regular space is maximal R-closed.

Effect of NaF and TiF4 varnish and solution on bovine dentin erosion plus abrasion in vitro

Objectives. This in vitro study aimed to analyze the effect of TiF4 compared to NaF varnishes and solutions, to protect against dentin erosion associated with abrasion. Materials and methods. Bovine dentin specimens were pre-treated with NaF-Duraphat (2.26% F), NaF/CaF2-Duofluorid (5.63% F), experimental-NaF (2.45% F), experimental-TiF4 (2.45% F) and placebo varnishes; NaF (2.26% F) and TiF4 (2.45% F) solutions. Controls remained untreated. The erosive pH cycling was performed using a soft drink (pH 2.6) 4 x 90 s/day and the toothbrushing-abrasion 2 x 10 s/day, in vitro for 5 days. Between the challenges, the specimens were exposed to artificial saliva. Dentin tissue loss was measured profilometrically (mu m). Results. ANOVA/Tukey's test showed that all fluoridated varnishes (Duraphat, 7.5 +/- 1.1; Duofluorid, 6.8 +/- 1.1; NaF, 7.2 +/- 1.9; TiF4, 6.5 +/- 1.0) were able to significantly reduce dentin tissue loss (40.7% reduction compared to control) when compared to placebo varnish (11.2 +/- 1.3), control (11.8 +/- 1.7) and fluoridated (NaF, 9.9 +/- 1.8; TiF4, 10.3 +/- 2.1) solutions (p < 0.0001), which in turn did not significantly differ from each other. Conclusion. All fluoridated varnishes, but not the solutions, had a similar performance and a good potential to reduce dentin tissue loss under mild erosive and abrasive conditions in vitro. Risk patients for erosion and abrasion, especially those with exposed dentin, should benefit from this clinical preventive measure. Further research has to confirm this promising result in the clinical situation.

Blood Pressure, Metabolic and Autonomic Responses to Insulin and Intralipid (R) Infusion in Chagasic Patients

Background: Intralipid (R) and heparin infusion results in increased blood pressure and autonomic abnormalities in normal and hypertensive individuals. Objective: To evaluate insulin sensitivity and the impact of Intralipid (R) and heparin (ILH) infusion on hemodynamic, metabolic, and autonomic response in patients with the indeterminate form of Chagas' disease. Methods: Twelve patients with the indeterminate form of Chagas' disease and 12 healthy volunteers were evaluated. Results: Baseline blood pressure and heart rate were similar in both groups. Plasma noradrenaline levels were slightly increased in the Chagas' group. After insulin tolerance testing (ITT), a significant decline was noted in glucose in both groups. ILH infusion resulted in increased blood pressure in both groups, but there was no significant change in plasma noradrenaline. The low-frequency component (LF) was similar and similarly increased in both groups. The high-frequency component (HF) was lower in the Chagas' group. Conclusion: Patients with the indeterminate form of Chagas' disease had increased sympathetic activity at baseline and impaired response to insulin. They also had a lower high-frequency component and impaired baroreflex sensitivity at baseline and during Intralipid (R) and heparin infusion. (Arq Bras Cardiol 2012;98(3):225-233)

The antinociceptive effect of electroacupuncture at different depths of acupoints and under the needling surface

Background The stimulation of acupoints along the meridians, but not the non-acupoints outside of the meridians, produces analgesia. Although the acupoint is defined at the body surface, the exact location of the acupoints is not known. This study aims to examine whether the intensity and duration of the analgesic effect of electroacupuncture (EA) at the Zusanli (ST36) and Sanynjiao acupoints (SP6) change according to the depth of the stimulation. Methods Ninety-six male Wistar rats classified as responders were arbitrarily allocated into 16 groups of six rats each. Six groups received EA with uninsulated acupuncture needles (type I) or needles that were immersed in varnish and had the varnish circularly peeled 0.2 mm from the tip (type II), 0.2 mm at 3 mm (type III) or 5 mm (type IV) from the tip, or 0.2 mm at 5 and 1 mm from the tip (type V), or EA sham for 20 min. Five groups received injection of formalin into the acupoint bilaterally at 5 mm or 1 mm deep into ST36, 5 mm below ST36 but inserting the needle at 45° to the skin surface, or 5 mm deep into non-acupoints. The remaining groups received intraplantar injection of saline, 1% or 2.5% formalin. The analgesic effects were measured by the rat tail-flick test. Results The bilateral stimulation of ST36 and SP6 by uninsulated or insulated needles produced analgesia in the rat tail-flick test. The stronger and longer lasting effects occurred after EA with the types I and V needles, or injection of formalin 5 mm deep into ST36. The remaining needles produced weaker and shorter lasting effects. Slow analgesic effect also occurred after formalin injection at 1 mm or 5 mm below ST36 by inserting the needle at 45° to the skin surface. Conclusion The experimental results suggest that the efficacy of the EA stimulation depends on the spatial distribution of the current density under the needling surface rather than only the acupoint or the depth of needling.