As técnicas adesivas permitiram inovações nos tratamentos restauradores da atualidade. Este estudo investigou a qualidade de união de diferentes sistemas adesivos ao substrato dentinário afetado e infectado por cárie, através de testes de microtração e microscopia eletrônica de transmissão e varredura (MET). Os resultados sugerem que a resina adesiva pôde infiltrar na dentina infectada e envolver as bactérias na camada híbrida. Esse conceito de controle da cárie foi denominado de "Restauração-Selante Modificada" (RSM). Por outro lado, a empresa Kuraray Med. Inc .(Japão) desenvolveu um sistema adesivo com propriedades anti-bacterianas (ABF), o qual é comercializado nos EUA como Protect Bond. Para avaliar a efetividade do sistema ABF sobre cáries radiculares, empregou-se testes de resistência adesiva e análise por microscopia eletrônica. O sistema ABF foi capaz de formar uma estrutura interfacial semelhante à camada híbrida, através da infiltração na superfície da dentina cariada radicular e os valores de resistência de união foram em média de 23 MPa. Os achados sugerem que a combinação da técnica RSM com o sistema ABF parece ser uma alternativa para o emprego da terapia de mínima invasão em cáries radiculares.

Hybridized dentin permits dental treatments that were previously impossible with conventional techniques, opening new frontiers in modern adhesive dentistry. We have investigated the adhesive property of current bonding systems to caries-infected dentin by a microtensile bond strength test (µTBS) and transmission electron microscopy (TEM), and suggested that bonding resin could infiltrate into caries-infected dentin partially to embed carious bacteria within hybrid layers. We have named this concept of caries control as modified sealed restoration (MSR). On the other hand, Kuraray Medical Inc. (Tokyo, Japan) has developed an antibacterial adhesive system (ABF, now marketed in USA as Protect Bond). So as to evaluate the effectiveness of ABF on root caries control, we have examine the microtensile bond strengths (µTBS) of ABF to normal versus carious root dentin and the interfacial morphology by a scanning electron microscopy (SEM). ABF could form the hybrid-like structures by infiltrating into the surfaces of the root carious dentin, and the mean value of µTBS of ABF to root carious dentin was 23.0 MPa. These results suggested that MSR combined with ABF might be an advantageous minimal invasive therapy for root caries.

Over the last decade, the classic concept of 3-step bonding to dental tissues has developed rapidly to more user-friendly, simplified adhesive systems. These comprise the total-etch 2 step, self-etch 2step and the self-etch "all-in-one" adhesives. These adhesives carry along with simplicity some characteristics that are relevant to their efficacy in providing long-lasting bond stability. They share with the glass ionomer cements a class of materials that have high affinity for water. Such hydrophilicity renders such adhesives very permeable and denies their ability to hermetically seal dentin surfaces. Additionally, the water flux across simplified adhesives may compromise bonding in certain circumstances and their durability in the oral environment. This paper presents evidences of the water transport across simplified adhesive systems and glass ionomer cements and relates them with clinical implications of the phenomenon.

Este trabalho focaliza os aspectos que podem afetar a permeabilidade de resinas adesivas na matriz de dentina desmineralizada durante o desenvolvimento do processo adesivo. Os efeitos da umidade de superfície, respectivamente aos sistemas adesivos e aos problemas relacionados com a formação incompleta da camada híbrida são apresentados.

This paper has focused on the factors that may affect the permeability of adhesive resins into the demineralized dentin matrix during the development of the bonding process. The effects of surface moisture are discussed respectively to the adhesive systems, and the problems related to incomplete hybrid layer formation presented.