In Vitro Evaluation Of The Antimicrobial Activity And Apical Sealing Ability Of Nanomaterial

Aim: To observe antimicrobial activity and apical sealing ability of two kinds of nanomaterialMethod:1. Antimicrobial activity: Experimental materials were devided into four groups. Group 1: Zinc oxide-eugenol sealer (ZOE) (the control group); group 2: hydroxyapatite sealer (HA); group 3: nano-zinc-oxide sealer (N-ZO); group 4: nanohydroxyapatite sealer (NHA). In order to have the same sealer volume, four kinds of experimental materials were manipulated into standard holes (5×4mm~2) of a sterile apparatus. The sealers were tested immediately, 24h, 48h and 7 days after manipulation respectively. The sealers were placed on the Agar plates after Staphylococcus aureus, Candida albicans and Enterococcus faecalis had been inoculated.The plates were kept in a 37 ℃ incubator for 24 h. Zones of inhibition of microbial growth were observed. The antimicrobial activity of the four kinds of materials were assessed according to the zones of inhibition of microbial growth.2. Apical sealing ability:40 straight human maxillary anterior teeth were divided randomly into four experimental groups of 8 samples each and two control groups of 4 samples each. The root canals were prepared using step-back technique and obturated with gutta-percha and one of the sealers by the laterial condensation technique. Group 1: filled with zinc oxide-eugenol sealer and gutta-percha (ZOE); group 2: filled with hydroxyapatite sealer and gutta-percha (HA); group 3: filled with nano-zinc-oxide sealer and gutta-percha (N-ZO); group 4: filled with nanohydroxyapatite sealer and gutta-percha (NHA). The teeth were placed into microleakage model. Glucose leakage from the coronal to apical was measured by the concentration of glucose in apical reservoir at 1,2,4,7, 10, 15, 20,25 and 30 days with GOD (glucose oxidase) method. The apical sealing ability of the materials were assessed according to the concentration of glucose leakage.Results:1. Agar diffusion test: At four times after manipulation, HA and NHA had not antimicrobialactivity, there were statistical difference among the zones of inhibition of microbial growth ofZOE and N-ZO. ZOE demonstrated higher antimicrobial activity than N-ZO; There werestatistical difference among three kinds of bacteria (p<0.001) The zones of inhibition ofmicrobial growth of ZOE and N-ZO against Enterococcus faecalis were the smallest; There werestatistical difference among four times (p< 0.0001) The antimicrobial activity of the sealersreduced with time. (p<0.0001)2 . The glucose leakage of four kinds of materials differed significantly (p<0.0001) The glucose...