Finding a curing light to match a dentists’ particular needs seems to be a daunting task these days. Understanding the technology between each of the different curing systems is a must for the dental operator to make an educated decision on which curing light to use. Currently, the different systems include: conventional halogen, fast halogen, plasma arc, argon laser, ultra high output water cooled lights, and the Light Emitting Diode LED curing lights. This article will spotlight LED technology and my personal experience with one of the most current and versatile LED lights, the Bluephase LED curing light by Ivoclar Vivadent.
In the last five years it seems there has been a trend to move away from the traditional halogen-tungsten and xenon plasma arc (PAC) curing sources. Instead of a heat producing filament as used in traditional sources, LED’s curing lights are using the same technology from the semi-conductor industry. A voltage is applied to the semi conductor chip and a quantum of electromagnetic energy is emitted in the form of a photon of light. This photon of light results in the production of pure blue light. Most of the newest generation of LED’s produce a wavelength of blue light that is in the absorption spectrum of the two most common photoinitiators. These photoinitiators are camphoroquinone (CQ) and phenylpropanedione (PPD). The CQ is initiated at approximately 460 nm, while the PPD is activated in the adhesives, and cements.
At the 2002 meeting of the International Association for Dental Research (IADR), it was summarized that “LED technology is a viable alternative to polymerize adhesives and composites”. Now that we know LED technology works, let’s examine briefly why it is here to stay and some of the benefits over other curing methods.
Energy efficiency is one of the main reasons LED technology is going to be around for a while. This is why most of the LED units are smaller in size. This is also true because they don’t need the extensive cooling systems that traditional halogen and PAC lights need reduce heat output. LED depth of cure has approached that of traditional curing methods and is ever increasing with the newer generations. Long service life and a need to not replace filters or bulbs, as with halogen lights, are tremendous advantages as well.
Let’s face it, as dentists we are concerned with a few main things when looking for a curing light. Does it cure my composites, bonding agents, bleaching materials, cements, etc.? Is it easy, portable and cost efficient to use? Will it be reliable and last for a long time? The answer is an emphatic and definite yes. Halogens, PAC, lasers have been around longer and can get the job done, but one must consider a technology that has many more benefits and fewer disadvantages than the aforementioned curing systems. Light Emitting Diode is this technology and will continue to evolve and break barriers as it has done in the last few years.
Now let’s talk about a LED light that I have personally used over the last 6 months in a combined pediatric and orthodontic private practice. The Bluephase LED light by Ivoclar Vivadent comes equipped with 1 LED which consists of 4 semiconductors capable of producing 8 watts of power. This light has been developed and tested for at least 1,500 hours of curing use according to the manufacturer’s website. This may be considered lower than other manufacturers, but this may be because other manufacturers are including illumination instead of curing hours.
The Bluephase light is a cordless high performance LED light for all indications. It is suitable to cure materials within the range of 430 to 490 nm. This would include all materials with (CQ) as the photoinitiator. The manufacturer has listed a number of products on the market that it should not be used for on their website. It should be mentioned that there are only 5 products listed. The high light intensity of 1,100 mW/cm2 is very competitive between LEDs, allowing for shorter curing times with the standard curing depth of 2 mm. This unit is slightly larger than other LEDs but still maintains an ergonomic lightweight design. The larger design is to help accommodate the cooling fan to dissipate internal heat build up thus preventing the hardware from getting hot. The heat output from the tip is minimal unless directed over soft tissue for more than 30 seconds.
The battery is a modern lithium ion battery with a few great advantages over older Nickel Metal Hydride and other Lithium ion batteries. The advantages include shorter charging times, no memory effect, and a low self discharge while not in use. Full charging takes about 2 hours, but after only 10 minutes it can be used for 6 minutes according to the manufacturer. This light can continuously be used for 60 minutes according to Ivoclar Vivadent. I have not encountered too many battery type problems with this light as compared to some others. The display on the light has a battery use/indication icon which is useful. This way you or your staff can know when to recharge without emptying the battery. This light can also be used with a cord which can get you out of a jam if you need it right away or for extended periods of curing such as when bleaching.
The light can be turned on with one click of a button, a curing mode can be selected, and the same button to start the cycle. You can choose between 10, 20,30,40 and 120 second curing times. Curing modes include High, Low, and Soft Start depending on direct or indirect materials, area of polymerization, or indication for reduced shrinkage stress and reduced temperature build up. One of my favorite features is the radiometer that is built into the base. When the tip is placed over the port and turned on, the radiometer will indicate the light intensity to the nearest 200 mW/cm2. I like this feature because I am no longer playing the guessing game of how efficient my light is curing the material that I want to polymerize. It lets me know right away if I am having a problem with the light intensity.
One small drawback of this light is the poor stability of the anti-glare cone that is included. The small cones have come loose a few times in the patient’s mouth and I feel they may be a choking hazard. I have simply removed them and used alternate methods of light shielding. Another minor flaw is attributed to the cooling fan which takes a few seconds to get going before the unit can be programmed. Even without an immediate start feature when the unit is off, we are only talking about 3 to 4 seconds difference. There were really very few flaws when looking at all the benefits this light has to offer.
In conclusion, LED technology is here to stay so you might as well learn what you can about the available lights on the market relative to the materials and applications that you will be using them for. The Bluephase LED light is a versatile, high powered workhorse that is sure to fulfill your dental needs.