Root surface texture and early cell and tissue colonization after different etching modalities

The purpose of the present study was to compare the texture of dentin surfaces after etching with citric and phosphoric acids as well as EDTA with respect to mode of application and exposure time, and to assess possible effects on early cell and tissue colonization. It was concluded that EDTA operating at neutral pH was able to selectively remove mineral from a dentin surface, exposing a collagenous matrix. This was in contrast to etching with citric and phosphoric acids, both of which operate at a low pH. They both appeared to remove not only the mineral component but also the collagenous matrix. EDTA-treated dentin surfaces, compared to surfaces etched at low pH, appeared to be more inviting for cellular colonization and subsequent connective tissue formation. The reason for this may have been twofold: Dentin surfaces etched with an etching agent operating at neutral pH, as indicated above, retain more exposed collagen fibers than dentin surfaces etched at low pH. Furthermore, it can not be excluded that a low pH etching agent necrotized an area of the periodontal ligament in the immediate vicinity of the denuded dentin surfaces.