Most Commonly Asked Calset Questions

Q: Can Calset heat-treated composite be used for CEMENTING (i.e. LUTING) restorations?
A: Calset can and is being used for cementation of restorations. This is being done by several leading clinicians and at the University of Iowa Dental School.

Q: What effect does heat treatment with Calset have on polymerization shrinkage?
A: Heat is used to accelerate the polymerization reaction. All composites shrink in the course of polymerization to a maximum based on their individual properties. Heat just gets the material to reach maximal polymerization with lower light levels and in less time. (See chart by Prof. Jeffrey W. Stansbury). These results by Trujillo and Stansbury were presented at the 2003 IADR meeting and will soon be published in “Dental Materials.”

Q: Can composite be left in the Calset all day?
A: Compules can be left in the unit for up to 8 hours without causing premature polymerization of the composite (JW Stansbury, Univ of Colorado). It is recommended that the Doctor chooses the shade and places the compule(s) in the Calset at that time, then continue prepping the patient.

Q: Flowables are recommended as the first increment in the posterior is to provide a “cushion” or “shock absorber” effect due to its higher elasticity vs. microhybrids. Why should I use warmed composite instead of a flowable?
A: The concept of using flowable as a “shock absorber” is not universally accepted. The JADA article called “Contraction stress of flowable composite materials and their efficacy as stress-relieving layers” by Drs. Braga RR, Hilton TJ & Ferracane JL shows flowables do not provide any advantage for this purpose. Also, see attached study by Drs. M.N. Aksu, A:-ML Neme, S. Walker, F.E. Pink, J.B. Linger and W.C. Wagner study called “Effect of Pre-Heating Composite on Microleakage in Class II Restorations” which shows reduction of cervical microleakage using heated composite in the Calset.

Q: Does heating composite damage the pulp?
A: Data obtained at the Medical College of GA School of Dentistry indicate that the injection of composite resin heated to 130°F into a cavity preparation results in a pulpal temperature rise of only 2.9°F (Fred Rueggeberg, Medical School of GA School of Dentistry). This is well below the critical temperature rise thought to be the threshold for pulpal effects.

Q: How long does it take to warm the composite in the Calset?
A: When you turn the Calset on in the morning, it takes approximately 10 minutes to come up to temperature. Once the unit has been warmed, it only takes 2 – 3 minutes to warm the compule of composite.

Q: Can you warm a syringe of composite in the Calset?
A: You can dispense the composite directly into the well of the standard tray. It will take approximately 1 – 2 minutes to warm up.