Seeing the Light
Understanding recommendations for the proper use and maintenance of curing lights maximizes clinical outcomes
Pamela Maragliano-Muniz, DMD
The longevity of dental restorations depends upon, among other factors, the proper handling of the materials involved. Unfortunately, one aspect of restorative dentistry that is often overlooked is the correct use of the curing light. Many dentists assume that it is working properly if it turns on and the resin being cured appears to set. The use of a properly functioning curing light and an appropriate curing technique can make or break a restorative practice. If an improperly functioning curing light or an inappropriate curing technique is employed, the results may include restorations that lack longevity, a greater risk of the need for re-treatment, loss of productivity, and reduced bonding efficacy of indirect materials.
Each light-cured dental material requires a specific wavelength range in which the curing occurs, and each curing light produces a specific wavelength range of light. There are broad spectrum curing lights that will cure virtually all dental materials that are cured with visible light, and there are other curing lights that provide more narrow spectrums of light. Understanding the inherent capabilities and limitations of your curing light and confirming the compatibility of the materials that you use in the clinical setting will minimize the risk of dental materials being incompletely cured.
Each light-cured resin has specific manufacturer recommendations pertaining to the proper management of the material, including suggested incremental depths of placement and curing times. Specific curing times are unique to each material, and similar materials from the same manufacturer can have differing curing times. For example, a highly filled, opaque composite with a low value often has a longer curing time than a high-value, higher translucency composite resin from the same manufacturer. It is strongly suggested that practitioners refer to the instructions for use provided by the manufacturer to ensure that all materials are being cured in proper increments and for the recommended times.
Understanding the recommendations for proper use, storage, disinfection, and maintenance of your curing light will maximize its lifespan and ultimately, your clinical outcomes. Curing lights do not always provide a homogeneous beam of light, and understanding the irradiance values and proper technique (ie, holding statically versus rotating the light over the area to be cured, recommended distance from the area to be cured, amount of heat generated, etc) is necessary to minimize clinical complications. In addition, an understanding of the ideal conditions for curing with your specific curing light will assist you in making decisions when nonideal situations arise (eg, deep cavity preparations, difficult access, etc).
The periodic monitoring of curing lights is necessary to ensure that they are functioning properly. When curing lights are not functioning at an optimal level, the clinician may have to increase the amount of time for which materials are exposed or repair or replace the device. Early identification of any malfunctioning curing lights benefits a dental practice by minimizing the clinical complications related to the incomplete curing of materials.
Many clinicians attempt to protect their eyes from the curing light by looking away from the tooth during curing. This can result in drifting of the curing light and an incomplete cure of materials. It is suggested that clinicians utilize eye protection or protective shields to safeguard their eyes while curing in order to acquire visual certification that the area to be cured is being cured properly. Some newer curing lights offer "lane assist" features that alert the clinician if the light drifts from the area intended to be cured. This technology may be helpful for those who insist on looking away during curing.
It is shortsighted to think that a material is fully cured simply because it feels hardened when assessed with an explorer after curing. Knowing the requirements of your materials and prioritizing the functionality of your curing light are essential to enhancing restorative outcomes and the longevity of your restorations.
About the Author
Pamela Maragliano-Muniz, DMD, is a practicing prosthodontist, a faculty member at the Tufts University School of Dental Medicine, and a former dental hygienist. She maintains a private practice in Salem, Massachusetts, and is the editor-in-chief of Inside Dental Hygiene.