Carious teeth as indicators to lead exposure

Teeth and bones micro-slurries introduction to MIP OES for elements simultaneous quantification

This study aims development of new, rapid and direct method for simultaneous multi-elemental determination in micro-volume slurried samples of teeth and bones. The method proposed allow for direct, without prior sample decomposition, injection of 15 μL of slurries (Bone Meal NIST 1486, deciduous human and dog teeth) into microwave induced plasma optical emission spectrometer (MIP OES) and determination of Ca, Cu, Fe, K, Mg, Mn, Na, Pb, Sr and Zn. The optimization procedures were undertaken (univariate and simplex methods) to achieve the best values of parameters influencing the analytical signals. Minimum dead volume, high nebulization and slurry transport efficiency were obtained by using on-axis low-volume spray chamber/v-groove pneumatic nebulizer interface for 15 μL slurry injection in discontinues mode (at 1.2 mL min^-1 pump speed). Analytical parameters of the proposed method were assessed by determination of the limits of detection (LODs), absolute detection limit and precision (RSDs). The obtained LODs were appropriate (in the range of mg/kg) for the determination of the elements in the standard reference material (Bone Meal NIST 1486) for validation procedure and successful application in two real samples (deciduous human and dog teeth).

A biobank of primary teeth within the Norwegian Mother and Child Cohort Study (MoBa): a resource for the future

The Norwegian Mother and Child Cohort Study (MoBa) is a prospective population-based cohort study including >100 000 pregnancies and following the children through childhood, using questionnaires and collecting biological samples. The aim of MoBa is to test specific aetiological hypotheses by estimating the association between exposure and disease, aiming at prevention. A biobank for exfoliated primary teeth collected from the children participating in MoBa has been established (MoBaTooth Biobank). Samples of tooth tissues from the primary dentition can give information about exposure to toxic and essential elements during fetal life and early infancy. Prenatally and postnatally formed tooth tissues permanently document early exposures unlike other biomarkers, as teeth form incrementally at a known rate. Results from tooth analyses will be coupled with corresponding information in the multiple questionnaires and data from analysis of other biological samples collected by MoBa. Invitations to donate one or more teeth are sent to all mothers/children in the period 2008-2016, when the child is 6.75 years old. By August 2011, 7400 participants had been recorded into the MoBaTooth database donating altogether 9798 teeth (1.3 teeth per child). The response rate was 24%, but there is a lag of >1 year in the response. Data from the tooth biobank can supply MoBa with important additional information on the uptake of trace elements during fetal life and early infancy. This information can illuminate possible causal factors of health and disease in the future.

Do the levels of selected metals differ significantly between the roots of carious and non-carious teeth?

Since the metals deposited in teeth during formation and mineralization processes are to a large extent retained, human teeth receive a considerable attention as the indicators of the heavy metal exposure. The use of permanent teeth is limited because the extraction of healthy permanent teeth just for this purpose is hardly acceptable. As the issue of the loss of elements from a carious lesion in the coronal part of a tooth remains controversial, the valuable material could only be the root of carious and fractured permanent teeth. However, to ensure the validity of the results, it should be ascertained that the levels of certain toxic and essential elements do not differ significantly between the roots of non-carious and carious teeth, and therefore this is the aim of this project. The levels of cadmium, chromium, copper, iron, manganese, lead, zinc, potassium, sodium, calcium and magnesium were determined in the roots of 344 permanent teeth (189 carious and 155 caries-free teeth) from the residents of Ruda Slaska, Poland, aged 18 to 34. No statistically significant difference between the concentration of these metals in the roots of non-carious and carious teeth was found. This finding applies to both the general population and after the grouping by donor's gender and tooth type. The concentration of lead, iron, calcium and manganese in the roots of non-carious and carious teeth exhibited dependence upon tooth type, as well as the concentration of potassium in the roots of carious teeth. Since the mineral composition of the roots of permanent teeth is similar for the non-carious, as well as the carious teeth, they can be indiscriminately selected for the tests required by a research project, as they will produce the comparable results. However, in the case of lead, iron, calcium, potassium and manganese, the comparison should be made after grouping by tooth type.

Multivariate statistical analysis of metal concentrations in teeth of residents of Silesian region, southern Poland

Concentrations of 11 metals (Cd, Cr, Cu, Fe, Mn, Pb, Zn, Na, K, Ca, and Mg) were assayed in the teeth of two populations of the Silesian region. The first group (n = 83) comprised the residents of Katowice-Szopienice, a town located in the center of the Upper Silesian industrial region, in close proximity to a Pb plant, whereas the other was a group of residents of the agricultural community Strumień (n = 44). The concentrations of all the trace metals were found to be higher in the teeth of Katowice-Szopienice residents. The methods of cluster analysis distinguished two clusters of metals in the teeth: essential (Ca, Na, Mg, Zn, and K) and trace (Cd, Mn, Cr, Cu, Fe, and Pb) elements. Euclidean distances reflected the differences in concentrations between the two groups. The results obtained were analyzed using principal component analysis. Four principal factors accounted for 68.1% of the total variance for Katowice-Szopienice residents and for 80.1% for Strumień residents. The first factor showed high contributions of Cu and Cr, elements present in humans as a result of diet, and also Mn for Katowice-Szopienice residents because of environmental contamination. The second factor was characterized by large Zn and Cd fractions and, for Katowice-Szopienice residents, Pb and K as well. The diversified exposure of both populations was reflected by the differences in Euclidean distances and contribution of particular elements with respect of principal components.

Aluminum concentrations in human deciduous enamel and dentin related to dental caries

The aluminum (Al) concentrations in the enamel and dentin of 314 human deciduous teeth were determined in order to examine the relationship between Al and dental caries. The sample teeth were divided into three groups: the sound tooth group, carious tooth group and filled tooth group. The teeth of the carious tooth group were further classified into three groups depending on the stage of caries. The Al content was determined using graphite furnace atomic absorption spectrometry. In both the enamel and dentin, the Al concentrations were unaffected by sex, but did depend on tooth type. In enamel, the Al concentration was significantly higher in the sound tooth group (42.8 +/- 37.3 microg/g) than in the three carious groups (20.7 +/- 17.1-24.9 +/- 22.0 microg/g) and the filled tooth group (27.3 +/- 25.5 microg/g). As for dentin, the Al concentration was also significantly higher in the sound tooth group (36.2 +/- 35.1 microg/g) than in the three carious groups (15.1 +/- 13.3-24.5 +/- 23.4 microg/g) and the filled tooth group (17.2 +/- 20.6 microg/g). Even when analyzing incisors alone, the Al concentrations were significantly higher in the sound tooth group than in the other groups, for both enamel and dentin. Furthermore, the Al levels in carious enamel and dentin did not decrease with the advance of caries. These findings indicated that the deciduous teeth containing higher Al concentrations on average had less caries than the teeth with lower Al concentrations, and suggest that Al acts as a possible cariostatic agent by itself.

Aluminum concentration in deciduous teeth is dependent on tooth type and dental status

Aluminum (Al) concentration was assessed in deciduous teeth in relation to sex, year of birth, tooth type, and the presence of caries and roots. Three hundred and twenty-three deciduous teeth from children born during the period 1952 93 in a county in southeast Sweden were sampled, and the Al content determined by graphite furnace atomic absorption spectrophotometry. The arithmetic mean of the Al concentration was 0.58 +/- 0.64 ppm dry weight (mean +/- standard deviation) and differed significantly between incisors (1.05 +/- 1.04 ppm) and canines (0.48 +/- 0.50 ppm) and between incisors and molars (0.53 +/- 0.55 ppm). A significant difference was found between teeth with and without caries. No significant differences were found between sexes. The Al concentration correlated significantly with tooth weight for incisors (r = -0.47) and canines (r = -0.45) but not for molars (r = 0.03). No significant change in Al concentration was found over time. Caries-free deciduous molars are suggested as the most useful teeth for biological monitoring of aluminum.

Dental lead levels in residents from industrial and suburban areas of Kuwait

The present study describes lead concentrations in whole incisor teeth (non-carious) of 216 Kuwaiti resident's aged 3-74, collected from industrial and suburban areas of Kuwait. The mean concentration of lead in all age groups (3-74) showed a significant correlation between both the sexes. Statistical analysis showed a significant correlation between lead levels of males compared with industrial and suburban areas. A similar correlation was also noted in the case of females supporting that industrial residents were more exposed to lead levels than those in suburban areas. A further significant correlation was noted between males and females of industrial and suburban areas which showed that males accumulate more lead concentration than females. A significant correlation was not observed when each age group was compared with that of the respective sexes representing industrial and suburban areas. However, a significant correlation was noted when lead levels in each age group was compared with that of the other age groups except in age groups ranging 35-42. The mean lead levels of 216 teeth were in the range 2.21-2.50 micrograms/g which is less than the range indicated by other investigators in the recent past.

Variability of trace element content in human tooth sequences – a multivariate analysis

Analyses of human bone material expand our knowledge of aspects of modern and historical population ecology, the etiology of diseases, reconstruction of historical diets, and the social and economic status of human groups. 35 adult lower jaw tooth sequences from the 17lh-century Cracow population were analysed. The skeletons were found in crypts of the medieval St. Mark’s church, following international standards. Levels of Pb, Zn, Cu and Cd were determined in undamaged permanent teeth PI, P2, Ml, M2 and M3, using anodic stripping voltammetry (ASV), while strontium concentrations were determined using AAS method. There were statistically significant differences in the levels of the analysed trace elements within the investigated tooth sequences. High interspecimen variability in the amount of accumulated microelements, probably resulting from nutritional, developmental and physiological stress, was also observed. The accumulation of Pb, Cd and Zn was the highest in M3 teeth and the lowest in M l. The results indicate that only one type of teeth should be used for intergroup and intragroup comparison of trace element content.

Lead in primary teeth from Norway: changes in lead levels from the 1970s to the 1990s

Lead is one of the most important and widely distributed pollutants in the environment. In the human population children are particularly at risk. Local dentists in all 19 counties in Norway collected 2746 primary teeth from 1990 to 1994. Tooth substance from whole, ground teeth were analyzed for lead concentration by electrothermal atomic absorption spectrophotometry. The geometrical mean for the entire material was 1.27 micrograms lead/g tooth substance (S.D. 1.87). The mean lead levels in each of the counties were significantly lower than those obtained in a corresponding study in the 1970s. Two counties, Oslo and Vest-Agder, had significantly higher lead levels than the majority of the other counties. Tooth lead concentration and atmospheric deposition of lead in the same areas were significantly and positively correlated, as shown by analysis of naturally growing moss. We conclude that lead concentrations in primary teeth from children in Norway have been reduced by approx. 50% from the 1970s to the 1990s. The reduction probably reflects a decrease in the environmental lead burden in Norway.

Occurrence of heavy metals, sodium, calcium, and potassium in human hair, teeth, and nails

Heavy metals in biological samples: nails, teeth, and hair were examined during 1991-1993. Investigations of biological samples (hair n = 249 samples, teeth n = 145, nails n = 80 samples) were provided for inhabitants of selected towns in Beskid Slaski. The towns are small mountain towns in southern Poland: Wista, Szczyrk, Istebna, Koniakow, and Jaworzynka. The analysis of ANOVA and MANOVA variances were used for biological samples in the context of age, sex, and type of samples for 12 elements (Pb, Cd, Cr, Zn, Fe, Cu, Mn, Ni, Co, Ca, Na, and K). The matrix correlation and cluster analysis were applied to explain the behavior of metals in human hair, teeth, and nails.