Laser Technology: Its Role in Treating and Managing Periodontal Disease

Through research with confocal scanning electron microscopy, dentistry/medicine has more insight than ever before on biofilms and how they affect oral and overall health. The dental industry now understands that the destructive host response manifested as chronic inflammation in periodontal disease is not in response to free-floating organisms in the periodontal pocket but, rather, to microbes thriving in highly organized biofilm communities attached to the tooth surfaces and to opposing soft tissue.¹ Biofilms are formed when free-floating microorganisms collect on a surface and organize into complex polymicrobial communities.² Oral biofilm environments are an accumulation of a mixed population of bacteria, fungi, or protozoa that produce large amounts of extracellular polysaccharide or slimy substance that protects the newly formed bacterial colonies. Immature biofilms are elastic and can easily move across surfaces while remaining intact, even when mechanically disturbed. In the oral environment, mature biofilms can change over time from a slimy, sticky substance into a solid substance referred to as calculus.²

One of the goals of dental professionals in the initial nonsurgical approach for managing periodontal disease is to disrupt and remove biofilm plaque and calculus from teeth coronal and apical to the gingival margin, as well as to remove the diseased pocket epithelium, in an effort to establish an environment that will promote healing and enhance attachment gain. Mechanical instrumentation or SRP deep within a periodontal pocket is challenging; it can be difficult to accomplish thorough debridement of the biofilm and achieve bacterial reduction when performed as a solo procedure. The profession has recognized this limitation and has embraced antimicrobial irrigation and the use of locally administered antibiotics as an adjunct therapy to SRP to try and minimize the microbial population thriving deep within the periodontal pocket.

The use of laser therapy as an adjunct to SRP has been shown to be effective and efficient in both bacterial decontamination and debridement of the infected tissue lining of the periodontal pocket.³ Bacterial decontamination of the periodontal pocket with a high fluence technique using an Nd:YAG (neodymium-doped yttrium aluminum garnet) 1064-nm and the 970-nm to 980-nm class diode lasers significantly reduces the periopathogenic bacteria both on the tooth root surface, deep within the cementum, and the inflamed inner lining of the periodontal pocket. The 970-nm to 980-nm wavelengths are highly absorbed into water, melanin, and hemoglobin. Biofilm and inflamed tissue have a high water content, readily attracting and absorbing the 970-nm and 980-nm wavelengths. Upon absorption of the laser light energy, they are quickly heated to 100°C, causing protein denaturization and vaporization of the biofilm and bacteria. However, an equally important outcome of laser therapy is the creation of a blood clot following removal of the diseased tissue. When using a laser to treat a periodontal pocket, the wavelength and parameters must be conducive to creating a fresh bleed upon completion of the therapy. This will allow a fibrin clot to form between the inner lining of the pocket wall and the disinfected root surface. The fibrin clot contains growth
factors and cytokines that signal the start of the wound repair and healing process.⁴

Clinicians must always use prudent judgment when selecting an appropriate laser and technique for use in their clinical practice. A laser that enables the clinician to achieve a desired result with a minimal amount of thermal damage to the surrounding tissue is ideal. The biologic effect and tissue interaction attained is dependent upon the wavelength, amount of laser energy used (watts), temporal mode, handspeed, and composition of the target tissue. The Nd:YAG 1064-nm laser with its extremely high peak power and very short emission pulse is an effective device to create the proper environment for periodontal healing. The high-powered 970-nm to 980-nm class diode lasers with their increased absorption in water⁵ and variable control over the duty cycle also offers clinicians the ability to use a high fluence technique while controlling the average power absorbed into the target tissue.

Using the proper device and having a thorough understanding of treatment objectives enables the clinician to control the laser and its related tissue interaction to obtain the desired outcome. By utilizing a laser in a high fluence mode, the laser emits a pulse with a high peak power and a very short pulse duration, permitting an extended thermal relaxation time (TRT) that allows the surrounding tissue to remain in a relatively normal temperature range. This enables the practitioner to control the tissue interaction to create an environment to facilitate the establishment of a periodontal attachment apparatus with minimal sulcular depths.

Pre-sets in a laser can offer guidelines for appropriate settings, but clinicians must understand that tissue composition or the level of inflammation, infection, and keratinization varies from patient to patient and from site to site in the same patient. For this reason, having a thorough understanding of the patient’s tissue composition and the tissue’s interaction with laser energy is extremely important. Also, choosing a laser that enables the clinician to control the interactions in order to maximize a desired outcome is paramount. Lasers with the ability to use a high fluence technique are ideal for both the doctor and hygienist in the management of periodontal disease.

It is essential that clinicians be educated on the safe and effective use of lasers for all procedures they are performing. The American National Standards Institute (ANSI) standards Z136.1 and Z136.3 require that all laser operators have device-specific, live, hands-on training and education for the procedures being implemented.^6,7 Device-specific training and understanding is not only required but is crucial if the practitioner expects to obtain optimal outcomes for all procedures being performed.

The use of lasers in the treatment and management of periodontal disease is changing how dentists currently manage this disease today. The goal of periodontal therapy is to re-establish the periodontal attachment apparatus and create a cleansable and maintainable environment. As dentistry continues to better understand periodontal disease and its systemic ramifications, treatment protocols will continue to advance in an attempt to more effectively manage the oral inflammatory process of this disease, thereby improving patients’ overall health. As with the use of any technology, appropriate training and education is extremely important and necessary to fully understand the risks and benefits of lasers as a potential treatment modality and to maximize the treatment outcome through proper protocols.

Jan LeBeau, RDH, BS
Director of Dental Hygiene
Pacific Dental Services, Inc.
Irvine, California