Studies on Load and Strain on the Compression of the Seat Mucosa of Complete Dentures

Abstract

The fact that the compressed distortion of the seat mucosa of complete dentures (just the seat mucosa will be substituted for the seat mucosa of complete dentures in subsequent sentences) varies from an area to another is considered one of the primary factors to adhesive retention, stabilization and masticating efficiency of dentures and problems of the seat mucosa.Some researches have been already reported on the compressed distortion of the mucosa, is rather difficult to find any clinically significant values in them form the following 1) they measured just strain under a given load, whereas load itself varies regionally mucosa. 2) they have not represented accurate relationship between load and strain condition of the compressed distortion under various loads.Since the new type transducer was designed and developed by the auther, it became measure both the load and strain simultaneously in a given condition of the seat mucosa also to compare physical hardness and tension of the mucosa at different regions.The following conclusions were obtained.1) The simultaneously measured load and strain of the seat mucosa were shown in Tables -4. It was obvious that the load and strain of the seat mucosa were different regionally and they were summarized as follows.a) Both the load and strain of the seat mucosa of anterior alveolar ridge were greater than those of the seat mucosa of posterior alveolar ridge.b) In the mucosa of palate, the load in anterior region was greater than it in posterior and the strain increased with a small difference in turn in the region of middle palate, rugae and foveola palatini. And the strain in those three regions were with significance smaller than those in the palatal side of the region of premolar and in the region of posterior palatine foramen where the greatest strain was acquired from.c) When comparison was made between the load in the region of alveolar ridge and it in the region of palate, and the strain in those two regions:i) The load in anterior ridge had a tendency to be slightly smaller than it in theregion of rugae, but to be greater than it in the region of middle palate, the palatal side of the region of premolar and the region of posterior palatine foramen, and was distinctly greater than it in the region of foveola palatini.The load in posterior ridge had a tendency to be slightly greater than it in the region of rugae, although the differen between the two was little, and was obviously greater than it in the other regions, that is, middle palate, foveola palatini, palatal side of the region of premolar and posterier palatine foramen.ii) The strain in anterior ridge had a tendency to be slightly smaller than it in the region of rugae and was obviously greater than those in the region of middle palate, foveola palatini, palatal side of the region of premolar and posterior palatine foramene.The strain in posterior ridge had a tendency to be greater than it in the region of rugae and middle palate, but a tendency to be smaller than it in the region of foveola palatini and was obviously greater than those in the palatal side of the region of premolar and in the region of posterior palatine foramen. It was a trend in the aged person over 60 years, however, that difference of strain in anterior ridge, in the region of middle palate and foveola palatini became on the decrease.3) The load and strain of the seat mucosa increased with age. It was, especially, evident in the load in posterior alveolar ridge and in the region of palate. And the strain in anterior ridge and in the region of rugae remarkably increased with age.4) The load in upper alveolar ridge was significantly greater than it in lower. On the other hand, the strain in upper ridge had a tendency to be greater than it in lower, but no significant difference between the two was found.