RESUMO
Background and aim: Colonization of residual organisms in the root canal are major causes of root canal treatment failure. Therefore, the effective removal of organisms during root canal cleaning stages is of great importance. In this study, we aimed to investigate and compare the antimicrobial effects of several methods including high power laser irradiation, photodynamic therapy and triple antibiotic paste (TAP) on Enterococcus faecalis in the root canal. Materials and methods: For the present laboratory study, 80 anterior single canal teeth were randomly divided into seven experimental groups (970 nm diode laser irradiation, 445 nm diode laser irradiation, 660 nm photodynamic therapy with doxycycline as a photosensitizer, TAP, 970 nm diode laser combined with TAP, 445 nm diode laser combined with TAP and sodium hypochlorite groups), each containing 10 teeth, and two positive and negative control groups, each containing five teeth. Afterwards, an E. faecalis suspension was prepared and injected into the root canals of all groups (except the negative control group), and after using the desired lasers or drugs and incubating for the necessary time, the grown colonies were counted and significance level of less than 0.05 was considered. Results:Among seven experimental groups, in those that included triple antibiotic paste (TAP, 970 nm diode laser with TAP, and 445 nm diode laser with TAP groups), no bacteria grew, while the 970 nm and 445 nm diode laser groups had the highest bacterial growth. Statistically, all studied groups were effective, and the results showed a statistically significant difference between groups (P value < 0.05). Conclusion: The findings of the present study show that all of the above-mentioned methods were effective enough for bacterial reduction. Triple antibiotic paste was proved to achieve complete bacterial elimination. Photodynamic therapy with doxycycline as a photosensitizer was shown to provide significant results of bacterial reduction and diode laser irradiation at both wavelengths (970 nm and 445 nm) were also reported to have antibacterial effect, although slightly lower than the previous methods.
RESUMO
BACKGROUND: Although it is shown that probiotic agents might reduce Streptococcus mutans, no study has evaluated this effect in the form of probiotic mouthrinse. The purpose of this study was to compare the effect of probiotic experimental mouthwash Lactobacillus plantarum versus sodium fluoride and placebo mouthwashes on the number of S. mutans present in dental plaque around orthodontic brackets in fixed orthodontic patients. MATERIALS AND METHODS: This study was a randomized clinical trial. The total of 38 patients participate consisting of 12 patients in the fluoride group, 13 in the probiotic, and 12 in the placebo group. They were given mouthwashes to use twice a day for 2 weeks. Plaque sampling was performed using the 4-pass technique in all three groups in two stages: before the intervention and after 2 weeks of using the mouthwash. The number of bacteria present in the dental plaque was then reported based on the number of colonies grown on agar medium. Data were analyzed using Kruskal-Wallis and Wilcoxon tests (α = 0.05). RESULTS: Gender distribution, mean age, and protocol adherence were not significantly different among all three groups. After the intervention, the number of S. mutans present in the dental plaque followed an increasing manner in the placebo (P = 0.005) and probiotic (P = 0.158) groups and decreased in fluoride group (P = 0.025). CONCLUSION: The L. plantarum probiotic mouthwash was ineffective in reduction of S. mutans in dental plaque. However, fluoride mouthwash is considerably effective against S. mutans and thus recommended.
RESUMO
Resistance of Pseudomonas aeruginosa strains to the broad-spectrum cephalosporins may be mediated by the extended-spectrum beta-lactamases (ESBLs). These enzymes are encoded by different genes located on either chromosomes or plasmids. This study aimed to investigate the prevalence of ESBLs and antimicrobial susceptibilities of P. aeruginosa isolated from burn patients in Tehran, Iran. Antimicrobial susceptibility of 170 isolates to cefpodoxime, aztreonam, ciprofloxacin, ofloxacin, ceftazidime, cefepime, imipenem, meropenem, cefotaxime, levofloxacin, piperacillin-tazobactam and ceftriaxone was determined by disc agar diffusion test. Polymerase chain reaction (PCR) amplification of the genes encoding OXA-10, PER-1 and VEB-1 was also performed. All isolates (100%) were resistant to ceftazidime, cefotaxime, cefepime and aztreonam. Imipenem and meropenem were the most effective anti-pseudomonal agents. The results revealed that 148 (87.05%) of the isolates were multidrug resistant and 67 (39.41%) of the isolates were ESBL positive. Fifty (74.62%), 33 (49.25%) and 21 (31.34%) strains among 67 ESBL-producing strains amplified blaOXA-10, blaPER-1 and blaVEB-1 respectively. In conclusion, the high prevalence of multidrug resistance (87.05%) and production of OXA-10, PER-1 and VEB-1 genes in P. aeruginosa isolates in burn patients confirm that protocols considering these issues should be considered in burn hospitals.
