Improving Anterior Esthetics with All-Ceramic Restorations
Layer-free zirconium oxide material masks endodontic post while providing strength and lifelike translucency
J.A. Reynolds, DDS, and Matt Roberts, CDT
The lockdowns and social distancing restrictions imposed during the COVID-19 pandemic pushed millions of business professionals out of the workplace to work remotely from home. As that trend continues in 2021 and beyond, interpersonal office, classroom, workshop, trade event, and conference table interactions have been replaced with virtual meetings, remote video conferencing, and one-on-one video calls through the high-resolution lenses of computer cameras. Virtual instead of in-person interaction has become commonplace.1
With businessmen and women spending hours each day staring at their own faces on their computer screens, many focused more attention on their appearances,2 especially their smiles. Anterior teeth with small chips, discolored teeth, and even restorations that didn't quite match the color and shape of adjacent teeth became exaggerated when they appeared larger-than-life on the computer screen.
Although there has always been a strong connection between our external appearance and internal sense of health and well-being that motivates us to want to project a positive image to others with whom we communicate, social media in all its forms has impacted the perception of smile esthetics and increased the demand for dental procedures to enhance the vitality of patients' smiles.3,4
A long-time female patient in her early 70s presented to the practice unhappy with the unesthetic shade and shape of tooth No. 10 (Figure 1). She and her husband had founded a not-for-profit corporation that provides counseling workshops for married couples, but during the pandemic, they shuttered their in-person workshops to meet remotely with their clients using social media platforms. Seeing her face and smile elevated on the computer screen had made the patient keenly aware of the misshapen nature of the crown on tooth No. 10 and the fact that the color did not match that of the adjacent teeth. Many years earlier, the tooth had been endodontically treated, and a metal post was inserted to rebuild and strengthen the tooth for placement of a metal-ceramic crown (Figure 2), which was designed to mask the underlying color of the post.
Upon examination, the clinician alerted the patient to the presence of chipping on the mesial surface of tooth No. 8, which he suggested that they also address, as well as the discoloration of teeth Nos. 7 and 9 (Figure 3). The preferred treatment plan that was recommended involved placing all-ceramic restorations for teeth Nos. 6 through 11. After the patient agreed to treatment, the clinician acquired a series of retracted and unretracted preoperative photographs for communication with the laboratory. The most beneficial photograph for digital design is a full-face smile portrait with the teeth slightly apart.
At the preparation appointment, unpolarized and polarized photographs of the patient's existing dentition with a shade tab (VITA classical shade guide [A1], VITA North America) were acquired for additional laboratory communication (Figure 4 and Figure 5). The patient was then anesthetized, the crown on tooth No. 10 was removed, and teeth Nos. 6 through 11 were prepared to receive full-contour crowns. To communicate the stump color to the laboratory, the preparations were photographed with a shade tab (IPS Natural Die Material Shade Guide [ND-7], Ivoclar Vivadent) (Figure 6) and then digitally scanned (Trios® 4, 3Shape). Temporary restorations were created using a premade splint fabricated from the original diagnostic design (PerfecTemp® II, DenMat) (Figure 7). After the temporary restorations had remained in place for several weeks, the patient reported that she was pleased with the function and esthetics.
The clinician created a PowerPoint presentation that included all of the preoperative, postpreparation, and temporized patient photographs and sent it to the laboratory, noting the slight cant of the temporary restorations on the patient's left side and the stump color of tooth No. 10, which might prove problematic to mask, and requesting that they use an all-ceramic restorative material.
At the Laboratory
A photograph of the temporized patient smiling and looking directly into the camera was uploaded into CAD software (3Shape Dental Designer Premium, 3Shape). Using the software's tools, the interpupillary and perpendicular midlines were established to orient the photograph in facial context and straighten the image to the overall esthetic plane, correcting a slight cant that had been noted by the clinician (Figure 8). A scan of the temporary restorations was aligned with the photograph, and a scan of the digital model was superimposed to ensure that complete alignment was achieved (Figure 9). Next, a boundary of translucency was established in the photograph by drawing a line around the inner lip line. This allowed the proposed 3D digital design to show through so that it could be confirmed to be in harmony with the upper and lower face (Figure 10). In this case, the technician had to take into consideration that one of the patient's eyes was slightly higher than the other.
The scan of the temporary restorations was used as a guide to design the shape, form, and position of the final all-ceramic restorations as well as to evaluate different layering textures to create translucency and add characterization (Figure 11 and Figure 12). Once completed, the final design was imported into the CAD software's dynamic virtual articulator for a functional evaluation of the protrusive and excursive guidance as well as the contact points (Figure 13).
For this case, it was critical to select a restorative material that had the ability to mask the post and core of the endodontically treated tooth while exhibiting maximum translucency and esthetics to blend the six crowns with the existing dentition in the esthetic zone. The technician chose to use a high-strength zirconium oxide restorative material (IPS e.max® Prime Esthetic, Ivoclar Vivadent) because its layer-free progression of shade and translucency offers coordinated opacity in the cervical region with high levels of translucency in the incisal region for optimal esthetics with 850 MPa of strength.
Following confirmation of the selected material, the six full-contour crowns were milled (PrograMill PM7, Ivoclar Vivadent) with subtle surface texture for the addition of shading liquids prior to staining, glazing (IPS Ivocolor, Ivoclar Vivadent), and sintering (Figure 14 and Figure 15). Stump dies were utilized to achieve true shading (Figure 16). The completed final restorations, which exhibited a natural level of translucency and a seamless gradient transition from dentin to enamel (Figure 17 and Figure 18), were then delivered to the practice.
Try-In and Cementation
After the clinician anesthetized the patient and tried in the restorations to assess their fit, function, and esthetics, each crown was cleaned and cemented using a resin-modified glass-ionomer cement (RelyX™ Luting Plus, 3M). The patient expressed that she was thrilled with the outcome (Figure 19 through Figure 22).
About the Authors
J.A. Reynolds, DDS
American Academy of Cosmetic Dentistry
Matt Roberts, CDT
American Academy of Cosmetic Dentistry
CMR Dental Laboratory
Idaho Falls, Idaho
1. Saad L, Wigert B. Remote work persisting and trending permanent. Gallup website. https://news.gallup.com/poll/355907/remote-work-persisting-trending-permanent.aspx. Published October 13, 2021. Accessed November 24, 2021.
2. Valenti L. How staring at our faces on zoom is impacting our self-image. Vogue website. https://www.vogue.com/article/body-dysmorphia-zoom-face. Published Augusts 3, 2020. Accessed November 24, 2021.
3. McMahon S. Selfie culture, young adults, and cosmetic dentistry: dysmorphia creates new aesthetic demands from teenagers and young adults. Dentistry Today. 2021;40(4).
4. Theobald A, Wong B, Quick A, Thomson M. The impact of the popular media on cosmetic dentistry. N Z Dent J. 2006;102(3):58-63.