Discussion
’, moisture retention, denture adhesives, denture, dry mouth
DRY MOUTH, CAVITY
In this pilot trial, we compared a novel denture adhesive for dry mouth (PK) to an array of other conditions. The other four tested conditions were conventional cream-type denture adhesive, oral moisturizer, denture moisturizer with an oil-based ingredient, and a negative control. In general, PK showed promising results in terms of achieved retentive strength over time and subjective outcomes.In this study, BT, which has a high viscosity, was selected among the oral moisturizers. Yamagaki et al. [Regarding the testing procedures, used devices followed standards set by a previous study, starting by the retentive force measuring device. To define the direction of traction, the angle gauge used in this study (Digital angle gage WR300 Type 2®, Wixey, US) can be set with reference to any plane. First, the arm at the end of the maintenance force measuring device was used to align the reference to the Frankfort plane of the participant, from which the device was tilted to 60° for traction. The use of the Camper’s plane as the reference plane in setting the virtual occlusal plane seems reasonable since it is used in daily clinical practice. In a study by Bandai et al. [This study also standardized the time for experimental procedures. Considering the diurnal variation of salivary secretion and body temperature [The two null hypotheses, that retentive force does not change with time and that the retentive force does not change with the type of substance, were rejected by one-way ANOVA. PK, NP, and BT showed higher retentive force than the control immediately after fitting. On the other hand, no significant difference was observed between DW and controls. Therefore, DW may not be able to increase retentive force. After 10 min, the retentive force of BT decreased to the same level as that of the control, suggesting that the duration of the effect of BT on the palatal plate was approximately 10 min only. BT contains more water-soluble components such as glycerol, which may have been washed out from the mucosal surface by saliva, resulting in a shorter duration than that of NP. After 20 min of application, NP showed the highest retentive force. PK showed higher retentive force than the control, but lower than NP. Since NP binds to water and exhibits adhesive properties, it became compatible with the water in the oral cavity in approximately 20 min, which generated a strong retentive force. A significant difference was observed after 30 min, suggesting that its effect lasts from 20 to 30 min, compared with the control. However, the retentive force decreased over time, so it could be necessary to apply again after 30 min of use. NP remained to have high retentive force, suggesting that it is effective in increasing the retentive force for more than 30 min. PK showed a gradual decrease in retentive force over time. Meanwhile, NP showed a rapid increase in retentive force from immediately after the application to 10 min afterwards. Compared with the other test substances, 10 min is necessary for it to take effect and for the retentive force to stabilise. When using BT, the retention force was stronger immediately after application than at other time points, and decreased after 10 min. Therefore, its duration of effect was within 10 min, and its effectiveness as a substitute for denture adhesives was limited. Finally, DW did not show significant differences over time, suggesting that it is unlikely to be effective in increasing retentive force.In terms of subjective properties, the null hypothesis that the usability does not change when the sample is changed was rejected by one-way ANOVA. PK performed relatively well for wettability and washability, which can be explained by its moisturizing ingredients (e.g., sodium polyacrylate and sodium hyaluronate). Due to its higher moisture retention, its ‘wettability’ is higher in the subjective evaluation. Its ‘washability’ is also higher due to its high content of water-soluble components. A report by Ohno et al. [The limitations of the present study include taking measurements from healthy study participants without dry mouth and subjects having stable oral environmental conditions. Furthermore, this measurement time was 30 min, which was assumed to be the duration of one meal, but the effect of a longer using was not clear. A study by Ohno et al. [