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A Muramatsu

Publications and source records attributed to A Muramatsu.

At least 73 records · Page 4Linked to original sources
PubMed1981

[Studies on the performance of the dental air turbine handpieces. (Part 4) Analysis of the rotational performance of air turbine handpieces (N = N0 - CvFv gamma (author's transl)].

By the introduction of the diamond instruments and carbide burs measurably improved the quality and ease of cavity preparation, the several kinds of the air turbine handpieces, that is, standard type, torque type and miniature type air handpieces have been recently developed. In this paper, the performance tests of these air turbine handpieces have been carried out, and obtained the relations are indicated speeds and the vertical and horizontal loads or torque using the test bur. These relations are indicated by the logarithmic expressions, N = N0 - CvFv gamma, where N is the rotational speed of the air turbine handpieces during rotation, N0 is the free rotational speed of the air turbine handpieces, Fv is the vertical loads on the tests burs and Cv and gamma is the experimental constants. And then, the maximum performed work or the air turbine handpieces is presented by the expression as follows. W max = pimicrod/60(1/Cv)1/ gamma gamma (N0/gamma + 1)(1 + gamma)/gamma And we proposed the formula to be calculated for the performance ability of the air turbine handpieces.

Dental High-Speed Equipment↗
PubMed1981

[Studies on the performance of the dental air turbine handpieces. (Part 5) Rotational performance of various kinds of dental air turbine handpieces (N = N0--CvFv gamma) (author's transl)].

Making research on the rotational performance of the dental air turbine handpieces widely used for dental cutting instruments, we investigated with the relation between rotational speed and load on many kinds of dental handpieces used for clinical divisions and with the applications of the theoretical equations to have be shown in the previous report. And then we have the investigation on these properties. Dental handpieces to measured with these properties were classified the four types, standard types, torque type, miniature type and air bearing type. And we applied the experimental equations to these experimental values and determined the rotational coefficients, gamma and Cv. The rotational speed N and normal force Fv, which occurred the maximum work of air turbine handpieces, were calculated with our analysis and then these values of N and Fv were compared with the experimental results. These results, that is, experimental and calculated values have a good agreement and the development of the theoretical approach is useful for the estimation of the rotational performance. And we examined the possibility of rotational performance's estimation with the process of simple experiment on these air turbine handpieces.

Dental High-Speed Equipment↗
PubMed1980

[Studies on the performance of the dental air turbine handpieces. (Part 2) Classification and rotational performance of the dental air turbine handpieces (author's transl)].

For the purpose of the clinical and technical uses, air turbine handpieces are widely used for the high speed cutting instruments. And then, there are the many kinds of air turbine handpieces which are classified with the standard, minutia and torque types etc. So, in this paper, we examined the rotational properties of air turbine handpieces in the consideration of these classifications. And the relations between the reduction of the rotational speed and the rotational loads on the handpieces are fundamentally investigated. As the results of these investigations, it was revealed that rotational forces of the toque type air turbine are very excellent and the rotational speed of the air bearing type air turbine is higher than that of other type handpieces. And we obtained the practical properties of the rotational ability of air hand pieces.

Air↗
PubMed1980

[Studies on the performance of the dental air turbine handpieces. (Part 3) Torque measurements of the air turbine handpieces (author's transl)].

Air turbine handpieces, electro-micro motors and electric engines are widely used as the dental cutting instruments for the clinical use. So, this paper examined the measurement of rotational torque of the high speed dental instruments used for cutting works. For the measurement of torque of the dental instrument, we have measured the pushing load of the test but as used for cutting tools. But, in this paper, we attempted the new trials which are the measuring the tangential force of test bur rotated with the high speed velocity. And then, the kinetic energy values of rotational bur are obtained with using the value of the test bur's rotational torque. Besides we examined the interrelations of the rotational torque and pushing as the results, and both measurement value show the good relations for air turbine handpieces.

Air↗
PubMed1979

[Studies on the performance of the dental air turbine handpieces. (Part 1). Air pressure and bur length to be influenced over the rotational performance of the air bearing type handpieces (author's transl)].

Air turbine handpieces are used as the dental cutting instruments for the clinical use and many appliances. But, there are no studies on the performance of air turbine handpieces. So, this paper shows the rotational performance of air turbine handpieces which are influenced over the supplying air pressure and cutting bur length. Experimentally used air turbine handpieces is air bearing type and it's set up air pressure to be supplied is 3.5 kg/cm2. So, in this experiments, the range of air pressure is 1.8 approximately 3.5 kg/cm2, which is established five stages. And the bur length of the rotational parts is 5 approximately 9 mm with five steps. As the results, the rotational performance of air handpieces are influenced over these factors of the air pressure and the bur length. And air pressure to be supplied are influenced to be not only over the rotational speed but the load for the putting a stop to the revolutions.

Air Pressure↗
PubMed1978

[(author's transl)].

Explore the source record for details and available documents.

Dental Cavity Preparation↗
PubMed1978

[Some studies on the ability appreciation of dental handpieces (author's transl)].

Dental handpieces are usually used for cutting teeth instruments of dental treatments. But as ability appreciation of cutting instruments are widely influenced with cutting tools and then these studies have scarcely been reported until now. This paper shows the one method of the ability appreciation of handpieces which are used for test bur as the cutting tools. Test apparatus used for ability appreciation are manufactured for trial as the same way as the dental treatments and experiments of handpiece are carried out. Handpiece test specimens are standard type (air bearing type) made by own country as basic characteristics and then compering with the ability of the type differences, standard, miniature, supertorque and air bearing type made by foreign country are experimented. These results of tests are examined the influence of service air pressure and load speed to be bases on the relation between push load revolution of test burs. And then equivalent efficiency of the works of handpieces are discussed for the experimental results of these characteristics.

Air↗
PubMed1978

[Studies on the cutting ability of dental diamond points--the trial manufacture of the cutting test apparatus (author's transl)].

Diamond points and tungstencarbite burs are used as the dental cutting tools for many appliance accordingly with the many purpose of used positions. Notwithstanding that the dental cutting tools have been usually applied for many purpose of dental treatment, the paper on these studies have scarcely been reported. In this studies the test of dental cutting tools curried out using the diamond points and examined these characteristics. As the problems on the cutting tests are the push load of cutting tools and the cutting quantities. This studies tried to make the test apparatus for the cutting test of dental diamond points considering to dental treatments. The glass plates used for photograph are used for cutting materials supposing to the enamel properties of teeth and the cutting tests put into practice for the types of diamond points with different diameter. The cutting characteristics of the diamond points are examined with the using of the test results and are appreciated with the considering to the test apparatus.

Dental High-Speed Equipment↗
PubMed1977

Familial medullary carcinoma of the thyroid through 3 generations.

A family with high genetic penetrance of medullary carcinoma of the thyroid was reported. Seven proven (6 patients and one autopsy case) and 2 probable cases of medullary carcinoma were present in 25 members through 3 generations. An endogemy had intervened in the prior generation of these cases. Preliminary results in clinicopathological examinations of 7 proven cases were as follows; clinically, all of the cases showed B type blood group. Glycosuria was found in 2 cases, and diarrhea in one case. Serum thyrocalcitonin being estimated in two cases showed high levels. The autopsy cases coexisted with medullary carcinoma of the thyroid and pheochromocytoma of the right adrenal. Pathologically, the majority of tumors occurred in both thyroid lobes, and were present from the middle to upper portion of the thyroid. The tumor showed a variety of histological features even in the same tumor. In the tumor cell, numerous membrane-limited granules were seen with an electron microscope. Amyloid was demonstrated only in the tumor tissue.

ABO Blood-Group System↗
PubMed1976

[Studies on the strength and the cutting performance of dental canal reamer. (I) Strength properties of raw materials of dental canal reamer and these standard (author's transl)].

Pulp canal reamers have been widely used for dental treatments of the root of teeth. The work's accuracy and cutting capability of these instruments are treated by the standarization of JIS and ADA etc. Especially Japanese industrial standarization (JIS) treated the dimensions of the configurations, materials and ability of dental canal reamers. But there is no report of the studies on the work and fracture strength of these dental instruments. So, this paper makes a report on these problems, which are the measurements of the diameter of the bite tips, are concerned the strength of the raw materials of dental canal reamers and are compared with the standarization (JIS) of these instruments. Test of the raw materials of reamers are tensile properties and are measured the strength and elasticity of these materials. And phase of fracture of these materials are investigated with the scanning electric microscope and the fracture modes are compared with the tensile strength properties.

Dental Instruments↗
PubMed1976

[Studies on the strength and the cutting performance of dental canal reamer. (II). Torsional strength and tip diameter of dental canal reamers (author's transl)].

Strength of pulp canal reamers are important problems for cutting treatments of the root of tooth at the dental regions. Reamers have been used as cutting tools by the twisting movements, and then, fracture of reamers are especially caused by the shearing stress at the bite tips. So, this paper treated the shear strength of dental canal reamers, which are torsional strength and twisting rigidity of these cutting instruments. And we made the torsional apparatus for cutting and twisting tests, and tested the torsional strength of raw materials and pulp canal reamers. Type of reamer's configuration are treated by Japanese industrial standard (JIS) and these properties are readjusted with dimensions of diameter of reamers. Shear strength of reamers are 120 approximately 140 kg/mm2 and strength of straight bar with taper are about two times of that of reamers which are about 40 kg/mm2 (except reamer's number 1, 2). Scattering of value of strength and torsional angle of these reamers are examined and showed the range of scattering of these properties. Effectiveness of torsional angle on the fracture properties are considered on the clinical treatments and treated the safety of fracture of these reamers.

Dental Instruments↗
PubMed1976

[Studies on the strength and the cutting performance of dental canal reamer. (III) Cutting performance and torsional fracture (author's transl)].

Characteristics of cutting torque and fracture strength of pulp canal reamers are important problems as for the severity used at many of dental cutting tools. And it is the most difficult problems that reamers are cutting tools to be used for magnification of root canals. So, this paper makes a report on the measurements of reamer's section and dimension of the under hole, which are required for cutting test, and on the safety of characteristics of dental canal reamers. Diameter of under hole are determined by the relationship of reamer's section. And these results of measurements are compared with the Japanese Industrial Standard values and we discussed the probabilities of the clearance of these dimensions. Cutting torque of reamers are measured with twisting test machine of our making. Concerning the safety of fractures, we apply the theoretical analysis for the fracture to torque of bite tips and estimated the fracture torque of cutting section of reamers. And probablity of twisting fracture of reamers are existed about from one half to one-fifth values for the dental reamers of practical used.

Dental Instruments↗