15 research outputs found
(A) clinical study of dental amalgam restoration : reasons for replacement and duration of primary reatoration
์น์ํ๊ณผ/์์ฌ[ํ๊ธ]
์ถฉ์ ์ฌ๋ฃ์ค ์ค ์น๊ณผ์ฉ ์๋ง๊ฐ์ ๋น๊ต์ ์กฐ์์ด ๊ฐํธํ๊ณ , ๋ฌผ๋ฆฌ์ ์ฑ์ง์ด ์ถฉ์ ์ฌ๋ฃ๋ก์
์ ๋นํ๋ฉฐ, ๊ฐ๊ฒฉ์ด ์ ๋ ดํ๋ฉฐ, ์ค๋ซ๋์ ์ฐ์ฌ์ ธ ์๊ณ , ๊ฐ์ฅ ๋๋ฆฌ ์ฌ์ฉ๋๊ณ ์์ผ๋ ๋๋ฆฌ์ด
๊ทธ ๋๋ฌธ์ ์์์์ ์์ดํ๊ฒ ์ทจ๊ธํ๋ ๊ฒฝํฅ์ด ์์ด ์ด์ฐจ์ฐ์์ ๋ฐ์์ด๋ ํ์ , ํ๋ฝ, ํฌ
๊ธฐ์ ๋ณํ ๋ฐ ๋ณ์, ๋ถ์ํ์ ๋ฑ์ผ๋ก ์ฌ์ถฉ์ ์ ์ํ๋ ๊ฒฝ์ฐ๊ฐ ์ผ๊ธฐ๋๋ค. ์ด์ ๊ฐ์ ๊ฒฝ์ฐ
๋ ์ฌ๋ฃ์์ฒด๋ ํ์์ ๊ตฌ๊ฐ๊ด๋ฆฌ ์ฌํ์๋ ๋ฌธ์ ๊ฐ ์๊ฒ ์ผ๋ ์ ์์ ๋ถ์ฃผ์, ๋ถ์ ์ ํ ์กฐ์
์ด ๋ ํฐ ์์ธ์ผ๋ก ์ง์ ๋๊ณ ์๋ค.
1977๋
๋ถํฐ ์ค์๋ ์๋ฃ๋ณดํ์ ํ๋๋ก ์๋ง๊ฐ ์ถฉ์ ์์๋ ๋ค๋ฅธ ์ถฉ์ ์ฌ๋ฃ์ ๋นํด ๊ทธ ์ด
์ ๋ณด๋ค ํ์ ํ ์ฆ๊ฐ๋๊ณ ์์ผ๋ฉฐ, ์ฌ์ถฉ์ ํด์ผ ํ ๊ฒฝ์ฐ๋ ๋์ฑ ๊ฒฉ์ฆํ๋ฆฌ๋ผ ์์๋๋ค.
์ด์ ์ ์๋ ์๋ง๊ฐ ์ถฉ์ ๋ฌผ์ ์ฌ์ถฉ์ ์ด์ ๋ ์ฌ์ถฉ์ ๊น์ง์ ๊ธฐ๊ฐ์ ์กฐ์ฌํ๋ ๊ฒ์ ์์
์์ ๋ณด๋ค ์ข์ ์น๋ฃ๋ฅผ ์ํด ๊ธด์ํ ๊ณผ์ ๋ผ ๋ฏฟ์ด 1975๋
1์๋ถํฐ 1977๋
12์๊น์ง ์ดํ์ฌ
์๋ํ๊ต ๋ถ์๋ณ์ ์น๊ณผ์ ๋ด์ํ ํ์ 2,856๋ช
์ ๋์์ผ๋ก ์น๊ณผ๋ณ๋ก๋ถ๋ฅผ ์ด์ฉํ์ฌ ์ฌ์ถฉ
์ ํ ์๋ง๊ฐ 260์์ค ๋จ์ผ ์์ธ์ด๊ณ ๊ธฐ๊ฐ์ด ๋ช
์๋์ด ์๋ 205์์ ์ฌ์ถฉ์ ์ด์ ๋ฐ ์ฌ์ถฉ
์ ๋๊น์ง์ ๊ธฐ๊ฐ์ ๋ํด ์กฐ์ฌํ์๋ค.
๊ทธ ๊ฒฐ๊ณผ๋ ๋ค์๊ณผ ๊ฐ๋ค.
1. ๋ด์ํ์์ ์ ์ฒด์ถฉ์ ๋ฌผ ์ค 58.5%๋ ์๋ง๊ฐ์ด์์ผ๋ฉฐ, ์ด ์ค ์ฌ์ถฉ์ ์ ํ ๊ฒ์ ์ ์ฒด์ถฉ
์ ์๋ง๊ฐ์ 15.13%์ด์๋ค.
2. ์๋ง๊ฐ ์ฌ์ถฉ์ ์ด์ ๋ก๋ ์ด์ฐจ์ฐ์์ฆ์ด 56.10%, ํ์ ์ด 27.80%, ํ๋ฝ 8.78% ์์ด์๋ค
.
3. ์ฌ์ถฉ์ ์๋ง๊ฐ์ 52.2%๊ฐ 3๋
์ด๋ด์, 70.7%๊ฐ 5๋
์ด๋ด์, 89.8%๊ฐ 10๋
์ด๋ด์ ์ฌ์ถฉ
์ ํ ๊ฒ์ผ๋ก ๋ํ๋ฌ๊ณ , 10๋
์ด ๋์ํ ์ฌ์ถฉ์ ํ ๊ฒฝ์ฐ๋ 10.2%์ด์๋ค.
[์๋ฌธ]
Ease of manipulation, adequate mechanical properties, long years of experience
and economical cost are the factors which have established amalgam as the most
widely used material for dental restorations.
But amalgam restoration may require replacement because of secondary caries,
fracture, "fall-out", dimensional change tarnish or corrosion etc. These failures
of amalgam restorations seem to arise from failures during operations rather than
from the inherent shortcomings of the material itself or of the patient's
mismanagement.
It is anticipated that restoration of amalgam and it's failures will both
increase after more extensive utilization of the medical insurance which began in
1977. So, the author thinks that it would be helpful, for the development of better
treatment in daily dental practice, to know the duration of amalgam restorations
and the reasons for their replacement.
The data for this survey was compiled from 2,856 out-patients of the Department
of Dentistry, Ewha Woman's University Hospital from January 1975 to December 1977.
260 cases among 1, 718 fillings were studied, of which 205 cases both had a single
reason for replacement and recognized the date of the previous filling.
The results obtained were as follows;
1. Amalgam fillings were 58.5 percent of all dental restorative materials. Of
these, 15.13 percent of the amalgam restorations had to be replaced.
2. Among those amalgms requiring replacement, 52.2 percent had been in place less
than 3 years, 70.7 percent within 5 years and 89.8 percent had been in place less
than 10 years. Only 10.2 percent had been in place more than 10 years.restrictio
Feasibility of High_Frame-Rate Ultrasound for Thyroid Elastography
MasterThyroid nodules are a very common clinical problem. Thyroid cancer is becoming the most common cancer among Korean women, surpassing breast cancer. a fine-needle aspiration (FNA) biopsy is recommended because FNA is the standard procedure for the preoperative evaluation of thyroid nodules. However, FNA is costly, and a large percentage (approximately 70%) of these FNAs turn out to be benign findings. Thus, it would be beneficial to reduce the number of FNAs on many benign nodules. US elastography has the potential to make a noninvasive differential diagnosis between benign and malignant thyroid nodules. With the conventional US imaging method, when the tissue motion or deformation occurs quickly (e.g., shear wave elasticity imaging or cardiac strain rate imaging), the frame rate may not be high enough to track this fast tissue deformation. Therefore, high-frame-rate US imaging methods have been developed. One of the most widely used methods in achieving high-frame-rate US is to use unfocused US beams (i.e., flash imaging). In this paper, we presents feasibility of high frame rate US for thyroid elastography whether it can provide additional information compared to conventional US imaging or not. We observed that the sum of the power spectral densities for a normal thyroid gland is larger than that for a benign nodule in the frequency range higher than 100 Hz(p < 0.05). It seems that the difference in the power spectral density sums between a normal thyroid gland and a benign nodule result from the presence of a high frequency range. We also found that the sum of power spectral densities depended on the ROI selection (distance from carotid artery and ROI size). Based on these study results, further investigations are required on data acquisition from subject with consistent view of a thyroid gland to reduce the ROI dependency of the power spectral density and on reducing undesirable motion from patients' respiration and / or transducer. To increase a confidence level of our feasibility study, enough data acquisition ( over 50 data set ) and various signal analysis methods would be needed