An introduction to lasers in dental hygiene

What is a laser?

The word laser is an acronym for 'light amplification by stimulated emission of radiation.' We can thank Albert Einstein for theorizing that photoelectric amplification could emit a single frequency, or stimulated emission, which explains how a laser operates. Light is a form of energy that exists as a particle, called a photon, and travels in a wave. A photon wave has three basic properties.

Velocity: The speed of light.

Amplitude: The vertical measurement of the height of the wave, from the zero axis to the peak, which describes the energy of that wave. For convenience, energy is measured in millijoules, or thousandths of a joule.

Wavelength: The horizontal distance between any two corresponding points on the wave. In dentistry, we use wavelengths that range between 450 nm and 10,600 nm.

Laser light is distinguished from ordinary light in that it is monochromatic, it can be visible or invisible and each wave is coherent or identical in physical size and shape. Laser energy is nonionizing radiation.

Lasers were introduced to dentistry in 1960 and are capable of providing results comparable to or superior to conventional techniques and instruments. There are more than two dozen indications for laser use ranging from simple gingival troughing for homeostasis to caries detection, caries removal, tooth preparation and curing. Laser energy can be reflected, absorbed, transmitted or scattered within the target tissue or can pass through without any effect on the tissues. The diode family of lasers range in wavelengths from 808 nm to 1064 nm. These are soft-tissue lasers and are absorbed in hemoglobin, other blood components and melanin.

The Nd:YAG 1064 nm wavelength is also a soft-tissue laser and also absorbed in hemoglobin, blood components and melanin. Hydroxyapatite does not absorb these wavelengths. The two erbium lasers are the only hard-tissue lasers with wavelengths of 2,780 nm and 2,940 nm. This laser energy is best absorbed in water and tooth structure.

The CO₂ laser is also a soft-tissue laser with a wavelength of 10,600 nm. This wavelength is best absorbed, such as the erbium family, in water and tooth structure. However, this laser is only used on the soft tissues. A dentist or hygienist must choose the best laser for the desired treatment.

Erbium lasers use extremely short pulse durations and can easily ablate layers of calcified tissue with minimal thermal effects. Because of the unique absorption properties, all wavelengths have different penetration depths within the tissues. The erbium and CO₂ lasers are absorbed on the surface of the target tissue where the diode and Nd:YAG lasers can reach several thousand microns deep into the tissues.

Lasers in daily practice

With the integration of lasers, I finally have the ability to achieve a higher level of health for my patients.

The first laser I use in my clinical appointment is the 655 nm wavelength laser to detect sub-gingival and supra-gingival calculus with the laser perio tip attached (Note that the DIAGNOdent uses a standard tip for caries detection and a separate tip for perio calculus detection, so two tools in one just by changing the tip.). Calculus has never been easier to detect, making my clinical scaling time minimal. My patients leave with less sensitivity, trauma and discomfort. Secondly, I use my diode laser to reduce the bacteria and pathogens within my client’s sulcus or periodontally infected pocket by simply taking a small optic fiber, almost half the size of a periodontal probe, and shining photonic laser energy into the sulcus.

This is what we in the laser hygiene community call laser decontamination¹, or laser bacterial reduction (LBR), which is the reduction of the bacteria and pathogens within the sulcus.

I then proceed with the use of ultrasonics and hand instruments for biofilm and calculus removal from the hard tissues, finishing with the use of the diode laser for laser degranulation (curettage), so again entering a diseased periodontal infected pocket with the same optic fiber.

I am able to selectively remove granulation tissue produced by infections and inflammatory diseases like periodontitis. Today hygienists have the ability to simply and selectively remove bacteria living in our clients’ mouths. Research shows, 96 per cent of the germs that are found in the periodontal pocket are pigmented and can thus be selectively destroyed by the laser.

By simply shinning photonic laser energy into our clients’ sulcular tissue, we can safely and effectively lower the bacteria in our clients’ sulcus for up to 56 days.² Additionally, the light energy through biostimulation can speed up the process of wound healing and similar regenerative processes.

For a finale, I end my client’s appointment with the same 655 nm wavelengths for laser caries detection, again the KaVo DIAGNOdent. I can give my clinician the necessary information to diagnose decay in our patient’s teeth for a higher gold standard of minimally invasive dentistry. Treating caries at its earliest inception preserves our patients’ natural enamel for their lifetimes.

My newest laser purchase has been the KaVoGENTLEray 980 nm Premium. This laser has water irrigation. Water irrigation offers less tissue trauma, along with 12 watts of gentle micro-pulsing energy.

Pulsing allows the tissues to thermally relax and cool before each additional pulse. Each pulse is taking place within milliseconds. I personally use Closys to irrigate while lasing the tissues, producing an antimicrobial irrigation along with water cooling. This is the only diode laser of its kind available. I am thoroughly enjoying the healthy rewards this laser has offered my clients. Having worked with and instructed on diode lasers of wavelengths from 808 nm to 1064 nm wavelengths over the past eight years, I highly recommend the benefits the 980 nm wavelength has to offer my clients. This wavelength is also absorbed more readily in water vs. the other diode wavelengths.

Any disadvantages?

A perceived disadvantage of some practices is the initial cost. However, with proper training and laser integration (I consider this to be my specialty), the ROI (return on investment) can be less than three months.

The bottom line

I love working with dental offices through out the country, assisting them in the integration of laser technology, offering their clients’ this new gold standard in technology. The offices I have worked with are seeing improved health for their clients. In conjunction, they are seeing their hygiene departments run at a profit.

I highly recommend that if you are going to use laser technology, you seek out education. The Academy of Laser Dentistry (ALD) is a non-bias resource for laser education, www.laserdentistry.org. Invest in laser technology, invest in a higher level of health for your clients. Profit from hygiene excellence.

About the author

Jeanne M. Godett, has been making a professional difference in people’s lives for over 25 years. She has consulted with hygienists throughout the United States and Canada providing instruction, guidance and productivity guidelines related to hygiene and the use of lasers. Contact Godett at jghygiene@aol.com.