Development and evaluation of an English learning system using smartphones in Japanese dental hygiene education

Purpose: To develop and evaluate the effects of an English learning system using smartphones in Japanese dental hygiene education.Methods: Forty-three third-year undergraduate university dental hygiene students took a preliminary examination and then were randomly divided into two groups, Group I or II, according to their results to make the English level of each group approximately equal. Group I took examination A as a pre-examination and examination B as a post-examination. Group II took examination B as a pre-examination and examination A as a post-examination. Each examination was composed of dental terminology and speaking sections. All participants studied English learning materials via a learning management system, which included a series of four subtopics related to dental caries prevention, as re- and self-learning.Results: In the terminology section, both groups showed significantly higher post-examination scores than pre-examination scores, regardless of which examination (A or B) was taken as the pre-examination (Group I: p < 0.0001, Group II: p =0.0025).Conclusions: The English learning system using smartphones developed in this study effectively increased participants’ dental English vocabulary. English speaking skills showed no improvement and another learning style should be evaluated in a future study

Reduction of Streptococcus mutans Adherence and Dental Biofilm Formation by Surface Treatment with Phosphorylated Polyethylene Glycol▿

Initial attachment of the cariogenic Streptococcus mutans onto dental enamel is largely promoted by the adsorption of specific salivary proteins on enamel surface. Some phosphorylated salivary proteins were found to reduce S. mutans adhesion by competitively inhibiting the adsorption of S. mutans-binding salivary glycoproteins to hydroxyapatite (HA). The aim of this study was to develop antiadherence compounds for preventing dental biofilm development. We synthesized phosphorylated polyethylene glycol (PEG) derivatives and examined the possibility of surface pretreatment with them for preventing S. mutans adhesion in vitro and dental biofilm formation in vivo. Pretreatment of the HA surface with methacryloyloxydecyl phosphate (MDP)-PEG prior to saliva incubation hydrophilized the surface and thereby reduced salivary protein adsorption and saliva-promoted bacterial attachment to HA. However, when MDP-PEG was added to the saliva-pretreated HA (S-HA) surface, its inhibitory effect on bacterial binding was completely diminished. S. mutans adhesion onto S-HA was successfully reduced by treatment of the surface with pyrophosphate (PP), which desorbs salivary components from S-HA. Treatment of S-HA surfaces with MDP-PEG plus PP completely inhibited saliva-promoted S. mutans adhesion even when followed by additional saliva treatment. Finally, mouthwash with MDP-PEG plus PP prevented de novo biofilm development after thorough teeth cleaning in humans compared to either water or PP alone. We conclude that MDP-PEG plus PP has the potential for use as an antiadherence agent that prevents dental biofilm development

Long-Term Mastication Changed Salivary Metabolomic Profiles

Saliva is an ideal biofluid for monitoring oral and systemic health. Repeated mastication is a typical physical stimulus that improves salivary flow and oral hygiene. Recent metabolomic studies have shown the potential of salivary metabolomic components for various disease monitoring systems. Here, we evaluated the effect of long-term mastication on salivary metabolomic profiles. Young women with good oral hygiene (20.8 &plusmn; 0.3 years, n = 17) participated. They were prohibited from chewing gum during control periods (4 weeks each) and were instructed to chew a piece of gum base seven times a day for 10 min each time during the intervention period. Paired samples of unstimulated whole saliva collected on the last day of the control and intervention period were compared. Liquid chromatography&ndash;time-of-flight mass spectrometry successfully quantified 85 metabolites, of which 41 showed significant differences (p &lt; 0.05, Wilcoxon paired test corrected by false discovery rate). Except for a few metabolites, such as citrate, most metabolites showed lower concentrations after the intervention. The pathways related to glycogenic amino acids, such as alanine, arginine, and glutamine, altered considerably. This study suggests that long-term mastication induces unstimulated salivary component-level changes