as does the tubule lumina [48], resulting in the water content
or wetness of the dentin increasing 20-fold from superficial
to deep dentin in patent tubules [48]. This may have clinical
implications. If the deeper dentin is exposed to the oral
environment, it has relatively larger dentinal tubules in
closer proximity to each other compared to the original
surface dentin structure of the tooth. This has the potential
for more rapid tubular orifice fluid flow and sensitivity,
greater tubular occlusion necessary to alleviate symptoms.
Conversely, the opposite appears to be the case clinical, with
small, newly exposed dentin lesions, exhibiting minimal
tooth wear at the buccal cervical amelocemental junction,
with patent tubules in the region of about 1 μm [33], often
causing excruciating sensitivity in the young individual
[49]. In explanation, the tooth has excellent reparative ca-
pability with reactionary and reparative dentin deposition
giving rise to considerable heterogeneity in tissue structure
from regular to dysplastic atubular structure [50]. The grossly
worn dentition rarely being sensitive if occurring over many
years, whereas rapid wear in a young adult, is often sensitive,
resulting in pain symptoms. The sensitivity of dentin corre-
lates well with tubule patency [6]. The capability and speed of
the reparative processes of the tooth and resulting tubule
occlusion, as well as age of the pulp, are likely to be very
important factors in the susceptibility of an individual to
experience the pain of dentin hypersensitivity.