EmpreThins — "The future of
Prepless Veneers"

By Dr. David Hornbrook

One of the hottest topics in dentistry today is "Prepless" or "Minimal Prep" Veneers. There are two primary reasons for the interest in this concept: 1) A major manufacturer is marketing Prepless veneers to the public creating widespread interest, and 2) it provides an opportunity to provide conservative aesthetics to those patients not desiring traditional aggressive tooth preparation, this increasing potential for performing more smile designs in our practices.

Unfortunately, the fabrication of very thin veneers (less than 0.5 mm) has been very inconsistent. This is a result of either the ceramists' inability to master the technique or the limited physical properties of the ceramic itself. Often times, clinicians utilize laboratories or materials that cannot meet the artistic challenge required to optimize aesthetic and smile design. These limitations have caused many astute clinicians to refuse to offer their patients very minimally prepped veneers or have consistently performed
much more aggressive preparation to
achieve desired results.

It is important to realize that "Prepless" or "minimal Prep" veneers are a technique, not a specific material. I have had numerous doctors e-mail me or show me models of unprepared dentition asking me if the patient was a candidate for "Lumineers™ (Den Mat)". In my opinion, Lumineers™ offer many limitations that using a different material with an artistic ceramist can offer. One of these being direct communication with the fabricating ceramist. A second being able to utilize a ceramist that has attended numerous live patient and hands-on courses to
truly understand how important of a
role the ceramist plays in "designing the smile".

In terms of different ceramic materials available for minimal pre- or non-prep restorations, almost any ceramic can be used. Unfortunately, based of material misunderstanding, IPS Empress was never advocated for this technique because of the need to be a minimal thickness that often times would not be acceptable if there was no-preparation for the veneer. Empress, however, became the material of
choice for prepped veneers, full coverage crowns, and inlays and onlays due to its strength, wear compatibility, and marginal integrity. In the last few years, through careful ceramic manipulation and expertise, Gold Dust dental lab has perfected the "pressed
Ceramic" or Empress very thin veneer. They call them Emprethins™ and they can be as thin as 0.2 mm with all the advantages traditional pressed ceramic has shown and the aesthetics only an experienced, artistic ceramist can provide. (See figures 1-8)

The technique for the Emprethins™ is similar to traditional veneer procedures. It is recommended to take very accurate polyvinyl impressions and then send them to the laboratory with instructions that it will be a no-prep or minimally prep case. An example of an Emprethin wax-up prescription would be as follows:

Rx:  Please wax-up teeth #'s 4-13. This is going to be a non-preparation veneer case, so do not reduce any of the stone model on any teeth prior to waxing the case. Make centrals 11.0 mm long and the laterals 0.5 mm shorter than centrals. Lengthen canines to the same length as the centrals and make sure we have canine guidance. Wax as minimally as possible, but you need to be able to reproduce the wax-up in ceramic. Also, if there are any areas on any teeth that you feel need to be slightly reduced prior to waxing, call me to discuss. After wax-up is complete, please fabricate a wash-lined putty matrix of the wax-up.

Fig 12: After 2 minutes the Silicon Matrix is removed and the aesthetics are evaluated. Any voids are filled with a flowable resin. Excess BIS-Acryl is gently removed from the gingival. Fig 13: A 0.3 mm depth cutting diamond (Brasseler) is used to place depth cuts directly into the BIS-Acryl. Fig 14: After depth cuts are placed in the gingival, middle, and incisal thirds, the BIS-acryl is removed. If there are any areas where the depth cuts penetrated the enamel, a chamfer diamond is used to reduce the facial enamel down to depth the cuts. Often times, there is no enamel preparation

Gold Dust will wax the case and make a Putty matrix of the wax-up (see figures 9 & 10). The clinician will then load the putty matrix with a BIS-Acryl resin (Luxatemp, Zenith) and place it over the unprepared teeth. (See figure 11 & 12). After 2 minutes in the mouth, the putty Matrix is gently removed. This will result in a transfer of the wax-up onto the patient's teeth to evaluate aesthetics (length, thickness, shape, etc.). (See figure 13). After aesthetics are evaluated and approved, the clinician will utilize a 0.3 mm depth cutting diamond (Brasseler) and place depth cuts at the gingival, middle, and incisal thirds of the teeth. (See figure 14 &15). After the depth cuts are placed, the BIS-acryl resin is removed and any depth cuts into the teeth will be removed by reducing the facial enamel down to the depth cut. This can usually be done without the need for anesthetic. This Matrix technique ensures that there is adequate room for the 0.3 mm Emprethin™ veneer. Most often, if the case was properly diagnosed, there will be no remnant of any depth cut and it truly will be a “no prep” case.