Parameters Influencing Increase in Pulp Chamber Temperature with Light-curing Devices: Curing Lights and Pulpal Flow Rates

2010 ◽  
Vol 35 (3) ◽  
pp. 353-361 ◽  
Author(s):  
S-H. Park ◽  
J-F. Roulet ◽  
S. D. Heintze
Keyword(s):  
Light Intensity ◽  
High Power ◽  
Clinical Relevance ◽  
High Power Density ◽  
Pulp Chamber ◽  
Cavity Preparation ◽  
Flow Rates ◽  
Chamber Temperature ◽  
Light Curing ◽  
Short Time

Clinical Relevance Because increase in temperature is related directly to light intensity and exposure time, curing devices with high power density (>1200 mW/cm2) should only be activated for a short time (<15 seconds), even in teeth without cavity preparation.

Comparison of Temperature Changes in the Pulp Chamber Induced by Various Light Curing Units, In Vitro

10.2341/05-26 ◽  
2006 ◽  
Vol 31 (2) ◽  
pp. 261-265 ◽  
Author(s):  
A. R. Yazici ◽  
A. Müftü ◽  
G. Kugel ◽  
R. D. Perry
Keyword(s):  
Clinical Relevance ◽  
Critical Factor ◽  
Pulp Chamber ◽  
Temperature Changes ◽  
Thermal Transfer ◽  
Light Curing

Clinical Relevance The thickness of the residual dentin is a critical factor in the reducing thermal transfer to pulp, and this transfer varies with the curing unit used.

A Study of Temperature Rise in the Pulp Chamber during Composite Polymerization with Different Light-curing Units

2007 ◽  
Vol 8 (7) ◽  
pp. 29-37 ◽  
Author(s):  
Christopher Millen ◽  
Martyn Ormond ◽  
Gillian Richardson ◽  
Ario Santini ◽  
Vesna Miletic ◽  
...  
Keyword(s):  
Light Intensity ◽  
Temperature Rise ◽  
Bonding Agent ◽  
Pulp Chamber ◽  
Data Logger ◽  
Bonding Agents ◽  
Pulp Temperature ◽  
Light Curing ◽  
Temperature Records ◽  
Group 2

Abstract Aim The study compared pulp temperature rise during polymerization of resin-based composites (RBCs) using halogen and LED light-curing units (LCUs). Methods and Materials A total of 32 teeth extracted from patients aged 11-18 years were used in the study. Thermocouples placed on the roof of the pulp chamber using a novel ‘split-tooth’ method. In Group 1 a halogen LCU with a light intensity of 450 mWcm-2 was used and in Group 2, an LED LCU with a light intensity of 1100 mWcm-2 was used. The teeth were placed in a water bath with the temperature regulated until both the pulp temperature and the ambient temperature were stable at 37°C. Continuous temperature records were made via a data logger and computer. The increase in temperature from baseline to maximum was calculated for each specimen during the curing of both the bonding agent and the RBC. Results The rise in pulp temperature was significantly higher with the LED LCU than with the halogen LCU for bonding and RBC curing (p<0.05). The major rise in temperature occured during the curing of the bonding agent. During the curing of the RBC, rises were smaller. Conclusions Curing of bonding agents should be done with low intensity light and high intensity used only for curing RBC regardless of whether LED or halogen LCUs are used. Citation 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 November; (8)7:029-037.

Evaluation of Light Intensity Output of QTH and LED Curing Devices in Various Governmental Health Institutions

2011 ◽  
Vol 36 (4) ◽  
pp. 356-361 ◽  
Author(s):  
MM Al Shaafi ◽  
AM Maawadh ◽  
MQ Al Qahtani
Keyword(s):  
Light Intensity ◽  
Clinical Relevance ◽  
Restorative Materials ◽  
Light Curing ◽  
Health Institutions

Clinical Relevance Evaluating the intensity of a light curing unit regularly prior to the application of tooth-colored restorative materials is essential to assure the quality of restorative procedures.

Full Scale Simulation of an Integrated Monolithic Heat Sink for Thermal Management of a High Power Density GaN-SiC Chip

2015 ◽  
Author(s):  
Tanya Liu ◽  
Farzad Houshmand ◽  
Catherine Gorle ◽  
Sebastian Scholl ◽  
Hyoungsoon Lee ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Management ◽  
Power Density ◽  
Mass Flow ◽  
High Power ◽  
Heat Sink ◽  
High Power Density ◽  
Flow Rates ◽  
Mass Flow Rates ◽  
Insight Into

Advances in manufacturing techniques are inspiring the design of novel integrated microscale thermal cooling devices seeking to push the limits of current thermal management solutions in high heat flux applications. These advanced cooling technologies can be used to improve the performance of high power density electronics such as GaN-based RF power amplifiers. However, their optimal design requires careful analysis of the combined effects of conduction and convection. Many numerical simulations and optimization studies have been performed for single cell models of microchannel heat sinks, but these simulations do not provide insight into the flow and heat transfer through the entire device. This study therefore presents the results of conjugate heat transfer CFD simulations for a complex copper monolithic heat sink integrated with a 100 micron thick, 5 mm by 1 mm high power density GaN-SiC chip. The computational model (13 million cells) represents both the chip and the heat sink, which consists of multiple inlets and outlets for fluid entry and exit, delivery and collection manifold systems, and an array of fins that form rectangular microchannels. Total chip powers of up to 150 W at the GaN gates were considered, and a quarter of the device was modeled for total inlet mass flow rates of 1.44 g/s and 1.8 g/s (0.36 g/s and 0.45 g/s for the quarter device), corresponding to laminar flow at Reynolds numbers between 19.5 and 119.3. It was observed that the mass flow rates through individual microchannels in the device vary by up to 45%, depending on the inlet/outlet locations and pressure drop in the manifolds. The results demonstrate that full device simulations provide valuable insight into the multiple parameters that affect cooling performance.

scholarly journals Temperature Rise Within the Pulp Chamber During Composite Resin Polymerisation Using Three Different Light Sources

2008 ◽  
Vol 2 (1) ◽  
pp. 137-141 ◽  
Author(s):  
A Santini ◽  
C Watterson ◽  
V Miletic
Keyword(s):  
Light Intensity ◽  
Temperature Rise ◽  
High Energy ◽  
Energy Output ◽  
Light Sources ◽  
Potential Hazard ◽  
Pulp Chamber ◽  
Data Logger ◽  
Significant Difference ◽  
Light Curing

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. Methods: 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°±1°C. Group 1 (control): Prismatics® Lite II (Dentsply Detrey, Konstanz, Germany), a halogen LCU, light intensity 500 mW/cm2. Group 2: Bluephase® ( Ivoclar Vivadent, Schaan, Liechtenstein), light intensity 1100 mW/cm2. Group 3:Elipar Freelight2 (3M ESPE, Seefeld, Germany), light intensity 1000 mW/cm2. Temperature changes were continuously recorded with a data logger connected to a PC. Results: 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). Conclusion: 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.

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