In Vitro Evaluation Of The Antimicrobial Activity And The Apical Sealing Ability Of Three Root Canal Sealers

Objectives The purpose of this study was to compare the quality of the in vitro antimicrobial properties, lateral canals and apical sealing performance.among i Root SP,AH Plus and ZOE. The findings we obtained will evaluation of three kinds of sealants,analysis its causes and provide a the theoretical basis for clinical.Methods 1 Direct contact test, DCT: Three microbial in suspension was allowed to directly contact the three root canal sealers, after 24 h survival of microbial was determined by using 10-fold serial dilution and inoculated onto agar plates. After incubation for 24 h, colony-forming units(CFU) were calculated and their log10 values converted.The data were analyzed using ANOVA and LSD-t tests(α=0.05)(n=5).2 Lateral canals sealing experiment:Thirty six freshly extracted single-rooted human teeth model with simulated lateral canals were randomly assigned to three groups,There are 12 specimens in experiment group, i Root SP, AH Plus, ZOE. The roots that were filled with the test material, using the root canal preparation technique and root filling technique,X-ray, the depth of the filling materials in lateral canals was measured and the obturated lateral canals were counted. The data of the depth of the filling materials in lateral canals were analyzed using ANOVA and LSD-t tests(α=0.05) The data of obturated lateral canals were counted were analyzed using the χ2and tests and Fisher’s exact test(α=0.05)(n=12).3 Bacterialmicro Ieakage experiment:Comparison of lateral root canal sealing effect, we will coated with nail polish teeth 2 times on the root surface outside the teeth root apical 2 mm. placed in the bacterial leakagemodel, were mounted in a two-chamber bacterial leakage model and Enterococcus faecalis was added to the upper chambers. The lower chambers of all of the specimens were checked every day during the test period(90days). The day of turbidity was recorded for each sample. Statistical analysis was performed using the χ2 tests and Fisher’s exact test(α=0.05). Make a note of duration model for leakage, Statistical analysis was performed using the Kaplan-Meier test and Log-rank(α= 0.05). 4 SEM observation: Select the teeth from each group after the experiment of microleakage sample, slice, keep apical partm, section in the process of continuous water spray cooling, in order to avoid the heat effect of experimental results.The distilled water to rinse the surface dirt. dry themat the normal breakthrough point and plate them with the gold film.observed with SEM and then take photos.Results 1 DCT experimental resultsshowed that: The antimicrobial activity of Enterococcus faecalis, there was no statistically significant between i Root SP and AH Plus(P>0.05), i Root SP and AH Plus showed the highest antifungal activity, and better than ZOE, There was statistically significant(P<0.01);The antimicrobial activit of Staphylococcus aureus and Candida albicans, there was statistically significant between i Root SP and AH Plus(P<0.05), i Root SP and AH Plus showed the highest antifungal activity, and better than ZOE, There was statistically significant(P<0.01). 2 The experiment of lateral canals sealing showed that: i Root SP group, AH Plus group and ZOE group the ration of the obturated lateral canals were 91.7%, 75.0%, 16.7%. There was statistically significant(P<0.01). Between the three groups, the depth of the filling materials in lateral canals was1.22±0.42 mm, 0.85±0.53 mm, 0.11±0.27 mm, The difference was statistically significant(P<0.01). 3 Bacterial micro Ieakage experiment:After90 days of evaluation bacterial leakage was observed in 50.0 % of the teeth root filled with i Root SP, and in 58.2%of the teech root filled with AH Plus, 100.0%of the teech root filled with ZOE amalgam showed leakage.The difference was statistically significant(P<0.05); Days of microleakage were 10~82 days, 6~76 days, 1~74days.The medians were 82.00, 69.00, 23.00. The mean were 67.16, 57.91, 32.41. The difference was statistically significant(P<0.01). 4 150 times under the scanning electron microscopy(sem) shows that: i Root SP group almost no gap exists; AH Plus group has some small gap exists; ZOE group has large number of cracks existed; 1000 times under the scanning electron microscopy(sem) shows that: i Root SP root canal sealer sealants most infiltration dentin tubule, AH Plus root canal sealer to assimilate into the large number of dentin tubule, ZOE root canal sealer not penetrate the dentin tubule.Conclusions 1 i Root SP showed the highest antifungal activity,and better than AH Plus root canal sealses, the antifungal activity of ZOE was the worst. 2 Comprehensive lateral canals sealing experiment,bacterial leakage experiment and scanning electron microscopy,the apical sealing of i Root SP performance is better than AH Plus, ZOE was the worst.