A light-curing device is now commonly found in dental practices across the country. Some assume that a “point and shoot” technique is sufficient. However, in order to achieve optimal results, dental curing lights must be used correctly. Read on to find out more about how to use a dental curing light so that the resin-based restorations you place in patients’ mouths will be as successful as manufacturers’ claims.

How a dentist uses a light-curing unit makes a large difference in the amount of energy a restoration receives. Even when the device is handled correctly, if the energy level is insufficient, then the resulting restoration may not attain expected longevity; this may explain why resin-based restorations last only five to seven years when actual life expectancy should be 15 years or more.

In a collection of articles written for ADA Professional Product Review, Jack L. Ferracane, Professor and Chair, Restorative Dentistry Division Director, Biomaterials and Biomechanics, Oregon Health & Science University in Portland, Oregon states that there is “considerable evidence that delivering inadequate energy to the restoration will result in a restoration that has less than optimal properties and poor clinical performance.”

Ferracane goes on to say that light-cured resin-based composite restorations most often need replacing because of secondary caries and restoration fracture. Other reasons include staining, marginal breakdown, wear, a broken tooth or nerve death. Inadequate delivery of light or energy to the restoration can result in the early breakdown of a light-cured restoration. Therefore, a dental curing light must deliver adequate light energy to attain the best physical, chemical, and optical properties of a resin-based composite restoration.

Some of the current high powered lights are recommended to cure a material within one second. These lights put out a tremendous power (4000 mW/cm2) compared to typical lights that emit either 600 or 1200 mW/cm2 and are recommended to cure a material within 20 seconds. The big difference between these high powered units and the typical units is that the material is forced to set all at once with no heat dissipation during the curing time. This amount of heat build up is sufficient to cause skin burns and tissue damage.

Several clinicians and researchers speak of how the material reacts to this instant cure, whether the material has internal stresses built-up, or not, and whether a ramping up of curing is preferred to reduce these "internal" stresses.