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.

Qualitative analysis of the margins of restorations made with different filling resins.

PURPOSE: In this study the comparative results obtained from examinations of two different restorative composites with different cavities filling method are presented. Micro-CT was used for the evaluation of the marginal integrity and quality of composite fillings in connection with microstructural investigations made by both optical and scanning electron microscopy. MATERIALS AND METHODS: The examinations of dental tooth filings in bulk-fill technique were based on micro-CT and microscopy observations. Two different restorative composites were selected for the study, namely SonicFill- bulk fill and conventional Filtek Z550. RESULTS: The experiment has shown that micro-CT screening analysis for identification of individual components of tooth and fillings systems gives a high quality of images. Thanks to that it was possible to analyze and identify the porosity in the fillings. But the microscopy analysis has shown more information about the internal structure and quality of bonding between composite and enamel/dentin. The SonicFill gives better quality and bonding to structure of teeth than Filtek. CONCLUSIONS: SonicFill's filling have more homogenous structure than Filtec. It has a greater share of reinforcement in the form of polygonal particles, in Filtek particles have a shape close to spherical. Sonic Fill gives a better adhesion to tooth. CLINICAL RELEVANCE: The evaluation of clinical relevance in this research is crucial to simplify the transfer of knowledge from research by materials engineering into practice in dentistry.

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.

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

The aim of the study was to determine interrelationships between bone tissue metabolism indices and morphological, biomechanical and densitometric properties of hard dental tissues. First primary maxillary incisor from 6-month-old pigs (N=27) was evaluated in terms of weight and length. Mean volumetric tooth mineral density, total tooth volume, enamel total volume, enamel volumetric mineral density, dentine total volume and dentine volumetric mineral density were estimated with the use of quantitative computed tomography and micro computed tomography techniques. Tooth mineral density and tooth mineral content were evaluated with the use of dual-energy X-ray absorptiometry. Microhardness of enamel was measured using Vicker's test. Evaluations of total calcium, ionized calcium, magnesium, phosphorus, alkaline phosphatase, bone alkaline phosphatase, osteocalcin, C-terminal telopeptide of type-I collagen (CTX), insulin-like growth factor-1, growth hormone and parathyroid hormone were performed in plasma and serum samples. Pearson's correlation coefficients were determined between all the investigated variables, and P<0.05 was considered as statistically significant. The obtained results have shown mainly mutual dependences between biochemical indicators of bone metabolism. Evaluation of CTX concentration in serum of pigs has shown the highest predictive value in relation to morphological, densitometric and biomechanical properties of teeth.

Relationships between biochemical bone metabolism indices and morphometric, densitometric and mechanical properties of mandible in 6-month-old pigs.

INTRODUCTION AND OBJECTIVE: Mandible is used as a bone model for monitoring bone tissue responses to various factors influencing skeletal homeostasis. Considering the lack of experimental data on interrelationships between bone metabolism indices and morphometric, densitometric and mechanical properties of mandible, the aim of this study was to perform such an evaluation in 6-month-old pigs. MATERIALS AND METHODS: Quantitative computed tomography was used to determine bone volume, mean volumetric bone mineral density, cortical bone density and cortical bone area. Using dual-energy X-ray absorptiometry, bone mineral density and bone mineral content were measured for ramus, body and whole jaw. In the three-point bending test, maximum elastic strength and ultimate strength of jaw was determined. Assessment of calcium (Ca), phosphorus (P), magnesium (Mg), parathormone (PTH), growth hormone (GH), insulin-like growth factor-1 (IGF-1), alkaline phosphatase (ALP), bone-specific alkaline phosphatase (BAP), osteocalcin (OC) and C-terminal telopeptide of collagen type-I (CTX) in blood was performed. RESULTS: Statistically significant correlations in relation to the investigated traits of the jaw were found in the case of ALP, OC, CTX, GH and IGF-1. Significant correlations of ALP activity, OC and IGF-1 concentrations with final body weight were stated (p<0.05). CONCLUSIONS: This study shows the highest predictive value of ALP activity determination in relation to assessment of morphological, densitometric and biomechanical properties of mandible. Evaluation of Ca, P, Mg, BAP and PTH has not confirmed its significance for morphological, densitometric and biomechanical properties prediction in the jaw of pigs. ALP activity, OC and IGF-1 concentrations would be prognostic for body weight prediction.

Effects of combined maternal administration with alpha-ketoglutarate (AKG) and ß-hydroxy-ß-methylbutyrate (HMB) on prenatal programming of skeletal properties in the offspring.

BACKGROUND: Nutritional manipulations during fetal growth may induce long-term metabolic effects in postnatal life. The aim of the study was to test whether combined treatment of pregnant sows with alpha-ketoglutarate and ß-hydroxy-ß-methylbutyrate induces additive long-term effects on skeletal system properties in the offspring. METHODS: The study was performed on 290 pigs obtained from 24 sows divided into 4 equal groups and subjected to experimental treatment during two weeks before delivery. The first group consisted of control sows, while the second group received alpha-ketoglutarate. The third group was treated with ß-hydroxy-ß-methylbutyrate and the fourth group underwent combined administration of alpha-ketoglutarate and ß-hydroxy-ß-methylbutyrate. Piglets obtained from sows were reared until slaughter age to perform morphometric, densitometric and mechanical analyses of femur. Serum evaluations of growth hormone, insulin-like growth factor-1, bone-specific alkaline phosphatase and osteocalcin were performed in newborns and 90-day old piglets; additionally, plasma amino acid concentration was measured in newborns. RESULTS: Maternal treatment with alpha-ketoglutarate and ß-hydroxy-ß-methylbutyrate significantly reduced fattening time and increased birth body weight, daily body weight gain, bone weight, volumetric bone mineral density, geometrical parameters and mechanical endurance of femur. These effects were associated with increased serum concentrations of growth hormone, insulin-like growth factor-1, bone-specific alkaline phosphatase and osteocalcin. Furthermore, alpha-ketoglutarate and ß-hydroxy-ß-methylbutyrate administered solely or in combination significantly increased plasma level of 19 amino acids. CONCLUSIONS: Hormonal and amino acid evaluations in pigs indicate additive effects of AKG and HMB on systemic growth and development; however, determination of bone properties has not shown such phenomenon.