| Add RSS Feed

May 9, 2008

By Erica Migliorati, DDS

Editorial

The use of laser light in dental medicine and its application in some of the procedures performed in the oral cavity are becoming a reality. Laser light can be used in the periodontal field as an adjunct to conventional therapy (phase I) or as a tool in periodontal/oral surgery. Lasers are also used on oral hard tissues (teeth) in restorative dentistry. In endodontics, lasers represent one of the most effective means of bacterial reduction and microorganism elimination in the root canal. It is not conceivable in modern dentistry to deliver root canal therapy without adjunct laser bacterial reduction.

Laser light is an excellent adjunct to dental treatment and should be regarded as such. Lasers can substitute some of the tools used in dental procedures presently but ideally lasers should be used as adjuncts to periodontal/dental therapy.

In order to properly use this technique, the clinician should have comprehension of the physics of lasers and understand the differences between the wavelengths and how each of them is absorbed and interacts with the target tissues. The lack of understanding of safe, optimal parameters and protocols can lead to improper use of laser equipment and harm to the patient.

When deciding to buy high-power laser equipment, the professional must also follow some prerequisites necessary for using it. Professionals using laser light equipment should:

• Have prior knowledge of laser technology
• Have knowledge about the absorption of laser by irradiated tissue, as well as its wavelength and different specialties in which it may be used
• Take short duration courses
• Attend workshops of longer duration to improve knowledge of the technology
• Search through current literature for information on methodologies and materials used
• Study parameters for the use of laser technology

There are several laser types used in the field of medicine/dentistry: Diode (815 nm), Neodymium-doped: Yttrium-Aluminum-Garnet (Nd:YAG-1064 nm), Erbium, Chromium-doped: Yttrium-Scandium-Gallium-Garnet (ErCr:YSGG-2780nm), Erbium-doped: Yttrium-Aluminum-Garnet (Er:YAG-2940nm), Carbon dioxide (CO₂-10,600nm), Argon (488nm-515nm), Excimer (193nm), and Alexandrite (377nm). Some of these wavelengths have received FDA clearance for certain procedures in the oral cavity and others are still being studied in vitro.

Based on the absorption of the laser light by the target tissue, lasers can be used on oral soft tissue or on hard dental tissue. In addition to their use in surgery, the Nd:YAG (1064nm) and the CO₂ (10,600nm) lasers have also been approved for soft tissue treatment in periodontics because of their superior ability of soft tissue ablation, accompanied by strong hemostatic and bactericidal effects.(1,2)

In the past, the CO₂ laser was only available in the continuous wave (CW) mode, but recent advances have been made and now the CO₂ UltraSpeed (DEKA Lasers Technology LLC, Florence, Italy) has brought new applications of this wavelength in periodontal/dental treatment. This is the most efficient laser technology developed for all soft tissue management. UltraSpeed technology has eliminated all of the documented drawbacks of older generation surgical lasers, such as carbonization of tissue, retardation of the healing process, and the prohibitions of working near hard tissue structures and implants.

These limitations have been removed, and the UltraSpeed CO₂ is the only surgical laser that can replace the scalpel in speed and accuracy. It is the ideal tool for soft tissue surgery. It can be used in many of the steps in implantology and has applications near hard tissue structures (troughing). In the periodontal pocket, it can be used for bacterial reduction and de-epithelialization of the periodontal pocket wall to promote better healing. The CO₂ can also be used in microsurgical procedures and in esthetic and cosmetic dentistry.

The speed of pulse repetition prevents any trauma to tissue, resulting in very low or no postoperative discomfort. Technical requirements for these innovations, the Sapphire Resonator Technology (developed by DEKA), have brought about these changes. This new technology fulfills the perception of the patient seeing the laser as the "future" and, at the same time, gives the dental practitioner a tool "today" for patient-friendly therapy, with extensive problem-solving skills assuring optimal clinical results(3) (See Figure 1).

Figure 1 — DEKA Laser Technologies LLC — CO₂ laser (10,600nm)


Procedures on dental hard tissue can be performed with the Er:YAG (2940nm) and the ErCr:YSGG (2780nm) also known as Waterlase (BIOLASE). The ErCr:YSGG (2780nm) and the Er:YAG (2940nm) are close in wavelengths and therefore are expected to have similar performances on target tissues. These two laser wavelengths are referred to as erbium family lasers. They are capable of ablation of both soft and hard tissues and studies are being conducted to show that this wavelength is safe to be used in the removal of periodontal bone during crown lengthening procedure.(4,5,6) Also, the hard tissue laser devices can selectively remove diseased tooth structure because caries have a much higher water content than healthy tissue, and water is the primary absorber of that wavelength of laser light (See Figures 2 and 3).

Figure 2 — Er,Cr:YSGG (2780nm) also known as Waterlase by BIOLASE


Figure 3

Although the pathogenesis of periodontal disease is not completely understood, it is well established that periodontal disease is an infectious disease and that the host's immune and inflammatory response to the microbial challenge mediates tissue destruction. Based on this view, the therapeutic strategies for the treatment of periodontal disease have been directed toward two different and complementary paths: antimicrobial therapy and host modulation. Considering that the primary etiology of the disease is bacteria in the dental plaque or biofilm and their products, mechanical and chemical approaches to reduce the presence of periodontopathogens in this plaque have been largely used in the treatment of periodontal patients.(7)

The laser light could be used to replace chemicals such as the local delivery antibiotics. In general terms, the ideal antibiotic (local delivery or systemic use) does not exist because antibiotics are effective against certain periodontal pathogens only; they can be toxic; sometimes lack substantivity; and can be quite expensive if periodontitis is generalized. Most important, antibiotics should not be used in the treatment of oral conditions long term if they are indicated in general use for the treatment of other systemic and more devastating diseases.

The advantage of the laser light, which is based on a principle of physics and is only a light, is three-fold: does not create adverse drug reaction (it is a light), patient compliance is not an issue because it is delivered locally in the periodontal pocket, and due to the reduced time of application, it can be used in generalized periodontitis cases. The last and most important advantage is that it does not cause microbial resistance. Studies show no selectivity to the elimination of bacteria, eliminating all bacteria equally. The positive aspect of this observation is that indigenous flora repopulates the periodontal pocket, while some studies show that periodontal pathogens do not reappear as fast or at all.(8,9,10)

In localized or generalized periodontitis cases, the increase of patient chair time is minimal and can be estimated to be about a 60-second application per tooth. The cost increase can be calculated in about 10% to 20% on an average appointment cost.

Host modulation is another important aspect of periodontal therapy. Recently, a better understanding of the participation of host immune-inflammatory mediators in the disease progression has increased the investigation of the use of modulating agents as an adjunctive therapy to the periodontal treatment.(7) Other studies have shown that laser light used as an adjunct to periodontal therapy can control the production of some inflammatory cytokines and improve fibroblast proliferation.(11,12)

In other words, the aim of the periodontal treatment is to restore the biological compatibility of periodontally diseased root surfaces for subsequent attachment of periodontal tissues to the treated root surface. As lasers can achieve excellent tissue ablation with strong bactericidal and detoxification effects, they are one of the most promising new technical modalities for nonsurgical treatment.(13) Based on these concepts, clinicians and researchers have published clinical observations and designed studies to validate the use of the laser light as an adjunct to periodontal therapy.(14,15,16)

During phase I of periodontal treatment, the objective is to reach and maintain a state of health. It is generally accepted that in cases of advanced periodontal disease in a susceptible host, in the presence of other risk factors, the clinician must use additional methods to conventional scaling and root planing.(17) The use of laser light for bacterial reduction, control of inflammation, and fibroblast stimulation could be one of these methods of treatment.

In other words, the clinician can observe the benefits of the laser light as an adjunct to phase I periodontal therapy due to reduction in pocket depth, reduction in bleeding on probing, less edema, and achievement of healthy colored tissues.

However, there are some disadvantages to the current dental laser instruments. They are relatively high in cost and require training. Also, no single wavelength will optimally treat all dental disease.

Clinical cases will be presented and discussed in future issues.

Erica K.J. Migliorati, DDS, graduated from the University of Sao Paulo (USP), Brazil in 1973. She holds a postgraduate degree in periodontology from USP. She held teaching positions at the University of Sao Paulo, University of California San Francisco, University of Florida Gainesville, and University of Zurich Switzerland. Dr. Erica Migliorati has worked in periodontology for the last 30 years in all capacities including teaching, research, and patient care. Dr. Migliorati was one of the pioneers in the dental field in HIV infection and AIDS when working in San Francisco, Calif., in the early 1980s. Working as a member of different oncology teams, she has also been involved in the periodontal treatment of patients with cancer, patients in need of bone marrow transplant, and those affected by oral complications of cancer therapy. As an associate in a dental laser clinic, Dr. Migliorati had the opportunity of developing skills in the field of lasers. Her research work included the use of the laser light as an adjunct to procedures performed in the oral cavity, and in HIV infection and immunosuppression. Currently she is an assistant professor in the Department of Periodontology, responsible for the course of Laser Dentistry at NSU College of Dental Medicine in Fort Lauderdale. Dr. Migliorati is a member of the American Dental Association, American Academy of Periodontology, and the American Academy of Laser Dentistry. You may contact Dr. Migliorati at merica@nova.edu.

References

1. Dederich DN, Pickard MA, Vaughn AS, Tulip J, Zachariasen KL, Folwaczny M, Aggstaller H, Mehl A, Hickel R, Benner KU, Flasskamp B. Comparative bactericidal exposures for selected oral bacteria using carbon dioxide laser radiation. Lasers Surg Med 1990; 10: 591-594.

2. Neil ME, Mellonig JT. Clinical efficacy of the Nd:YAG laser for combination periodontitis therapy. Pract Periodontics Aesth Dent 1997; 9:1-5.

3. Christoph M. Justen, DEKA Laser Technologies LLC, personal observation.

4. Sasaki KM, Aoki A, Ichinose S, Yoshino T, Yamada S, Ishikawa I. Scanning electron microscopy and Fourier transformed infrared spectroscopy analysis of bone removal using Er:YAG and CO₂ lasers. J Periodontol 2002; 73:643-652.

5. Kimura Y, Yu DG, Fujita A, Yamashita A, Murakami Y, Matsumoto K. Effects of erbium, chromium:YSGG laser irradiation on canine mandibular bone. J Periodontol 2001; 72:1178-1182.

6. Wang X, Zhang C, Matsumoto K. In vivo study of the healing processes that occur in the jaws of rabbits following perforation by an Er, Cr:YSGG laser. Laser Med Sci 2005; 20:21-27.

7. Kirkwood KL, Cirelli JA, Rogers JE, Giannobile WV. Novel host response therapeutic approaches to treat periodontal diseases. Periodontol 2000. 2007; 43:295-315.

8. Moritz A, Schoop U, Goharkhay K, Schauer P, Doertbudak O, Wernisch J, Sperr W. Treatment of periodontal pockets with a diode laser. Lasers Surg Med 1998; 22:302-311.

9. Cobb CM, McCawley TK, Killoy WJ. A preliminary study on the effects of the Nd:YAG laser on root surfaces and the subgingival micro-flora in vivo. J Periodontol 1992; 63:701-707.

10. Ben Hatit Y, Blum R, Severin C, Maquin M, Jabro MH. The effects of a pulsed Nd:YAG laser on subgingival bacterial flora and on cementum: an in vivo study. J Clin Laser Med Surg 1996; 14:137-143.

11. Sakurai Y, Yamaguchi M, Abiko Y. Inhibitory effect of low-level laser irradiation of LPS-stimulated prostaglandin E₂ production and cyclooxigenase-2 in human gingival fibroblasts. Eur J Oral Sci 2000; 108:29-34.

12. Qadri T, Miranda L, Tuner J, Gustafsson A. The short-term effects of low-level lasers as adjunct therapy in the treatment of periodontal inflammation. J Clin Periodontol 2005; 32:714-719.

13. Aoki A, Sasaki KM, Watanabe H, Ishikawa I. Lasers in nonsurgical periodontal therapy. Periodontol 2000, 2004; 36:59-97.

14. Schwartz F, Sculean A, Georg T, Reich E. Periodontal treatment with an Er:YAG laser compared to scaling and root planing. A controlled clinical study. J Periodontol 2001; 72:361-367.

15. Schwartz F, Sculean A, Berakdar M, Georg T, Reich E, Becker J. Clinical evaluation of an Er:YAG laser combined with scaling and root planing for nonsurgical periodontal treatment. A controlled, prospective clinical study. J Clin Periodontol 2003; 30:26-34.

16. Schwartz F, Sculean A, Berakdar M, Georg T, Reich E, Becker J. Periodontal treatment with an Er:YAG laser for scaling and root planing. A 2-year follow-up split-mouth study. J Periodontol 2003; 74:590-596.

17. Seymour GJ, Taylor JJ. Shouts and whispers: An introduction to immunoregulation in periodontal disease. Periodontol 2000. 2004; 35:9-13.

| Add RSS Feed