片側性二重冠遊離端義歯支台の変位分析 : 片持ちバリ固定性義歯支台との比較
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概要
- 論文の詳細を見る
To analyse the mechanical behavior of a cantilevered fixed partial denture (CFPD), Simulation models, Kennedy class II with lower left first and second molar missing had been constructed by Itose, and the displacement of abutment teeth 5^^-, 4^^- and 3^^- had been measured by digital type laser displacement sensors with a load placed on a piece of test food put on the lower dental arch including each abutment tooth on the working side, and he already reported the measurements which were reciprocally compared through the statistical analyses. Under the same conditions, what sort of change in the displacement of the abutment teeth will be revealed if a distal extension removable partial denture instead of a CFPD is designed? The purpose of this study lies in the above theme to be reviewed. The results obtained were as follows : 1) Four displacement forms : parallel movements, inclinations, twist-like movements and depressions were recognized in individual abutment tooth of the single, the two splinted, and the three splinted abutment casting, but the abusolute magunitude of the displacement had a tendency to be slightly smaller except in twist-like movement compared with that of CFPD which Itose have reported. 2) The displacement of abutment teeth as well as that of CFPD increased in company with increasing load in any designs. 3) Parallel movements and inclinations displaced to distolingual direction, and twist-like movements rotated clockwise around the vertical axis in every design and every abutment tooth like that of CFPD. 4) Although it has been reported that greater displacement on the most anterior abutment tooth was recognized than that of the adjacent abutment one to the edentulous region in CFPD, the displacement of the adjacent abutment in designs used in this experiement was the greatest excepting the twist-like movement. 5) Especially, inclinations and parallel movements in the abutments 5^^- and 4^^- of the design T and D had a tendency to increase compared with those of each control, but twist-like movements in the single abutments and the most anterior ones of 3^^- showed a tendency to decrease. 6) By increasing the number of abutment tooth, twist-like movements in the abutment teeth 5^^- and 4^^- decreased significantly, but inclinations in them including abutment 3^^- showed little change. Splinting the abutment tooth mutually and reducing the dental tooth had scarcely any effects on the displacement magnitude of abutments in the plate denture used in this experiment compared with CFPD. 7) Although the displacement magnitude of abutment teeth in design T-1P were the smallest in all designs, little difference was recognized between those of designs T-1P and T-2P, especially on inclinations. The foregoing results suggested that expanding the denture plate was more effective for inhibiting the distal tipping of abutment teeth rather than reducing the area of occlusal table even though it was very useful in CFPD.
- 九州歯科学会の論文
- 1998-08-25