Three-dimensional tooth positions on maxillary dental casts of twenty-two male and female young Japanese having clear cusps. were measured by clinical measuring method.
Average measuring errors between measuring persons were 0.12mm, 0.14mm, or 0.15mm, for antero-posterior. bucco-lingual. or supero-inferior measurement, respectively.
First, setting the incisal point as the original point for measurement, three-dimensional positions of the middle points of the edges of lateral incisors, the tips of canines, the buccal/lingual and distal/menial cusp tips of the first and second premolars and the first and second molars, were measured antero posteriorly, buccal-lingually, and supero-inferiorly.
The measured three-dimensional positions of each measured points on the left and right dental arrangements on the maxillary dental casts were averaged and the arithmetical means of their standard deviations were calculated.
Average measuring errors between measuring persons were about 14^th, 15^thor 8^thof the arithmetical means of the standard deviations of antero-posterior, buccal-lingual, or supero-inferior positions, respectively, indicating the deviation between measuring samples are prevailing over the measuring errors between measuring persons.
Any statistically meaningful difference between left and right dental arrangements did not existed in antero-posterior and buccal-lingual positions, in contrast to that, some statistically meaningful difference between left and right dental arrangements existed in supero-inferior positions, indicating the existence of possible correlation between supero-inferior positions and lateral displacements of the mandible or chewing habit.

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[in Japanese]

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Based on the results of our previous study, we carried out 2 types of experiments on the effective removal method on the adhesion surface contaminated with saliva as the primary factor inhibiting adhesion. In Experiment 1. adhesion tests were performed, and adhesion strength was evaluated. In Experiment 2, a reagent for the salivary amylase reaction was used, and residual amylase solution was examined. The following results were obtained.
(1) Experiment 1: No significant differences were observed among saliva alone. washing with water, and alcohol. Sandblasting showed the maximum value.
(2) Experiment 2: Salivary amylase reactions were observed for saliva alone, washing with water, alcohol, and dichloromethane.
(3) Both Experiments 1 and 2 showed a similar tendency.
(4) The results of Experiments 1 and 2 suggested the usefulness of Oxydol. ultrasonic cleansing, tooth surface cleaning machine, and sandblasting.

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[in Japanese]

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[in Japanese]

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