geoscience.net logo
+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Pulpal-temperature rise and polymerization efficiency of LED curing lights


, : Pulpal-temperature rise and polymerization efficiency of LED curing lights. Operative Dentistry 35(2): 220-230

This paper assesses the effects of light characteristics and irradiation time on the Vickers microhardness (VH) of a dual-photoinitiator commercial composite and on temperature increase in the pulp chamber (deltaT). Four recent light-emitting diodes (LEDs)--bluephaseG2 (BG2), bluephase16i (B16i), G-Light (G) and Freelight2 (F2)--and one control halogen light (XL3000-X) were tested on two shades of Tetric EvoCeram (A2 and Bleach XL), whose respective commercial formulations differed based on their concentration of camphorquinone and lucirin TPO. Three different irradiation times were applied--10, 20 and 40 seconds-and VH was measured on the upper and lower surfaces of 2-mm thick samples. The deltaT was measured by using a K-type thermocouple inserted into the pulp chamber of a molar that had been prepared to obtain a 2-mm thickness of dentin. The measurements were made either during polymerization of a 2 mm composite (Shade A2 or Bleach) or with an empty mold. The data were analyzed with the two-way ANOVA (p < 0.05) test. For shade A2, all but one irradiation condition (F2-10 seconds, lower surface) generated VH values that were statistically equal to or better than the standard chosen for this study (X-40 seconds). For Bleach shade, the VH values obtained with G and BG2-20 and 40 seconds were statistically comparable to X-40 seconds for both the upper and lower surfaces. This was not the case with either G and BG2-10 seconds or for all the procedures with other LCUs for which a VH of at least one of the surfaces was significantly lower than the reference. The results also highlight differences between the two material shades, whether the upper or lower surface is considered. Regarding temperature measurements for shade A2, B16i-20-40 seconds, BG2-40 seconds and G-40 seconds induced significantly higher deltaTs (3.98, 5.98, 5.21 and 4.95, respectively) than X-40 seconds (3.09). For Bleach shade, B16i-20 and 40 seconds, F2-20 and 40 seconds, BG2-40 seconds and G-40 seconds generated deltaTs significantly higher than the control values (2.70, 4.05, 3.03, 4.58, 2.74 and 2.44, respectively). The deltaT values obtained with uncovered tooth were generally higher than those obtained with a 2-mm layer of composite. In conclusion, this research emphasizes that a perfect correspondence between light and material spectra is of prime concern, both to insure optimal polymerization and to limit heating in the pulp chamber. Some reduction in curing time is possible, but only within certain limits.

US$19.90

PMID: 20420066

DOI: 10.2341/09-203-L


Other references

Franck, N.; Daprati, E.; Michel, F.; Saoud, M.; Dalery, J.; Marie Cardine, M.; Georgieff, N., 1998: Gaze discrimination is unimpaired in schizophrenia. Interpersonal communication is largely dependent on interpretation of facial expression and emotion. Difficulties in face processing, and more specifically in gaze discrimination, have been described in schizophrenic patients. According to Baron-C...

Schena, F.Paolo., 2006: The role of the Italian Directory of Nephrology Units. Journal of Nephrology 19(5): 587-587

Claassen, J.N., 1999: The benefits of the CAGE as a screening tool for alcoholism in a closed rural South African community. Objective. Testing the benefits of the CAGE questionnaire (a four-item test with questions on Cutting down, Annoyance at criticism, Guilty feelings and use of Eye-openers) in screening for possible alcoholism in rural underserviced South Africa. D...

Lodin Z.; Hartman J.; Lisa V.; Faltin J.; Jankaskova B.; Srajer J., 1987: Correlation between changed biophysical properties of surface membranes and embryonic brain cell adhesivity influence of detergents fixation egta colchicine vinblastine increased potassium ouabain and dma on the primary cellular adhesivity of embryonic brain cell. Embryonic mouse brain cells were rotated for 120 min and cellular adhesivity was tested under normal conditions and in the presence of substances which change the membrane properties. A marked decrease of cellular adhesivity (but not complete inhi...

Grami, R.; Mansour, W.; Mehri, W.; Bouallègue, O.; Boujaâfar, N.; Madec, J-Yves.; Haenni, M., 2016: Impact of food animal trade on the spread of mcr-1-mediated colistin resistance, Tunisia, July 2015. We report a high prevalence of MCR-1 and CTX-M-1-producing Escherichia coli in three Tunisian chicken farms. Chickens were imported from France or derived from French imported chicks. The same IncHI2-type plasmid reported to carry those genes in c...

Cella, D., 2004: Quality of life considerations in patients with advanced lung cancer. Quality of life (QOL) is an important consideration in the treatment of patients with advanced lung cancer because treatment is largely palliative. Moreover, QOL predicts survival in non-small cell lung cancer, and there is increasing acceptance b...

Engelhardt, W., 1997: Intra-clinic transport of patients with increased intracranial pressure. Zentralblatt für Neurochirurgie 58(1): 50-51

Sekine I.; Kawase Y.; Oot J.; Matsumoto K.; Ito M.; Okumura Y.; Ikeda T.; Nishimori I., 1986: Radiation induced tumors study based on biopsied and surgical materials. So-called radiation-induced tumor cases following radiation therapy have been collected for the purpose of elucidation the relationship between ionizing radiation and carcinogenesis. Presented in this paper is a summary of cases obtained from biop...

Hsuchou, H.; Pan, W.; Kastin, A.J., 2007: The fasting polypeptide FGF21 can enter brain from blood. FGF21 recently has been proposed as a missing link in the biology of fasting, raising the question of whether it directly reaches the brain. We used multiple time-regression analysis to quantify the influx rate of this polypeptide across the blood...

Artz N.E.; O'rourke J.T.; Gilles J.L.; Aro R.S.; Narjisse H., 1986: Social inputs in range development planning. Joss, P J , P W Lynch And O B Williams (Ed ) Rangelands: A Resource Under Siege; Second International Rangeland Congress; Adelaide, South Australia, May 13-18, 1984 Xv+634p Cambridge University Press: New York, New York, Usa; Cambridge, England, Uk Illus 357-361