Frequency of damage to and need for repairs of removable dentures.
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Acrylic Resins↗
Biomedical subjects
R Lappalainen
Publications and source records attributed to R Lappalainen.
Assessment of the condition of removable dentures worn by 58 year old men. Relationship between clinical and subjective findings.
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Age Factors↗
Mg content of healthy and chronically diseased human cancellous bone in relation to age and some physical and chemical factors.
The magnesium (Mg) content of human cancellous bone was studied in relation to its elemental composition and mineral density. The material was collected from 138 cadavers consisting men and women of different ages. Duplicate specimens from anterior iliac crest (one macerated and one fixed with alcohol) were obtained from individuals who had died suddenly or whose deaths were due to chronic immobilizing diseases. The cation concentrations were analyzed with an atomic absorption spectrophotometer, fluoride with the ion specific electrode, from macerated samples. The samples fixed in alcohol were used for determination of the mineral density with gamma rat attenuation. The mean Mg concentration (+/- SD) was 2.84 +/- 0.29 mg/g in the samples obtained from individuals who had died suddenly with no correlation with age. In the group with chronic diseases the mean Mg levels decreased slightly with increasing age. There was a significant, positive correlation between the Mg and Ca concentrations. In the linear regression analysis 16.4% of the variance of Mg concentration was accounted for by Ca. This relationship was more evident in men than in women. Only the postmenopausal women suffering from chronic diseases and having bone loss showed correlation between the bone Mg and Ca contents. The Mg/Ca ratio in men was quite constant and did not change significantly with age. In women the Mg/Ca ratio versus age showed no statistically significant relationship. The correlation between Mg and other elements was weak. The weak relationships between F and Zn to Mg clearly have no significant effect on the contents of these elements in bone.
Aging↗
Lead content of deciduous molar enamel in Finland, as measured by proton-induced X-ray emission.
The lead content of deciduous molar enamel was measured with an accurate physical technique based on proton-induced X-ray emission. The absolute values were calibrated according to the animal bone standard of the International Atomic Energy Agency. The results obtained from five different communities indicated little difference between communities in the lead content of the deciduous molar enamel of children born in 1960-1975. The overall mean for all samples analyzed was 3.2 (SD 1.6) micrograms/g (N = 120); the highest individual value measured was 10.0 micrograms/g. Judging from the lead content of the teeth, the general population in Finland does not yet seem to be exposed to detectably higher amounts of artificially occurring environmental lead, neither in urban nor in rural areas. It would seem that naturally occurring environmental lead still plays a decisive role in the integrated long-term exposure in Finland.
Child↗
Fluoride content related to the elemental composition, mineral density and strength of bone in healthy and chronically diseased persons.
The fluoride (F) content of bone was determined and compared to the elemental composition, mineral density and compressive strength in bone specimens from the crista iliac of 88 subjects who had died suddenly, and from 50 subjects who had died as the result of chronic immobilizing diseases. The elemental composition of bone was determined using an atomic absorption spectrophotometer, mineral density using gamma-ray attenuation, compressive strength using a strain transducer, and F content using an ion-selective electrode. The increase of F content with age was not statistically significantly different between the groups. The Ca content of bone decreased more with age in post-menopausal women who had suffered from chronic diseases than in women who had died suddenly. The same was true for the negative correlation coefficient between Ca and F. A similar trend was found for mineral density. This does not support the idea that the F concentration obtained produces any effect that would clearly prevent bone loss in post-menopausal women when compared to those who had died suddenly. In both groups F content was correlated with Zn and Mn; in the sudden-death group Zn concentration explained 12.9% of the F concentration. The relation between Zn and F may be important in the formation and structure of biological apatite.
Adolescent↗
Copper in human subgingival calculus.
The Cu concentration as well as the Ca, Mg, Fe, Pb, Zn, and F concentrations were determined in subgingival calculus and the relation of Cu to Zn, Ca, Mg and Fe described. Samples of human subgingival calculus of 60 pieces from 60 subjects were ashed in an acid solution and the cation concentrations were determined with atomic absorption spectrophotometry. The F content was analyzed with an ion-selective electrode. The data was analyzed using the multiple linear regression analysis. The mean +/-SD of the Cu concentration in the subgingival calculus was 48.4+/-59.0 micrograms/g. Four elements, Zn, Ca, Fe and Mg, explained 41.1% of the Cu content. Zn explained 25.5% and the correlation was positive, whereas Ca (10.4%) had a negative correlation with the Cu content. The results showed such a high Cu content that it could affect the mineralization of calculus.
Calcium↗
Atomic absorption spectrometric evidence of relationships between some cationic elements in human dentine.
Dentine samples were prepared from 123 permanent teeth and Co, Cu, Mg, Mn, Ni, Pb, Sr and Zn concentrations were determined with an atomic absorption spectrophotometer. Relations between the cations were evaluated using the correlation matrix and multiple linear regression analysis. When the simultaneous variation of the concentrations of all determined elements was taken into consideration, the following statistically significant positive correlations were found: Cu-Mn, Mn-Co, Ni-Mn and Sr-Ni. A weaker correlation was obtained between Ni and Mg and between Ni and Pb. The only negative correlation was between Sr and Pb, but the explanation percentage in the regression model was low. The results indicated that the chemically and physically related elements Co, Cu, Mn and Ni formed positive correlations. Sr-Ni and Mn-Cu relationships were similar to those reported for human cancellous bone.
Adolescent↗
Interaction between Li, Ni and Sr content in human cancellous bone.
Li, Sr and Ni content of human cancellous bone and their relation to elemental composition was studied in specimens obtained from 88 subjects with a normal mineral status and from 50 subjects having osteoporotic changes due to chronic immobilizing diseases. The concentrations of Ca, Mg, Cd, Co, Cu, Mn, Ni, Li, Pb, Sr and Zn were analyzed with an atomic absorption spectrophotometer and fluoride with an ion selective electrode. The data was analyzed with the linear multiple regression analysis. Ni had a statistically significant inverse relation to Li. There was a significant positive correlation between Sr and Ni contents. Chronic immobilizing diseases did not affect significantly Li, Sr and Ni contents. Also no age dependent changes of these elements were found. The mean concentration S.D. of Li was 0.23 +/- 0.14 microgram/g, of Sr 65.5 +/- 40.7 micrograms/g and Ni 1.29 +/- 0.83 micrograms/g, respectively. The strong interrelation between Li, Sr and Ni suggest that these elements should be analyzed together in studying the role of these elements in the mineralization.
Adolescent↗
The concentration of Pb, Cu, Co and Ni in extracted permanent teeth related to donors' age and elements in the soil.
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Adolescent↗
A 55Fe excited x-ray fluorescence method for the analysis of Ca content in enamel.
A 55Fe excited X-ray fluorescence method has been developed for the quantitative nondestructive analysis of Ca content in surface layers of teeth. To eliminate the effects due to curved enamel surface and the localisation of the tooth a special measuring geometry was constructed. The reproducibility of the method remained under 2%. The effect of acid treatment on the Ca content in enamel was demonstrated.
Acid Etching, Dental↗
Zn and Cu content in human cancellous bone.
Duplicate cancellous bone samples from the iliac crest were obtained from autopsies of 88 persons with a normal mineral status and 50 having osteoporotic change due to chronic immobilizing diseases. The following parameters were determined: the minimal density with gamma-ray attenuation, the compressive strength with a strain transducer, the concentrations of Ca, Mg, Cd, Co, Cu, Mn, Ni, Li, Pb, Sr and Zn with an atomic absorption spectrophotometer and the concentration of F with an ion-selective electrode. The data were analyzed with linear multiple regression analysis. Altogether 34.8 per cent of the Zn concentration was accounted for in all the variables. The selected variables, after the nonsignificant and those with very low explanatory power were removed, explained 38.3 per cent. The two most important variables were the F concentration (16.1 per cent) and Cu concentration (13.7 per cent). The third variable was Mn concentration (8.5 per cent). All variables explained 41.7 per cent of the Cu concentration and five selected variables 40.7 per cent, respectively. The concentration of Zn explained itself as much (20.1 per cent) as four other variables (Ca 7.7 pe cent, Mn 5.9 per cent, Sr 3.9 per cent and Co 3.2 per cent) together. Age and sex did not significantly affect the concentration of Zn and Cu. No remarkable difference was found between the bone samples representing a normal mineral status and osteoporosis.
Adolescent↗
The concentrations of Zn and Mg in human enamel and dentine related to age and their concentrations in the soil.
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Adolescent↗
Zn concentration of human subgingival calculus related to F, Mg and Cu contents.
F and Zn content of human subgingival calculus was studied with respect to its Ca, Mg, Cu, Fe and Ph contents. The material consisted of 60 subgingival calculus samples from 60 persons. The element concentrations were determined with an atomic absorption spectrophotometer except for the F content, which was measured with an ion-selective electrode. The data were analyzed using the multiple linear regression analysis. 24% of F content was explained by Zn and none of the other elements were significantly related to F content. Altogether, 55.4% of Zn content was accounted for in all variables. The selected variables after the removal of nonsignificant ones explained 54.8%. The most important variable was F (24.0%) and the explanation power of Cu was 18.3% and of Mg 12.5%. The regression coefficients of these variables were positive. The mean +/- s.d. concentration of F in the samples was 221.2 +/- 174.1 micrograms/g and of Zn 498.6 +/- 499.1 micrograms/g, respectively.
Adult↗
X-ray diffraction patterns in human dentin, enamel and synthetic apatites related to Zn concentration.
The crystallization of human dentin and enamel containing different concentrations of Zn was studied using X-ray diffraction analysis. The concentrations of Ca, Mg, Mn, Fe, Zn, Cu, Co, Ni, Sr and Pb in the samples were determined by atomic absorption spectrophotometry. The concentration of F was assayed with a combination fluoride electrode. The increase of the Zn concentration (microgram/g) from 150 to 572 in dentin was found to intensify apatite reflections indicating changes parallel to c-axis. A slight increase parallel to a-axis (or better crystallization) of lattices was demonstrated in both dentin and enamel. The increase of Zn concentration from 164 microgram/g to 692 microgram/g in enamel weakened 002 and 112 reflections. The effect of Zn on the crystallinity of synthetic apatite prepared at 37 degrees C was of the same kind as its effect on the dentin.
Adolescent↗
The rate of calcium extraction during EDTA decalcification from thin bone slices as assessed with atomic absorption spectrophotometry.
The rate of calcium extraction with EDTA (ethylenediamine tetraacetic acid) from thin bone slices (300 micrometer-3 mm thick) was determined by aid of an atomic absorption spectrophotometer. A 0.5 mm thick bone slice was completely decalcified with 15% (0.40 M), 8% (0.22 M), and 4% (0.11 M) EDTA in 24 h, 3 days, and 5 days, respectively (vol. 15 ml, temp. 4 degrees C, pH 7.4). At 37 and 60 degrees C the speed of demineralization was slightly increased as compared with that at 20 degrees C, while no difference was observed between 4 and 20 degrees C. Bone slices with a thickness of 0.3, 0.5, 1 and 2 mm were decalcified -- in the same order -- in 24 h, 2, 3, and 5 days (8% EDTA, 4 degrees C, pH 7.4). At pH 7.4, the decalcification rate was a little slower than at pH 5.0 and 8.5. Agitation did not affect the decalcifying velocity, nor did the volume of the agent, except when the volume was very small. The demineralization of ordinary bone, containing both compact and spongy bone, was found to be more rapid than that of homogeneous bone reported earlier. The acidic buffers and New Decalc, which served as reference substances, exerted a more vigorous decalcifying effect thatn EDTA. K formate/formic acid buffer, pH 3.15, demineralized a 1 mm thick bone slice in 24 h and 2 days was needed with Na lactate/lactic acid buffer, pH 3.70. With New Decalc, pH 0.9, the corresponding demineralization was accomplished in 1.5 h. Atomic absorption spectrophotometer proved to be a useful tool in the evaluation of calcium extraction velocity from bone slices.
Animals↗
Effect of Zn and Mg on the formation of whitlockite in human subgingival calculus.
X-ray diffraction analyses were carried out from pooled samples of old subgingival calculus. Also the concentration of Ca, Mg, Zn, Sr, Pb, Fe and Cu from these samples were determined by means of atomic absorption spectrophotometry. The comparison of the samples containing almost the same Zn concentration and two different concentrations of Mg (9 mg/g and 16 mg/g) showed an increase of 2.0.10 and 220 whitlockite reflections with an increasing Mg concentration. The increase of Mg concentration shifted whitlockite reflections suggesting a contraction of a-axis. The increase of Zn concentration showed an increase of 2.0.10 and 220 reflections indicating the fitness of Zn into the lattice of whitlockite. No changes of a-axis were detectable. When comparing all diffractograms and the results obtained from chemical analyses, the presence of Zn-MG-whitlockite proved evident.
Calcium Phosphates↗
The distribution and accumulation of Cd, Zn, Pb, Cu, Co, Ni, Mn and K in human teeth from five different geological areas of Finland.
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Adolescent↗
Concentrations of Ca, Mg, Mn, Sr and Zn in supra- and subgingival calculus.
The concentrations of Ca, Mg, Mn, Sr and Zn in supra- and subgingival calculus collected from mandibular anterior teeth mainly of the same persons were analyzed with atomic absorption spectrophotometry. The results showed highly significantly (P less than 0.001) greater Zn and Sr concentrations in subgingival samples. The mean value of Zn was 5.4 times higher in subgingival calculus than in supragingival calculus. In contrast, the concentration of Mn was significantly (P less than 0.01) higher in supragingival calculus. The difference in the concentration of Mg in supra- and subgingival calculus was highly significant (P less than 0.001) only when samples from the same person were compared. The concentration of Ca was very similar in both types of calculus and individual variations were very small.
Adult↗