Do You SPA
Do You SPA
There is nothing wrong with referring back to basic technology to put us on track to be perfectionists throughout our careers. These basics lay down the foundation to create the professionals we are today.
Between 1956 and 1958, Dr. Frush cowrote a series of articles about how to avoid the denture look. He did so by very simply summing up what natural esthetics are all about: The SPA factor. The SPA factor breaks down into three parts:
Sex: The entire physique differs in human men and women. Everything about a woman appears soft, curvy and rounded. Everything about a man appears bold, strong and edgy. Those features are also noticeable in their teeth as indicated in Figures 4a and 4b. In a man, the insisal edges appear wider and more cornered in shape, where as in a woman, her teeth have more of a softer, rounder appearance than a man’s. When choosing denture teeth for a patient, the choice of a masculine and feminine shape should be considered.
Personality: Part of making an esthetic denture is to make it look natural as well. Personality plays a part in that. If you look at Figures 5a and 5b, one man appears to be a night club entertainer and the other appears to be an outdoorsman. If you were to fabricate a denture for the entertainer, you would set them up with the classic orderly tooth set up format where the teeth are of a light shade and straight. However, if you were to fabricate a denture for the outdoorsman, a set up similar in style as the entertainer would look very unnatural. To fit this patient’s character, you would set up the teeth slightly out of line and not so (traditionally) uniform. The shade would not be as white, and you may even want to create a slight space between some of the teeth.
Age: The last major consideration regarding tooth selection is the patient’s age. Perfectly straight, white teeth will not improve the patient’s appearance in all cases. Today, there is considerable demand for bleached teeth in restorative dentistry, and a proper place for them as well. However, they are not for everyone. Natural teeth naturally discolor as we age so the doctor (as well as the patient) should take that into consideration when selecting a shade for denture fabrication. Figure 6a shows a woman in her early 20s. Figure 6b shows a woman in her upper 40s. Both these women have their natural teeth. But if you were to fabricate a restoration for the older woman, you would not want to give her a bright white shade. You can certainly give her a whiter smile with a light shade and it will still produce a natural appearance. However, some doctors may go overboard and prescribe a B-1 shade or even lighter shade which would not produce a natural look for a patient this age.
In 2003, Swiss dental technician Jan Langner ,MDT, continued the SPA tradition by designing the first commercially available composite denture tooth. Langner was unable to find denture teeth that looked as natural as a ceramist’s hand designed tooth. He stated, “I didn’t want to create denture teeth, but teeth that come as close as possible to the real thing.”
Candulor took Langner’s 3D design (Figure 7) that beautifully mimics natural teeth and manufactured a tooth with a material that also wears like natural teeth. Instead of manufacturing these teeth out of acrylic, or porcelain, the material of choice was Nano-Filled Composite (NFC). This composite was developed with a Urethane Dimethacrylate Matrix (UDMA), combined with fillers consisting of Silicon Dioxide (SiO²) fillers and Silicon Dioxide Nanoparticles. NFC teeth are four-layer teeth. Two layers are composed of NFC, which provides the particularly abrasion-resistant properties. The other two layers (tooth neck and tooth core) are made of Poly Methyl Methacrylate Acrylic (PMMA) layers which permit good bonding with the denture base material (Figure 8).
Now when Langner designed these teeth, he kept the SPA factor in mind by categorizing them in four groups.
Delicate (group 55): These molds would be for patients with a slender, delicate or feminine physique. They have a soft, youthful insisal design, characteristic mamelons, and no abrasions (Figure 9).
Universal (group 66): This group is intended to be suitable for a wide range of physical types which will also work for all age groups. They are designed with a square central, and tapered lateral incisors (Figure 10).
Vigorous: Suitable for all age groups in cases where a distinctively masculine impression is to be achieved. This group has a sturdy build and appearance (Figure 11).
Individual: This group would work well for all age groups as well as those that require an individual set up where a certain character is to be achieved (Figure 12).
The manufacturer has more molds to choose from to meet the esthetic requirements of the case being fabricated, and can be viewed on their Website www.candulor.com.
In recent years, I have asked at lectures how many attendees have heard this information before. Out of the hands that were raised, the majority were advanced technicians. Many of the younger people I’ve asked have not heard of the SPA factor. That’s unfortunate because the SPA philosophy still applies today.
