Objective: This study aimed to evaluate comparatively the effect of two different natural irrigations (Aloe vera and Propolis), as root canal irrigants on root canal dentin microhardness
Materials and methods: Thirty extracted human single rooted premolar teeth were selected. Decoronation was done to standardize the length at 16 mm. The samples were divided to three equal groups according to the type of irrigant used (n = 10); Group I (90% Aloe vera), Group II (4% propolis) and Group III (2.6% NaOCl). The roots were split longitudinally into two halves. Both halves of each sample were embedded in autopolymerized acrylic resin. One half of each sample was considered as control for its other experimental half. An equal volume of 2 ml of each solution was used for 5 minutes. The microhardness was measured at three different points for each sample on the cervical, middle and apical level with a Vickers indenter under a 200-g load and a 15-second dwell time. We calculated the decrease in microhardness as a percentage.
Results: The highest microhardness percentage change (%) was found in samples irrigated by 4% Propolis followed by 2.6% NaOCl samples while the lowest value was found with 90% Aloe vera. Post hoc pairwise comparisons showed there was a significant difference between all groups (p < 0.001).
Conclusion: 90% Aloe vera as root canal irrigant improved dentin microhardness, while both 4% propolis and 2.6% NaOCl decreased microhardness of root canal dentin.