In vitro cytotoxicity and antibacterial activity of hypochlorous acid antimicrobial agent.

Background/purpose: Bacteria-associated oral diseases such as dental caries and periodontitis are widespread epidemics that cause oral pain and loss of function. The purpose of this study was to evaluate the in vitro cytotoxicity and antibacterial activity of different concentrations of hypochlorous acid (HOCl). Materials and methods: Five different concentrations (100, 200, 300, 400, and 500 ppm) of HOCl were evaluated for their antimicrobial efficacy against Gram-negative (A. actinomycetcmcomitans and P. gingivalis) and Gram-positive bacteria (S. mutans and S. sanguinis) after treatment for 1 and 10 min. Sodium hypochlorite (NaOCl) and chlorhexidine (CHX) were used as positive controls. In addition, HOCl was examined for L929 cytotoxicity and RAW 264.7 growth. Results: The bacteriostatic ratio of NaOCl was comparable to that of CHX and significantly (P < 0.05) higher than that of all HOCl solutions. Higher HOCl concentration had significantly (P < 0.05) higher antibacterial effect, and the bacteriostatic ratio of 10 min treatment was slightly higher than that of 1 min treatment. CHX and NaOCl seeded into L929 cells resulted in low cell viability with only 30-39%, much significantly (P < 0.05) lower than all HOCl groups (greater than 80%). All HOCl solutions met the recommendations of ISO 10993-5 and showed no cytotoxicity, although there was a concentration-dependent decrease in cell viability. All antimicrobial agents showed the same trend of response to RAW 264.7 as L929. Conclusion: Within the limit of this study, 400 ppm HOCl disinfectant may be a potential antimicrobial candidate for mouthwash, endodontic irrigants, and periodontitis treatment.

Effects of hypochlorous acid mouthwash on salivary bacteria including Staphylococcus aureus in patients with periodontal disease: a randomized controlled trial.

BACKGROUND: The effects of a low concentration of hypochlorous acid (HOCl) mouthwash on salivary bacteria remained unclear. We aimed to evaluate the antibacterial effects of 100 ppm HOCl mouthwash on salivary bacteria, including Staphylococcus aureus (S. aureus), in patients with periodontal disease (PD). METHODS: Patients with PD were randomized into mouthwash-only (MW, n = 26) and mouthwash with periodontal flosser (MWPF, n = 27) groups. Patients without PD were selected for the control group (n = 30). S. aureus culture and saliva samples (before and after the intervention) were collected for bacterial DNA extraction. A real-time polymerase chain reaction assay and serial dilutions of S. aureus culture and saliva samples were used to measure the salivary bacteria total count (SBTC) and confirm the antibacterial effects of the mouthwash using S. aureus. RESULTS: No significant difference in demographic data was observed among the three groups. Before the intervention, the baseline SBTC of the MW and MWPF groups was significantly higher than that of the control group. After the mouthwash rinses, the SBTC data significantly changed in the MW and MWPF groups only (by 62.4% and 77.4%, respectively). After the base-2 log-transformation of the SBTC data, a similar trend was observed. Linear regression revealed that baseline SBTC and the MWPF intervention significantly affected SBTC reduction percentage by volume. After incubation with 10% (v/v) of mouthwash, the survival rates of 106 and 107 colony-forming units/mL of S. aureus were 0.51% ± 0.06% and 1.42% ± 0.37%, respectively. CONCLUSIONS: These study results indicated that 100 ppm HOCl mouthwash treatment could effectively reduce SBTC in patients with PD and the abundance of S. aureus. It provides that the HOCl mouthwash can be an option for individuals to help control SBTC, especially in patients with PD. TRIAL REGISTRATION: The study protocol was approved by the Institutional Review Board of Kaohsiung Medical University Hospital (KMUHIRB-F(I)-20200042) on 20/03/2020 and retrospectively registered at ClinicalTrial.gov (NCT05372835) on 13/05/2022.

Intelligent image analysis recognizes important orchid viral diseases.

Phalaenopsis orchids are one of the most important exporting commodities for Taiwan. Most orchids are planted and grown in greenhouses. Early detection of orchid diseases is crucially valuable to orchid farmers during orchid cultivation. At present, orchid viral diseases are generally identified with manual observation and the judgment of the grower's experience. The most commonly used assays for virus identification are nucleic acid amplification and serology. However, it is neither time nor cost efficient. Therefore, this study aimed to create a system for automatically identifying the common viral diseases in orchids using the orchid image. Our methods include the following steps: the image preprocessing by color space transformation and gamma correction, detection of leaves by a U-net model, removal of non-leaf fragment areas by connected component labeling, feature acquisition of leaf texture, and disease identification by the two-stage model with the integration of a random forest model and an inception network (deep learning) model. Thereby, the proposed system achieved the excellent accuracy of 0.9707 and 0.9180 for the image segmentation of orchid leaves and disease identification, respectively. Furthermore, this system outperformed the naked-eye identification for the easily misidentified categories [cymbidium mosaic virus (CymMV) and odontoglossum ringspot virus (ORSV)] with the accuracy of 0.842 using two-stage model and 0.667 by naked-eye identification. This system would benefit the orchid disease recognition for Phalaenopsis cultivation.

Effect of Loading Devices on Muscle Activation in Squat and Lunge.

CONTEXT: Squats and lunges are common exercises frequently applied in muscle-strengthening and therapeutic exercises. The loading devices are often used to increase the training intensity. OBJECTIVE: To determine the effect of loading devices on muscle activation in squat and lunge and to compare the differences in muscle activation between squat and lunge. DESIGN: Cross-sectional cohort. PARTICIPANTS: Nineteen healthy, male, recreationally active individuals without a history of lower limb injury. INTERVENTIONS: Each participant performed 10 repetitions of a squat under 5 conditions: unloaded, barbell, dumbbell, loaded vest, and kettlebell, and 10 repetitions of a lunge under 4 conditions: unloaded, barbell, dumbbell, and loaded vest. MAIN OUTCOME MEASURES: The electromyography signals of quadriceps, hamstrings, tibialis anterior, gastrocnemius lateralis and medialis were measured. One-way repeated-measure analysis of variance was used to compare the difference among different loading conditions. Paired t test was used to compare the difference between squat and lunge. RESULTS: The muscle activation in the loaded conditions was significantly higher than that in nonloaded conditions in squat and lunge. Compared with the barbell, dumbbell, and loaded vest conditions, the semitendinosus showed significantly higher activation, and the tibialis anterior showed significantly lower activation in kettlebell condition in squat. No significant difference in muscle activation was found among barbell, dumbbell, and kettlebell conditions in lunge. In addition, quadriceps and hamstring activities were significantly higher in lunge than in squat. CONCLUSIONS: Muscle activation was affected by the loading devices in squat but not affected in lunge. Kettlebell squat could be suggested for targeting in strengthening medial hamstring. Progressive strengthening exercise could be recommended from squat to lunge based on sequential activation level.

Accuracy of Implant Placement with a Navigation System, a Laboratory Guide, and Freehand Drilling.

PURPOSE: Computer-aided surgery under navigation system guidance is widely applied in dental implant procedures. However, the accuracy of drilling with such navigation systems has not been comparatively evaluated alongside those of laboratory guide-based and freehand drilling. Therefore, this study aimed to compare the accuracies of these three drilling systems. MATERIALS AND METHODS: A navigation system, a laboratory guide, and freehand drilling were used to drill 150 holes on 30 cast models. Two master models-one each for the maxilla and mandible-were prepared with the idea of placing five implants per cast. After drilling five holes on each cast, postoperative cone beam computed tomography images were acquired to measure the magnitude of errors. RESULTS: The navigation system and laboratory guide were more accurate than freehand placement with respect to total errors at the entry and apex, lateral error at the apex, and angular error. The navigation system was more accurate than the laboratory guide with respect to angular error. Laboratory guide-based drilling was more accurate than freehand drilling in terms of lateral error at entry. CONCLUSION: In comparison with the laboratory guide and freehand placement, the navigation system exhibited lower angular and axial errors. Despite its higher accuracy, the navigation system requires the operator to pay greater attention.