Interaction between dentin bonding agents and dentin: from in situ proteolytic activity to mechanical test

• Ano de defesa: 2019
• Autor(a) principal: Giacomini, Marina Ciccone
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: Adesivos dentinários; Camada híbrida; Dentin; Dentin bonding agents; Dentina; Hybrid layer; Inibidores de proteases; Proteases inhibitor
• Link de acesso: http://www.teses.usp.br/teses/disponiveis/25/25148/tde-26082019-181641/

The use of the versatile universal adhesive systems aims to improve adhesion to dentin and simplify the bonding procedure. The association between functional monomer as 10-methacryloyloxydecyl-dihydrogen phosphate (10-MDP) and proteolytic inhibitors seems to be a promising strategy to improve the longevity of hybrid layer. Therefore, this study aimed to evaluate the performance of Adper Single Bond Universal (SU) combined with proteolytic inhibitors, especially chlorhexidine (CHX), in different dentin substrates overtime. In article 1, the interaction between CHX and E-64 with SU (in etch-and-rinse mode) was investigated in sound, artificial carious and eroded dentin over 18 months aging. It was found that carious substrate was the most affected and none of the inhibitors tested were able to maintain stability over 18 months. Furthermore, it was observed that CHX negatively impacted regardless of the substrate, leading to the hypothesis of possible competition between CHX and 10-MDP, since both involve calcium ions in their mechanism of action. For a better comprehension, article 2 purposed the evaluation of proteolytic activity and bonding to dentin tests, focusing on the performance of SU in both modes (etch-and-rinse and self-etching) compared to a conventional MDP-free 2- step adhesive system (Adper Single Bond 2), associated with CHX over 6 months aging. It was observed that proteolytic activity was evidenced when all dentin bonding systems (DBS) was used. SU in self-etching mode showed the highest values of microtensile bond strength. CHX was able to reduce proteolytic activity, regardless of DBS even in 6 months aging. Moreover, CHX did not affect negatively mechanical properties. In conclusion, CHX is capable of reduce proteolytic activity, however it did not provide long lasting up to 18 months.