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Otimização dos parâmetros de um PNTA e sua influência na resistência adesiva à dentina
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Advisor(s)
Abstract(s)
Objetivo: Otimização dos parâmetros de aplicação de um dispositivo de PNTA na dentina. Avaliação da resistência adesiva da interface resina-dentina integrando a aplicação do PNTA previamente a um sistema adesivo universal;
Materiais e Métodos: Foram utilizados 34 molares humanos, dos quais 14 foram utilizados para otimização dos parâmetros do PNTA. Os dentes foram seccionados em discos de dentina de 2 mm e distribuídos em 9 grupos experimentais (n=3), variando a "distância de aplicação do PNTA" (2 mm, 4 mm, 6 mm) e o "tempo de aplicação" (10 s, 20 s, 30 s). O ângulo de contacto entre cada espécime e uma gota de água destilada foi medido antes e depois da exposição ao plasma, através de um goniómetro.
Os 20 dentes restantes foram divididos em dois grupos (n=10), um sem PNTA e outro com aplicação de PNTA previamente ao sistema adesivo Prime&Bond Active. A criação de smear layer foi feita com lixa de carbeto de silício 600. Foram realizadas restaurações com resina composta e os espécimes armazenados a 37 ºC. Após 24 horas, foram testados sob forças de microtração, numa máquina de testes universal. Os resultados foram tratados estatisticamente através do software SPSS.
Resultados: O ângulo de contacto apresentou diferenças estatisticamente significativas entre as condições com e sem plasma (p < 0,001) e entre as distâncias de 4 mm e 6 mm (p = 0,015). Não existiram diferenças significativas em relação ao tempo de aplicação (p >0,05). Quanto à resistência adesiva, não foram encontradas diferenças significativas entre os grupos com e sem PNTA (p > 0,05).
Conclusões: A aplicação do PNTA estudado reduziu o ângulo de contacto na dentina , sendo 10 s e 4 mm distância a condição de aplicação mais vantajosa. No entanto, não demonstrou influenciar na resistência adesiva sob forças de microtração.
Purpose: Optimisation of the application parameters of a NTAP device in dentin. Evaluation of the adhesive strength of the resin-dentin interface by integrating the application of NTAP prior to a universal adhesive system; Materials and Methods: Thirty-four human molars were used, 14 of which were used to optimise the PNTA parameters. The teeth were sectioned into 2 mm dentin discs and distributed into 9 experimental groups (n=3), varying the ‘PNTA application distance’ (2 mm, 4 mm, 6 mm) and the ‘application time’ (10 s, 20 s, 30 s). The contact angle between each specimen and a drop of distilled water was measured before and after exposure to plasma using a goniometer. The remaining 20 teeth were divided into two groups (n=10), one without PNTA and the other with PNTA applied before the Prime&Bond Active adhesive system. The smear layer was created using 600 silicon carbide sandpaper. Restorations were made with composite resin and the specimens were stored at 37ºC. After 24 hours, they were tested under microtensile forces in a universal testing machine. The results were statistically analysed using SPSS software. Results: The contact angle showed statistically significant differences between the conditions with and without plasma (p < 0.001) and between the distances of 4 mm and 6 mm (p = 0.015). There were no significant differences in relation to application time (p >0.05). As for adhesive strength, no significant differences were found between the groups with and without PNTA (p > 0.05). Conclusions: The application of the PNTA studied reduced the contact angle in the dentin, with 10 s and 4 mm distance being the most advantageous application condition. However, it did not prove to influence adhesive strength under microtensile forces.
Purpose: Optimisation of the application parameters of a NTAP device in dentin. Evaluation of the adhesive strength of the resin-dentin interface by integrating the application of NTAP prior to a universal adhesive system; Materials and Methods: Thirty-four human molars were used, 14 of which were used to optimise the PNTA parameters. The teeth were sectioned into 2 mm dentin discs and distributed into 9 experimental groups (n=3), varying the ‘PNTA application distance’ (2 mm, 4 mm, 6 mm) and the ‘application time’ (10 s, 20 s, 30 s). The contact angle between each specimen and a drop of distilled water was measured before and after exposure to plasma using a goniometer. The remaining 20 teeth were divided into two groups (n=10), one without PNTA and the other with PNTA applied before the Prime&Bond Active adhesive system. The smear layer was created using 600 silicon carbide sandpaper. Restorations were made with composite resin and the specimens were stored at 37ºC. After 24 hours, they were tested under microtensile forces in a universal testing machine. The results were statistically analysed using SPSS software. Results: The contact angle showed statistically significant differences between the conditions with and without plasma (p < 0.001) and between the distances of 4 mm and 6 mm (p = 0.015). There were no significant differences in relation to application time (p >0.05). As for adhesive strength, no significant differences were found between the groups with and without PNTA (p > 0.05). Conclusions: The application of the PNTA studied reduced the contact angle in the dentin, with 10 s and 4 mm distance being the most advantageous application condition. However, it did not prove to influence adhesive strength under microtensile forces.
Description
Dissertação para obtenção do grau de Mestre no Instituto Universitário Egas Moniz
Keywords
PNTA Ângulo de contacto Dentina Adesivo universal