A morphological comparison of radicular dentin following root planing and treatment with citric acid or tetracycline HCl.

The conditioning of root surfaces with saturated solutions of citric acid or tetracycline is unpredictable in facilitating new attachment, perhaps due to the low pH of these solutions which may be denaturing the organic matrix of the root as well as demineralizing the surface. The purpose of the present study was to compare the effects of a saturated solution of citric acid (pH = 1) with that of a 0.5% solution of tetracycline HCl (pH = 3.2) on radicular dentin with regard to the removal of the smear layer, exposure of dentinal tubule openings, and demineralization of the peritubular dentin. 10 bovine incisors were used in this study. The crowns and apical 1/3 of the root were resected and the resulting root segments were then frozen in icy freon. The cementum was fractured off of the root to produce a fracture-exposed, non-instrumented dentin surface. This fracture-exposed dentin surface was divided into 4 specimens, the 1st being a fracture-exposed, non-instrumented dentin control specimen (FE). After removal of the (FE) specimen from the root segment, the remainder of the fracture-exposed dentin surface was thoroughly root planed and then subdivided into the 3 remaining specimens. One of these specimens served as the root planed dentin surface (RP); another specimen (CA) was immersed in saturated citric acid (pH = 1) for 5 min and then washed in water for 5 min; the final specimen (T) was immersed in a 0.5 mg/ml solution of tetracycline HCl for 5 min and rinsed in water for 5 min.(ABSTRACT TRUNCATED AT 250 WORDS)