Antibacterial Efficacy of Pastes Against E Faecalis in Primary Root Dentin: A Confocal Microscope Study.

OBJECTIVES

Management of abscessed primary teeth often present endodontic failure owing to questioned efficiency of dressings or obturating pastes to eliminate Enterococcus faecalis, a resistant bacterium, residing in depth of dentinal tubules. The present study evaluates the antimicrobial efficacy of two antibacterial and two obturating pastes in dentinal tubules of primary teeth infected with Enterococcus faecalis using viability stain and confocal laser scanning microscope (CLSM).

STUDY DESIGN

Total 28 samples were prepared.Four groups with 6 samples each were made according to antibacterial pastes i.e. 1% or 2%Chlorhexidine (CHX) + calcium hydroxide (CH), CH + iodoform (Metapex) and Zinc Oxide Eugenol (ZOE). Dentinal tubules from the root canal side were infected with E. faecalis by centrifugation of the bacterial suspension. Two specimens from each group were subjected to 1, 7 and 15 days antibacterial pastes exposure. Viability staining followed by CLSM were used to quantitatively analyze the dead cell count directly inside dentin.

RESULT

Univariate analysis showed that all medicaments were significantly effective (p<.05). Kruskal wallis ANOVA test did not show significant difference among four medicaments at day 1 while it was significantly different at day 7 & 15. Paired sample student's t-test revealed significant difference in efficacy between 1& 15 days for 1%CHX+CH; between 1&15,and 7&15 days; between all days for ZOE. Ranking of antimicrobial efficacy of tested medicament was (most effective to the least): 1%CHX+CH(15)> ZOE(15)> Metapex(15)> 2%CHX+CH(15)> 2%CHX+CH(7)> 2%CHX+CH(1)> 1%CHX+CH(7)> 2%CHX+CH(15)> Metapex(1)> ZOE(1)> ZOE(7).

CONCLUSIONS

All medicaments were effective against E. faecalis in dentine of primary teeth and their efficacy increased with longer contact with 1%CHX+CH being most effective at day 15. Inclusion of 1% CHX in dressings or obturating pastes might minimize the endodontic relapse and maximize the tooth retention in functional state in pediatric dentistry.