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STUDY OF THE STRUCTURE OF ROOT CANALS OF TEETH AFTER
PHOTODYNAMIC EXPOSURE
Eshmurodova Farangiz Bakhrom kizi
2nd year clinical ordinator of the Department of
Therapeutic Dentistry of the Tashkent State Dental Institute
https://doi.org/10.5281/zenodo.14048845
Introduction.
To date, there are numerous surgical intervention
techniques that allow for the avoidance of tooth extraction in chronic
periodontal processes. However, surgical revision in the area of multi-rooted
teeth leads to bone loss in the surgical intervention zone, increases the risk of
vascular-nervous bundle damage, and prolongs the treatment duration for
patients. In this regard, the search for new methods to optimize treatment is a
pressing task.
Objective:
Adhesion of the root filling to the wall of the root canal
depends on the degree of its cleansing from the smear layer blocking the
dentinal tubules. Along with traditional medical and instrumental treatment of
root canals (EDTA 17%, sodium hypochlorite 3-5%), which has its own
disadvantages (long-term treatment of root canals, the possibility of chemical
burns of periapical tissues), photodynamic exposure is the method of choice for
removing the smear layer.
Materials and methods.
An experimental study was conducted to study
the ultrastructure of the root canal wall after PDT. A total of 46 intact single-root
teeth were examined, removed for orthodontic reasons. The root canals of all
teeth were treated with manual and machine endodontic instruments without
using 17% EDTA solution. The teeth were divided into a control group (10
teeth) and a main group (36 teeth). In the root canals of the teeth in the control
group, only mechanical treatment was performed, in the main group, the canals
were treated using the PDT method, which were divided into two subgroups (18
teeth each) depending on the device used. The PDT technique consisted of the
following: 0.5% photoditazine gel was applied to the root canals of the teeth of
the main group with different exposure times (1.5 and 2 min), after removing
the gel, laser exposure was carried out for different times (1, 2 and 3 min). Two
devices were used: Lazurit (England) with a wavelength of 635 nm, an output
power of 50-100 mW and Fotosan (Denmark) with a wavelength of 635 nm and
an output intensity of 2000 mW/cm2). Then the teeth of the control and main
groups were sawn vertically and fixed in blocks. The ultrastructure of the root
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canal dentin was studied on a JEOL JSM-6510 scanning electron microscope
(Japan) and micrographs of its wall were obtained at 2000-fold magnification in
the orifice, central and apical parts. The efficiency of removing the smear layer in
the obtained images was assessed using the following scale: 0 points — no
smear layer and the maximum number of open dentinal tubules with a depth of
2-3 microns per unit area is determined, 1 point — an insignificant amount of
smear layer, multiple openings of dentinal tubules, 2 points — a large amount of
smear layer, no open dentinal tubules. The smear layer was assessed in the
orifice, central and apical parts of the canal.
Results and discussion.
According to the electron microscopy data, it was
revealed that the root canal wall of the teeth in the control group was covered
with a smear layer throughout the root canal. When examining the obtained
images of the teeth in the main group, it was found that with exposure to 0.5%
photoditazine gel for 1 min and a laser radiation time of 1.5 min, an insignificant
amount of smear layer was noted in the orifice part of the canal, multiple
openings of dentinal tubules, which corresponded to 1 point on a scale, a lot of
smear layer was noted in the central part of the canal, open dentinal tubules
were practically absent, which corresponded to 2 points on a scale, a lot of
smear layer was noted in the apical part, which corresponded to 2 points on a
scale. With an exposure of 1 min and a laser radiation time of 2 min, an
insignificant amount of smear layer was determined in the orifice of the canal,
which corresponded to 1 point on the scale, in the central part of the canal - a
large amount of smear layer , which corresponded to 2 points on the scale, in the
apical part of the canal there was also a large amount of smear layer , which
corresponded to 2 points on the scale. With an exposure of 2 min and a laser
exposure time of 1.5 min, there was no smear layer in the orifice of the root
canal and the maximum number of open dentinal tubules was determined per
unit area, which corresponded to 0 points on the scale; in the central part of the
canal - an insignificant amount of smear layer, which corresponded to 1 point on
the scale, in the apical part of the canal - a lot of smear layer, open dentinal
tubules were practically absent, which corresponded to 2 points on the scale.
With a 2-minute exposure and 2-minute laser exposure time: no smear layer
was observed in the orifice portion of the canal, corresponding to 0 points on the
scale, in the central portion — an insignificant amount of smear layer,
corresponding to 1 point on the scale, and a significant amount of smear layer in
the apical portion, corresponding to 2 points on the scale. With a 3-minute
exposure of 0.5% Photoditazine gel and a 1.5-minute laser exposure time, no
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smear layer was observed in the orifice and central portions of the canal (0
points), and an insignificant amount of smear layer was observed in the apical
portion (1 point). With a 3-minute exposure of 0.5% Photoditazine gel and a 2-
minute laser exposure time: no smear layer was observed in the orifice and
central portions of the root canal (0 points), and an insignificant amount of
smear layer was observed in the apical portion (1 point). Thus, the analysis of
the results showed no differences when using different sources of laser
radiation (Lazurit and Photosan).
Conclusion.
Photoactivation of 0.5% Photoditazine gel is an effective technique
for removing the smear layer of the root canal wall and can therefore be
proposed as an alternative to its traditional drug treatment.
