Choosing a Laser for Orthodontics

Currently, dozens of lasers are available to orthodontists, each with special features and characteristics. Choosing the “best” laser can be difficult for many orthodontists and requires a different approach to the “normal” orthodontic workload. The primary consideration for many is to “stay out of trouble,” so it may be helpful to examine features not wanted in a soft tissue laser.

Although manufacturers claim all wavelengths are capable of performing soft tissue procedures, most orthodontists should avoid lasers that can ablate hard tissue, such as the erbium family of lasers (Er:YAG, Er,Cr:YSGG). Laser portability and movement from chair to chair are critical in orthodontic therapy, so the bulky, heavy erbium lasers are a poor choice. Diode lasers, currently available in four distinct wavelengths (810-830, 940, 980, and 1064 nm), and neodymium-doped yttrium-aluminum-garnet (Nd:YAG, 1064 nm) lasers are well absorbed by hemoglobin and melanin and thus work well for ablation of pigmented and vascular tissues such as oral mucosa.¹ Diode lasers have a much shallower depth of penetration than Nd:YAG lasers and may be less likely to cause pulpal damage, making diodes an excellent choice in orthodontics.²^,³ Carbon dioxide (CO₂) lasers are well absorbed by water. Oral mucosa is more than 90% water, so CO₂ lasers would also be an excellent option for an orthodontist. Although CO₂ lasers are portable units, capable of moving from chair to chair, they are larger and more expensive than diode lasers.

Therefore the two major advantages of diode lasers are cost and portability. Diode lasers are the least expensive and most portable of all laser wavelengths. Currently, diodes vary in price from $4000 to $13,000, and although some orthodontists are reluctant to charge for procedures to avoid offending their general dentist colleagues and other professional referrals, the cost of a diode laser is easily justified without charging for procedures. If an orthodontist purchases an $11,000 diode laser and finances it at 7% interest over 5 years, the monthly payment is just under $218. The Journal of Clinical Orthodontics reports that the value of an orthodontic appointment is between $200 and $400 (calculated by dividing the total fee collected by the number of appointments).⁴ Thus, if an orthodontist is able to save even one appointment per month, the cost of a laser is easily justified.

In reality, orthodontists who have adopted laser use save appointments several times a day. By charging for some or all procedures, the return on investment can occur more quickly. The orthodontist establishes a fee based on a combination of the time necessary for a given procedure and the investment cost of the equipment and training. Depending on the personal business philosophy, the patient can be billed for the procedures, or the fees can be submitted to the patient’s dental or medical insurance. When submitting for reimbursement for any laser procedure, it is not necessary to specify that a laser was used. For example, a laser gingivectomy would be submitted using the usual American Dental Association (ADA) code for a gingivectomy (D4210 or D4211), depending on the number of teeth involved). When submitting for a lingual frenotomy (releasing a tongue-tie), it is often more effective to submit to the medical insurance policy for reimbursement. For this purpose, use a “Medical Insurance Claim Form” number 1500 (blank forms can be downloaded from the Internet or purchased from software or office supply companies). When submitting for medical insurance, both a diagnosis code and a procedure code must be specified. In general, providing two or three diagnosis codes and a single procedure code is optimal for each procedure (Table 13-1).

Table 13-1 Common Codes for Submission to Medical Insurance

Although studies have detailed the use of CO₂,⁵^,⁶ diode,⁷ and argon⁸ lasers in orthodontics, this chapter focuses on diode lasers in orthodontic treatment. No “ideal” laser exists for every orthodontic practice; all soft tissue lasers will perform the procedures quickly and easily. The selection of the proper laser is based on each practitioner’s individual preference. The reader is strongly urged to take multiple courses. Make certain that the instructors have experience performing procedures with multiple wavelengths. Find mentors who have experience with multiple wavelengths (see Chapter 16).

Procedural Steps

When using a soft tissue laser, well-trained staff can perform most duties related to setup, patient explanation, and cleanup. Recognizing that proper preparation requires an accurate diagnosis and treatment plan (to be discussed shortly), efficient delivery of these services involves the orthodontic staff preparing the patient and laser as well as providing postoperative instruction.

Prepare the Patient

Explain to the parents and patient that most procedures can be performed by using only topical anesthetic and that most patients have no pain during or after the procedures. Confirm that the patient has no allergies to the anesthetic and no clotting abnormalities (e.g., hemophilia) or other medical contraindications to treatment. Discuss the pros and cons of alternative treatments.

Let them know that results cannot be guaranteed, and the patient may experience relapse. Although infection is unlikely, saltwater rinses are recommended for the first few days postoperatively. Vitamin E oil can also aid healing and keep the treated area moist.

Once informed consent has been obtained, isolate and dry the field to assist with anesthesia and provide a better view. Apply topical anesthetic liberally to the entire treatment area and wait for onset of anesthesia. Depending on the amount of tissue to be removed, the vast majority of laser procedures in an orthodontic office may be performed with only topical anesthesia. An effective topical anesthetic for soft tissue procedures is TAC 20, a thin gel containing 20% lidocaine, 4% tetracaine, and 2% phenylephrine with a shelf life of 3 months.

Topical anesthesia may be ineffective in areas where isolation is difficult, as when removing opercula from distal aspects of second molars or performing a lingual frenotomy. In these situations, first apply a topical anesthetic to prepare the site, then follow with an injection anesthetic to provide profound anesthesia. Gently probe the soft tissue through the topical medication to confirm anesthesia. The patient may feel pressure but should not feel anything sharp. The time required to achieve profound anesthesia varies with the tissue thickness and type of anesthetic. In general, start checking about 3 minutes after placement of topical anesthetic.

Prepare the Laser

While waiting for anesthesia, place the laser unit next to the patient. All units have a key-lock switch that must be turned to the “on” position and a “ready/standby” switch that is left on standby until the clinician is ready to begin the procedure. Prudent laser technique demands that laser surgeons use the minimal amount of power necessary to accomplish a given procedure. Depending on the tissue thickness, for most tissue removal procedures, 1 to 1.4 W is a sufficient power setting; a higher power is rarely necessary. Higher settings may result in excessive energy absorption by the tissue, leading to thermal damage, tissue necrosis, sloughing, and postoperative discomfort.

Most diode lasers have two temporal emission modes: continuous wave (CW) and pulsed or “chopped” wave. Using a pulsed wave reduces the heat to surrounding tissues,⁹ but if the procedure can be carried out without charring, CW mode is more effective. Newer diode lasers have “superpulsed” modes, in which the laser can emit a very short pulse of high power for a very short period. These superpulsed lasers cut with better efficiency and less charring than conventional CW or gated-pulse models (see Chapter 2).

It is standard protocol to cleave (cut) the fiberoptic cable at the end of each procedure to ensure the laser is ready for the next procedure (Figure 13-1). The fiberoptic cables are made of quartz/glass. After repeated use, the quartz/glass fiber tip can become scratched and will not emit laser energy or ablate soft tissue as efficiently. Cleaving removes the scratched part of the fiberoptic cable, exposing a fresh, highly polished cable surface capable of transmitting laser energy to the tissue efficiently.

FIGURE 13-1 • A, Cleaving with scoring tool (after scoring, break off remainder). B, Cleaving with special scissors. Note that it is critical to keep the scissors perpendicular to the fiber. Also, consider the length of fiber to be discarded.

If the end of the fiberoptic cable has not yet been cleaved, first make sure that sufficient cable (1-2 inches [2.5-5 cm]) extends out of the protective plastic jacket. If not, remove the protective jacket as suggested by the manufacturer (Figure 13-2). Next, cleave a few millimeters of the fiberoptic cable. If cleaving involves scoring, hold the cable flat against a hard surface and score it with the glass-cutting device supplied by the manufacturer, then break the end off at the score line. A well-scored fiber should break off cleanly. When glass cutting scissors are provided for cleaving, make sure the scissors are perpendicular to the fiber when cleaving. In either case, confirm that the cleave left no sharp edges by shining the cable against a flat surface, and confirm that the aiming beam describes a circular pattern without a “comet tail” or oval appearance (Figure 13-3). If the beam is irregular, recleave to obtain a clean cut. Using a laser without a sharp cleave can result in bleeding as the tissues are “cut” by the irregular glass of the fiberoptic cable.

FIGURE 13-2 • A, Insert the protected fiber to the end of the jacket removal tool. B, Close the jacket removal tool, and firmly grip fiber with the other hand without bending or crimping. C, Pulling firmly, remove the protective jacket, leaving uncovered fiberoptic tubing ready to be inserted into the handpiece.

FIGURE 13-3 • A, Appearance of aiming beam from a well-cleaved fiber. B, Comet-tail appearance of unevenly cleaved fiber.

Place the fiberoptic cable into the handpiece, then slip it through the appropriate guide, leaving 3 to 4 mm beyond the guide. Most diode lasers use a plastic fiber guide (Figure 13-4). With a plastic guide, it is necessary to “straighten” the guide as much as possible when inserting the fiber. Attempting to insert the fiber without straightening the guide can result in binding and fracture of the fiber inside the plastic guide, thereby wasting fiber. After feeding the fiberoptic through the guide, confirm fiber integrity by shining the aiming beam against a smooth surface. If it is not visible, check if you can see the aiming beam within the plastic guide, which would indicate a broken fiber. In this case, carefully refeed the fiber through the guide without breakage.