Written by Jeffrey A. Sherman, DDS, et al Wednesday, 31 December 2008 19:00
Radiosurgery is one of the most important and versatile instruments in dentistry today. Its numerous uses range from performing surgical incisions and excisions to establishing hemostasis. It offers the advantages of safe, fast, and efficient incisions/excisions with an excellent field of visibility. The patient receives a pressureless cut with a minimal amount of bleeding that often requires no suturing. Studies by Hultcrantz and Ericsson and Miller report less thermal damage and faster healing with the 4 MHz Radiowave technology over the scalpel or lasers.
In the general dental practice, radiosurgery can be used throughout the day for a number of very common procedures: exposing subgingival decay, gingivectomies, gingivoplasties, and frenectomies. Radiosurgery can also be used for cosmetic periodontal surgery involving the removal of gingival pigmentation due to excessive amounts of melanin.
Radiosurgery uses a 4 MHz radio signal to produce a fine microsmooth incision with no overt lateral heat being sent to the surrounding tissues. This is extremely important for extensive areas of oral surgery, where proximity to the underlying soft and hard tissue requires a delicate incision. Traditional electrosurgical machines with lower frequencies and lasers produce higher temperatures in tissue and are not recommended for this and other oral procedures.
The main advantage to radiosurgery can be found in its ability to produce coagulation in an operative area which would often have extensive bleeding. This enhances the surgeon’s vision and the ability to perform a more accurate incision. The absence (or minimal amount of bleeding) during surgery allows the procedure to be performed more rapidly and with more confidence. Patients are less apprehensive due to the lack of bleeding, and this even decreases their awareness that surgery is being performed.
Contraindications of radiosurgery and bipolar surgery include cardiac pacemakers, cardiac defibrillator implants, and cochlear implants.
RADIOSURGICAL WAVEFORMS AND INSTRUMENTATION
Radiosurgery offers a variety of waveforms for making incisions. The Fully rectified filtered waveform is the waveform of choice for performing deep precise surgical incisions. This waveform mimics the cut of a scalpel blade, however it is pressureless and therefore it cuts with only minimal coagulation. The filtered waveform, when used with a VariTip (Ellman International) straight wire electrode, produces the most delicate of incisions and offers the least amount of tissue alteration histologically. The fully rectified waveform produces an incision with concurrent coagulation. The advantage of using this waveform in comparison to the filtered waveform is that increased visibility is established due to the enhanced coagulation. The partially rectified waveform is strictly a coagulating waveform and can be used to establish coagulation in areas of bleeding or oozing. Areas of extensive bleeding can be controlled with the aid of the bipolar coagulating electrode or the fulguration waveform on those instruments that do not offer bipolar capabilities.
Bipolar surgery is used for excision as well as hemostasis of soft tissue. The bipolar electrode consists of 2 parallel wires, one to make the incision and the other to act as the antenna to receive the radio signal. This modality is believed to minimize transmission of the radio signal to the surrounding tissue and thereby eliminating any lateral heat. Another excellent use for bipolar is pulpotomies.
A new proprietary Advanced Composition (Alloy) Electrode (known as the ACE Electrode [Ellman International]) has just been developed to reduce tissue damage and heat generated to the surgical site. The ACE Electrode has been shown to produce thermal damage in micrometers no greater than 10 µm in comparison to tungsten electrodes that have produced thermal damage as high as 30 µm. Another important advantage of the ACE electrodes is their ability to minimize tissue sticking to the electrode tip. This insures a clean-cutting tip providing a more precise microfine incision. These electrodes are easily identified by the orange coloring of the protective sleeve. The physics behind the reduced thermal damage is matching the alloy to the frequency, waveform, and wattage to produce a harmonic signal around the RF electrode.
Figures 1a and 1b. Aesthetic results achieved following crown lengthening (gingivectomy) and depigmentation with RF surgery.
Figures 2a and 2b. Clinical views of a case before and 6 months after the depigmentation.
|Table 1. Comparison of Gingival Depigmentation Methods.|
Gingival melanin pigmentation is an aesthetic problem, not a medical problem. The color and display rate of the gingiva when smiling is an essential part of overall aesthetics for today’s high cosmetic expectations. Since brown-black melanosis lesions mostly involve anterior vestibular gingiva, heavily pigmented gingiva can cause an unaesthetic smile. Therefore, depigmentation procedures have attracted much interest, and numerous procedures have been introduced with similar results up to date (Figure 1). However, a novel gingival melanin pigmentation removal method performed with RF surgery offers advantages over other depigmentation methods such as speed, reliability, lack of postoperative pain, bleeding, and the discomfort of a local anesthesia injection (Figure 2) (Table 1).
Figures 3a to 3b. Application of the tapping electrode to the pigmented gingiva.
The pigmentated area is anesthetized using a topical 10% lidocaine spray. Patients report little or no discomfort during the depigmentation procedure. Minimal discomfort is reported, if an increased time of tissue contact is attempted with the active electrode without the use of additional anesthetic spray. In areas of extensive pigmentation the area can be infiltrated with a local anesthetic solution.
Figures 4a to 4d. Clinical views of a case before and after the procedure.
|Figures 5a to 5d. Total removal of heavily pigmented lesions done in 2 RF sessions within a 4-week period of time.|
|Table 2. Patient Evaluation.|
|Smoking habit (duration and number per day)
Duration of pigmentation
Perioral pigmented lesions (lips, face)
Systemic diseases (Addison’s disease)
Systemic symptoms of malignancy (fatigue, malaise, weight loss)
Characteristic of the pigmented lesions (size, number, distribution, shape, color, surface, and borders)
Place the lip retractor and apply the anesthetic spray to the region of interest. Adjust the Radiolase II or Surgitron to the Filter Cut mode with a power setting of 10 to 11. On smaller areas of pigmentation use the Partially Rectified Coag mode at a power setting of 7. Since melanocytes are primarily located in the basal and suprabasal cell layers of the epithelium, touch the pigmented areas lightly with the electrode tip. Remove the electrode as soon as the tissue around the electrode becomes whitish. Repeat the procedure for all pigmented areas.
After the first week, slight redness is observed around the margins of the surgical site. Epithelization is completed in 10 days and at 2 weeks post-op a second procedure can be performed in cases with heavy pigmentation (Figures 4 and 5). Postoperatively, the patient is given chlorhexidene rinses and a prescription for an analgesic medication. The patient is instructed to perform only gentle tooth brushing in the area(s) of the surgery.
Not only is gingival melanin depigmentation a reliable procedure, it has an extremely short learning curve and can be easily and quickly performed by the general dentist, oral surgeon, or periodontist. The cosmetic result is rewarding to these patients who are often self-conscious about their condition.
Arikan F, Gürkan A. Cryosurgical treatment of gingival melanin pigmentation with tetrafluoroethane. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2007;103:452-457.
Axéll T, Hedin CA. Epidemiologic study of excessive oral melanin pigmentation with special reference to the influence of tobacco habits. Scand J Dent Res. 1982;90:434-442.
Hedin CA. Smokers’ melanosis. Occurrence and localization in the attached gingiva. Arch Dermatol. 1977;113:1533-1538.
Hultcrantz E, Ericsson E. Pediatric tonsillotomy with the radiofrequency technique: less morbidity and pain. Laryngoscope. 2004;114:871-877.
Kauzman A, Pavone M, Blanas N, et al. Pigmented lesions of the oral cavity: review, differential diagnosis, and case presentations. J Can Dent Assoc. 2004;70:682-683.
Miller WW. Using high-frequency radiowave technology in veterinary surgery. Vet Med. 2004;99:796-802.
Sherman JA. Oral Radiosurgery: An Illustrated Clinical Guide. 2nd ed. London, England: Martin Dunitz; 1997.
Sherman JA. Advances in radiosurgery. Inside Dentistry. Jul/Aug 2006:2-3.
Sherman JA. Implant exposure using radiosurgery. Dent Today. Apr 2007;26:92-96.
Disclosure: Dr. Sherman’s textbook and video on radiosurgery are sold by Ellman.
Disclosure: Dr. Gürkan declares that he has no financial involvement or affiliations with any companies or products mentioned in this article.
Disclosure: Dr. Arikan declares that he has no financial involvement or affiliations with any companies or products mentioned in this article.
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