Electrosurgery – Electrosurgery has been used in dentistry for several decades, but the technique is not widely practiced. However in last few years with increased understanding of the technique and principles of electrosurgery, some misunderstandings about the healing of electrosurgical wounds, is able to clear up.
Electrosurgery (ES) -has been defined as the intentional passage of high-frequency waveforms, or currents, through the tissues of the body to achieve a controllable surgical effect. By varying the mode of application of this type of current, the clinician can use Electrosurgery for cutting or coagulating soft tissues.
Tissues are naturally resistant to high-frequency waveforms; when these waveforms pass through it, intense intracellular heat is produced within the tissues contacted by the active electrode tip. This heat volatilizes cells, and as the electrode is guided through the tissue, it leaves a path of cell destruction in the form of an incision or surface coagulation.
Electrosurgery is applicable to almost every branch of clinical dentistry, and it is particularly relevant to general dentists who routinely perform minor oral surgical procedures.
The Electrosurgery unit consists of four components:
1. The current generator produces the high- frequency waveforms, which range from 1 to 4 MHz. The higher frequencies are better because they produce less lateral heat.
2. The active electrode in Electrosurgery is the one through which the high-frequency waveforms enter the tissue being operated. A wide range of active electrodes are available, but all of them basically belong to one of three types of electrode: single-wire electrodes are used for incision or excision; loop electrodes are used for tissue planing; and heavy, bulkier ball electrodes are used for coagulation.
3. The passive electrode (ground plate) is a flat plate that has a broad, indirect contact with the patient’s body. Like an antennae, it receives the waveform that has entered the patient’s body and allows it to return to the unit.
4. The on-off switch activates or deactivates the Electrosurgery unit. This can be operated by a foot control or by a switch on the hand- piece. The foot control is preferred because the operator will usually find it difficult to control the switch and the cutting stroke at the same time with the same hand.
ELECTROSURGERY WAVEFORMS AND THEIR APPLICATIONS
A wide variety of Electrosurgery units, with varying power, frequency, and waveform options, are available. Depending on the model, an Electrosurgery unit can produce up to four different waveforms.
Fully Rectified, Filtered Waveform This is a pure, continuously flowing current that permits a very smooth incision. Because this waveform produces the least lateral heat and minimal surface coagulation, the incision made by this current closely resembles a scalpel incision. The wound also heals with very little tissue shrinkage.
This waveform can be used for all soft tissue surgeries, such as frenectomy, incision and drainage, and gingival troughing procedures around the anterior teeth.
Fully Rectified, Unfiltered Waveform in Electrosurgery
This is a pulsating current that has slightly less cutting efficiency. In addition to a smooth incision, this waveform produces superficial coagulation, leading to effective hemostasis. This waveform causes tissue shrinkage and additional lateral heat; therefore, it cannot be used on tissues that are in close proximity to bone.
It is suitable for most minor oral surgery procedures, including gingivectomy, gingivoplasty, pulpotomy, tissue removal for exposing cervical caries, excision of hyperplastic soft tissues, and gingival sulcus troughing for the posterior teeth.
Partially Rectified Waveform in Electrosurgery
This is an intermittently flowing, high frequency current, which is excellent for producing hemostasis but inefficient for incising soft tissues. Because it produces a great amount of lateral heat, use of this waveform near bone must be avoided. Inflammed soft tissue can be excised with a fully rectified waveform, and the hemorrhage can be controlled by the partially rectified waveform.
Endodontically treated and discoloured teeth can be bleached by the thermocatalytic technique in Electrosurgery, in which heat is utilized to release oxygen from a hydrogen peroxide solution, which As quicker the active electrode is passed over the tissue, the lesser is the lateral heat, it has been estimated that to generate an effective incision, while keeping the lateral heat at a minimum level, the electrode must be guided over the tissue at a speed of 7 mm/s.
The active electrode must not remain in contact with tissue for more than 1 to 2 seconds at a time, and successive applications of the electrode on the same spot must have a 10 to 15 second interval. This interval allows the heat produced on the wound to dissipate and prevents overheating of the tissue surface before the next application of the electrode.
Because thicker electrodes produce more lateral heat, the interval between the strokes has to be increased according to the electrode thickness. The heat source is the Electrosurgery current. However, this technique is indicated only for resistant stains that fall to respond to other bleaching techniques.
Inadvertent contact of the Electrosurgery electrode with the tooth and the resulting lateral heat has been reported to cause some damage to the periodontal apparatus, and this may lead to cervical resorption. However, precautions taken to prevent overheating of the periodontium may prevent this effect. This is done by isolating the tooth with rubber dam and limiting every electrode application to no longer than 1 second with 5 seconds interval between each application.
This is a halfway modulated current, also called the sparking current. The spark occurs as a result of a high-voltage surge of power without the passive electrode.
When activated, the initial surge of current produces a spark that passes from the electrode tip to the tissue, causing superficial destruction by carbonizing the tissue surface. This sparking current is ideal for the destruction and removal of remnants of cysts following their enucleation. Because the clinical application for this waveform is very limited, thlguration capacity is available only in some Electrosurgery units. Only a person experienced in electrosurgery should use this waveform.
ADVANTAGES OF Electrosurgery
1. Tissue separation is clean, with little or no bleeding.
2. A clear view of the surgical site is provided.
3. Planing of soft tissue is possible.
4. Access to difficult-to-reach areas is increased.
5. Healing discomfort and scar formation is minimal.
6. Chair time and operator fatigue are reduced.
7. The technique is pressure-less and precise.
DISADVANTAGES OF Electrosurgery
1. The initial cost of the ES equipment is far greater than the cost of a scalpel.
2. The odour of burning tissue is present if high-volume suction is not used.
3. Although Electrosurgery units are compatible with most modem pacemakers of today, it cannot be used on patients with older pacemakers that are not shielded against external interference.
4. Electrosurgery units cannot be used near inflammable gases.
Electrosurgery can never completely replace the scalpel, but although ES requires more know- how and skill, its advantages outnumber and outweigh its disadvantages. An Electrosurgery unit costs only a small fraction of the price of a CO2 laser unit and can be used to perform many of the soft tissue surgical procedures being carried out with lasers. If the clinician practices ES techniques in the laboratory and applies them clinically according to the principles, he or she will surely find Electrosurgery to be of immense use in clinical dentistry.