Interrelationships between tooth properties and biochemical bone turnover markers investigated on six-month-old pig model

Interrelationships Between Morphometric, Densitometric, and Mechanical Properties of Teeth in 5-Month-Old Polish Merino Sheep

Interrelationships between morphological, densitometric, and mechanical properties of deciduous mandibular teeth (incisors, canine, second premolar) were investigated. To perform morphometric, densitometric, and mechanical analyses, teeth were obtained from 5-month-old sheep. Measurements of mean volumetric tooth mineral density and total tooth volume were performed using quantitative computed tomography. Microcomputed tomography was used to measure total enamel volume, volumetric enamel mineral density, total dentin volume, and volumetric dentin mineral density. Maximum elastic strength and ultimate force of teeth were determined using 3-point bending and compression tests. Pearson correlation coefficients were determined between all investigated variables. Mutual dependence was observed between morphological and mechanical properties of the investigated teeth. The highest number of positive correlations of the investigated parameters was stated in first incisor indicating its superior predictive value of tooth quality and masticatory organ function in sheep. Positive correlations of the volumetric dentin mineral density in second premolar with final body weight may indicate predictive value of this parameter in relation with growth rate in sheep. Evaluation of deciduous tooth properties may prove helpful for breeding selection and further reproduction of sheep possessing favorable traits of teeth and better masticatory organ function, leading to improved performance and economic efficiency of the flock.

Interrelationships between Morphological, Densitometric and Mechanical Properties of Eggs in Japanese Quails (Coturnix Japonica)

Eggshell quality in birds results from mineral density and composition determining its mechanical endurance. The aim of the study was to determine interrelationships between morphological, densitometric and mechanical properties of eggs in Japanese quails. Twenty four eggs randomly collected from 17-week-old quails were subjected to morphological, denstiometric and mechanical evaluation using dual-energy X-ray absorptiometry (DEXA), quantitative computed tomography (QCT) and three-point bending test. Weight, height and width of eggs were positively correlated with the densitometric parameters obtained using DEXA (egg mineral density (EMD) and egg mineral content (EMC)) and QCT (total egg volume (TEvol) and total eggshell volume (TESvol)). Positive correlations were stated between TEvol and TESvol (r=0.52; P<0.05) and EMD and EMC r=0.83; P<0.05). Egg mineral density revealed positive correlations with TEvol and mean volumetric eggshell mineral density (MvESMD), while EMC was positively correlated with TEvol, TESvol and MvESMD (all P<0.05). Eggshell breaking strength was positively correlated with MvESMD (r=0.53; P<0.05) and negatively correlated with eggshell thickness (r=−0.50; P<0.05). In conclusion, the results obtained in this study showed numerous interrelationships between morphological, densitometric and mechanical properties of eggs in Japanese quails. Both DEXA and QCT were shown to be valuable tools for evaluation of whole egg and eggshell quality with superior prognostic value of QCT for eggshell mechanical endurance prediction. The elaborated experimental model may serve for further investigations on physiological, pharmacological, environmental, nutritional and toxicological factors influencing egg quality.

Morphological aspects and physical properties of enamel and dentine of Sus domesticus: A tooth model in laboratory research

This study aims to describe and analyze morphological and physical properties of deciduous teeth of Sus domesticus. Ultrastructural analysis, mineral composition and microhardness of enamel and dentine tissues were performed on 10 skulls of S. domesticus. External anatomic characteristics and the internal anatomy of the teeth were also described. Data regarding microhardness and ultrastructural analysis were subjected to statistical tests. For ultrastructural analysis, we used the analysis of variance (ANOVA) with Tukey's post hoc (p≤0.05) test. In the analysis of microhardness, the difference between the enamel and dentine tissues was analyzed by a Student's t test. Values were expressed as mean with standard error. The results of ultrastructural analysis showed the presence of an enamel prism pattern. A dentinal tubule pattern was also observed, with a larger diameter in the pulp chamber and the cervical third, in comparison to middle and apical thirds. We observed an average microhardness of 259.2kgf/mm(2) for enamel and 55.17kgf/mm(2) for dentine. In porcine enamel and dentine, the chemical elements Ca and P showed the highest concentration. The analysis of internal anatomy revealed the presence of a simple root canal system and the occurrence of main canals in the roots. The observed features are compatible with the functional demand of these animals, following a pattern very similar to that seen in other groups of mammals, which can encourage the development of research using dental elements from the pig as a substitute for human teeth in laboratory research.

Morphometric, densitometric and mechanical properties of mandibular deciduous teeth in 5-month-old Polish Merino sheep

Background

Caries, enamel hypoplasia, molar incisor hipomineralization, amylogenesis imperfecta, dentine dysplasia, hypophosphatasia and other dental disorders lead to tooth mineralization disturbances and structural abnormalities, decreasing masticatory organ functions. Dental disorders in sheep can lead to premature slaughter before they have attained final stage of their reproductive life and induce economic loss due to high flock replacement costs. Growth rate, health status and meat quality of sheep depends on tooth properties and quality determining in large extent efficiency of the masticatory apparatus and initial food break up. Considering lack of basic anatomical and physiological data on teeth properties in sheep, the aim of the study was to evaluate morphometric, densitometric and mechanical traits of deciduous mandibular incisor, canine and the second premolar obtained at the slaughter age of 5 months of life.

Results

The obtained results have shown the highest values of weight, total tooth volume, enamel volume and dentine volume in second premolar. Morphometric and mechanical parameters of incisors reached the highest values in first incisor and decreased gradually in second and third incisor, and in canine. Densitometric measurements have not revealed significant differences of the volumetric tooth mineral density in hard dental tissues between the investigated teeth.

Conclusions

In conclusion, proposed methodological approach is noninvasive since the deciduous teeth undergo physiological replacement with permanent teeth. Deciduous teeth can be easy collected for analyses from large animal population and may reflect mineral status and metabolism resulting from postnatal growth and development of the whole flock. In individual cases, evaluation of properties of deciduous teeth may serve for breeding selection and further reproduction of sheep possessing favorable traits of teeth and better masticatory system functions.