Effect of composite shade, increment thickness and curing light on temperature rise during photocuring.
ABSTRACT To examine the effect of composite shade, increment thickness and curing light characteristics on the temperature rise associated with composite photocuring.
Four shades (C2, A4, B1 and B3), four sample thicknesses (2, 3, 4 and 5 mm) of a hybrid resin composite and two curing units, one with two modes of curing, were investigated. The composite samples were packed in polytetrafluoroethylene (PTFE) moulds and cured for 40 s. Samples cured with the ramp curing mode were irradiated for only 20 s. Temperature rises on the undersurface of the curing resin composite were measured using an infrared scanning system.
Shade C2 produced the highest maximum temperature of all shades (56.7 degrees C). Thinner samples produced greater temperature rises (2mm induced 60.9 degrees C, 5 mm induced 45.7 degrees C). Samples cured with Optilux 501 unit produced greater temperature rises (60.9 degrees C) than those cured with Dentsply unit (56.2 degrees C).
There was a quantifiable amount of heat generated during visible light curing of resin composite. The amount of heat generated was influenced by shade selected, thickness of material and characteristics of the light curing unit.
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ABSTRACT: The purpose of this study was to investigate the polymerization temperature of a bulk filled composite resin light-activated with various light curing modes using infrared thermography according to the curing depth and approximation to the cavity wall. Composite resin (AeliteFlo, Bisco, Schaumburg, IL, USA) was inserted into a Class II cavity prepared in the Teflon blocks and was cured with a LED light curing unit (Dr's Light, GoodDoctors Co., Seoul, Korea) using various light curing modes for 20 s. Polymerization temperature was measured with an infrared thermographic camera (Thermovision 900 SW/TE, Agema Infra-red Systems AB, Danderyd, Sweden) for 40 s at measurement spots adjacent to the cavity wall and in the middle of the cavity from the surface to a 4 mm depth. Data were analyzed according to the light curing modes with one-way ANOVA, and according to curing depth and approximation to the cavity wall with two-way ANOVA. The peak polymerization temperature of the composite resin was not affected by the light curing modes. According to the curing depth, the peak polymerization temperature at the depth of 1 mm to 3 mm was significantly higher than that at the depth of 4 mm, and on the surface. The peak polymerization temperature of the spots in the middle of the cavity was higher than that measured in spots adjacent to the cavity wall. In the photopolymerization of the composite resin, the temperature was higher in the middle of the cavity compared to the outer surface or at the internal walls of the prepared cavity.Journal of applied oral science: revista FOB 08/2013; 21(4):293-9. · 0.39 Impact Factor
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ABSTRACT: While it is reasonably well known that certain dental procedures increase the temperature of the tooth's surface, of greater interest is their potential damaging effect on the pulp and tooth-supporting tissues. Previous studies have investigated the responses of the pulp, periodontal ligament, and alveolar bone to thermal irritation and the temperature at which thermal damage is initiated. There are also many in vitro studies that have measured the temperature increase of the pulp and tooth-supporting tissues during restorative and endodontic procedures. This review article provides an overview of studies measuring temperature increases in tooth structures during several restorative and endodontic procedures, and proposes clinical guidelines for reducing potential thermal hazards to the pulp and supporting tissues.Restorative dentistry & endodontics. 08/2013; 38(3):105-112.
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ABSTRACT: The purpose of the study was to compare temperature rise during polymerisation of resin based composites (RBCs) with two LED light curing units (LCUs) compared to a halogen control light. Forty-five extracted molars, patients aging 11-18 years were used. Thermocouples (TCs) were placed in contact with the roof of the pulp chamber using a 'split-tooth' method. Teeth were placed in a water bath with the temperature of the pulp chamber regulated at 37 degrees +/-1 degrees C. GROUP 1 (CONTROL): Prismatics((R)) Lite II (Dentsply Detrey, Konstanz, Germany), a halogen LCU, light intensity 500 mW/cm(2). GROUP 2: Bluephase((R)) ( Ivoclar Vivadent, Schaan, Liechtenstein), light intensity 1100 mW/cm(2). Group 3:Elipar Freelight2 (3M ESPE, Seefeld, Germany), light intensity 1000 mW/cm(2). Temperature changes were continuously recorded with a data logger connected to a PC. Significantly higher temperature rise was recorded during bond curing than RBC curing in all 3 groups. (Halogen; p =0.0003: Bluephase; p=0.0043: Elipar; p=0.0002.). Higher temperatures were recorded during polymerisation of both Bond and RBC with both LED sources than with the halogen control. There was no significant difference between the two LED,LCUs (Bond:p=0.0279: RBC p=0.0562: Mann-Whitney). The potential risk of pulpal injury during RBC polymerisation is increased when using light-curing units with high energy output compared to low energy output light sources. The rise is greatest when curing bonding agent alone and clinicians are advised to be aware of the potential hazard of thermal trauma to the pulp when using high intensity light sources. However the mean temperature rise with all three units was below the limits normally associated with permanent pulp damage.The Open Dentistry Journal 01/2008; 2(1):137-141.