Effectiveness of pre-procedural rinsing with essential oils-based mouthrinse to reduce aerosol contamination of periodontitis patients

This research aims to evaluate the effectiveness of pre-procedural rinsing using essential oils-mouthwash (Listerine®) in reducing bioaerosol contamination in a dental clinic. Thirty (30) subjects who consisted of those receiving treatment for periodontitis problems were randomly assigned to rinse with either 20 mL of Listerine® or 20 mL of placebo as control rinse. Every subject was instructed to gargle using the rinse for 1 min. Microbial samples of environmental air and saliva were collected before and after the rinse. All samples were further analyzed for total plate counts to measure the microbial level. Rinsing using Listerine® showed significant reduction in the level of microbial load in saliva compared to the control mouthrinses. Analysis done at three defined distance intervals from the operating site showed the level of bioaerosol contamination was highest at distance nearest to the treatment point of 1 ft. Based on counts of cfu, there was higher presence of microbial contaminant in bioaerosols of the control-rinsed group compared to the test-rinsed group using Listerine®. Therefore, it can be concluded that rinsing using Listerine® was effective towards reducing the microorganisms in saliva and oral cavity in general

Muscle spindles provide servo-assistance to jaw-closing muscles for chewing hard foods

The fundamental pattern of chewing induced by the network of neurons called central pattern generator has been reported to be modified by the information arising from the various oro-facial sensory receptors including muscle spindles of jaw closing muscles. The cell bodies of primary afferent neurons from these muscle spindles lie in mesencephalic trigeminal nucleus (MTN) in the brainstem. The aim of the study was to understand whether muscle spindles from jaw-closing muscles play any role in hard food chewing. Single neuronal discharge of muscle spindle afferents was recorded from the MTN simultaneous with jaw-movement and electromyograpic (EMG) activities of the left masseter (jaw-closing) muscle during chewing soft and hard foods (apple and pellet) in awake rabbits. Ten consecutive chewing cycles were taken for analysis. Discharge of nineteen muscle spindles from seven rabbits was successfully recorded. Muscle-spindle discharge was significantly higher during the closing phase of jaw-movement for the hard food chewing than for the soft food. The jaw-closing muscle EMG activity was significantly higher during hard food chewing compared to soft food. The spindle discharge was higher when the masseter muscle activity was greater for chewing hard food. Significant positive (r=0.822, p=<0.001) correlation was found between the difference of muscle activity between apple and pellet and the difference of spindle discharge between apple and pellet. Above findings suggest that the increase of spindle discharge during hard food chewing may play a role for facilitating jaw-closing muscle activities and thereby provides servo-assistance to jaw-closing muscles to compensate the hardness of food