Why should I test my dental curing lights?

Dental light curing is an integral part of restorative dentistry and a daily practice in every dental office. In fact, at least 50% of revenue-generating procedures in any dental practice rely on the successful use of a dental curing light.

Across 275,000+ light evaluations gathered with our CheckMARC technology, one pattern is consistent: all curing lights degrade with use over time. When light-emitting diode (LED) curing lights hit the market, the perception was that they would have long lives and maintain output for years. However, that is simply not the case (1).

In this post, we will cover some of the causes of light-curing under-performance, the effects of under-curing and over-heating, and how often you should be testing your curing lights.

What causes your curing lights to underperform?

So, you have an LED curing light. You click the button and the blue light comes on, everything must be working properly, right? Not quite.

LED curing lights can still burn out gradually, or various elements on the LED chip can burn out, causing some of the light to be lost. Maintenance is another issue that can affect performance. These issues include:

• Material adhering to the tip: not being cleaned properly and blocking light output.
• Damage to the unit: autoclaving, dropping, or cracks in the case or tip.
• Battery charge: curing light output can drop as the battery is drained.
• Infection control barrier: tinted or opaque barriers can block light output.

Additionally, under-performance can occur when material instructions for use and light output are not properly understood. Optimal curing times vary based on light output, so it is essential to test your curing lights to find your output and properly understand the relationship between your light and each material. Understanding that relationship is pivotal to avoiding under-cured materials or overheated soft tissue.

What can happen if the wrong curing time is used?

If you are not curing for long enough, or if a light is under-performing, significant issues can affect the success of your restorations. This has the potential to lead to secondary caries or re-intervention. Under-curing is associated with:

• Discoloration
• Debonding
• Fracture
• Excessive wear

Conversely, clinicians sometimes overcompensate by adding another cycle and curing for longer without knowing the output of their light. Adding an extra, “just in case” curing cycle can end up doing more harm than good. Some of these lights are very powerful, and if you use them for too long you risk overheating and damaging (1) the soft tissue, the gingiva, and the pulp.

Many of these issues may be the cause of post-operative sensitivity or patient discomfort. It is also worth keeping in mind that heat management techniques, such as taking breaks between curing cycles, allow heat to dissipate and lessen potential heat concerns.

How often should you test your curing lights?

Testing your dental curing lights is recommended not only by national dental associations such as the ADA and CDA, but also in many light and material instructions for use.

Changes in output can depend on the quality of the light you use. We always recommend purchasing a good-quality, reliable curing light unit (remember: price is not always an indication of quality, so do your research). The worry is that with lower-end curing lights, output could change based on the day of the week or the battery charge. Lower-end lights are more susceptible to burnout and maintenance issues (2).

Regardless of the light, we always recommend striving to test daily. The more you test, the better. If you drop your light or any visible damage occurs, test. If you are applying an infection control barrier, test with the barrier on. If you want to be confident in your curing light output, test.

How do you test your curing lights?

There are many solutions on the market that let you check curing light output, including radiometers and spectrometers. Radiometers are commonly used in dental practices; however, they offer a very simple output reading and studies have shown they can be less accurate than other options available (3).

A spectrometer is needed to identify a specific issue for multi-wave LED lights, since blue or violet LEDs can burn out and change the spectral profile. A spectrometer is also required to identify whether a filter has been damaged in halogen or plasma-arc lights.

Our spectrometer-based CheckMARC technology provides highly accurate light measurements, can detect spectrum issues, and calculates optimal curing times for your light-cured materials. A CheckMARC evaluation tests every light, and every operator, in your practice and hands back the real numbers, so clinic-wide curing standards are built on measurement rather than assumption.

To measure what your lights actually deliver, a CheckMARC evaluation puts an expert-led radiometer and spectrometer on every light in your practice, accounts for the materials you stock, and generates precise curing times for each restoration: a defensible measure of light output without a lab visit.

To sum it up

Light curing best practices are often overlooked in dental clinics, but they ultimately play a huge role in the success of your clinic and the satisfaction of your patients. Just like your dental handpiece, it is important to pay attention to your curing light units and be aware of possible issues. Routine maintenance checks, regular light testing, and implementing optimal curing times are the best ways to increase success for both you and your patients.