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Comparison of the Amount of Temperature Rise in the Pulp Chamber of Teeth Treated with QTH, Second and Third Generation LED Light Curing Units: An In Vitro Study

Rajesh Harivadanbhai Mahant, Shraddha Chokshi, Rupal Vaidya, Pruthvi Patel, Asima Vora, Priyanka Mahant




Introduction: This in vitro study was designed to measure and compare the amount of temperature rise in the pulp chamber of the teeth exposed to different light curing units (LCU), which are being used for curing composite restorations.

Methods: The study was performed in two settings; first, an in vitro and second was mimicking an in vivo situation. In the first setup of the study, three groups were formed according to the respective three light curing sources. i.e. Quartz-Tungsten-Halogen (QTH) unit and two light-emitting diode (LED) units (second and third generations). In the in vitro setting, direct thermal emission from three light sources at 3 mm and 6 mm distances, was measured with a k-type thermocouple, and connected to a digital thermometer. For a simulation of an in vivo situation, 30 premolar teeth were used. Class I Occlusal cavity of all the teeth [RM1] were prepared and they were restored with incremental curing of composite, after bonding agent application. While curing the bonding agent and composite in layers, the intrapulpal temperature rise was simultaneously measured with a k-type thermocouple.

Results: The first setting of the study showed that the heat produced by irradiation with LCU was significantly less at 6 mm distance when compared to 3 mm distance. The second setting of the study showed that the rise of intrapulpal temperature was significantly less with third generation LED light cure units than with second generation LED and QTH light cure units.

Conclusion: As the distance from the light source increases, less irradiation heat is produced. Third generation LED lights cause the least temperature change in the pulp chamber of single rooted teeth.



Pulp chambers, LED dental curing lights, Temperature, Intrapulpal temperature rise, LED lights, QTH units, Third generation LED lights


Khounganian R, Ashour M. Scanning electron microscopic study of visible light curing effects on the oral mucous membrane. East Mediterr Health J. 1997;3(3):540– 8.

Guiraldo R D, Consani S, Lympius T, Schneider L F, Sinhoreti M A, Correr-Sobrinho L. Influence of the light curing unit and thickness of residual dentin on generation of heat during composite photoactivation. J Oral Sci. 2008; 50:137-42.

Santini, A. Current status of visible light activation units and the curing of light-activated resin-based composite materials. Dent. Update 2010; 37(4): 214–6, 218–20, 223–7.

Zach L, Cohen G. Pulp response to externally applied heat. Oral Surg Oral Med Oral Pathol. 1965;19: 515-30.

Leprince J, Devaux J, Mullier T. Pulpal-temperature Rise and Polymerization Efficiency of LED Curing Lights. Oper Dent. 2010; 35(2): 220-30.

Wahbi M, Aalam F, Fatiny F. Characterization of heat emission of light-curing units. Saudi Dent J. 2012;24(2): 91-8.

Asmussen E, Peutzfeldt A. Temperature rise induced by some light emitting diode and quartz–tungsten–halogen curing units. Eur J Oral Sci. 2005;113:96–8.

Martins G, Cavalcanti B, Rode S. Increases in intrapulpal temperature during polymerization of composite resin. J Prosthet Dent. 2006; 96: 328-31.

Busemann I, Lipke C, Schattenberg A. Shortest exposure time possible with LED curing lights. Am J Dent. 2011;24(1):37-44.

Nakamura S, Mukai T, Senoh M. Candela-class high-brightness InGaN/AIGaN double-heterostructure blue-light-emitting diodes. Appl Phys Lett. 1994; 64(13), 1687-9.

Shortall, A, Harrington E. Temperature rise during polymerization of light activated resin composites. J Oral Rehab. 1998; 25: 908–13.

Lloyd C, Joshi A, McGlynn E. Temperature rises produced by light sources and composites during curing. Dent. Mater. 1986; 2: 170–4.

Yap AU, Soh MS. Thermal emission by different light-curing units. Oper Dent. 2003; 28: 260-6.

Millen C, Ormond M, Richardson G, Santini A, Miletic V, Kew P. A study of temperature rise in the pulp chamber during composite polymerization with different light-curing units. J Contemp Dent Pract. 2007;8(7): 29-37.

Ebenezar A, Anilkumar R, Indira R. Comparison of temperature rise in the pulp chamber with different light curing units: An in-vitro study. J Cons Dent. 2010;13(3):132-35

Santini A, Watterson C, Miletic V. Temperature Rise within the Pulp Chamber During Composite Resin Polymerisation Using Three Different Light Sources. Open Dent J. 2008; 2: 137-41.

Goodis H, White J, Andrews J, Watanabe L G. Measurement of temperature generated by visible-light-cure lamps in an in vitro model. Dent Mater. 1989;5:230-4.

Goodis H, White J, Gamm B, Watanabe L. Pulp chamber temperature changes with visible light-cured composites. In vitro study. Dent Mater. 1990;6(2):99-102.

Kavitha M, Kailash S, Maheswari S. Thermographic analysis of temperature rise in the pulp chamber with LED and QTH light curing units: An in vitro investigation. SRM J Res Dent Sci. 2013;4(1):1-5.

McCabe J. Cure performance of light-activated-composites by differential thermal analysis (DTA). Dent Mater J. 1985; 1: 231–4.

DOI: https://doi.org/10.22037/jlms.v7i3.10409