PURPOSE: To investigate the difference in improvement of oral health-related quality of life (OHR-QoL) depending on the oral and denture conditions of a complete denture wearer when using a cream or powder type denture adhesive in a 10-center parallel randomized clinical trial. METHODS: Two hundred edentulous subjects who wore complete dentures were allocated to each of the three groups according to denture adhesive type: cream, powder, and control (saline solution). The materials were applied to the mucosal surface of the dentures for 4 days, and baseline data and data after the intervention were collected. OHR-QoL was assessed using the Japanese version of the modified Oral Health Impact Profile for Edentulous Patients (OHIP-EDENT-J) scale for outcome. Multivariate analysis was used to investigate improvements in OHR-QoL according to participant characteristics among complete denture wearers using these materials. RESULTS: OHIP-EDENT-J scores were significantly decreased in all groups after the intervention (p < 0.05); however, there were no statistically significant differences among the groups. Multiple logistic regression analysis revealed a significant association between the vertical height of the maxillary and mandibular alveolar ridge and OHIP-EDENT-J scores in the cream-type denture adhesive group. In contrast, there were no significant association between participant characteristics and OHIP-EDENT-J scores in the powder-type adhesive and control groups. CONCLUSIONS: The use of denture adhesives could improve OHR-QoL for complete denture wearers. The cream-type denture adhesives may be expected to improve OHR-QoL in patients with poor residual ridge conditions compared with patients with good residual ridge conditions.

PURPOSE: The purpose of this study was to investigate the effect of denture adhesives on oral moisture in a 10-center parallel randomized clinical trial. METHODS: Two hundred edentulous subjects wearing complete dentures were allocated into three groups: cream-type adhesive, powder-type adhesive and control groups. The adhesives (and saline solution in the control group) were applied to the mucosal surface of the dentures for 4 days, and baseline data and data after the intervention for eight meals over 4 days were obtained. For the main outcome, oral moisture was measured with a moisture checking device. Secondary outcomes were denture satisfaction, masticatory performance, denture retention, and occlusal force. In addition to between-group and within-group comparisons of oral moisture, investigations for secondary outcomes were undertaken in subgroups classified according to the degree of oral moisture at baseline (normal subgroup and dry mouth subgroup). Intention-to-treat analysis was also performed. RESULTS: Between-group and within-group comparisons of oral moisture showed no significant differences. The cream-type and powder-type denture adhesives were significantly effective in the dry mouth group for denture satisfaction ratings of ability to masticate, stability, retention, and comfort of mandibular dentures (p<0.05). The masticatory performance and retentive force of the dry mouth denture adhesive using groups were significantly improved after intervention (p<0.05). CONCLUSIONS: The oral moisture of complete denture wearers was not influenced by the use of denture adhesives. Our findings showed that denture adhesives improved subjective denture satisfaction, masticatory performance, and retention for complete denture patients with oral dryness.

INTRODUCTION: Many reports show that denture adhesives improve the retention and stability of dentures. However, few randomized controlled trials have examined the effects of denture adhesives. OBJECTIVE: This 10-center randomized controlled trial with parallel groups involving 200 edentulous patients wearing complete dentures aimed to evaluate the effects of short-term use of cream and powder denture adhesives. METHODS: Patients were allocated into 2 cream- and powder-type adhesive groups and 1 control group. Intervention groups were treated with the 2 adhesives (1 each), and the control group received saline solution. Adhesive or control was applied to the denture-mucosal surface for 4 d, and data at baseline and after day 4 of intervention (i.e., 8 meals) were obtained. Patient satisfaction was evaluated with a 100-mm visual analog scale. Oral health-related quality of life was measured with the Japanese version of the Oral Health Impact Profile for Edentulous Patients. Perceived chewing ability was evaluated by a questionnaire regarding ease of chewing and swallowing food. Between-group comparisons were performed with Kruskal-Wallis tests with the Mann-Whitney U test adjusted by Bonferroni correction. Within-group comparisons of pre- and postintervention measurements were performed with the Wilcoxon signed-rank test. Intention-to-treat analysis was also performed. RESULTS: Between-group comparisons showed no significant differences for general satisfaction or Oral Health Impact Profile for Edentulous Patients. However, significant differences in satisfaction with various denture functions with cream- and powder-type adhesives were seen in pre- and postintervention comparisons (P < 0.05). Significant differences were also observed for perceived chewing ability of hard foods (P < 0.05). CONCLUSION: These results suggest that although denture adhesives do not invariably improve denture function, they do affect subjective evaluations and possibly chewing of hard foods. Therefore, the effects of denture adhesive use are insufficient to resolve any fundamental dissatisfaction with dentures ( ClinicalTrials.gov NCT01712802 ). KNOWLEDGE TRANSFER STATEMENT: The results of this study suggest that denture adhesives should be applied under certain conditions; however, an appropriate diagnosis is important before application. These practice-based data provide information to establish evidence-based guidelines for applying denture adhesives.

Despite the important role of oral texture perception in feeding and nutritional homeostasis, its impairment has not been of particular clinical interest, and no clinical protocol is available to evaluate its acuity. This preliminary study aimed to establish a method to evaluate the acuity of oral texture perception. Because texture perception is regarded as reflecting integrity of the sensorimotor system of the jaw and mouth, we hypothesized that the ability to perceive various aspects of food texture would correlate with each other, and tested our hypothesis in 11 healthy adults. First, we prepared three types of test foods with different dominant textures, each of which comprised a series of stimuli with different ingredient concentrations; we used these test foods in discrimination tests involving pairwise comparison. Tests performed using the up-down staircase method revealed significant correlation among the discrimination thresholds for three test foods, suggesting that acuities of texture perception correlated with each other across different textural attributes. Second, we examined the associations between the acuity of texture perception and some aspects of mechanical sensation of the tongue: tactile and two-point discrimination thresholds, as well as the graininess recognition threshold. The acuity of texture perception of the subjects whose sensitivity was low for at least one of these aspects of mechanical sensation (n = 5) was significantly lower than that exhibited by the other subjects (Wilcoxon rank-sum test, p = 0.0417). We concluded that oral texture perception ability can be evaluated by discrimination tests for specific aspects of texture, using appropriate test foods.

Atrophy and infection of the tongue mucosa contribute to dysgeusia resulting from changes in lingual papillae. However, influences of the changes of lingual papillae on oral mechanoreceptive sensation is unclear. Previous studies have suggested that filiform papillae function as a unit of the mechanoreceptive system and play an important role in somatosensation. We hypothesized that lingual papillae including filiform papillae participate in intraoral texture sensation. The aim of present study was to investigate the relationship between morphometric characteristics of lingual papillae and the texture sensation in tongue-hard palate. Sensory evaluation was performed in 10 healthy participants to evaluate the sensitivity of the tongue-hard palate to granularity. The sample food was an aqueous suspension containing crystalline cellulose, with an average particle diameter of 50 &mu;m, and a concentration of 0 to 6.4 wt%. The participants were divided into high- or low-sensitivity groups (n=6 vs. 4) by evaluating the sensitivity to the granularity of the suspension. To assess the quantitative and morphometric parameters of lingual papillae, the surface roughness defined by JIS was measured by using X-ray micro-CT for image analysis of the surface configurations, which were recorded by silicone rubber impressions taken from the anterior region of the tongue. A concentration of the sample for determining the granular sensitivity threshold ranged from 0.4 to 3.2 wt%. Comparison of the high- and low-sensitivity groups revealed that the root mean square deviation (Rq) and arithmetical mean deviation (Ra) were significantly larger in the high-sensitivity group. In contrast, the lowest valley (Rv) was significantly larger in the low-sensitivity group. These results suggest that the morphometric characteristics of lingual papillae, evaluated in terms of surface roughness, may play a role in intraoral texture sensation.