EFFECT OF SODIUM HYPOCHLORITE AND CITRIC ACID IRRIGATION, INDIVIDUALLY AND IN ALTERNATION, ON DENTIN MICROHARDNESS AT THE FURCATION AREA OF MANDIBULAR MOLARS.

Aims: Aim of the study was to evaluate the effect of irrigation regimens on dentin microhardness at the furcation area of
mandibular molars, using sodium hypochlorite and citric acid individually and in alternation. Methods and Material:
Twenty mandibular molars were used in the study. The occlusal surface was removed and the pulp chamber was exposed. The roots were cut
transversally 5 mm below the cementoenamel junction, to produce 20 tooth blocks. The apical opening of canal was sealed with composite resin
and the pulp chamber access was left open. The tooth blocks were embedded in self-curing, fast setting acrylic resin. The tooth block sets were
distributed into 4 groups of 5 specimens each, according to the irrigation regimens: 3 % NaOCl, 10% citric acid, 3 % NaOCl + 10% citric acid and
distilled water (control). After the irrigation treatment, the tooth sets were bisected longitudinally in a mesiodistal direction and the Knoop
microhardness of dentin at the furcation area was evaluated. The results of t Results: his study indicated that all irrigation solutions, except for
distilled water (control), decreased dentin microhardness. Citric acid showed a signicant difference when compared to NaOCl, and Citric acid+
NaOCl showed a maximum decrease in microhardness. From the results of the pre Conclusions: sent study, it may be concluded that 10% Citric
acid, alone or in combination with 3% NaOCl signicantly reduced the dentin microhardness at the furcation area in mandibular molars.