Abstract
In order to estimate the long-term clinical effects of wearing partial dentures, the authorsundertook follow-up on2140dentures with which1564patients were fitted at Tokyo Medical and Dental University.Clinical examinations were performed at the time when the dentures were inserted.Six months to five and a half years thereafter a questionnaire was sent out to each case to ask several simple questions on the dentures, and to attend for re-examination. 722 cases received re-examination and590partial dentures of them were used at that time. We examined the fractures in these dentures.
The following results were obtained:
1) The denture fractures were observed in96cases (16.3percent) of the examined partial dentures.These fractures occurred in39cases (6.6percent) at the denture base, in25 cases (4.2percent) at the artificial tooth and in 38 cases (6.4percent) at the retainer.In73 cases of590cases (12.4percent) occurred the deformations of the retainers.On the other hand the repairs of the dentures were observed in23cases (3.9percent).
2) The denture fractures, especially the fractures of the denture bases, occurred more in male than in female.
3) Comparing the upper partial dentures with the lower partial dentures, the denture bases and the retainers fractured more in the latter than in the former.
4) The fractures of the denture bases occurred more in the anterior and posterior dentures than in the anterior dentures or the posterior dentures.
5) The rate of the fractures at the denture base increased with the decrease of remaining teeth.
6) The examined dentures were divided according to their antagonistic teeth into full denture, partial denture and natural teeth.Their rates of the fractures were not significantly different.
7) The rate of the denture fractures did not increased with the lapse of time after their insertion.
