Autor(es): Pacheco, Filipe Gaudêncio
Data: 2016
Identificador Persistente: http://hdl.handle.net/10451/26149
Origem: Repositório da Universidade de Lisboa
Assunto(s): Materiais dentários; Resinas acrílicas; Clorexidina; Teses de mestrado - 2016; Domínio/Área Científica::Ciências Médicas::Medicina Clínica
Tese de mestrado, Medicina Dentária, Universidade de Lisboa, Faculdade de Medicina Dentária, 2016
The use of controlled-release agents has being studied as therapeutic alternatives for the treatment of denture stomatitis. The main purpose of this study was to evaluate mass variation color stability and drug release of acrylic reline resins loaded with chlorhexidine after thermal aging. Three different materials were evaluated in the present study, Kooliner, Ufi Gel Hard and Probase Cold. For each, one control group and four experimental groups with chlorhexidine (2.5%, 5%, 7.5% and 10% (w/w)) were produced. A total of 45 cylindershaped specimens were evaluated. Mass was calculated using a precision scale and color was evaluated using a spectrophotometer. These measurements were made before and after a thermocycling aging procedure of 1000 cycles of thermal fluctuations between 5ºC and 55ºC (20 seconds each bath). After that, the cylinders were stored individually in graduated falcon tubes and covered with saliva at pH=7. The falcons were then placed into an incubator and, at specific time intervals, an aliquot were collected from each falcon and the same amount of artificial saliva was renovated, in order to simulate the constant salivary renovation. The samples were analyzed by UVspectroscopy and chlorhexidine content was determined. Data were submitted to nonparametric tests according to Mann-Whitney and Kruskall Wallis methods (p<0.05). Results showed that thermocycling caused variationsin mass in all the materials. For Ufigel and Kooliner specimens, chlorhexidine incorporation caused a mass decrease when compared to control. However, clorhexidine incorporation didn’t affect mass variation on Probase Cold. It was also observed that thermocycling caused color variation in all the specimens but chlorhexidine incorporation didn’t affect the color stability. Color variation was higher in Probase Cold followed by Ufi Gel Hard and Kooliner. after thermocycling, it was perceived that only Probase Cold released chlorhexidine whose quantification was superior to 0.6 μg/mL (minimum detectable capacity of the technique used). Overall, results indicate that chlorhexidine delivery systems based on acrylic reline resins are a potential approach in the treatment of denture stomatitis.
