Degradação de condicionadores teciduais em próteses totais: estudo in situ

• Autor(a) principal: Elsemann, Rogério Brasiliense
• Data de Publicação: 2007
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional PUCRS
• Texto Completo: http://hdl.handle.net/10923/372
• topic: ODONTOLOGIA; PRÓTESE DENTÁRIA; PATOLOGIA BUCAL; RESISTÊNCIA DOS MATERIAIS (ODONTOLOGIA)

This in situ study evaluated the degradation of tissue conditioners as a function of the timespan of clinical use measuring the variables Shore A hardness and quantity of plasticizer phthalate. The three tissue conditioners evaluated were Coe-Comfort, Dura Conditioner, and Softone. The materials were prepared according to each manufacturer’s instructions and inserted into grooves (5x15x2 mm) made in the palatal inner surface of maxillary complete dentures of nine patients at the FO-PUCRS Complete Dentures Clinics. These patients were selected following the inclusion and exclusion criteria and used their dentures during the evaluation period. Data collection was performed at baseline and 3, 7, and 14 days after the insertion of the materials into the dentures grooves. Shore A hardness was recorded by using an analogical Shore A durometer. The quantity of plasticizer phthalate was measured by means of infrared spectroscopy. One specimen of each material was randomly chosen at each test-time for observation of surface topography in scanning electron microscope. Data were analyzed by ANOVA for repeated measures followed by Tukey test, and by simple linear regression, at the 5% significance level.All tested tissue conditioners showed decrease of quantity of phthalate and increase of hardness over time. The overall degradation was similar for all tissue conditioners but the pattern of phthalate lixiviation and of hardness alteration was material-specific. The largest changes of phthalate concentration and Shore A hardness of the tested tissue conditioners occurred in the first three days of clinical use. Comparing baseline and day 3 data, Coe-Comfort showed 25% decrease of initial phthalate concentration, which was statistically different from the other materials with reduction of 50%. No significant alteration of phthalate concentration was detected between days 3 and 7. The quantity of plasticizer in the material is inversely related to the hardness of the tissue conditioner.