Types of light-curing units in dentistry

July 6, 2021

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There are several types of equipment that are necessary for dentistry. This dental equipment is necessary for every dental procedure. Light-curing units play an imperative role in dentistry. They make the procedures in dentistry easy for the dentists as well as comfortable for the patients. Light-curing units are handheld devices that polymerize dental materials which are visible light-activated. There are different kinds of light-curing units. These are light-emitting diode (LED), quartz-tungsten-halogen (QTH), and plasma arc curing (PAC) units. These light curing units as well as their properties, mechanism and advantages have been discussed here. This would help understand the intricacies of how each of these light-curing units functions and further help the dental procedures in any dental healthcare environment.

LED light-curing units

LED light-curing units are extremely important for dentistry. They usually emit light between 440 and 490 nm. This is the blue part of the visible spectrum. Also, LED light-curing units do not need filters and do not emit heat. They are powered through rechargeable batteries. New LED light curing unit have a combination of multiple LEDs across a vast range of wavelengths and expand the spectrum of the light which is emitted. Therefore, they increase the total intensity and polymerize all the visible-light activated dental materials in the required manner. Through these various advantages, LED light-curing units make it easier for dentists to perform dental procedures in a dental health care environment.

QTH light-curing units

QTH light-curing units are the most commonly used light-curing units. This is because they have several advantages and uses. The QTH light-curing units are manufactured from a quartz bulb which consists of a tungsten filament inside a halogen environment. QTH units give out ultraviolet irradiation and visible light in the broad spectrum. This visible light is filtered which helps to limit the wavelength output and keep it between 400 and 500 nm. This also minimizes heat. Even though the intensity of light given out by a QTH bulb varies from 400 to 1200 mW/cm2, it can decrease with use over time.

Therefore, it is recommended to use a radiometer to monitor the routine of the light intensity as well as to permit the built-in fan to cool the QTH bulb. This helps to maximize the working of the device. Through these benefits, the QTH light-curing units help dentists perform dental operations with ease. They also improve the entire healthcare of the patients in the oral healthcare environment.

PAC light-curing units

PAC light-curing units work on the principle of containing a xenon gas that produces plasma by ionizing. The high-intensity white light which is emitted is then filtered so as to reduce the heat generated. This also helps to control the output to the violet-blue part of the visible spectrum which ranges from 400–500 nm. Here, the argon laser units emit the highest intensity by emitting light at a single wavelength of approximately 490 nm. PAC light-curing units have extensive costs of using and maintaining them because of which they are used comparatively lesser. These multiple advantages prove that PAC light-curing units are vital for any dental healthcare environment.

Since the past three decades, composite resins have been used extensively in the domain of dentistry. Due to this, the demand for esthetic restorative materials has been increasing. The resins need to be polymerized for performing the dentistry operations and during this, the monomer units need to bond. For this, the resins need to be polymerized completely and several factors contribute to that. These are the intensity and wavelength of the output of light curing unit, locations as well as dimensions of the dental cavity, the radiation duration, composite’s composition, bandwidth and wavelength of the curing light, irradiation time, direction as well as distance of the device’s tip, the composite’s color and thickness.

Due to the importance of these factors in the process of polymerization, it is imperative to have the right light-curing units for a smooth practice. The light-curing units not only help the dentists go on with their work in a relaxed manner, but they also make the patients, who are strangers to the dental operations, more confident and comfortable. Due to this two-way advantage, light-curing units are essential to any oral healthcare environment and help to improve the overall health of the patients.