Losing our individuality

Transcription

1 Breaking Cookie the Cutter Finding our way back to individuality with shape, form and texture by Bill Marais, RDT Bill Marais is trained and has extensive experience in all aspects of dental technology, including crowns and bridges, neuromuscular dentistry, dentures, neuromuscular dentures and implants. He received his bachelor s degree in prosthetic science in Cape Town, South Africa. Marais is also a key opinion leader for GC America. 50 APRIL 2016 // dentaltown.com Losing our individuality Years ago, my good friend Arian Deutsch, who is a tremendously talented removables technician, told me something profound. He said, Cosmetic dentistry has hijacked individuality. Those words have never rung as true and clear as they do today. Our world is one of big business, global corporations and the vaporizing of the middle sector. Corporations idea of accommodation is a one-size-fits-all mentality in which time and money are the only driving factors. What happened to time spent on analyzing the individual s needs, personality and character? We are seeing the absolute loss of individuality in all sectors of our lives, and sadly, that includes the world of dentistry and dental technology. But we don t have to let it happen, and we shouldn t. Dentists make huge investments in CAD/CAM, where monolithic restorations are the common production units in dental offices and in production-line labs. In dentistry, little thought is often given to patient education. Dental professionals are not striving to negate the media s warped portrayal of what makes a beautiful smile. Patients are not aware of what constitutes a natural smile. CAD/CAM may be a necessity in the advancement of dentistry and dental technology, but I am also not opposed to monolithic restorations. We must, however, spend time on placing individuality and a human fingerprint on monolithic restorations and those created via CAD/CAM. Continued on p. 52

2 Continued from p. 50 Fig. 2a Fig. 1 Fig. 2b Fig. 3 Fig. 4 Dentists and dental technicians have to combine the human element with the machine. My friend Barry Brady, a fineart photographer, once told me, With technology at our hands, it has become too easy to make average work, and then mediocrity becomes the standard. We need to work against this not by trying to stop it, but by upping the quality and standard of our work. Bringing back individuality Here are several steps I take in my work every day to preserve individuality for patients while still striving for the highest standards (see Fig. 1). In nature, there are no straight lines. I look at nature and I see the number 3: the apex, middle and base of the tree; the head, thorax and abdomen of insects. Or when it comes to human teeth, the cervical third, middle third and incisal third. Even the interproximal surface is divided into three segments, as is the incisal edge. Changing the lengths or positions of these segments changes the shape of the tooth (Fig. 2a). How you position the mesial and distal line angles will also change the shape of the tooth. The three lobes on the facial A rough surface texture causes diffused reflection. surface of the tooth determine whether the surface is convex or concave. More importantly, natural teeth do not have a 100 percent flat, or a 100 percent round, facial surface. The long axis of the central and lateral incisors must run more or less parallel (Fig. 2b). A common mistake made today is keeping the long axis of the canine running parallel with the adjacent incisors. The long axis of the premolars will more or less run parallel to the canines. Far too little attention is given to the shaping of the lingual surfaces of the teeth. Curvatures on the lingual (Fig. 3) give rise to curvatures on the facial (Fig. 4). The purple arrows in the second figure indicate the curvatures and embrasures created by the indentations and curvatures on the lingual (red arrows in Fig. 3). I greatly appreciate the adequate prepping of lingual surfaces. This allows me Fig APRIL 2016 // dentaltown.com

3 Fig. 6a Fig. 6b Fig. 6c Fig. 7a Fig. 7b the space to properly create my lingual, and then facial, surfaces. A common error in creating natural smiles is ignoring the importance of incisal embrasures. The spaces created by the openings of the incisal embrasures follow somewhat of a Fibonacci sequence up to the first premolar (Fig. 5). Accurate impressions with tissue detail are vital for creating correct emergence profiles. In Fig. 6a, the emergence profile is incorrect. The tissue can be read in Fig. 6c, ensuring that the teeth emerge out from the tissues, as in Fig. 6b. When replicating natural dentition, surface texture should not be neglected. It is important to keep in mind that a smooth surface, which is unnatural, results in specular reflection. A rough surface texture causes diffused reflection. Keeping in mind that if natural teeth have a rough surface causing diffused reflection of light, clinicians should then ensure that restorations include surface texture that mimics the natural tooth, too. (Figs. 7a, 7b). We are seeing the absolute loss of individuality in all sectors of our lives, and sadly, that includes the world of dentistry and dental technology. But we don t have to let it happen, and we shouldn t. FREE FACTS, circle 6 on card dentaltown.com \\ APRIL

4 Fig. 8 Fig. 9 Fig. 10 Milled restorations in a precrystallized state. These restorations are acceptable... if all we want is acceptable. But by following the basic principles in this article, we can transform these milled restorations into unique, natural teeth that fit the individual. We can create enhancedquality restorations. It is helpful to use a red pencil to mark line angles, keeping in mind there are no straight lines and keeping with the principle of threes from nature. I m marking the three facial segments with a red pencil to help visualize the incisal, middle and cervical portions. Fig. 11 Fig. 12 Fig. 13 Here I use a contour check paint (I used Contour Check Silver from Harvest Dental) to emphasize texture, shape and form. I continue to use the red pencil to indicate my lines and segments as I create facial texture. Here I focus on lingual surfaces, which will aid in creating facial shape and form later. My preferred instrument for creating horizontal grooves is an old milling burr from the CEREC MCXL milling unit. Fig. 14 Fig. 15 Fig. 16 To create developmental grooves, lobes and vertical ridges, I use a diamond scribe from Harvest Dental. Incisal embrasures, horizontal texture, developmental grooves, lobes and vertical ridges are all evident in this photograph. Here I ve started the prepolishing/final shaping (heavier polishing and shaping) step, using a Diashine coarse light-gray wheel. Fig. 17 Fig. 18 Fig. 19 More prepolishing and shaping. Doing the final prepolishing/shaping with a Diashine medium gray wheel. Coarse/soft Diashine paste is used to remove all surface tension from the ceramic. The paste also helps create a natural sheen. 54 APRIL 2016 // dentaltown.com

5 Fig. 20 Fig. 21 The final result. The units are now ready to be crystalized, to be followed by the stain and glass stage, using GC Initial IQ Lustre Pastes and GC INvivo Ceramic Stains. Often after glazing, the ceramic can appear too shiny and overglazed, not resembling natural dentition. Final polish now occurs and I use the Diashine medium gray wheel in combination with the Diashine coarse/soft paste. Diashine coarse/ soft paste is not oil-based and is 100 percent water-soluble. It is easily removed in an ultrasonic or by steaming. Fig. 22 Final photograph shows tooth surfaces are not overglazed. They resemble the natural dentition, and this can be achieved only by the final polish described above. Conclusion Remember the rule of threes and pay close attention to your embrasures and line angles. The final restorations that you deliver should match the patient receiving them, not some computer algorithm. While a talented technician is not always an option, or the latest technology has altered your needs for a technician, this is not an excuse to ignore the basic elements of natural smile design outlined here. In today s technologically advanced world, too many technicians are bypassing the basics the foundation of individualized and quality work. By the basics, I mean the following: We absolutely need to have 10,000 to 15,000 hours of blood, sweat and tears at the bench. Mistakes are inevitable but we need to put in the hours to resolve technical and artistic issues. From Day 1 at the bench, we need to start performing art we must add the human element of creativity and imagination. If we remember and follow these basics in dental technology and dentistry as a whole, we will find our way back to individuality. After all, what is the difference between my work and 100% automated CAD work? It is detail and my fingerprint individuality. n Questions for the author? Comment on this article at dentaltown.com/magazine. FREE FACTS, circle 6 on card dentaltown.com \\ APRIL