Abstract

PIRES, Emanuene Galdino et al. Influência do pH de bebidas isotônicas sobre a microdureza de resinas compostaspH influence of isotonic drinks on composite microhardness. Arq. Odontol. [online]. 2015, vol.51, n.3, pp. 123-128. ISSN 1516-0939.

Aim: This experimental and in vitro study aimed to analyze the pH influence of isotonic drinks on composite microhardness. Methods: The assessment of endogenous pH was performed using a pHmeter Tecnaltwo TEC - Meter®. To evaluate microhardness, specimens were made with two different types of compound. For each type of compound seven samples were made according to the storage solution (isotonic drinks of Powerade® and Gatorade® brands with lemon, tangerine, and orange flavors, and distilled water as a control). The microhardness analysis of the samples was performed after a cycle of 21 days of immersion for 1 hour daily, followed by the remaining 23 hours of rest in distilled water. The microhardness tester (Microhardness Tester Fm-700; Futuretech, Tokyo, Japan) was used with a Vickers pyramid diamond indenter, applying a 50 g load for 30 seconds. The data were presented by descriptive statistics and evaluated using ANOVA and paired sample t, with p < 0.05. Results: All of the analyzed beverages showed lower pH levels, which are considered critical to the dissolution of the enamel (pH < 5.5), with the Powerade lemon presenting the lowest pH (2.98). It was observed that the samples that were immersed in isotonic drinks obtained statistically smaller hardness values when compared to the control. Conclusion: All drinks contained an acidic pH and changed the microhardness of the compounds.

Keywords : Hydrogen-ion.; Hardness tests.; Composite resins.; Energy drinks..