Avoiding edema dilemmas

March 1, 2006
We have noticed that many of our cosmetic patients are experiencing edema of the upper lip and sloughing of the epithelial tissue in the maxillary vestibule following the preparation appointment.

By Michael Miller, DDS

We have noticed that many of our cosmetic patients are experiencing edema of the upper lip and sloughing of the epithelial tissue in the maxillary vestibule following the preparation appointment. We originally thought this was due to dry cotton rolls tearing the epithelium, but we still experienced this after moistening the cotton rolls. Could this be due to the anesthetic? We are currently using 2% lidocaine (about 1/3-1/2 carpule per tooth).

Some patients just seem to be more prone than others to experience edema when treated in the maxillary anterior segment. Any insult can trigger this edema, including anesthetic injections, cotton rolls, retractors, and/or just manually lifting the lip to access the teeth. The same insults can lead to epithelial sloughing, especially in patients with shallow vestibules and short lips. While these negative sequelae may be disconcerting to both patients and the dental team, they are usually self-limiting and resolve uneventfully in a few days post-treatment.

Certainly, when a patient seems to be very susceptible to these untoward effects, it would be prudent to give added attention to the manner in which the tissue is manipulated. In other words, be extra gentle. Post-treatment steroids may also help. But just informing patients that these clinical events may occur and that they will usually resolve relatively quickly will go a long way to keep the episodes from being a patient management problem.

And, to put this issue in proper perspective, when does a patient have virtually any type of cosmetic procedure from our medical colleagues without some post-surgical edema and inflammation? When patients are told it may happen and, therefore, they expect it, the urgency disappears.

Why do some manufacturers of one-component self-etch adhesives not recommend using phosphoric acid for etching enamel (uncut) while others do? Could it be related to the etching depth of phosphoric acid, which can’t be filled in adequately by the self-etch adhesive, thus making enamel prone to fracture?

Most manufacturers of self-etching adhesives are quite cautious when it comes to giving advice concerning the treatment of unprepared enamel. One reason is that many of these manufacturers probably don’t even consider the need to bond to unprepared enamel. They figure that a dentist just needs to restore teeth to the cavosurface margin of a preparation. For Class I and II preparations, this is typically correct. But for Classes III, IV, and V, when you usually go beyond the prepared margin for esthetic blending purposes, this is not correct. Some more esthetically oriented manufacturers, therefore, properly advise that etching the unprepared enamel, especially on the visible part of the tooth, with phosphoric acid is a good idea.

However, if you inadvertently get the phosphoric acid on the dentin, you could overetch the tooth, which could lead to poor penetration of the adhesive into the dentin surface and lead to an incompletely infiltrated demineralized zone. This, in turn, could lead to sensitivity and lower bond strengths.

So, the fact that some manufacturers do and some don’t advise etching unprepared enamel with phosphoric acid probably has nothing to do with penetration of the adhesive into the enamel, making it prone to fracture. It has more to do with making sure you don’t overetch the dentin.

Nevertheless, in the 2006 Annual Edition of REALITY, there are new evaluations of three single-component, self-etch adhesives. In these evaluations, you will find the results of our bond strength tests, which demonstrate that on prepared enamel, phosphoric acid etching had no effect on enamel bond strength for one product, actually lowered the bond strength of the second product, but significantly increased it for the third.

I treat many children and would like to use a restorative material for primary molars that is fast and easy. What would you recommend?

For children with relatively high incidence of caries, it is still hard to beat a resin or glass ionomer. This is the only category of materials that really releases clinically relevant amounts of fluoride and, to top it off, is the original self-etching restorative. For small lesions, Fuji Triage works well, while larger ones are better restored with thicker materials such as Fuji IX or Vitremer.

For small patients with a lower incidence of carious lesions, a flowable composite combined with a self-etching adhesive is easy and, if you don’t overfill, requires almost no finishing.

Are there any new preventive strategies for treating children beyond the typical fluoride treatments?

Two relatively new products will definitely help, both of which are from GC and are featured in the 2006 Annual Edition of REALITY. The first is Prospec MI Paste, which incorporates ACP (amorphous calcium phosphate) to fight acidic demineralization of teeth. Another product is Saliva Check, which, as its name implies, analyzes the patient’s saliva to see if he or she is caries-susceptible. While there is no treatment directly associated with this product, it will alert you and the child’s parents as to whether the patient has a propensity for developing carious lesions.

I know prehybridization of a preparation has been batted around before, but it seems to have resurfaced a lot lately. What is your take? Is this process something we should consider doing?

By prehybridization, we assume you mean hybridizing a preparation before impressing for an indirect restoration, thereby sealing the dentin at the preparation appointment. This should prevent sensitivity between appointments and allow the seating of the definitive restoration without anesthesia.

While this procedure does get a lot of press and some clinicians are fervent advocates, there is very little, if any, clinical substantiation that it will provide for a healthier tooth and better retained restoration. In addition, Editorial Team Member Dr. Franklin Tay has demonstrated in his ground-breaking research on water trees that, unless you are hybridizing with an adhesive that uses a hydrophobic resin bonding agent as a final layer, you are probably not sealing the dentin anyway due to the semipermeable membrane effect of hydrophilic adhesives. In addition, trying to bond to this layer after the provisional phase might lead to compromised adhesion. Therefore, we still do not believe the evidence warrants adopting this procedure as routine.

Dr. Michael Miller is the publisher of REALITY and REALITY Now, the information source for esthetic dentistry. He is an international lecturer and a fellow of the American Academy of Cosmetic Dentistry, as well as a founding member. He maintains a private practice in Houston. For more information on REALITY and to receive a complimentary issue of his monthly update, REALITY Now, call (800) 544-4999 or visit www.realityesthetics.com.