title: The extension of resin tags in etched dentin: a misinterpretation?
abstract: OBJECTIVE
  The morphological characteristics of the filament structure, universally recognized as resin tags, in samples prepared using a new SEM methodology, are analyzed .
  
  
  METHODS
  Ten non-carious, human third molars were cut transversally to obtain 10 dentinal surfaces. They were filled using an adhesive restorative technique. Subsequently, the samples were cut lengthwise to be SEM observed, and then randomly divided into 6 main groups according to the preparation modality of the section surface: Group A: EDTA; Group B: H(3)PO(4); Group C1: H(3)PO(4)+NaOCl; Group C2 H(3)PO(4)+NaOCl+H(2)O(2); Group D1: HCl+NaOCl; Group D2: HCl+NaOCl+H(2)O(2).
  
  
  RESULTS
  The resin tags which originate from resin penetration and polymerization within the dentinal tubules are small conic-trunk shaped plugs that are a few microns long. The thinner extension of the resin tags is probably due to the persistence of the lamina limitans.
  
  
  CONCLUSIONS
  A new method of specimen preparation for SEM visualization is proposed in order to effectively evaluate the penetration capacity of the adhesive in the dentinal substratum. In addition to the use of strong acids and bases, an agent capable of degrading the glycosaminoglycans was employed to completely remove the dentinal organic component.
authors.affiliation: Department of Odontostomatology, University of Florence, Florence, Italy. l.giachetti@odonto.unifi.it
authors.forename: L
authors.initials: L
authors.lastname: Giachetti
authors.forename: F
authors.initials: F
authors.lastname: Bertini
authors.forename: D
authors.initials: D
authors.lastname: Scaminaci Russo
authors.forename: I
authors.initials: I
authors.lastname: Rubino
mesh_terms: D000134:Acid Etching, Dental; D016477:Artifacts; D003094:Collagen / Q000648:ultrastructure; D003188:Composite Resins / Q000032:analysis*; D045662:Dental Etching; D003804:Dentin / Q000187:drug effects / Q000648:ultrastructure*; D004492:Edetic Acid / Q000494:pharmacology; D005557:Formaldehyde; D006801:Humans; D006851:Hydrochloric Acid / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000494:pharmacology; D066298:In Vitro Techniques; D008855:Microscopy, Electron, Scanning / Q000379:methods*; D008964:Molar, Third / Q000187:drug effects / Q000648:ultrastructure*; D010756:Phosphoric Acids / Q000494:pharmacology; D011108:Polymers; D011309:Preservation, Biological; D011897:Random Allocation; D012973:Sodium Hypochlorite / Q000494:pharmacology; D013048:Specimen Handling / Q000379:methods*
chemical_list: D003188:Composite Resins; D010756:Phosphoric Acids; D011108:Polymers; D005557:Formaldehyde; D003094:Collagen; D004492:Edetic Acid; D006861:Hydrogen Peroxide; D012973:Sodium Hypochlorite; C030242:phosphoric acid; D006851:Hydrochloric Acid