2OO9 – 2O1O - Faculty of Dentistry - University of Otago

CATHARINA HAUMAN
BChD MMedSci (Pret) MDS (Otago)
Oral Rehabilitation
Senior Lecturer
Tina Hauman is researching the determination of bacterial
viability in dentine by fluorescence. A novel technique,
using Live-dead stain and confocal microscopy, has
been developed for ex vivo determination of bacterial
infiltration, distribution and viability in dentinal tubules.
This technique has been applied to test the efficacy of
different disinfection methods on resected root-end
cavities and has possible clinical implications for apical
surgery. Another study used this method to detect viable
bacteria in the dentinal tubules of teeth from different age
groups, showing that younger teeth have a denser bacterial
infiltrate near the canal lumen, with a decrease in bacterial
load from coronal to apical along the tooth root. These
roots were then examined under the scanning electron
microscope; dentinal tubules were counted to correlate
the bacterial density with dentinal tubule density along the
root length and in roots from different age groups. This
research is related to patient care and treatment outcome.
Research and Collaboration
This research has been done in collaboration with Dr
Geoff Tompkins, Dr Jonathan Leichter, Dr Ionut Ichim,
Associate Professor Nick Chandler and the Electron and
Confocal Microscope Unit (Department of Anatomy).
Recent Publications
Friedlander LT, Chandler NP, Hauman CHJ, Heays A,
Grierson L, Loomans R. Surface roughness of resected rootends
using recommended burs; an operating microscope
study. International Endodontic Journal 42: 1149 (2009).
Hauman CHJ, Aziz A, Tompkins GR, Chandler NP, Leichter
JW. Root-end cavity disinfection with chlorhexidine and
laser. International Endodontic Journal 42: 1149 (2009).
Aziz A, Hauman CHJ, Tompkins GR, Chandler NP. Infection
at the root apex: a confocal microscope study of bacterial
viability. International Endodontic Journal 42: 1150 (2009).
LIHONG HE
BDS (West China Med Sci) DDS (Sichuan) PhD (Syd)
Oral Rehabilitation
Senior Lecturer
Research and Collaboration
Dr. He’s primary research expertise is in the mechanical
properties and microstructure of dental biomaterials
and dental hard tissues. He is currently working with
Professor Swain and other staff on the nanoindentation
measurement and SEM observation of dental biomaterials
and hard tissues, particularly with respect to the
demineralization and bleaching of teeth. Collaboration
with Professor Mencik at the University of Pardubice
(Czech Republic) led to the development of a new testing
method on the viscous property of dental polymers by
nanoindentation. He also has interests on the optical
properties of aesthetic materials and is currently working
with Otago Biotronic Ltd. on the development of dental
shade matching device.
Recent Publications
He LH, Xu Y, Purton DG. In vitro demineralization of the
cervical region of human teeth. Archives of Oral Biology,
doi:10.1016/j.archoralbio.2010.11.009 (2010).
He LH, Purton DG, Swain MV. A suitable base material for
composite resin restorations: Zinc oxide eugenol. Journal
of Dentistry 38: 290-295 (2010).
He LH, Jansen van Vuuren L, Planitz N, Swain MV. A micromechanical
evaluation of the effects of die hardener on
die stone. Dental Materials Journal 49: 433-437 (2010).
Mencik J, He LH, Nemecek J. Characterization of viscoelasticplastic
properties of solid polymers by instrumented
indentation. Polymer Testing 30: 101-109 (2010).
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