This in vitro study was carried out for an
objective to compare the effect of a photo polymerized resin modified glass
ionomer versus a chemical cured conventional glass ionomer based desensitizing
agents. The comparison between both materials was done regarding their
abilities to occlude patent dentinal tubules, and also viewing their depth of
penetration inside the dentinal tubules. The two materials used in this study
were Vanish XT (RMGI) and Fuji Triage (CGI).
A total of 20 permenant molars were selected
for this study, teeth were mounted on acrylic blocks. An isometric saw was used
to remove the enamel proximally till the DEJ, then a digital caliber was used
to measure the thickness of the cervical enamel so as to be taken as a guide
for removing enamel buccally and lingually to expose the dentin surface, ranges
from 1.5 to 2 mm. Both buccal and lingual enamel were removed accordingly. EDTA
gel (17%) was applied for three min. to the whole buccal and lingual surfaces
of all specimens.
prepared fourty surfaces (20 buccal and 20 lingual) were divided into two
groups according to the type of desensitizing agent received. The mesial half
of both surfaces received different desensitizing agent while the other half was
left untreated as a control (EDTA only). Each group was divided into four
subgroups, the first subgroup faced abrasion challenge, the second faced
thermocycling, third faced both abrasion and thermocycling and the last was
left as a control group.
abrasion challenge was done by a custom made machine that simulate brushing technique
with standardized load and time, while thermocycling was done for the samples
for 2000 cycles with dwell time five sec. under a temperature 5 to 55 C. An
environmental electron microscope at 2000 magnification was used to observe the
patent surface area of dentinal tubules, and a digital Analysis program was
used to evaluate the patency.
showed that the percent of obliteration of dentinal tubules when the samples
faced abrasion only was higher in CGI than RMGI, same result when the samples
face termocycling only it was still higher in CGI than RMGI. Whereas there was
no statistical significance when the samples received both abrasion and
Under the limitations of the current study the
following conclusions could be derived :
abrasion resistance and the ability of CGI to withstand thermocycling makes it
better in occluding dentinal tubules rather than RMGI.
the resinous component of RMGI allows
better penetration inside the tubules, yet the lower abrasion resistance and
poor resistance to thermocycling made the material inferior in maintaining an efficient dentinal tubules seal.
investigations are required to test the desensitizing effect of different
compositioned glass ionomer based desesntizing agents on the dentin
permeabitily in comparison to its obliteration and depth of penetration inside
– Furthur researches
are required for assessing the performance of both RMGI and CGI as desenstizers
for treating hypersensitivity in vivo.
– Furthur studies are required for
hypersensitivity diagnosis and treatment.
evaluation for the effect of both desensitizing agents under different challenging
conditions other than tooth brushing abrasion and thermocycling such as storage
in acidic media.
– After this
study, it is recommended using CGI (Fuji Triage) rather than RMGI (Vanish XT)
in treating dentinal hypersensitivity as it has higher abrasion resistance and
more effective dentinal tubules sealing.