Despite the presence of lasers in dental practice since 1989, their use is still relatively scarce. While the initial cost might deter the clinician, the many and various laser wavelengths, together with the scope for adjunctive use in daily practice, have endorsed their position in modern dentistry. Used correctly, lasers can provide added predictability and precision to treatment, and the absence of complications can expedite success.
The following case highlights the use of a neodymium YAG (Nd:YAG) laser as an adjunct to the cosmetic restoration of the maxillary anterior teeth. The patient, a young female, was concerned about the appearance of her upper front teeth because of their size and arrangement and sought nonorthodontic treatment.
A 25-year-old female patient sought treatment to improve the appearance of her upper anterior teeth. Her clinical presentation revealed a healthy mouth with minimal posterior restorations. She had received fixed orthodontic treatment as a teenager to correct a class II division II malocclusion. Although this had reduced the overbite and lower crowding, there had been a slight relapse of the upper anterior alignment some years later. Her general medical history was uneventful.
Extraoral examination revealed no facial asymmetry. The TMJ on both sides and path of opening and closure of the mouth were normal. There was a competent lip morphology, although there was a high lip line on smiling.
|Figure 1. Preoperative view.|
Intraorally, the hard and soft tissues were healthy, with no pathology detected. Gingival probing showed general 2 to 3 mm pocketing with no bleeding. Radiographic examination of the upper anterior teeth revealed no periapical pathology, good crown-root ratio, and normal bone support. The teeth were vital to electric pulp testing and percussion was normal, with no tenderness or mobility (Figure 1).
DIAGNOSIS AND TREATMENT PLAN
It was concluded that there was a post-orthodontic residual upper anterior misalignment, together with short clinical crown length relative to the high lip line. In view of the patient not wishing to undertake further orthodontic treatment, it was suggested that her smile would be improved through a combination of laser gingival recontouring, crown lengthening, and the provision of veneer restorations on teeth Nos. 7 through 10.
POSSIBLE TREATMENT ALTERNATIVES
Possible treatment alternatives were the following: (1) no treatment, in view of the health of the hard and soft tissue; (2) orthodontic treatment; (3) gingival surgery—use of scalpel or electro-cautery; and (4) tooth restoration direct-bonded composite resin.
With regard to the use of a laser in improving the gingival contour, it is essential to maximize the advantages of this protocol through the choice of a wavelength that is preferentially absorbed by the pigmented soft tissue. The absence of bleeding, ease of healing, and stability of the post-treatment gingival margin endorses the use of the Nd:YAG laser in this case. Conversely, care needs to be exercised to ensure that the laser delivers the minimum energy to achieve the desired effect. The relatively delicate nature of healthy gingival tissue, its shallow depth, and the consequences of possible thermal damage to the underlying marginal bone would prove disastrous in such an elective procedure. Of special concern in this case would be the possibility of damage to the underlying tooth tissue through tooth cracking and pulpal damage.
A written outline was given to the patient and consent was given.
|Figure 2. Assessment of preoperative free-gingival width and attachment levels.|
The amount of free gingival tissue (2 to 3 mm of healthy margin) that is often found in this Angles classification would allow the removal of a 1- to 2-mm width of soft tissue without compromising the biological width of both gingival margin and the attached gingiva in general. A multiple-site assessment of pocket depth was recorded prior to treatment (Figure 2).
The maxillary anterior region was anesthetized using 2% lignocaine (lidocaine) with 1:80,000 epinephrine. Safety eyewear, commensurate with the wavelength being used, was worn by the patient and operating personnel. A test fire of the laser was carried out to ensure correct laser operation, spot size of the fiber, and patency of light delivery.
LASER OPERATING PARAMETERS
A Nd:YAG laser, 1064-nm wavelength (Fotona Twin-light, dd. Fotona, Slovenia) was used. Delivery of laser energy is through a free-running pulsed mode via a quartz fiber optic. The features of this laser and delivery configuration are as follows:
•wavelength: 1064 nm
•pulse width: 150 micro-seconds
•fiber diameter: 320m
•power used: 100 MJ per pulse, 20 Hz
•average power: 2.0 W (joules/sec)
•Treatment per tooth site: 30 seconds per tooth site, with intervals with high-power evacuation.
LASER TREATMENT SEQUENCE
Perhaps the greatest problem with using lasers as opposed to conventional instrumentation is the lack of tactile feedback. The desired surgical effect is through allowing the beam of laser light rather than the fiber optic to cleave the tissue. As such, this treatment is noncontact. Equally, care should be employed to prevent the buildup of heat in the target tissue through the employment of such factors as high-speed suction, nonlasing time intervals, and, occasionally, prelaser tissue cooling.
Additionally, the use of an optic fiber will result in the buildup of coagulation products. This material will be quickly converted to carbonized debris and as such will become superheated and will result in a distorted and exaggerated tissue cleave and direct thermal burns in the tissue.
The laser beam was directed at 90 to the gingival margin at the level of cleavage. Using a constant, sweeping motion, the beam was drawn along the gingival margin to establish an initial cut, with the fiber tip just out of contact with the tissue surface. A slight shrinkage and loss of color was observed in the cleaved tissue, and when separation was anticipated, the discarded marginal tissue was removed with a curette.
|Figure 3. Use of laser to release excess tissue.|
|Figure 4. Removal of excised tissue with curette.|
|Figure 5. Immediate post-laser phase.|
In this way, the 4 tooth sites were treated (Figures 3 through 5).
Due to the excellent interaction of this wavelength and pigmented soft tissue, there was no bleeding, and due to the presence of surface coagulation products, no dressing was required. The patient was given instructions not to disrupt the postoperation site through brushing for 24 hours and to avoid hard foods. Mild analgesics were prescribed as required, and contact information was given in the event of complications.
|Figure 6. Soft tissue healing phase at 2 weeks.|
The patient was reviewed at 14 days. The healing of the gingival margin was uneventful, in keeping with the expectation of lack of bacterial contamination and inflammation. Gentle probing of the periodontal tissues was carried out to confirm the pretreatment attached level, and each tooth was retested for vitality (Figure 6).
At this stage, the teeth were prepared in a conventional manner for the fitting of laboratory-constructed facial veneers (Empress, Ivoclar Vivadent).
|Figure 7. Completed prosthetic phase.|
At a subsequent visit 1 week later, the final restorations were fitted. The patient was reviewed at 1 month, the soft tissues assessed, and teeth vitality tested. At this stage, the patient was discharged (Figure 7).
A case is presented where a dental laser is used as an adjunct to conventional- albeit-elective restorative treatment. Whereas the objections offered against the integration of lasers into dental practice might be due to possible cost or misinformation, coupled with conventional, contemporary training alternatives, there is an ever-increasing demand on dental professionals to deliver precise, cosmetic, minimally invasive, and low-risk treatments to their patients. A thorough grounding in all aspects of laser use in dentistry must be considered mandatory, but once mastered, these instruments, when properly and judiciously administered, can enhance the enjoyment of dental procedures for both professional and patient alike.
Dr. Parker is in private practice in the United Kingdom. He is vice president of the Academy of Laser Dentistry, co-editor of Wavelengths, the academy journal, and chairperson of the Committee for Professional Recognition. He holds advanced proficiency in multiple laser wavelengths, is a recognized course provider and educator for the academy, and was awarded the 1999 Leon Goldman Award for clinical excellence. For further details on the use of lasers in dentistry, visit the Academy of Laser Dentistry’s Web site at laserdentistry.org. Contact Dr. Parker via e-mail at email@example.com.