Apatite crystal protection against acid-attack beneath resin-dentin interface with four adhesives: TEM and crystallography evidence. Dent Mater. 2012 May 7; Authors: Nurrohman H, Nikaido T, Takagaki T, Sadr A, Ichinose S, Tagami J Abstract OBJECTIVES: Interaction between specific functional groups and apatite crystals may contribute to adhesion. The present study investigated effects of four adhesives …