LightScalpel 10,600 nm CO₂ laser procedures in pediatric patients

Martin Kaplan, DMD, and Peter Vitruk, PhD, discuss the safety and efficacy of the CO₂ laser

Why 10,600 nm CO₂ laser?

Soft tissue surgical lasers have many advantages over traditional scalpel surgery, cryosurgery, and electrosurgery. However, not all lasers are equally efficient at both cutting the soft tissue and coagulating and hemostasis because light absorption in the soft tissue varies with wavelength.^1-3 Some dental laser wavelengths (around 1,000 nm such as diodes and Nd:YAG) are efficient coagulators but inefficient scalpels since they are poorly absorbed by the soft tissue. Other dental laser wavelengths (around 3,000 nm such as Erbium lasers) are well absorbed by the water-rich soft tissue and are great at cutting but are not as efficient at coagulating and hemostasis. The 10,600 nm CO₂ laser’s coagulation depth closely matches blood capillary diameters.² The radiant energy of the CO₂ laser is used directly to photo-thermally vaporize (cut, incise, ablate) and, at the same time, photo-thermally coagulate the soft tissues. The CO₂ laser is a “What You See Is What You Get” surgical soft tissue laser with minimal collateral thermal effects that are sufficient for sealing blood vessels, lymphatics, and nerve endings; the surface bacteria are efficiently destroyed⁴ on incision/ablation margins. The modern flexible fiber CO₂ lasers from LightScalpel, Inc. (Bothell, Washington) use scalpel-like ergonomic autoclavable handpiece (Figure 1) for (a) cutting, (b) ablation, and (c) photo-thermal hemostasis and coagulation. An important built-in safety feature is a sub-millimeter superficial depth of laser beam incision⁵ at low power settings (see Figure 1), which makes the CO₂ laser a gentler and more forgiving tissue vaporization instrument in comparison with a scalpel, electro-surge, or hot glass diode surgery. Also quick switch from cutting to coagulation mode is enabled by simply defocusing the beam (laser beam fluence dropping below the ablation threshold of 3 Joules/cm²).² For the CO₂ laser, its excellent coagulation efficiency is due to the close match between the sub-100 µm photo-thermal coagulation depth² and the oral soft tissue blood capillary diameters of approximately 20-40 µm.⁶

Minimized bleeding for enhanced visibility and precision

The enhanced hemostatic ability and precision of the CO₂ laser is especially valuable in visible (esthetic) zones. The CO₂ laser surgical removal of the tissue presented in Figures 2-8 illustrates excellent coagulation and hemostasis during soft tissue ablation.²

For example, Figures 2A-2C show the use of LightScalpel LS-1005 CO₂ laser (2 watts SuperPulse Repeat Mode with F1-6 through F1-8 settings) for soft-tissue crown lengthening of the maxillary incisors and for labial frenum revision. Both procedures were performed during the same visit while the patient received local anesthesia. No sutures were placed. Figure 2 presents the self-correction of a rotated tooth No. 9 after frenum revision. Laser frenectomies in Figure 3 resulted in spontaneous closure of midline diastemas.

The CO₂ laser accuracy is especially important for highly vascularized areas. For example, the 14-year-old patient in Figure 4 had a CO₂ laser lingual frenectomy performed during which a sublingual vein was exposed and coagulated (sealed) with defocused laser beam. As a result, no sutures were needed, and the surgical wound was left to heal by secondary intention.

Figure 5 summarizes the case of a 4-week-old bottle-fed baby, born at 8 lbs. 6 oz., not able to breastfeed and failing to gain weight during first 4 weeks of her life. The baby exhibited fussiness and gassiness post feeds and choked often during feeds. Oral exam revealed “wrinkled-looking” gingiva (possible sign of dehydration) and a restricted lip frenum that was corded, thick and tight, and an anterior, tight, calloused and short tongue-frenum causing a significant tongue mobility reduction (Figure 5A). Figure 5B illustrates the clean blood-free laser ablation. Release of tension and ability to flange the lip is now evident. At the 7-day follow-up (Figure 5C), the mother reported feeding times were more efficient, and baby’s weight gain was 1 lb. 11 oz. in the 7 days since surgery. At the 3-month follow-up, the baby now weighed 20 lbs. (9072 gm). There were no more feeding symptoms, and the baby was doing well. Unfortunately, the baby never returned to breastfeeding.

The CO₂ laser is also an excellent tool to remove the excess soft tissue. Many pediatric patients require banding of molars, but an overlying operculum gets in the way of placing appliances on these teeth. Figure 6 presents the LightScalpel LS-1005 CO₂ laser operculectomy (3 watts SuperPulse Repeat Mode F1-7) prior to band placement. Tissue hemostasis allows for banding to happen immediately after the CO₂ laser procedure — bands were seated shortly after operculectomy was performed, in the same visit.

CO₂ laser use in the presence of orthodontia hardware

Figures 7-8 demonstrate a completely bloodless CO₂ laser gingivectomy around the mandibular incisors in the orthodontic patient. CO₂ laser gingivectomies, such as the ones presented in Figures 7-8, help improving the esthetics and oral health; they also allow for more ideal bracket placement and quicker treatment with less appointments.

Gaining access to an impacted tooth or teeth is often necessary in order to place orthodontic braces. With conventional scalpel surgery, many problems occur when placing brackets, such as sutures breaking before brackets are bonded. Brackets will not bond properly if enamel is wet due to bleeding. Clean, bloodless enamel is necessary for enamel acid etching and bonding of the composite resin. Using the CO₂ laser to expose an impacted tooth produces a dry surgical field, thus creating conditions required for immediate bracket bonding. The CO₂ laser-assisted cuspid exposure procedure is shown in Figure 9. This quick CO₂ laser treatment allows access for bracket placement, saving the patient months of waiting for the tooth to erupt on its own. The CO₂ laser provides a clean, nonbleeding border. The CO₂ laser straight and angled handpieces, illustrated in Figure 1, permit a convenient reach into areas that may be obstructed by braces. Once an impacted tooth is exposed by laser ablation, the bloodless surgical field is ready for the next step. The orthodontic traction hook can be bonded to the exposed enamel immediately after ablation during the same visit saving time for both the patient and clinician.

Tissue healing

Studies have shown that there is a diminished risk of scarring and wound contraction associated with CO₂ laser surgery.⁹ Laser-induced wounds heal with greater fibroblast proliferation, with young fibroblasts actively producing collagen. Laser wounds also have been reported to contain smaller amounts of myofibroblasts (cells responsible for wound contraction), compared to scalpel wounds.⁹ Secondary intention healing and lack of scarring are especially important for treating lesions located in esthetic/visible zones.

Reduced postoperative pain and discomfort

Patients report less postoperative pain and discomfort with laser surgery.⁹ The healing process associated with CO₂ laser surgery is enhanced and less painful than with cryosurgery or electrosurgery.⁹

Summary

The many uses for a soft tissue CO₂ laser in pediatric dentistry and orthodontics — e.g., gingivectomies, frenectomies, exposure of impacted teeth, and others — feature minimal blood loss and reduced discomfort for the patients. In comparison with other dental laser wavelengths (circa 1,000 nm for diode and Nd:YAG lasers and circa 3,000 nm for erbium lasers), the CO₂ laser wavelength exhibits the least absorption rate by the stainless steel orthodontia hardware and the optimum coagulation depth closely matching gingival blood vessel diameters. The CO₂ laser ablation depth can be controlled to a few tenths of a millimeter, which characterizes this wavelength as a safe and gentle soft tissue removal tool, while the sub-100 µm  coagulation depth (significantly better than hot glass diodes)^2,5 allows for enhanced, scar-free healing of highly vascular oral tissues secondary intention.^5,9 The accuracy and precision of CO₂ laser surgery are increased by the visibility of the surgical field not being obscured by bleeding.