Estudo da ação de desinfetantes sobre a textura de moldes e moldeiras

Abstract

The disinfection of mold is a part of the daily routine in clinicai practice. This should be an efficient procedure without, however, altering the quality of the mold. With the objective of studying three disinfecting Solutions: chlorexidine at 0,5%, glutaraldeid at 2,0% and sodium hypochlorite at 1,0% on aluminum trays, alginate molds (Jeltrate) with aluminum trays, chemically activated acrylic resin (CAAR) trays , alginate molds with CAAR trays and zinc oxide and eugenol paste molds (Horus paste), with CAAR trays, techniqu es of UV-visible spectroscopy, atomic absorption spectrophotometry and turbidimetry were used. The sets mold/tray were, for standard comparison, immersed in water for a period of 60 minutes. To verify the action of the disinfectants on the aluminum, the method described by Basset et al. (1981), was used, which utilizes complexometry, permitting spectroscopic accompaniment, a variation of the concentration of the complex, in 535nm. The absorption of the Solutions was measured, in this wavelength after the immersion of the test samples during 10, 30 and 60 minutes. Complementing the tests, these Solutions were also analyzed by the atomic absorption spectrophotometric method. To verify the action of the disinfectant on the sets mold/tray and CAAR, the techniques of spectroscopy in the UV-visible region and turbidimetry were used. The action of the Solutions on the CAAR was verified after immersion, for a period of 60 minutes, of individual trays made of resin. To observe the action on the mold/tray sets the immersion time was 10, 30 and 60 minutes. A total of 135 molds were made from a metal model of maxilla edentulous: for each of the sets 45 test samples were used, 15 for each disinfectant agent and 5 for each immersion time period. The results permit us to conclude that there was no undesirable reaction to chlorexidine at 0,5% and glutaraldeid at 2,0% on the aluminum, on the CAAR and on the Horus paste in the immersion periods tested. Although sodium hypochlorite at 1,0% has shown the best results with Jeltrate and does not have undesirable action on the CAAR and Horus paste, its effect on aluminum is harmful. The clorexidine solution at 1,0% caused pronounced erosion on the Jeltrate trays, even with an immersion time of 10 minutes. This data therefore indicates the non-use of this disinfectant for the disinfection of molds of this commercial brand of alginate. The Solutions of glutaraldeid at 2,0% indicated food compatibility with Jeltrate, presenting insignificant erosion in the time periods analyzed.