Author/Authors :
Khatoon Khaksaran، Najmeh نويسنده Department of Dental Biomaterials, , , Jafarzadeh-Kashi، Tahereh-Sadat نويسنده Department of Dental Materials, Research Center for Science and Technology in Medicine, Faculty of Dentistry, Tehran University of Medical Science Jafarzadeh-Kashi, Tahereh-Sadat , Rakhshan، Vahid نويسنده Iranian Tissue Bank and Research Center, Tehran University of Medical Sciences, Dept. of Dental Anatomy and Morphology, Dental Branch, Islamic Azad University, Tehran, Iran. , , Zeynolabedin، Zahra Sadat نويسنده Department of Dental Biomaterials, , , Bagheri، Hossein نويسنده Department of Dental Biomaterials, ,
Abstract :
Background: Application of bonding agents (BA) into deep cavities and light curing them might
increase pulpal temperature and threaten its health. The purpose of this study was to evaluate
temperature rise of pulp by light curing six BA using two different light curing units (LCU), through
a dent in wall of 0.5 mm.
Materials and Methods: This in vitro experiment was carried out on 96 slices of the same
number of human third molars (6 BAs × 2 LCUs × 8 specimens in each group). There were 6
groups of BAs: N Bond, G-Bond, OptiBond XTR, Clearfi l SE, Adper Single Bond 2 and V Bond.
Each group of BA (n = 16) had two subgroups of light emitting diode (LED) and quartz-tungstenhalogen
light cure units (n = 8). Each of these 16 specimens were subjected to light emitting
for 20 s, once without any BAs (control) and later when a BA was applied to surface of disk.
Temperature rises in 140 s were evaluated. Their mean temperature change in fi rst 20 s were
calculated and analyzed using two-way repeated-measures and one-way analysis of variance
(ANOVA) and Tukey (? = 0.05). Furthermore rate of temperature increase was calculated for
each material and LCU.
Results: Minimum and maximum temperature rises in all subgroups were 1.7 and 2.8°C,
respectively. Repeated measures ANOVA showed that both of adhesive and LCU types had
signifi cant effect on temperature rise after application of adhesives. Tukey post-hoc analysis showed
Clearfi l SE showed signifi cantly higher temperature rise in comparison with Adper Single bond 2
(P = 0.047) and N Bond (P = 0.038). Temperature rose in a linear fashion during fi rst 30-40 s and
after that it was non-linear.
Conclusion: 20 s of light curing seems safe for pulpal health (with critical threshold of 5.5°C).
However, in longer durations and especially when using LED units, the process should be broken
to two sessions.
