Pressure transmission across dentine in response
to an external pressure: A laboratory study
Graham M. Woolley
, Peter R. Wilson
Private Practice, Melbourne, Vic., Australia
Restorative Dentistry Section, The University of Melbourne, 711 Elizabeth Street,
Melbourne, Vic. 3000, Australia
Accepted 30 January 2005
In contrast to earlier studies, more recent studies of
dentine permeability have used low perfusion pres-
sures of 1—3 kPa, which are close to the levels
measured in vivo.
Low perfusion pressures minimise disruption of
the organic contents of dentine tubules, which is
important if errors in calculating hydraulic conduc-
tivity are to be avoided.
At perfusion pressures of 35—68.9 kPa, removal
of pulp tissue and perfusion time have a minor effect
on ﬂuid ﬂow through dentine.
Under more phy-
siological conditions, with much lower ﬂuid ﬂow
rates and less disruption to tubule contents, pulp
Archives of Oral Biology (2005) 50, 799—805
Purpose: To determine whether transducers could provide a convenient method of
measuring dentine permeability and to investigate the effects of removal of pulp
tissue and perfusion time on the pressure increase across human dentine after low-
Method: Human premolar teeth that had been stored for 1—2 months were prepared
for full crown preparations. The pulp tissue was removed from half the samples and all
the coronal segments perfused with saline at 1.3 kPa for varying times. An external
pressure was then applied and the response within the pulp chambers recorded with
Results: Extirpation of pulp tissue reduced the rate of rise of pressure inside the pulp
chamber by approximately 50%. Perfusion at 1.3 kPa for up to 1 h had no effect on
pressure rise, but 6 h of perfusion produced a very signiﬁcant increase.
Conclusion: Transducers can provide a relatively simple, convenient and clinically
relevant measurement of dentine permeability. For stored coronal segments that
have been perfused at physiological pressures, extirpation of pulp tissue and perfusion
time have signiﬁcant effects on pressure transmission across dentine.
# 2005 Elsevier Ltd. All rights reserved.
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