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.

Here at Bluelight Analytics, we have gathered tens of thousands of curing light tests from all over the world with our CheckMARC technology and what we have found is that 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 fill you in on 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.

Just because it’s an LED light it doesn’t mean that everything is automatically operating effectively. 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 of your dental curing light unit is another issue that can affect the performance of your lights. 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, underperformance can occur when material instructions for use and light output are not properly understood. Optimal curing times will vary based on light output. So, it is essential to test your curing lights to find your light output in order to properly understand the relationship between your curing light and each material. Understanding this relationship is pivotal in avoiding under-curing materials or overheating soft tissues.

What can happen if the wrong curing time is used?

If you’re not curing for long enough or if a light is underperforming, then significant issues could be affecting the success of your restorations. This has the potential to lead to the formation of secondary caries or even require re-intervention, such as:

• Undercuring

  • Discoloration

  • Debonding

  • Fracture

  • Excessive wear

Conversely, clinicians sometimes overcompensate their curing by adding another cycle and curing for longer without knowing the output of their light. The fact is that 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

  • The pulp

Many of these issues may be the cause of post-operative sensitivity or patient discomfort. Also, it is good to keep in mind that implementing heat management techniques such as taking breaks in between curing cycles can allow heat to dissipate and will lessen potential heat concerns.

How often should you test your curing lights?

Testing your dental curing lights is not just recommended in national dental associations such as the ADA and CDA, but also in many light and material instructions for use (see appendix A for image).

Changes in output can be dependant on the quality of the light that you use in your practice. We always recommend purchasing a good quality and reliable curing light unit (Remember: the price isn’t always an indication of quality, so do your research).

The worry is that with lower end dental curing lights the output could change based on the day of the week or their battery charge. Lower end curing lights are more susceptible to light 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 available on the market today that allow you to test the efficacy of your curing light output including, radiometers and spectrometers.

Radiometers are commonly used in dental practices however, they offer a very simple light 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, as sometimes blue or violet LEDs could burnout and change the spectral profile. A spectrometer is also required to identify if a filter has been damaged in halogen or plasma arc type lights.

Our spectrometer-based CheckMARC technology provides highly accurate light measurements, can detect spectrum issues, and calculates the optimal curing times for your light-cured materials. You can book your free CheckMARC service test here. 

New technology now hitting the market combines spectrometer learned technology and artificial intelligence to create an app-based chairside solution called CheckUp.

It allows you to test your lights, track your materials and generates precise curing times for each restoration, all in the palm of your hand. This will offer a simpler, quicker and more effective way of light testing than ever before. Learn more about saving time and increasing restoration success with CheckUP, here.

To sum it up

Light curing best practices are often overlooked in dental clinics but ultimately play a huge role in the success of your clinic and the satisfaction of your patients.

Just like your dental handpiece, it’s 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.

(1) Ritter, A. V., Boushell, L. W., & Walter, R. (2019). Sturdevant's Art & Science of Operative Dentistry.

(2) Che, F., Felix, C. (2019). Endurance Testing of Dental Light Curing Units. J Dent Res, Vol 98 A, Abstract #1105

(3) Price, R. B., Strassler, H. E. Understanding Light Curing, Part 2. Delivering Predictable, Successful Restorations. Dentistry Today.