Removal Efficiency of Calcium Hydroxide Dressing from the Root Canal without Chemically Active Adjuvant

ABSTRACT Aim Compare the efficiency in removing two calcium hydroxide [Ca(OH)2] preparations from root canal and apical third using single use syringe, ultrasonics and RinsEndo® with saline solution. Materials and methods One hundred and eighty human singlerooted teeth were instrumented using ProTaper® rotary system, divided into two groups according to Ca(OH)2 filling. A: Powder mixed with water, B: Pulpdent®. Each group was divided into three subgroups for the irrigation: A1, B1: Single use syringe; A2, B2: Ultrasonics; A3, B3: RinsEndo®. Teeth were split longitudinally, photographed and imported into Adobe Photoshop. The percentage ratios of Ca(OH)2 remaining in the canal and in the apical third were calculated. Data were statistically analyzed using ‘ANOVA two-way’ and ‘univariate tests’. Results (a) Remnants of medicament were found in all teeth, (b) no statistically significant difference in the elimination of both Ca(OH)2 from the entire canal (p = 0.436), however, mixed powder was better eliminated from the apical third (p = 0.005), (c) no statistically significant difference among the irrigation techniques in the whole canal (p = 0.608), though, RinsEndo® and ultrasonics were the most effective in cleaning the apical third (p = 0.032) when mixed powder was used. Conclusion None of the techniques removed completely Ca(OH)2 from the canal. In the apical third, RinsEndo® and ultrasonics were the most effective when mixed powder was used. Clinical significance Ca(OH)2, the most commonly used intracanal dressing, should be completely eliminated before the obturation to assure a good endodontic sealing. Based on the results of this study, RinsEndo® and ultrasonics were the most effective in removal of Ca(OH)2 especially the powder mixed with water presentation. How to cite this article Maalouf L, Zogheib C, Naaman A. Removal Efficiency of Calcium Hydroxide Dressing from the Root Canal without Chemically Active Adjuvant. J Contemp Dent Pract 2013;14(2):188-192.

Discrimination and Attention in Dogs

Two dogs were trained to perform a left-right discrimination task in which depressing a treadle presented a compound visual and auditory stimulus in random order appropriate to one or the other of two distant reinforcement stations. Depression of the appropriate discrimination treadle was reinforced by water presentation. A modified correction procedure was used in training. Following acquisition, probe test trials consisting of the visual stimulus component alone, the auditory stimulus component alone, and reversed or cues-opposed compound stimulus were presented. Test trials demonstrated the visual component of the compound stimulus to have acquired discriminative control, but the cues-opposed test trials also demonstrated a low but extant degree of discriminative control exerted by the auditory stimulus component. As the compound stimulus employed here consisted of visual components differing only in location and auditory components differing only in pitch, implications for future research manipulating further these qualitative and quantitative variables were discussed.