Changes of blood flow in the mucosa underlying a mandibular denture following pressure assumed as a result of light clenching.

The aim of this study was to investigate the influence of the continuous compression assumed as a result of light clenching on the blood flow of the denture underlying mucosa in tissue-supported or tooth-tissue-supported denture wearers. Measurements were carried out on eight removable partial denture wearers (three males and five females, from 50 to 72 years, mean age: 61.5 years). The blood flow in the denture underlying mucosa was measured at the unilateral mandibular first molar region using an experimental denture base equipped with a laser Doppler flowmeter. The area of the experimental denture base was 2 cm2, and the loading force was 1 kgf. The loading time was set at 5, 10, 20, 30 and 60 s. The blood flow after 20 s loading was <15% in rest. The times from release of loading to the maximum blood flow and from release of loading to recovery up to 110% of the blood flow at pre-loading were significantly prolonged by an increase in the loading time. Even if it is light, a continuous clenching results in ischaemia and delays the recovery of blood flow in the mucosa underlying the denture after release of compression.