Methods: The study encompassed 44 randomly chosen patients with visible chronical periapical lesion determined by Rtg. For each sample, three swabs were taken for microbiological analysis. Sterilized paper points were used for swab taking and then placed in WMGA transport media for anaerobs. The first swab was taken before root canal instrumentation, and then standard hand instrumentation was performed up to a number 30 file with 2,5% sodium hypochlorite irrigation. After completed instrumentation, the second swab was taken and root canal was additionally treated with HealOzone for 40 sec. Finally, the third swab was taken and microbiological analysis of obtained samples was performed. Information was statistically processed with SPSS computer program.
Results: Distributions of all original variables were statisticaly significantly different from the normal distribution. Monte Carlo statistical significance of Kolmogorov-Smirnov one sample test varied from <0.001 up to 0.023. Therefore non parametric Friedman and Wilcoxon tests were used for the assessment of differences in median number of bacteria remained after the therapy and after the additional treatment with ozone.
Decrease in number of bacteria after the additional treatment with ozone were highly statistically significant: Z=-4.6, p<0.001 for aerobic, and Z=-4.5, p<0.001 for anaerobic bacteria. Median number of aerobic bacteria was decreased from 11.5 to 1.5 (median decrease of 87%) after the additional treatment with ozone. Median number of anaerobic bacteria was decreased from 5.0 to 0.5 (median decrease of 82%).
Conclusion: Since after standard hand instrumentation certain number of bacterial colonies always remain, HealOzone can be used for additional root canals disinfection.
The study was supported by grant 065-0352851-0410 of MZOS, Croatia