Citric acid demineralization of cementum and dentin: the effect of the storage medium

The purpose of this study was to see if the root surface topography of teeth, stored in saline and subsequently treated with citric acid, differred from the root surface topography of teeth that were treated immediately upon extraction, 12 freshly extracted adult human permanent teeth, with proximal surfaces free of caries and periodontal disease, were treated in succession. The crowns were removed at the level of periodontal attachment, the teeth sectioned buccal-lingually and a treatment area deligniated on each proximal section. The treatment area of 6 teeth was root planed to expose dentin (D) and scaled to remove adherent tissue and leave a cementum surfaces (C) on the other 6 teeth. A coronal-apical groove down the middle of the treatment area divided it into approximately equal parts or experimental regions. One proximal section of each tooth was placed in physiologic saline (S) and treated after 6 weeks of storage while the other proximal section was freshly treated (F). Treatment consisted of applying a 30% citric acid (CA) solution (pH = 1.60) for 5 min. Cotton pellets soaked in the citric acid solution were placed (P) on one half of the experimental area and heavily burnished (B) on the other half. Treatment areas were subsequently prepared for scanning electron microscopy analysis. Assessment was made of (i) the % of surface area tufted, (ii) fibril tufting depth (0.3) and (iii) fibril tufting density (1.3). Similarities were found in the data for both storage methods (F and S) across each application technique (P or B) and each tooth surface (D or C) with respect to the (i) % area tufted and (ii) frequency distribution of tufting depth scores. As for the application techniques, the data for burnishing was greater than placed across each storage method (F or S) and each tooth surface (D or C) for the same two parameters. The results of the study indicated that 6-week physiologic saline storage does not affect root surface demineralization by citric acid, as assessed by SEM.