The effect of cadmium exposition on the structure and mechanical properties of rat incisors.

Michał Świetlicki,Daniel Kamiński,Adam Prószyński,Sylwia Szymańczyk,Krystian Cieślak,Dariusz Wiącek,Kornelius Kupczik,Ewa Tomaszewska,Siemowit Muszyński,Izabela Świetlicka,Jose Luis Valverde Piedra

doi:10.1371/journal.pone.0215370

Abstract

Alterations in the structure and mechanical properties of teeth in adult Wistar rats exposed to cadmium were investigated. Analyses were conducted on two sets of incisors from female and male specimens, that were intoxicated with cadmium (n = 12) or belonged to the control (n = 12). The cadmium group was administered with CdCl2 dissolved in drinking water with a dose of 4mg/kgbw for 10 weeks. The oral intake of cadmium by adult rats led to the range of structural changes in enamel morphology and its mechanical features. A significant increase of cadmium levels in the teeth in comparison to the control, a slight shift in the colour and reduction of pigmented enamel length, higher surface irregularity, a decrease of hydroxyapatite crystals size in the c-axis and simultaneous increase in pigmented enamel hardness were observed. The extent of these changes was sex-dependent and was more pronounced in males.

Highlights

Enamel, the hardest material in the body consists on average of 95% hydroxyapatite (HA) crystals (Ca10(PO4)6(OH)2), 4% water and 1% organic matter [1]
atomic force microscopy (AFM), micro hardness, X-ray diffraction (XRD) and scanning electron microscopy (SEM) measurements were conducted on the labial surface or its parts covered by pigmented enamel, approximately at one-third of the tooth length measured from the tip (Fig 1)
Sex-related changes were observed in the case of L, which was significantly higher for males than females (p = 0.016 and p = 0.020 for the control and the cadmium group, respectively)

Summary

Introduction

The hardest material in the body consists on average of 95% hydroxyapatite (HA) crystals (Ca10(PO4)6(OH)2), 4% water and 1% organic matter [1]. The organic phase is composed of proteins (amelogenins, ameloblastin, enamelin, and tuftelin) and minor concentrations of proteoglycans and lipids [2,3,4]. Hydroxyapatite (HA) crystals, tightly packed into groups and bound together, form prisms, that along with the protein-rich interprism matter are assembled into prism bands [1, 5]. Enamel formation process (amelogenesis) is highly ordered and runs through three functional phases: pre-secretory, secretory and maturation stage [2, 3]. At each stage amelogenesis may be disturbed by environmental or developmental factors and each disturbance may translate into changes in the final structure of the tissue

Methods

Results

Conclusion