Immunocytochemical identification of type I collagen in acid-etched dentin.
The hypothesis tested in this study is that the application of phosphoric acid prevents collagen fibrils (CF) from maintaining their structural morphology, as assessed by their immunochemical antigenicity. Dentin was conditioned with EDTA and with 35% H3PO4 for 15, 30, and 60 s. For a control there was no treatment. A pre-embedding immunohistochemical procedure was evaluated under high-resolution SEM and a postembedding immunolocalization technique was performed on ultrathin sections at TEM level. Conditioning with EDTA resulted in a weaker labeling signal than for dentin conditioned with H3PO4. The most intense labeling was observed after dentin had been etched with H3PO4 for 15 s. The least intensive labeling was evident when the acid was applied for 30 s or for 60 s. A very weak signal was detected on the untreated dentin surface. These results provide evidence that a 15-s application of 35% H3PO4 causes mineral dissolution of the crystals enveloping the superficial CF without damaging the ultrastructure of the CF while longer applications of 35% H3PO4 cause alterations in the CF that decrease their antigenicity.
Breschi
Lorenzo
L
Dipartimento di Scienze Chirurgiche Specialistiche, University of Trieste, Trieste, Italy. lbreschi@biocfarm.unibo.it
Perdigão
Jorge
J
Gobbi
Pietro
P
Mazzotti
Giovanni
G
Falconi
Mirella
M
Lopes
Manuela
M
D000143:Acids; D024042:Collagen Type I / Q000378:metabolism*; D003804:Dentin / Q000378:metabolism* / Q000648:ultrastructure; D006801:Humans; D007150:Immunohistochemistry; D008855:Microscopy, Electron, Scanning
D000143:Acids; D024042:Collagen Type I