Abstract
Difference in the area of preliminary impression surface resulted from two different techniques for edentulous arches were examined. Thirty-five edentulous patients (70 sides of mandibular arch) were used for subjects. Projected areas on the tentative plane of occlusion and superficial areas of mandibular impression surface were measured. The areas and the ratio of areas (modeling compound/alginate) were examined in each of the anatomical zones. Subjects were divided into three groups according to the degree of alveolar bone resorption of mandible (severe, moderate and slight resorption groups).
In each anatomical zone, projected and superficial areas of modeling compound impression were larger than those of alginate impression. The ratio was the highest in the distolingual zone among mandibular anatomical zones regardless of the extent of alvealar bone resorption. The severe resorption group indicated the highest ratio in each anatomical zone.
From these results, it was revealed that the areas of modeling compound impression are larger than those of alginate impression in any anatomical zone and the ratio is the highest in the distolingual zone. The ratio also showed a tendency to increase depending on the advancement of bone resorption in each anatomical zone.
