Dentin demineralization of over 5 µm is not of much value to the clinical procedure, and may result from longer exposure of dentin to the acid. An increase in the demineralized dentin layer will not guarantee the formation of a thicker hybrid layer and a better bond, as the primer/adhesive may not have the capacity to infiltrate throughout its entire thickness, causing exposure of the collagen within and at the base of the hybrid layer, which could lead to degradation and leakage. The greater the flow of adhesive between the collagen fibrils and through the complex of demineralized channels, the better will be the quality of the hybrid layer, giving it a higher degree of resistance to hydrolysis and offering greater protection against microleakage (4,43).