Comparison of penetrating depth of chlorhexidine and chitosan into dentinal tubules with and without the effect of ultrasonic irrigation.

Background: Long term success of root canal treatment depends on complete removal of micro-organisms and their by-products. This can be effectively achieved by the ability of the irrigant to penetrate into the dentinal tubules, which is limited in the conventional mechanical debridement of the root canal system. Irrigant activation technique aids in movement of irrigants into the dentinal tubules. Aim: To compare the depth of penetration of root canal irrigants into the dentinal tubules with and without ultrasonics using light microscope. Materials and Methods: Forty noncarious mandibular premolars were used, all the tooth specimens were inoculated with an ATCC 29212 strain of E.faecalis and incubated under nutrient rich aerobic conditions at 37°C. Teeth were sectioned below the cementoenamel junction to obtain a standard length of 8 mm and instrumented with K-files, irrigated with 5.25% sodium hypochlorite and a final rinse of 17% EDTA. Teeth were divided into four groups of ten each. Group IA was irrigated with 2% Chlorhexidine (CHX) and agitated ultrasonically, Group IB was irrigated with 2% Chlorhexidine, Group IC was irrigated with 2% Chitosan and ultrasonically agitated, Group ID was irrigated with 2 % Chitosan. The tooth specimens were sectioned and subjected to gram staining and viewed under 100X oil immersion microscope. A micrometer grid was attached to the eyepiece to enable measurement of the depth of penetration of the irrigants. Group IA (2% Chlorhexidine with ultrasonic agitation) showed better penetration into the dentinal tubules as compared to Groups IB, IC, ID. Results: Irrigation with 2% Chlorhexidine with ultrasonic agitation had depth of penetration into the dentinal tubules upto 2350 μm. 2% Chlorhexidine without ultrasonic agitation penetrated upto 1800 μm. Chitosan with ultrasonic agitation penetrated upto1250 μm and Chitosan without ultrasonic agitation penetrated upto 44.80 μm. Conclusion: 2% Chlorexidine as irrigant with ultrasonic agitation was found to have maximum depth of penetration into the dentinal tubules when compared with Chitosan.