Cinnamon essential oil (CEO) has antibacterial properties, but its ability to suppress the formation of multi-species oral biofilms has not been fully elucidated. This study evaluated the antibacterial and antibiofilm activities of cinnamon essential oil nanoemulsion (CEON) against oral biofilms formed using a microcosm biofilm model. The biofilms were formed on bovine enamel specimens over a 7-day period, during which all specimens were treated with one of three solutions: 5% CEON (n = 35), 0.5% cocamidopropyl betaine (n = 35), or 0.12% chlorhexidine gluconate (CHX; n = 35). Antibacterial and antibiofilm activities were determined by the red/green ratios (R/G values) of 7-day-old mature biofilms photographed with quantitative light-induced fluorescence-digital, the number of aciduric bacterial colony-forming units (CFUs) within each biofilm, and the absorbance of bacterial suspensions. One-way and repeated-measures analysis of variance were performed to compare differences among the three solutions. R/G values were lowest in the 0.12% CHX group, but not significantly differ from the 5% CEON group. The number of CFUs and absorbance were lowest in the 5% CEON group. This study showed that nanoemulsified CEO inhibited the maturation of multi-species oral biofilms and the growth of oral microorganisms in biofilms, including aciduric bacteria that cause dental caries.

Objectives This study aimed to investigate the effects of indirect vision skills on head and shoulder posture in dental hygienists. Materials and Methods This cross‐sectional study included a total of 100 female clinical dental hygienists. It evaluated musculoskeletal symptoms of the neck, shoulders and back, head and shoulder posture (craniovertebral angle [CVA] and sagittal shoulder posture angle [SSPA]). Indirect vision skills were assessed using the O’Connor tweezer test under indirect vision with a mirror. To analyse factors associated with the CVA and SSPA, an independent t test, one‐way ANOVA, and multiple linear regression analysis were conducted, respectively. Results The body region in which the greatest number of symptoms of work‐related musculoskeletal disorders was recognised was the neck (89.0%). In the multiple linear regression model, which adjusted for other factors associated with musculoskeletal disorders, dental hygienists with poor indirect vision skills showed relatively small SSPA value (P < .05). However, indirect vision skills were not associated with the CVA value. Conclusions Good indirect vision skills contribute to the prevention of rounded shoulders in dental hygienists. Therefore, where possible, dental hygienists should perform clinical procedures using indirect vision with a dental mirror to maintain a balanced posture and reduce flexion of the back or the neck. A dental hygiene curriculum should include training to improve clinical skills, as well as education regarding dental ergonomics and a monitoring system to determine whether ergonomic principles are well observed.

Frog culture industry is not yet familiar but has much potential. Generally, in farm, the population density is higher than that of in nature and frog farm is not the exception. But when population density is high, it can easily leads to stressful condition, poor sanitation. When a disease occur, it is a primary factor that makes the population more susceptible and the results more grave. Because of severe Rhabditoidea-helminth infection and subsequent bacterial septicemia, 50∼70% of the total population had been died in a farm in Jeong-sun in Gangwon-do and Chungju in Chungcheongbuk-do from late June, 2012 to September, 2012. Diseased frogs showed ruptured lung, bloody ascites, liver discoloration, myocardium weakness, congested kidney, microcytic anemia and so on. Enterobacteriacea, Citrobacter.sp, Cupriavidus metallidurans, Acinetobacter.sp were isolated as major bacterium that had caused septicemia in frogs. Among isolated bacterium, Cupriavidus metallidurans, Ewingella americana, Shewanella aquimarina and Pseudoalteromonas sp. have not reported as potential pathogens in frogs before. It is a good example that severe helminth infection in frogs can lead to secondary infection of bacteria.