Katsuzo Ohki

Study on the Burden Capacity of Abutment Teeth of the Partial Denture. Influence of the Dental Root Shape.

Various attempts have been made to investigate what effects the constitutional elements of a partial denture have on the abutment teeth and how the difference in its design, retention and supporting method affects the abutment teeth. However, no analysis seems to have been reported as to the difference in the capacity of load that the abutment teeth have and the force on the periodontal tissues, which have different dental root shapes.Therefore, the strain in the periodontal membrane of the straight root and curving root shapes were investigated by using the 3-dimensional strain gauge system. The results were as follows:1. In both root shapes, the greater the load, the greater the strain on the periodontal membrane.2. There was a difference in the value and direction of strain between straight root and curving root shapes. Furthermore, the strain on the curving root shape was greater than that on the straight one.

A study on high-strength denture teeth. Part I. Wear resistance of anterior artificial teeth.

High-strength denture teeth (hereafter referred to as HS teeth) were developed to improve hardness and wear resistance of the conventional plastic denture teeth, while retaining their feature of easy occlusal adjustment.The objective of this study was to evaluate wear resistance of HS teeth. We conducted the wear test and measured surface roughness, using six types of anterior artificial teeth; ie.three types of HS teeth and three types of conventional plastic denture teeth (hereafter referred to as PL teeth) which served as the control.The result of the toothbrush abrasion test revealed that the HS teeth have about 5 times grater wear resistance than the conventional PL teeth. It was also found out that the type of artificial teeth and the number of wear-testing strokes made a significant influence on the surface roughness of artificial teeth.(P<0.05)

A questionnaire about the dental treatment for visiting patients at welfare center for the aged people

A questionnaire about the dental treatment for visiting patients at Welfare center for the aged people. Nowadays, 11 percent of the population is over 65 in Japan. According to the Minister of Health and Welfares Population Projection for Japan, it will grow to 20% at the beginning of the 21st century. Problems concerning old people will become some of Japans biggest challenges. In that situations, the dental treatments for visiting aged patients will become more important. Then, authors sent out a questionnaire about it on aged people who have no need of anyones assistance in their home lives. And we examined concrete countermeasures and problems about the dental treatments for visiting patients. The findings were as follows: 1. Even the aged people who have no need of anyones assistance in their home lives, they hope much carrying out the dental treatments for visiting them. 2. The dental treatments for visiting aged patients have some problems. But it will become one of the most important way to supply their demand for dental treatments, in spite of their latent requirements, a lot of old people give up to undergo dental treatments.