Influence of denture supporting tissue properties on pressure-pain threshold--measurement in dentate subjects

The present study was designed to clarify the relationship between the properties of the palatal mucosa and the pressure-pain threshold.

Three parts of the palatal mucosa of 17 dentate subjects were measured: the median part of the palate, the lateral part of the first molar, and the midpoint between these two parts. The subjects were instructed to press a pushbutton when he or she felt pressure-pain. The probe pressure was gradually increased (1N/s). The thickness (T) (mm) and elasticity (E) (MPa) were used as the parameters of the properties of the palatal mucosa, whereas pressure (P) (MPa), compressibility (C) (%), and subsidence (S) (mm) were used as the parameters of the pressure-pain threshold. The Shapiro-Wilk test was used to consider the data of distribution of normality for each measurement point, as obtained from the 17 subjects. A Kruskal-Wallis test and a Wilcoxon signed rank test were performed for multiple comparisons, the Bonferroni method was used to compensate for the P-value. Spearman's rank correlation coefficient was calculated.

T correlated with the values of S at the median points (P=0.001) and midpoints (P=0.011).

Thickness can be an index of the amount of relief where pain is caused easily. In addition, modulus of elasticity is important as an indicator of the bearing ability of denture support tissues, it is necessary to consider how to evaluate the modulus of elasticity and to evaluate the relationship between the parameters of the pain threshold.