So as to research what form the cast core is, the two-dimensional photoelastic specimens were turned various into the survival degree of labial and lingual part of the tooth crown, were made and observed the stress distribution. At the same time, the dynamic comparisons between the one and two stage system were carried out.
As the results of these efforts, the following conclusions were obtained.
1. The existence in the lingual substance of the tooth crown was effective the control of the displacement for the load direction and the leap of dowel pin apex.
2. The about one-third existence in the lingual substance of the tooth crown was brought on the decrease of the stress distribution at lingual lower part around the dowel pin and the labial neck part around the tooth root.
3. In case of the clinical normal tooth form, the stress distribution in the abutment form, that was the cast core, being existed the labial one-third and lingual one-half part of the tooth crown are little each part. As it was exhibited the balanced distribution, consequently, it was said that these form was stable dynamically.
4. The stress distributions between the one and two stage system for the dowel crown prosthesis of the two plane root surface type were little differed.

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Recently occlusion becomes a topic in dentistry. Complete denture service requires not only the functional requirement but also the application of the anatomical, physiological and pathological reqirements. The occlusal balance on restration of which are given on articulator, should be caused same as in patient mouth is most important keeping the gnatho-stomatological system healthy.
The major concern is for the prevention of further destruction of oral tissues and structures as a result of wearing complete dentures and for the care of oral health of edentulous patients. To accomplish this objectives, the occlusal relationship of patient's mouth should be exactly reproduced on articulator. Thus the face-bow is used to orient the upper cast the articulator.
The reproduceability of upper cast on articulator by face-bow transfer were evaluated on T. M. J. articulator (useing true hinge axis points), Dentatus articulator (useing arbitrary condyle points) and Whip-mix articulator (useing auditory meatus).
The measurements are done on our developed the three dimentional gnathometer. The face-bow transfers are done from a manikin and from a complete denture patient of age at fifty-five. An experienced operator of this face-bow transfer is the author and an unexperienced operator of this procedure is used a dental senior student.
The data are compared of reproduceability of upper cast on articulator between a manikin and a complete denture patient, and between an experienced and an unexperienced operator. Also the reproduceability of useing three base plate materials by face-bow transfer are evaluated.
The following conclusion are obtained.
1. The results of useing base plate materiales by face-bow transfer on manikin by an experienced operator, the reproduce-ability of upper cast on articulator are arranged in superior orders as follow; Self-curing acrylic resin>Shellac base plate>Baseplate wax.
2. The results of useing base plate materiales by face-bow transfer on human subject by an experienced operator, the reproduceability of upper cast on articulator are arranged in superior orders as follow; Self-curing acrylic resin>Shellac base plate>Baseplate wax.
3. The results of face-bow transfer on manikin by an experienced operator, the reproduceability of upper cast on articulator are arranged in superior orders as follow; T.M.J. articulator>Whip-mix articulator>Dentatus articulator.
4. The results of face-bow transfer on human subject by an experienced operator, the reproduceability of upper cast on articulator are arranged in superior orders as follow; Whip-mix articulator> T.M.J. articulator>Dentatus articulator.
5. The results of face-bow transfer on human subject by an unexperienced operator, the reproduceability of upper cast on articulator are arranged in superior orders as follow; T.M.J. articulator >Whip-mix articulator>Dentatus articulator.
6. The results of face-bow transfer by an experienced operator on manikin are always superior reproduceability than the results on human subject.
7. The results of face-bow transfer on human subject by an experienced operator are always superior reproduceability than the results by an unexperienced operator.

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