الفهرس 
Introduction…Only 14 pages are availabe for public view
 |  | from | 111 |  |  |
| | | from | 111 | | |
Abstract
The aim of this study was to evaluate the effect of remnants of three different forms of calcium hydroxide within the root canal on pH of root canal dentin and the apical leakage of two resin based sealers.
A total of 120 human single-rooted teeth were used in this study. Teeth were decoronated, cleaned and shaped using crown down technique. Samples were divided into four equal groups (40 teeth each)according to the CaOH2 delivery system (group I; CaOH2 powder, group II; CaOH2cones, group III; Injectable CaOH2 and group IV; without CaOH2). Each group was further subdivided into 3 subgroups (10 teeth each) (subgroup A; pH measurement, subgroup B; AH plus sealer and subgroup C; Real Seal SE sealer)
Two teeth were used as negative controls and other two teeth were used as positive control samples for leakage study. The amount of leakage was evaluated using fluid filtration method and nine teeth were evaluated using SEM.
Results showed that CaOH2 type, sealer type, time and their interactions had significant effect on the leakage. AH plus sealer showed significantly lower leakage values than that of the Real Seal SE. Control group (without CaOH2) showed the lowest leakage value while powder form showed the highest values. Leakage was decreased significantly with time.
Conclusion:
Under the condition of the present study, it was concluded that:
1. The sealing ability of resin-based sealers is directly affected by the presence of CaOH2 remnants on the dentinal walls .
2. The sealing ability of resin-based sealer is improved by time.
3. RealSeal SE is greatly affected by the presence of remnants of CaOH2.
Recommendations:
1. Further investigations for the effect of CaOH2 on long term sealing ability of resin based sealers.
2. Further studies can be employed to improve CaOH2 removal.