Monopolar vs. Bipolar. Electrosurgery vs. Radiosurgery

This article will discuss my use of “monopolar electrosurgery”, involving a single wire tip from which a current emanates and travels to an indifferent plate positioned behind the patient’s back.

Contrast that to “bipolar electrosurgery,” where the surgical tip includes two electrodes. The current flows from one tip (the “active” or “cutting” tip), to its twin tip, which serves as the indifferent plate. The cost of bipolar units is considerably greater than that of monopolar units. While there are certain advantages to the bipolar system (primarily hemostasis and the ability to work around metal restorations), precision cutting with a bipolar device is more challenging due to the broader dual-tipped electrode. For precision cutting and troughing procedures, the monopolar design remains king.¹ My comments in this article will be limited to monopolar devices.

For the record, “Electrosurgery” and “Radiosurgery” are one and the same. The latter term is more of a marketing semantic, but it stems from the fact that dental E-surge units operate at frequencies ranging from 1.5 to 4.0 megaHertz. For instance, my unit, the Parkell Sensimatic 600SE operates at 1.7 MHz, while another popular unit, Ellman’s Dento-surge 90, operates at 3.8 MHz. These are both radio frequencies.

I will purposely avoid most of the complexities and all of the bugaboos typical of an E-surge article, because in my experience E-surgery is utterly simple. Furthermore, clouding the air with needless cautions, irrelevant statements and arcane uses risks scaring away the would-be beneficiaries of this tried-and-true dental adjunct.

I will instead advise the purchaser to read the manual that comes with the unit and make sure of at least one thing:

Don’t forget to put the indifferent plate under your patient’s back or shoulder. This will allow smoother, more predictable cuts and reduce the chance of the patient’s experiencing any discomfort.

Three cases where you SHOULDN’T use an e-surge.

Don’t use an e-surge on patients who have pacemakers or cochlear implants. Granted, some authorities may say you can do it “if you take particular cautions” - but I want to keep things simple ... so I avoid situations where I have to “take particular cautions.”


Also, keep the probe away from metal implants and restorations and bone.

With those cautionary statements out of the way, let’s now focus on how I use my E-surge.

My electrosurge has 10 power settings, 3 cutting modes, and 7 different tips. That’s 210 options. I use one cutting mode (“cut/coag”), one power setting (“7”), and for 90% of my procedures, one tip (straight wire). For the other 10% I use a loop tip.

Basic Set Up:

First rule: Your E-surge unit must be chairside. If it’s not, you simply won’t use it as frequently as you could or should.

Consider it another handpiece that just happens to cut tissue instead of tooth. While a myriad of settings are possible, the button I use most is the “on-off” switch. I keep the waveform set to “cut with coagulation" and the power set to “7”. I use a long needle electrode 90% of the time and a narrow loop about 10% of the time. The other electrode shapes just sit in the drawer.

That’s it. One power-setting. One cutting mode. Two tips.

True, some lecturers love to discuss the subtleties of various tip and power selections. Those may matter for exotic applications - but not for what I use it for. Despite the many uses of the E-surge in the literature (everything from frenectomies to pulpotomies), I pretty much limit my usage to troughing for crown and bridge impressions and tissue-sculpting for anterior cosmetic rehabs.

Though this may sound rather restricted, these two applications keep me using my E-surge on a daily basis.

To trough or not to trough? That is the question…

Take a look at Figures 1 and 2 to see how #19 and #20 were returned to me post-endodontically. The distal margin of #20 was somewhat buried, but overall the tissue was attractively pink and reasonably well attached. Situations such as this (that is, non-esthetic zone, non-vital teeth) beg for E-surge exposure.

Why tamper with the attachment trying to stuff a retraction cord into the tightly bound sulcus? Instead, I used my needle electrode (Fig 3) to expose 19 and 20 for maximum visibility prior to core placement.

Then I applied Parkell’s Brush&Bond (Fig 4) to both teeth, followed by an automix core material (Fig 5). I prepped the cores (Fig 6) and took an impression even my mother could read (Fig 7). (No, she’s not a dentist.)

Figure 8 shows the finished crowns, tissue healed.

Despite the tissue’s sometimes charred appearance after electrosurgery, I’ve come to believe that the E-surge should be thought of as a kinder, gentler way to separate tissue from tooth before taking crown impressions. Though use of retraction cord is almost universal,² my experience has been that soft-tissue response after e-surge troughing is generally more predictable than after packing cord.

If the sulcus height is preserved during prep exposure, tissue will almost always regenerate to its original level. Even when tissue height is modestly reduced during surgery, it seems to return to the height you originally found it at so long as a poorly-fitting provisional doesn’t block its re-growth (more on this later).

Contrast this to the mechanical trauma that often accompanies the dentist’s least-favorite task of packing retraction cord ... a scenario well-known to encourage tissue recession.³

More than meets the eye

By the way, when I increased the magnification of my loupes, there was a corresponding jump in my confidence as an e-surgeon, so I wound up using my surges even more.

This makes sense. A thin wire electrode permits a precision, blood-free cut, difficult to achieve with a scalpel. But you can’t take maximum advantage of that enhanced control without magnification.

When I stepped up from 2.5X magnification to 4.8X, I saw an improvement in my results. Being better able to visualize the exact location of the needle electrode at all times prevents unwanted tissue removal from errant strokes.

Some readers may already know that I employ Orascoptic’s EyeMax 4.8 TTL loupes during all operative procedures. How can seeing better NOT elevate one’s level of performance? Is there such a thing as seeing “too well”?

So you touched the tooth. Big deal!

Some articles suggest that accidentally touching the tooth with the electrode is a disaster that kills the pulp, creates a black hole that threatens to swallow the solar system, and causes immediate revocation of your license.

Relax.

Enamel and dentin are fairly poor conductors of electricity. While I try to avoid electrode/tooth contact with vital teeth, I don’t panic if the tip momentarily brushes against a tooth surface.


My observation after accidentally touching more teeth over the years than I like to admit, is that as long as the contact is brief, the pulps survive just fine.^{4, 5} (By the way, I hear exactly the same thing from every other e-surgeon I talk to.)

Needless to say, non-vital preps relieve any apprehension about the anesthetized pulp, as it has already gone missing.

Much to be said about strokes

Well ... not really. Again, another area over-complicated.

You simply move the electrode where you want the tissue to be gone. My usual routine is to plant a solid finger rest with my fourth finger and hold the handpiece like a pencil.

I then make short oscillating strokes back and forth in the area I wish to remove. Such strokes travel two to three mm’s. I then inspect the cut and return to areas where small tissue tags remain. With my loupes I can easily track the electrode as it clears its path. This back-and-forth stroke keeps me from tarrying in any one spot - which might cause the tissue to overheat.

When I’ve finished, there will often be a little charred residue adhering to the margin of the prep. Using a fine diamond or a carbide finishing bur, I’ll quickly clean that up. In today’s world of shoulder-based, equigingival crown preparations, you don’t need much of a trough to expose the finish line. (see sidebar, How deep do you trough?)

I should also mention that there are still times when I desire the hemostatic benefits of an epi-soaked cord (we’ve all been there). Here I simply augment the retraction by using the needle electrode to open areas where the cord has not adequately retracted the tissue. This might be just a 3 mm zone of tissue on the mesio-buccal margin of a crown preparation.

Time out for an observation:

Touching up the tissue after packing cord takes only a couple of seconds, and that’s precisely why I keep a chairside e-surge in each operatory. If I had to lug the device from another room and then set it up, I’d probably forgo minor modifications like this. Yet the touch-up could be the difference between a pristine impression and one where the technician has to fudge a bit during die-trimming.

Two final cautionary statements: the first, a repeat: DON’T FORGET THE INDIFFERENT PLATE. The second, keep the high speed suction close to the operative site to control odor. Oh ... you don’t need plastic mirrors (old myth) and slightly moist tissue cuts better than dry tissue. That’s all you need to cloud your mind with. Let’s talk tissue-sculpting now.

Setting the Stage…

A patient presented wanting her smile improved (Fig. 9). Upon examination it was noted that previous treatment had included a two unit cantilevered bridge, #6-#7, and four direct composite veneers #8-#11.

One doesn’t need to be very far along in their dental education to realize that hopes of improving this smile depended on creation of more pleasing tissue contours. Gingival probing revealed a fair amount of “extra” gingiva. If removed, this would open the door to an attractive smile (Fig. 10).

After gathering all the diagnostic data, including a complete set of digital photos, the case was planned, beginning with the electro-surgery. #8’s tissue height plus 1 mm would serve as the guide for tissue-sculpting #8, 9 and 10. Additionally, an ovate pontic form would be created at the #7 site.

As is typical of such cases, I first obtain a digital smile simulation based upon a portrait of the patient. These simulations are created for me by Smile Vision (www.smilevision.net). In this instance, the planned tissue modification was included in the simulation prescription uploaded to Smile Vision. (Figs. 11 and 12)

Following patient approval, a closed-mouth impression was taken using a Premier Alfa Triple Tray® and vinyl impression material. This approach is fast, well-tolerated and accurate. The impression was sent to Smile Vision who in turn provided a mock up (Fig 13) as well as the corresponding templates for provisional fabrication and preparation guidance.

Built into the prep guide are the planned tissue heights following E-surge (Fig 14). The provisional templates (called “hard/soft” templates) will allow temporary fabrication in accordance with the newly-created tissue contours.

Showtime….

Following local anesthesia, tissue was removed using the Sensimatic needle electrode to a height that left behind 1 to 1.5 mm of sulcus depth. This is critical. E-surge gingivectomies that encroach on the biologic width are prone to long-term inflammation.

It was scalloped with the goal of creating a pleasing curve that reached its apex slightly distal to the midline. This typically requires ten minutes to complete (Fig. 15).

Following tooth preparation, I squeezed a new loop electrode slightly to make it oval, and used it to create an ovate pontic site in the #7 region (Fig 16). (New electrodes can easily be bent before use. Once they’ve been used, however, they harden and cannot be bent without breaking. So if you feel you’ve excessively deformed the electrode, and won’t need that shape again, just toss it after use. Fortunately, electrodes are cheap.)

Following surgery, I used dental floss to compare the relative tissue heights (Fig 17). Note the tame look to the sculpted tissue.

I routinely sculpt the gingiva with my e-surge, prep the tooth, and take the impression all at the same appointment.

When used after surgery, a carefully-fabricated provisional restoration not only protects the tooth and allows function, but also acts as a guide during tissue healing.

Modest convexity in the cervical aspect of your provisional teeth will allow the gingival margin to cozy up to it in a harmonious fashion.


Using the soft-hard template I received from Smile-Vision, I created a shrinkwrap provisional, which I meticulously trimmed to ensure that it didn’t encroach on soft tissue. Once again, higher magnification enhances this entire process.

A bottle of Oxyfresh® oral rinse was given to the patient, and she was told to use it daily in the effort to optimize tissue tone and color.

Figure 19 demonstrates very happy tissue adorned by a three-unit cantilevered bridge #5-#7 (porcelain fused to metal) as well as a series of porcelain veneers from # 8-#12 courtesy of Aesthetic Porcelain Studio in Los Angeles.

The final reward, of course, is the transformed patient, two months after case delivery (Fig. 20).

There is no doubt in my mind that the success of this case was due largely to the extra fifteen minutes I invested in tissue-plasty prior to impression taking.

When the e-surge is not enough

If all gummy cases lent themselves to such E-surge miracles, the cosmetic dental world would be a better place for all. Alas, sometimes ugly tissue can’t be easily corrected with an electrosurge. When sulcus depth is 1mm or less, more complex measures must be taken that involve removal of bone.

In these cases I frequently show patients simulations of smile rehabs done two ways;

• one with simulated tissue changes
• and the other without.

This lets patient preview the effects and decide whether or not the cosmetic result of periodontal surgery is worth the expense and effort.

If the patient elects the more complex treatment, both the simulation and the mock-up based templates can be supplied to the periodontist, enabling him to create the desired tissue contours.

Odds and Ends...

Again in an effort to demystify the e-surge, I should mention that it was not necessary to dress the minor wounds created by the procedures discussed in this article.

In fact, patient complaints regarding post-surgical pain related to tissue-plasty are, for the most part, non-existent.

Use of OTC analgesics can be suggested if the need arises, but they rarely will be needed.

One other helpful tip … If, during the course of a procedure, spot bleeding occurs that you’d like to quickly control with other means than the e-surge itself, 33% hydrogen peroxide (Superoxal®) applied and rinsed over five second intervals will do the trick. The whitish residue left behind will quickly fade.

And in conclusion…

To those of you who already enjoy the benefits of an e-surge, I hope you’ve picked up a few extra pointers that will enhance your experience.

For those who have abandoned their units or who have not been drawn to this tried-and-true practice adjunct, there’s still time to get on board.

The learning curve is short and the rewards are long. And as mentioned before, the cost is laughable when compared to the myriad of high-tech gadgets dangled in front of us every day. What are you waiting for?

Learn more about the Parkell Electrosurge Click here.
An entire library about e-surgery Click here.

This article is an expansion of one that appeared in Dentistry Today (Nov. 05). It is with the kind permission of that publication that it appears here.

1 Livaditis GJ. Comparison of monopolar and bipolar electrosurgical modes for restorative dentistry: a review of the literature. J Prosthet Dent.86(4):390-9, Oct 2001 Oct
2 Hansen PA, Tira DE, Barlow J. Current methods of finish-line exposure by practicing prosthodontists.
J Prosthodont.;8(3):163-70, Sep1999
3 Scott A. Use of an erbium laser in lieu of retraction cord: a modern technique. Gen Dent.
.53(2):116-9 Links Mar-Apr2005
4 Krejci RF, et al Effects of electrosurgery on dog pulps under cervical metallic restorations.
Oral Surg Oral Med Oral Pathol.;54(5):575-82.,Nov 1982
5 Robertson PB, et al. Pulpal and periodontal effects of electrosurgery involving cervical metallic restorations. Oral Surg Oral Med Oral Patho..;46(5):702-10. Nov 1978

Dr. Goldstein is a 1977 graduate of the University of Connecticut School of Dental Medicine and practices general dentistry in a group setting in Wolcott, Conn. He enjoys promoting the cosmetic side of his practice and has found it helpful to incorporate digital photography into his daily routine as a practice builder. Recently, Dr. Goldstein has been appointed to the staff of Contributing Editors at Dentistry Today. In addition to writing for Dentistry Today, Dr. Goldstein also writes for DentalTown, Contemporary Esthetics and Dentistry, the UK’s version of Dentistry Today.

Doctor Goldstein can be contacted at martyg924@cox.net or at his office at 203-879-4649. He is available for speaking engagements on both digital imaging in dentistry and the use of high tech methodology to further the cosmetic practice.

For a summary of Dr. Martin Goldstein's upcoming lectures and courses, go to
http://www.drgoldsteinspeaks.com