Bone Abstracts

The aim of this study was to determine interrelationships between final body weight, bone-specific alkaline phosphatase (BAP), IGF1 and morphological, densitometric and mechanical properties of deciduous mandibular teeth isolated from seven healthy Polish Merino rams. Four incisors (I₁–I₄) and second premolar (P₂) were obtained from 5-month-old sheep. Teeth were cleaned, weighed, and their length was measured. Mean volumetric tooth mineral density (MvTMD) and total tooth volume (Tvol) were determined using quantitative computed tomography (QCT) and SOMATOM EMOTION SIEMENS apparatus (Siemens, Erlangen, Germany) equipped with Somaris/5 VB10B software and Volume Evaluation application package. For Tvol and MvTMD determinations, volume-of-interest was defined between minimum and maximum density of the investigated samples at 0 and 3071 Hounsfield units (HU), respectively. Micro computed tomography (micro CT) and SkyScan 1174 apparatus (SkyScan n.v., Kontich, Belgium) were used to measure total enamel volume (Evol), volumetric enamel mineral density (vEMD), total dentine volume (Dvol) and volumetric dentine mineral density (vDMD). The volume-of-interest was defined between minimum and maximum density of the investigated samples at –1000 and 3071 HU. To determine mechanical properties, all incisors were subjected to a three-point bending test and maximum elastic strength (Wy) and ultimate force (Wf) were determined. In compression test Wf of P₂ was determined (Zwick/Roell Z010 apparatus; Zwick, Ulm, Germany). BAP and IGF1 were determined in serum of 28- and 150-day-old sheep using immunoenzymometric assays (Ostease BAP and IGF1 ELISA, Immunodiagnostic Systems Ltd, Boldon, Tyne & Wear, UK). Pearson’s correlation coefficient (r) between final body weight, BAP, IGF1 and morphological, densitometric and mechanical properties of teeth was determined. Final body weight was positively correlated with Tvol and Dvol of I₁, I₄ and P₂ (r>0.88; P<0.05). IGF1 in 28-day-old sheep was negatively correlated with MvBMD of I₁, I₂, I₃, I₄ and P₂ (r<−0.82; P<0.05). IGF1 in 28-day-old sheep was positively correlated with Wf of P₂ (r=0.84; P<0.05). IGF1 in 150-day-old sheep was negatively correlated with vDMD of I₂, and Tvol and Dvol of I₄ (r<−0.86; P<0.05). BAP in 150-day-old sheep was negatively correlated with Wy and Wf of I₂ and MvBMD of P₂ (r<−0.76; P<0.05). In conclusion, this study revealed that body weight of sheep is associated with morphological properties of teeth. Interrelationships of IGF1 and BAP concentration in serum with morphological, densitometric and mechanical properties were proven.