Introduction: Dentin hypersensitivity is a painful clinical condition.
The frequency of its occurrence varies from 8 to 57%, depending on
tested group and different methods of investigations. Recommended
desensitizing agents have different mechanism of action and
effectiveness. We are still looking for solutions that will improve
their effectiveness and simultaneously allow for wider use of e.g. as a
base material, counteracting postoperative hypersensitivity, reducing
marginal microleakage. The aim of the study was to assess the effect of
a selected desensitizing agent occluding dentin tubules with calcium
hydroxyapatite on marginal microleakage formation of a class V composite
restorations subjected to thermocycles.
Materials and Methods: In study it was used 40 molars and premolars,
which were alternately assigned into two groups. In both groups
standardized cavities were prepared. In the study group (study group —
SG) before application of bonding agent Teethmate Desensitizer (f.
Kuraray, Noritake Dental Inc., Okayama, Japan) was used. In the control
group (control group — CG) OptiBond All-in-one (f. Kerr, Bioggio,
Switzerland) bonding agent was used and cavities were filled using
composite material Gradia Direct (f. GC Europe N.V., Leuven, Belgium).
After storage in saline, teeth were subjected to 600 thermo-cycles,
passive dye penetration test was done, teeth were cut in the area of
filling, according to its long axis. Under light microscope
magnification value of microleakage was measured and marginal
microleakage rate (M) was counted. The results of the tests were
statistically analyzed using the package STATISTICA 12.0 (StatSoft, USA).
Results: The average value of M for the SG group was 0.46 (min 0.05, max
0.76, SD 0.226) and for CG was 0.22 (min 0, max 0.74, SD 0.235). The
differences between M values were statistically significant (p = 0.0094).
Conclusion: A reduction in the number of retention sites for the bonding
system, facilitates the formation of microleakage in the experimental
conditions and reduces the degree of adhesion of the composite material
to the hard tissues of the tooth.