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Abstract
The aim of this study was to evaluate the effect of silica gel
on dentin permeability, surface topography and leakage pattern in
endodontically treated teeth as well as to assess its
biocompatibility. The study was divided into 4 parts, in the first
part, twenty dentin discs were prepared and divided into two equal
groups which were treated with either silica gel or CO2 laser. A
fluid transport apparatus was used to assess dentin permeability
before and after surface treatment that was measured immediately
and after 5, 15 and 30 minutes.The statistical comparison of the percentage change in dentin
permeability showed that immediately, there was no statistically
significant difference between the two groups. While after 5, 15
and 30 minutes, the mean percentage change of dentin discs
treated with bioactive silica gel was lower than that recorded with
the Laser treatment, and this difference was statistically
significantly.The second part of the study was conducted to qualitatively
evaluate the effect of bioactive silica gel and CO2 laser
application on the resected root-end with and without the
preparation of a retro-cavity using SEM. The selected samples
were cleaned; shaped and obturated then root-end resection was
Summary & Conclusions
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performed. The samples were finally classified according to the
method of root-end management into two equal groups. In the
first group samples were left intact without performing a
retrocavity after the root end resection and they were either
left without surface treatment, treated with bioactive silica or
with CO2 laser.For group I the root end resection resulted in creation of
amorphous smear particles all over the resected surface. These
particles partially obliterated the dentinal tubules. Application of
the bioactive silica gel over the resected root end revealed even
precipitation and full coverage of the surface entire at low
magnification. However, at higher magnifications; there was
evident discrepancy in the size of the silica crystals with some
voids between them and even some patent dentinal tubules. While,
when CO2 Laser was applied on the resected surface, there was
evident dentinal melting and occlusion of the dentinal tubules.
While in the second group samples were filled with either IRM
only, treated with bioactive silica gel or treated with CO2 laser
before IRM placement.
SEM examination revealed the typical architecture of a zincoxide
based filler dispersed in a homogenous matrix, with almost
no evidence of any dentinal structures.