The comparison of intracanal medicaments, diode laser and photodynamic therapy on removing the biofilm of Enterococcus faecalis and Candida albicans in the root canal system (ex-vivo study).

BACKGROUND AND AIM: Long term success in endodontic therapy is attributed to removal and debridement of intracanal microorganisms. The aim of this study was to compare the antimicrobial effects of calcium hydroxide (Ca(OH)2), triple antibiotic paste (TAP), photodynamic therapy(PDT), toluidine blue(TOL), light emitting diode (LED) and 940 nm diode laser (DL) on the biofilm of Enterococcus faecalis and Candida albicans in the root canal system of ex-vivo human teeth. MATERIALS & METHODS: 84 intact, uniradicular, extracted human premolar teeth were prepared and the apical foramina were sealed with glass ionomer. The samples were transformed to microtubes containing sterile BHI and were sterilized. After incubation of E. faecalis and C. albicans into the canals, the samples were kept in an incubator for 8 weeks to form the biofilm. Then the samples were randomly divided into 7 groups of 12, including: control and groups treated with Ca(OH)2,TAP, TOl, LED, PDT, and DL. Then the samples were fixed, gold coated and observed under scanning electron microscope (SEM). RESULT: Significant reductions in biofilm thickness were noted in TAP,PDT and LED (P < 0.05). The greatest reduction in biofilm thickness was seen in TAP; however, the differences between TAP and PDT and LED were not significant (P > 0.05). CONCLUSION: Since one of the main purposes in root canal therapy is to eliminate the bacteria, this study showed that the application of TAP, PDT, and LED exposure lead to least biofilm thickness.

The effect of combined pulsed wave low-level laser therapy and mesenchymal stem cell-conditioned medium on the healing of an infected wound with methicillin-resistant Staphylococcal aureus in diabetic rats.

This study aims to investigate the combined effects of Pulsed wave low-level laser therapy (PW LLLT) and human bone marrow mesenchymal stem cell-conditioned medium (hBM-MSC-CM) on the microbial flora and tensiometrical properties of an infected wound model with methicillin-resistant staphylococcal aureus (MRSA) in an experimental model for Type 1 diabetes mellitus (TIDM). TIDM was induced in rats by streptozotocin (STZ). One full-thickness excision was made on the backs of the rats. Next, the rats were divided into the following groups: Group 1 was the control (placebo) group; Group 2 received hBM-MSCs-CM four times; Group 3 were laser PWLLLT (890 nm, 80 Hz, 0.2 J/cm2 ); and Group 4 received hBM-MSCs-CM +LASER. Wounds were infected with MRSA. Microbiological examinations were performed on days 4, 7, and 15. Tensiometerical examinations were carried out on the 15th day. One-way analysis of variance showed that laser and CM alone and/or in combination significantly increases the tensiomerical properties of the repaired wounds compared with control wounds. A combination of PW laser and CM was statistically more effective than other treated groups. Two-way analysis of variance showed that laser and CM alone and/or in combination significantly decreases the colony-forming units (CFUs) compared with the control group. The application of hBM-MSC-CM and PWlaser alone and/or together significantly accelerates the wound-healing process in MRSA-infected cutaneous wounds in TI DM in rats. Additionally, a combined application of hBM-MSC-CM and PWlaser demonstrates a synergistic effect on the wound-healing process in MRSA-infected cutaneous wounds in Type I DM rats.

The effect of combined photobiomodulation and curcumin on skin wound healing in type I diabetes in rats.

The purpose of the present scientific study was to analyze the effects of combined pulsed wave Photobiomodulation (PW PBM) and Curcumin on the microbial flora; in addition, the tensiometrical wounds properties for type one diabetes mellitus (TIDM) in an experimental animal model. TIDM induction was performed in thirty rats. In the entire animals, one full-thickness excision was implemented on their backs. Randomly, the divisions of rats into 5 groups took place. The primary group was considered as the control group and did not receive any treatment. The secondary group (placebo) received sesame oil by gastric gavage. The third group received PWPBM (890 nm, 80 Hz, 0.2 J/cm2). The fourth group received curcumin (40 mg/kg, which was dissolved in sesame oil) by gastric gavage. Eventually, the fifth group received PW PBM + curcumin. Precisely, on day 7, microbiological examinations, and on the 15th day microbiological and tensiometrical examinations were conducted. The data were analyzed by statistical tests. PW PBM, significantly exacerbated tensiometrical properties of the TIDM repairing wound. PW PBM, curcumin, and PWPBM + curcumin significantly decreased colony forming units compared to the control and the placebo groups indeed. It was remarkably attained that PW PBM significantly accelerated the process of wound healing in the STZ-induced TIDM. The PW PBM was statistically more compelling compared to the curcumin and PWPBM + curcumin. PW PBM, curcumin, and PWPBM + curcumin significantly decreased colony forming units compared to the control and placebo groups.

Comparison of the antimicrobial efficacy of photodynamic therapy with two mediators against Lactobacillus acidophilus in vitro.

BACKGROUND AND OBJECTIVES: Lactobacillus is a cariogenic microorganism. Different therapeutic approaches including photodynamic therapy (PDT) have been suggested for treatment of bacterial infection. The purpose of the current study was to compare the effects of PDT with Indocyanine green (ICG) and Methylene blue (MB) photosensitizers (PSs) on Lactobacillus acidophilus (L. acidophilus). MATERIALS AND METHODS: In this in-vitro experimental study, 84 samples of L. acidophilus (1 McFarland standard) were compared in 14 experimental groups including: MB, ICG, 660-nm laser, 808-nm laser (pulsed, 74s/continuous-wave, 37s), different combinations of lasers and PSs, Chlorhexidine (CHX) 0.2%, sodium hypochlorite (NaOCl) 2.5%, penicillin 6.3.3 and control groups. The samples were cultured in microplates containing blood agar culture medium. After incubation at 37 °C for 48 h, the colony forming units (CFUs) of L. acidophilus were counted and compared before and after therapeutic interventions. Data were analyzed using SPSS19 software program according to one-way ANOVA test. RESULTS: This study showed that the separate use of ICG, 660- and 808-nm lasers (pulsed, 74s/continuous-wave, 37s), and the combined use of 808-nm laser (pulsed, 74s/continuous-wave, 37s) and ICG have no significant inhibitory effect on L. acidophilus colonies (P > 0.05), whereas the separate use of MB and the combined use of 660-nm laser (continuous-wave, 37s/pulsed, 74s) and MB significantly inhibited the growth of L. acidophilus in comparison with the control group (p < 0.05). Likewise, CHX 0.2%, NaOCl 2.5% and penicillin 6.3.3 significantly inhibited the bacterial growth (p < 0.05). CONCLUSION: The results showed that separate use of MB and combined use of 660-nm laser and MB have a significant inhibitory effect on L. acidophilus growth.

Human Bone Marrow Mesenchymal Stem Cell Conditioned Medium Promotes Wound Healing in Deep Second-Degree Burns in Male Rats.

Burn wound treatment is difficult and one of the most challenging problems in the clinic. Researchers have examined the applications of mesenchymal stem cells as a cell-based therapy for skin regeneration. But the role of human bone marrow mesenchymal stem cell conditioned medium (hBM-MSC-CM) in the treatment of burn injury remains unclear. This research aims at detecting whether hBM-MSC-CM can increase the wound healing of deep second-degree burns in male rats. In this study, 32 adult male rats per each time point were randomly divided into four groups: (1) control group, (2) sham group (DMEM), (3) common treatment group (CT), and (4) conditioned media group (CM). A 3 × 3 cm circular burn was created on the back of the rats. On postsurgical days 7, 15, and 28, the wound closure area of each wound was measured and then the skin samples were removed and analyzed using stereological methods. Wound closure area was significantly increased in the CM and CT groups on the 15th and the 28th day after burn injury compared to the control and DMEM groups. The stereological parameters and immunohistochemistry analysis of the wounds revealed significantly improved healing in the CM group compared to the control and other groups. It is concluded that these findings indicate that hBM-MSC-CM promotes skin wound healing by increasing cell proliferation, regulating collagen synthesis and collagen composition, and inducing angiogenesis at the injury site.

The effect of combined photobiomodulation and metformin on open skin wound healing in a non-genetic model of type II diabetes.

This study intended to examine the combined influences of photobiomodulation (PBM) and metformin on the microbial flora and biomechanical parameters of wounds in a non-genetic model of type II diabetes mellitus (TII DM). We induced a non-genetic model of TII DM in 20 rats by feeding them a 10% fructose solution for 2weeks followed by an injection of streptozotocin (STZ, 40mg/kg). After 21days from the injection of STZ, we induced one full-thickness skin wound in each of the diabetic rats. We randomly divided the rats into four groups: i) placebo; ii) pulsed wave laser (890nm, 80Hz, 0.324J/cm2); iii) metformin; and iv) laser+metformin. Rats received daily intraperitoneal injections of metformin (50mg/kg). On days 7and 15 we inspected the microbial flora of each wound. On day 15 we obtained a standard sample from each healing wound for biomechanical analyses. PBM significantly decreased colony-forming units (CFUs) 7days after wound infliction compared to the placebo group (LSD test, p=0.012). Metformin significantly enhanced the biomechanical property (stress high load) of the wounds compared to the placebo group (LSD test, p=0.028). We observed the same significant result for PBM compared to the placebo group (LSD test, p=0.047). PBM significantly accelerated the wound healing process and significantly reduced CFUs of bacteria in a non-genetic rat model of TII DM.

Antibacterial effect of Iranian green-tea-containing mouthrinse vs chlorhexidine 0.2%: an in vitro study.

PURPOSE: Considering the antioxidant, anti-inflammatory and antimicrobial properties of green tea, this study aimed to evaluate the antibacterial effect of mouthrinses containing green tea extract vs 0.2% chlorhexidine on selected microorganisms in vitro. MATERIALS AND METHODS: The antibacterial activity of both mouthrinses and the pure green tea extract was assessed by using disk diffusion and the minimal inhibitory concentration (MIC) methods against five microorganisms: Streptococcus mutans, Streptococcus sanguis, Enterococcus faecalis, Pseudomonas aerogenosa and Escherichia coli. Growth inhibition zones were measured in mm after 24 h of incubation at 37°C. The two mouthrinses were assessed at concentrations of 1, 2, 4, 8, 16, 32, 64, 128, 256 and 512 mg/ml to determine the MIC, which was interpreted as the lowest concentration of the agent that completely inhibited the growth of the test species. RESULTS: 0.2% chlorhexidine produced a larger zone of growth inhibition than did the mouthrinse made of green tea extract (P < 0.01). Paradoxically, the growth inhibition zones of the tested bacteria were significantly larger in pure extract of green tea than in 0.2% chlorhexidine (P < 0.01). The chlorhexidine mouthrinse inhibited the growth of all tested species and exhibited significantly lower MICs than did the green tea mouthrinse (P < 0.01). CONCLUSIONS: Even though the mouthrinse made with green tea extract presented an in vitro antimicrobial activity inferior to 0.2% chlorhexidine, the pure extract had considerable bactericidal effect.

Evaluation of antimicrobial effect of MTA, calcium hydroxide, and CEM cement.

INTRODUCTION: The antibacterial effects of calcium hydroxide (CH), mineral trioxide aggregate (MTA), and calcium enriched mixture (CEM) cement against various spp. of microorganisms were assessed in-vitro using agar diffusion test. MATERIALS AND METHODS: A base layer of Petri plates was made using Muller-Hinton agar. Four cavities were made in agar and filled with freshly mixed materials after 24 h. The microorganisms were seeded by pour plate. The plates were pre-incubated for 2 h at room temperature followed by incubation at 37˚C for 24 h. The inhibition zones diameters were measured by an independent observer. RESULTS: The highest mean diameters of growth inhibition zones were founded around CH and CEM cement. According to One-way ANOVA there was a significant difference among test groups (p<0.001); Post Hoc test revealed no significant difference between the mean zones diameter of CH and CEM cement. However, there was significant difference among CH and CEM cement in comparison with MTA group (p<0.001). CONCLUSION: It appears that CEM cement is a potent antibacterial agent like CH.