Comparative Evaluation of Microleakage of Four Different Retrograde Filling Materials with or without Root End Bevel: An In Vitro Study

Aim: To compare the microleakage of four different root end filling materials with or without root end bevels using dye penetration technique under stereomicroscope. Materials and methods: Subsequent to decontamination and decoronation, 90 human maxillary central incisor were instrumented and obturated with gutta percha using lateral compaction technique. Ten samples were used as control group where no retrograde cavity preparation was done except removal of 3mm of apex at 0 degree bevel and 45 degree bevel in 5 samples each. 40 teeth were apically resected at an angle of 45 degrees and the remaining 40 teeth were subjected to 0 degree resection to the long axis of root. Root end cavities were then prepared to 3 mm depth. The samples were thus divided into nine groups with ten samples each in the eight experimental groups and ten samples in the control group. In each experimental group, root end cavities were filled with one of the following materials: Silver Amalgam, Intermediate Restorative Material (IRM), Mineral Trioxide Aggregate(MTA) and Giomer. Following this, the teeth were stored in incubator for 2 weeks. The samples were coated with nail varnish and after drying were immersed in Indian ink dye for 72 hours. The teeth were then rinsed, sectioned longitudinally and observed under stereomicroscope. The depth of dye penetration was measured in millimetres. Results: The results showed that microleakage was found to be least in case of MTA followed by IRM, Silver Amalgam and Giomer. Regarding the choice of apical preparation of bevel as demonstrated in this study, retrograde preparations without bevel demonstrated less leakage as compared to retrograde preparations with the use of bevel for all the test materials. Conclusion: MTA as root end filling material without bevelling the root end may be considered as a clinical procedure of choice with predictable clinical results.