To clarify the maintenance plan for periodontal disease in prosthodontic treatment for partially edentulous patients, clinical examination for plastic deformation of underlying soft tissues, improvement of disclosing method for denture fitness, development of new relining material and clinical evaluation of periodontal tissues on the abutment teeth of partial denture wearer were investigated.
1. Study on the plastic deformation of underlying palatal mucosa
1) Swelling of mucousa membrane in the non-pressure-supporting area are occurred immediately after denture insertion, and the swelling height reaches about 80% of it's maximum value in three days in the lower posterior region. Thereafter, but, it changes very slow.
2) A cleanliness of the border between the non-pressure- and pressure-supporting area is high in the alveolar crest region and low in the buccal border side of the area.
2. Improvement of disclosing method for denture fitness
1) Disclosing method is usually applying on the chec
king of denture fitness, on the densitmetry anarisis for the record of white silicone, more than 70% of the ratio of the most closest area of the record shows good fitness, however, it is ill-fitting to the ratio of less than 50%.
2) The denture fitness goes down gradually when the mucous membrane bears unequal supporting load on the basal surface made by the mucostatic impression, however, it is scarcely change when the mucous membrane bears an equal supporting load on the basal surface made by the the functional impression.
3. Development of new relining material
1) Relining for the denture base improves denture fitness, however, usual material of the relining makes much irritation and bad taste during preparation. Therefore, a new nonirritating relining material for direct relining method is developed.
2) There are many cases difficult to prepare the complaint of pain caused by thin underlying tissues. For these patients, it is needed to seat a resilient material between basal surface and soft tissue. Therefore, a new resilient relining material for direct relining method is developed.
4. Clinical evaluation on the periodontal tissues of abutment teeth
1) Investigations employing a disclosing solution showed that the smallest degree of plaque deposit occurred on the buccal surface of the teeth and that plaque deposit was clearly greater on the lingual surface. Plaque deposit tended to be greatest on the surface adjacent to the base.
2) Periodontal pockets tended to be slightly deeper on the lingual side and the side adjacent to the base than on the buccal side. Less