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: [email protected]
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 _______________________________________________
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