Comparison of micro-leakage around temporary restorative materials placed in complex endodontic access cavities: An in-vitro study

Objective: To compare mean micro-leakage around 3 types of temporary restorative materials in-vitro, when placed adjacent to permanent restorations (amalgam) in complex endodontic access cavities. Study Design: Randomized controlled trial. Place and Duration of Study: Dental Clinics, Dental Laboratory and Research Laboratory at The Aga Khan University Hospital, Karachi, from January to June 2014. Methodology: After random allocation of 60 teeth into 3 experimental groups, each group had conventional class II cavities prepared and amalgam placed. After 14 days, endodontic access cavities were made in these teeth, followed by placement of Cavit, IRM and CLIP (depth of 4 mm each). After thermo-cycling and immersion in 0.5% methylene blue dye, the teeth were sectioned mesio-distally and observed under stereoscopic microscope (magnification x4) along 2 interfaces 'a' and 'b' (tooth-temporary restoration and temporary restoration-primary restoration), respectively. Depth of dye penetration was measured in millimeters. Results: IRM was leakiest at interface 'a', cavit had highest dye penetration at interface 'b', while CLIP exhibited least micro-leakage at 'a' and 'b'. The mean dye penetration for Cavit was 0.80 ±0.23 mm at 'a', and 2.24 ±0.48 mm at 'b'. For IRM, it was 1.82 ±0.09 mm at 'a', and 0.44 ±0.13 mm at 'b'. For CLIP, the mean dye penetration was 0.43 ±0.05 mm at 'a', and 0.32 ±0.12 mm at 'b'. The difference in dye penetration observed between the 3 groups at both interfaces was statistically significant. Conclusion: In a complex access cavity made adjacent to a pre-existing amalgam restoration, CLIP exhibits the least micro-leakage, followed by IRM and Cavit.