불화우유 투여에 의한 백서 대퇴골의 특성변화
Changes in thickness and strength of the rat femur after administration of fluoridated milk
곽동호, 권영미, 이길량, 배용철, 김선하,
소속 상세정보
곽동호 ( ) - 경북대학교 치과대학 예방치과학교실
권영미 ( ) - 경북대학교 치과대학 예방치과학교실
이길량 ( ) - 경북대학교 치과대학 예방치과학교실
배용철 ( ) - 경북대학교 치과대학 예방치과학교실
김선하 ( ) - 경북대학교 치과대학 예방치과학교실
KMID : 0355420010250030273
Abstract
The purpose of this study was to investigate mechanical and histomorphological changes of the rat femur after administration of various concentrations of fluoride in the commercial pasteurized milk,
48 female Sprague-Dawley rats were randomly divided into 4 groups, and they were supplied with 0 (control), 1, 5 and 50 ppm of fluoridated pasteurized milk ad libitum for 6 and 12 weeks. Bone strength was measured by comparing the stress at failure of both femurs at the middle point of total length of femur and femoral neck with Instron (Model 4202, Instron Co.; U.S.A.).
Central regions of the femur shafts were fixed, demineralized and embedded in paraffin. Paraffin sections of 4 gm thickness were cut in the transverse plane and stained with hematoxylin and eosin. The cross sectional area of the compact bone, average of long and short diameter were measured by digitizing the outline of external and internal perimeter of compact bone and analyzing them with NIH image software (public domain, version 1.60 ; NIH, Bethesda, MD.). Data analysis were conducted using the SAS 6.12 package. Differences between groups were compared by the one-way ANOVA and Duncan´ s multiple range test was also adapted for post-hoc tests. Corresponding p-values were considered significant at values less than 0.05.
Bone strength increased significantly in the animals given 1 and 5 pprn of fluoride in the pasteurized milk, as compared to the control group with no fluoride both at 6 and 12 weeks. There were significant decreases of stress at fracture in 50 ppmF group compared to the 1 and 5 ppmF groups both at 6 and 12 weeks.
We found the similar trends of bone strength at the femoral neck fracture test, but there were no statistical significances both at 6 and 12 weeks. This indicates that, under the conditions of this study, low
concentration of fluoride (1-5 ppm) had the expected biological effect.
Such a trend in bone strength was also observed in the measurement of femur cortical thickness. Cortical bone thickness of the femur increased in the 1 and 5 ppmF groups compared to the control group. However, the thickness of 50 ppmF group also decreased significantly as compared to 1 and 5 ppmp groups.
All of the findings presented support the conclusion that, within the range of doses used and under the specific conditions of this experiment, low fluoride dosage (1-5 ppmF) could increase the bone strength. There would be a linear relationship between dose and cortical bone thickness and strength in animals receiving 0, 1 and 5 ppm fluoride groups, but not in 50 ppm fluoride group. Results indicated that cortical bone thickness and strength increased with low fluoride dosage (1-5 ppmF), and decreased with high fluoride dosage (50 ppmF) in rats.
키워드
불화우유;대퇴골;골강도;골두께;골면적
원문 및 링크아웃 정보
등재저널 정보