New paper on mechanical properties of enamel and dentine in dolphins
Dear MARMAM subscribers, We are pleased to announce the publication of the following paper in the current issue of the Archives of Oral Biology: Mechanical properties of dental tissues in dolphins (Cetacea: Delphinoidea and Inioidea) Carolina Loch, Michael V. Swain, Ludwig Jansen van Vuuren, Jules A. Kieser and R. Ewan Fordyce doi:10.1016/j.archoralbio.2012.12.003 Volume 58, Issue 7, July 2013, Pages 773–779 Abstract (1) Mammalian teeth play a major role in food acquisition and processing. While most mammals are heterodont and masticate their food, dolphins are homodont with simplified tooth morphology and negligible mastication. Understanding mechanical properties of dental tissues in dolphins is fundamental to elucidate the functional morphology and biomechanics of their feeding apparatus. This paper aims to study the hardness and elastic modulus of enamel and dentine in dolphins. (2) Teeth of 10 extant species (Inioidea and Delphinoidea) were longitudinally sectioned, polished and mounted in a UMIS nanoindenter. Indentations were performed from dentine to outer enamel. Hardness and elastic modulus were calculated using the Oliver–Pharr method. (3) Mean values of hardness and elastic modulus were similar on buccal and lingual surfaces. While dentine hardness was statistically similar among species, enamel hardness varied from 3.86 GPa (±0.4) in Steno bredanensis (rough-toothed dolphin) to 2.36 GPa (±0.38) in Pontoporia blainvillei (franciscana). For most species, there was a gradational increase in hardness values from inner to outer enamel. Enamel and dentine elastic modulus values clearly differed among species. In enamel, it ranged from 69.32 GPa (±4.08) in the rough-toothed dolphin to 13.51 GPa (±2.80) in Stenella coeruleoalba (striped dolphin). For most species, elastic modulus values were highest at inner and outer enamel. (4) Differences in mechanical properties between species, and within the enamel of each species, suggest functional implications and influence of ultrastructural arrangement and chemical composition. Full text is available at: http://www.sciencedirect.com/science/article/pii/S0003996912004323 Or alternatively, a pdf can be requested at: carolina.loch@otago.ac.nz Best regards, MSc. Carolina Loch Silva PhD Candidate Geology Department, University of Otago Dunedin 9054, New Zealand http://www.otago.ac.nz/geology/people/students/loch/index.html & Laboratório de Mamíferos Aquáticos UFSCFlorianópolis, SC - Brasil
participants (1)
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Carolina Loch