The “Trial Smile” is a common term applied to the technique of evaluating a change in the position of the teeth and appearance of the smile.
Patients and dentists commonly think of using a Trial Smile to compare an individual's existing, or pre-treatment smile appearance, to the improved change that a proposed outcome the restorative and/or collaborative dentistry will create.
There are many different fabrication techniques utilized to create the Trial Smile. It can be performed intraorally (direct) or extra-orally (indirect). Direct technique includes free-hand application of composite resins to the undersized or mal-positioned teeth to alter dimension or arrangement.
Typically, no adhesion process is utilized to “permanently” attach the composite to the teeth. Once the composite is applied, the patient can view the proposed “smile” changes.
The most common indirect technique is to have a diagnostic wax-up fabricated that alters the size and position of the anterior teeth. An index (silicone or vacuum-formed) is then fabricated over the diagnostic wax-up. To create the intraoral Trial Smile, a provisional material like bis-acryl is placed into the index and applied over the patient's teeth.
Once the bis-acryl is hard, the index is removed and the remaining “trial smile” can be assessed. There are some limitations to each technique, but the goal is to create an opportunity for the patient to preview the proposed esthetic changes available through collaborative restorative dentistry.
Direct techniques are challenging and time-consuming. The freehand nature of creating changes to the tooth contour and position requires patience and skill with the use of composite resins. Additionally, they require significant chair time to complete.
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The phrase “time is money” is very true as it relates to creating Trial Smile templates with this technique. While the outcome can be beautiful, there is no guarantee that the patient will accept the proposed changes and proceed with treatment. The chair time spent in fabricating the Trial Smile is costly and if actual treatment does not follow, there is a significant loss of income. As powerful as this “Trial Smile” technique may be to motivate patients toward treatment, it only takes a few “no” responses from patients, and the lost production, before the practitioner will avoid suggesting the technique for future patients.
Indirect techniques also have their downside. As stated earlier, a diagnostic wax-up is commonly utilized as the basis for changes of the tooth size and positions. While the wax-up provides accuracy and realism, there is a significant expense attached to the creation of the wax-up. A Trial Smile constructed from the wax-up will create dramatic appearance change for the patient. But, again, the expense of creating the wax-up may deter many patients from committing to treatment.
If the goal is to use a “Trial Smile” to motivate patients to commit to restorative therapy, it is more appropriate to have the patient first observe the Trial Smile, get motivated, and then approve and accept the diagnostic wax-up as a tool for definitive therapy. Most dentists are reluctant to spend on a diagnostic wax-up if patients are not committed to the recommended treatment. But there is an alternative “Trial Smile” technique that may be applied!
The Trial Smile overlay template
One Trial Smile technique that is often overlooked and under-utilized is the overlay template. This is an indirect technique that is simple to fabricate and does not require the fabrication of a diagnostic wax-up. This template technique may be utilized to evaluate tooth position change, tooth size alteration, gingival contours and even tooth color or shade changes. It is very versatile and inexpensive. It only requires some application of treatment planning concepts and a few minutes of the dentist’s time and energy in the office dental lab area. I have found it to be a great communication tool for patients to better understand and accept restorative treatment.
The Trial Smile overlay template technique is an indirect technique. The dentist must obtain a series of patient photographs and a set of diagnostic casts (preferably facebow-mounted). I also recommend obtaining a photo of the proposed tooth shade changes. With these records, the overlay template can be fabricated easily and accurately.
The overlay template will take 15-20 minutes to fabricate and be ready for patient application. I find it to be efficient, effective and well received by patients!
The material of choice for fabricating the overlay template is Revotek LC. It is a light-cured composite resin designed for use as a provisional.
Revotek LC is made and distributed by GC America. It is a shapeable composite material with firm consistency. Since it is light-activated (cured), there is enough working time to manipulate and contour the shape and form of the proposed changes before hardening. It comes in stick form in a light-proof container and a spatula is provided with the kit.
The material is relatively inexpensive. While there is only one shade available (approximately VITA A1), it is possible to apply conventional composite resin of a different shade on the cured surface if a shade change is required.
I’ll describe the technique of fabricating the Trail Smile overlay template using a recent patient case in which I was contemplating orthodontic intrusion and restoration of the lower teeth. The patient, Nancy, was new to my practice and wanted to improve her smile and function.
The patient had ignored her dental health in recent years but had decided that it was important to improve her health to retain her existing teeth. She really disliked the appearance of the over-eruption of her lower teeth and was embarrassed to smile.
Obviously, there was significant collaborative treatment planning involved in the case. In this article, I will not be able to get into the overall treatment plan. But the patient wanted to see the outcome of her treatment. An overlay template helped her see the possibilities and provided her with the motivation to pursue collaborative treatment. As a side note, it is imperative that Facially Generated Treatment Planning concepts and templates are integrated into the planning and design of the patients proposed outcome.
The necessary photographs and models of the teeth were obtained. Following the guidelines created from the FGTP templates, the appropriate incisal edges and future gingival margins were drawn on the casts. The casts were then coated with a stone separator material to allow the overlay template to be removed from the casts once they were fabricated.
There are many different stone-separating materials available. Two common separators that I use frequently are from COE-SEP and Great Lakes. Both products are brushed onto the casts and air thinned. They do not have to be completely dry to continue with the technique.
With the casts lubricated with separator, an appropriate amount of Revotek LC is removed from the package. The amount you’ll need to use varies depending on the number and extent of the teeth involved. The goal when applying the Revotek to the model is to create a template approximately 1-mm thick.
With that being the goal, the “ball” of Revotek removed from the case is thinned across the casts of teeth to approximate 1-mm thickness. This thinness also allows visualization through the material of the incisal edges and gingival contours scribed on the cast.
Once thinned and applied on the cast, the Revotek is sculpted to the appropriate contours, positions and shapes of the proposed restoration. I like sculpting the template with a Hollenback carver. I thin and remove the uncured revote to approximate the proposed tooth outlines. Addition and subtraction of the un-cured material is possible.
Once the contours are acceptable, the cast and Revotek must be light activated (cured). This may be accomplished with a curing wand, but it is most efficient to place the cast into a light-curing oven (e.g., Triad oven). Total hardening (cure) time is about two minutes. Once cured, the cast is removed from the oven and the template is ready to be trimmed and polished.
The overlay template must be gingerly removed from the cast. Fracture of the connectors (contacts) is the concern. I use the pointed end of the Hollenback to “free up” multiple areas of the template from the cast. As individual areas release, I move to another. Eventually, with caution, the template is removed from the cast in one piece (though it is possible to re-attached broken segments using a flowable composite).
Trimming and polishing the fragile template can be challenging. I use a combination of discs, rubber wheels, diamond discs and carbide burs in my laboratory motor (or straight chairside handpiece) at low speed.
If adequate time was taken during the sculpting process, minimal finishing with burs and discs is necessary. Polishing a thin template is virtually impossible. Therefore, the final luster is achieved by using an overlay glaze material such as GC Optiglaze (GC America) or Palaseal(Pala by Kulzer). Either will create a shine and luster that mimics tooth reflectivity and appearance.
When the patient is re-appointed for the Trial Smile consult, the overlay template is “snapped” into place. The proposed changes and contours may now be visualized by the patient.
In this patient's case, the extruded teeth were “Sharpied” to visually eliminate the appearance of the incisal edges. The overlay template provides opportunity for the patient to visualize the proposed outcome. In my experience, these overlay templates provide vision, reassurance and motivation for patients to proceed with esthetic and collaborative treatment.
To sum up, the Trial Smile overlay template is a simple, convenient, cost-effective and non-invasive tool to provide patients with the opportunity to visualize potential appearance changes to their teeth and tissues. I encourage all dentists to utilize this technique and tool with their esthetic treatment planning.
Jeffrey Bonk, D.D.S., is a member of Spear Resident Faculty.