Antibacterial Efficacy of Silver Nanoparticles Impregnated Calcium Hydroxide: An in Vitro Study

Abstract

OBJECTIVE: To compare the in-vitro antibacterial effectiveness in terms of enterococcus faecalis elimination of conventional unmodified calcium hydroxide paste with an experimental calcium hydroxide impregnated with 1% silver nanoparticles. METHODOLOGY: This in vitro study was conducted during the period July 2019 - January 2020 at Materials Research Laboratory, Centralized Resource Laboratory (University of Peshawar) and Pathology Laboratory (Peshawar Medical College). Sixty human premolar teeth having single root with mature apices were obtained. These were distributed into two groups randomly (n=30); experimental group for testing the antibacterial efficacy of calcium hydroxide impregnated with 0.1% by weight silver nanoparticles and the other was used as a control group for testing the antibacterial efficacy of unmodified calcium hydroxide. Dentine specimens (size 4 x 4x 1mm) were prepared from the teeth using slow speed cutting saw machine. Smear layer was removed with EDTA. Specimens were autoclaved to sterilize them. Then each specimen was contaminated with enterococcus faecalis and incubated anaerobically for 24 hours at 37?C. After the application of medicaments, the zone of inhibition was measured and number of viable bacteria were determined using SEM. Statistical significance was calculated using t-test. p<0.05 was taken as significant. RESULTS: After the application of medicament, the zone of inhibition was greater (9.63mm) in experimental group when compared to control group (4mm) (p<0.001). Number of viable bacteria before application of medicament were 239 and 208 while after application of medicament reduced to 90 and 54 in control and experimental groups respectively (p<0.001). CONCLUSION: The addition of silver nanoparticles to calcium hydroxide significantly enhanced its potential to eliminate biofilm of enterococcus faecalis on dentin specimens. KEYWORDS: Silver nanoparticles, Calcium hydroxide, Root canal infections, Root canal medicament.