My curing light is one of the most valuable pieces of equipment in my office. We would need to shut the office down until we got a replacement if all of ours stopped working. Given the importance, understanding how to protect and maintain this investment is important. Many offices protect the end of the curing light with a protective barrier. I have seen finger cots used for this purpose, the barrier sheets designed to stick to light handles, and manufacturer designed protective shields. Is there value to using a barrier on the light tip, and if so what kind should we be using?
Contamination is the first thing I am concerned about when the light is uncovered. Once the curing light has been in the mouth, we now have the issue of disinfection. Most of the manufacturers have very specific instructions on how to disinfect and care for their curing lights. Every light comes with a specific set of recommendations, but let’s look at two for purposes of this discussion. Kerr recommends for their Demi Plus LED, wipe the handle and charger with specific disinfecting wipes. There are many products that are not approved to disinfect the handle and charger, and it should not be sprayed. Once wiped the handle should be allowed to dry completely before being placed back on the charger. As for the light tips, they are designed to be autoclaved, not exposed to a disinfectant. Similarly, Ivoclar recommends disinfectant wipes for the body, anti-glare shield and stand of their Blue Phase Curing lights and autoclaving the light tip. For most offices being able to autoclave the light tip in between patients can be a challenge due to time, and the expense of having enough light tips that they can be changed out between patients. Exposing them to liquid disinfectant will shorten their life span, so the use of a protective barrier becomes critical.
The other challenge of using a light without a barrier is getting bonding resin or composite onto the tip during curing. This material then has to be chipped off with a sharp instrument, possibly leaving residue behind or scratching the tip, diminishing the effectiveness of the light for curing. If you are thinking no problem, I will just hold the light a little away from the tooth surface to prevent this, be cautious. The angle and distance of the light from the resin significantly impacts depth of cure and effectiveness. So we want to place the tip flat against the surface to be cured, and in close, touching proximity. Given this and the negative impact of getting composite on the tip, a protective barrier will protect your investment.
So, what should we use as a protective barrier? There is very clear research that many of the things we use routinely as barriers alter the effectiveness of the curing light dramatically. The barriers need to be clear, and designed to allow for light penetration. Most of the manufacturers recommend a barrier for their unit. Finger cots and other materials that have not been designed for this purpose may reduce the light intensity by as much as 30-40%. Use a barrier that you know will not have a negative impact on your ability to fully cure the resin, because uncured material at the base of a restoration causes post op sensitivity and premature failure of the restoration.