EFFECT OF DIFFERENT IRRIGATING SOLUTIONS AND MECHANICAL AIDS ON THE REMOVAL OF CALCIUM HYDROXIDE INTRA-CANAL MEDICATION FROM STRAIGHT AND CURVED CANALS

aim: to study effect of different irrigating solutions and mechanical aids on Ca(OH)2 removal from straight and curved canals.
 
materials and methods: Forty five maxillary central incisors with straight roots (group I) were prepared with step back technique until apical size 55 and forty five mandibular first molars with curved mesio buccal canals (group II) prepared with Pro Taper universal system up to apical size F2. Calcium hydroxide was applied into all canals and the accesses were sealed with temporary dressing. All teeth were placed in wax mould and digital radiographs were taken to confirm canal filling with Ca(OH)2 to length. Every group was subdivided into 3 subgroups according to the irrigating solution used; subgroup A irrigated with 5.25% NaOCl only, subgroup B irrigated with 5.25% NaOCl and 10% H2O2, and subgroup C irrigated with 5.25% NaOCl and 17% EDTA. Every subgroup was further subdivided into 3 subgroups (1, 2, and 3) according to the mechanical aid for Ca(OH)2 removal; in subgroup 1 used master apical file, in subgroup 2 used master apical file and apical patency, in subgroup 3 used master apical file, apical patency and increase in canal size. Post removal digital radiographs were taken for all teeth in their wax mould. Any traces of Ca(OH)2 were traced by “Image J” software and estimated as a percentage to the total canal space and statistically analyzed.
results: There was no significant difference between the subgroups A, B, and C in anterior and posterior teeth either in subgroup 1, 2, or 3. In anterior teeth group, there were significant differences between subgroups 1, 2, and 3 in subgroup B and C but, in subgroup A, there was no significant difference. In posterior teeth group, there was a significant difference between subgroups 1, 2, and 3. in subgroup A but, in subgroup B and C, there was no significant difference. Anterior and posterior teeth were compared and the results were significant differences in subgroups A1 and A2 but, in subgroup A3 there was no significant difference. In subgroup B, there were significant differences in subgroups B1, B2 and B3. In subgroup C, there was no significant difference in subgroups C1, C2 and C3.
 
conclusions: Under the tested conditions of this study, the most successful method of Ca(OH)2 removal was the use of master apical file (hand or rotary), apical patency and increase one size filing with the combination of EDTA and NaOCl irrigation in both anterior & posterior teeth.