Simplifying the single central

My father has been practicing dentistry for more than 35 years. He told me back in the “old days,” many lecturers would shy away from doing a single central incisor and just do both teeth. Considering how common the single central circumstance is, it appears that the technician who masters the task will be in great demand.

Modern technology with higher quality materials, digital photography and better shade options enable the technician to create single central restorations that melt into the environment.

Unlike doing two or more teeth, where the dentist and technician have the freedom of altering contours and shades to the patient’s desire, when doing a single central the task is one of working within the limitations and restraints of the existing dentition. A technician who welcomes limitations and restraints gets the chance to exercise his or her true creative ability, and use his or her knowledge of color, form, texture and digital photography.

Case presentation

01 The first task in this type of case is to obtain a clean, clear image of the tooth in the surrounding environment. The criteria for this image is proper focus, a wide depth of field and proper image size (Fig. A). This image becomes the foundation for the information needed.

02 We enter the image into any photo-editing software program. The software will provide us with the ability to view a value image, a saturated image for color and an inverted image for form (Fig. B). Video extra: See the video below for a demonstration of how to create the different images using Adobe Photoshop.

03 Another important image is a shot of the natural abutment shade, which is key when selecting the proper material for the restoration (Fig. C).

04 These images help the technician to evaluate the ceramic selection based on the shade tabs fired in their personal calibrated furnace (Fig. D).

05 With the photographic information to provide the necessary details, the first bake can be achieved, layering in the details using the GC Initial Zr Ceramic System from GC America (Fig. E).

The technician should limit the number of firing cycles to limit the loss of color that occurs when excessive grinding is required after each bake.

06 The technician also has to layer the ceramic in its exact place to replicate the colors from wet ceramic to fired ceramic (Fig. F).

07 After the first firing cycle the restoration should exhibit the depth and color we need (Fig. G).

08 Once the contacts are adjusted, the technician can now begin the detail work of creating proper form. Colored pencils are a great tool to help guide the technician in the right direction of contour and surface treatment (Fig. H).

09 When finalizing the form and surface treatment it is important to check the restoration from every angle so as not to miss any details (Fig. I).

10 Once every angle is checked and the first bake and contouring is complete, we can glaze the restoration and add some minor details. It is these details that help differentiate a great restoration from a mediocre one. Some of the details include a halo, and line angle adjustments.

We accomplish this by mixing a low fusing ceramic to our layered ceramic with a 60/40 mix (Fig. J).

11 Once glazed and polished we can go to the mouth for our try-in, hoping the steps we took yielded an accurate restoration (Fig. K).

12 To check our work we can convert an intraoral image of our restoration to black and white to confirm value (Fig. L).

With accurate form, value and surface texture the single central becomes less of a challenge. The goal of the single central is to blend harmoniously into an existing site and not to overpower the surrounding dentition (Figs. M - O).

Conclusion

It is through working within the restraints and limitations of the existing site that the technician can exhibit maximum creativity when completing this rather common occurrence in dental practice. 

Dentistry by Dr. Harry Monokian

About the author

Joshua Polansky earned his Bachelor of Arts degree, Summa Cum Laude, from Rutgers University in 2004. While working part- time at a dental laboratory, he took advantage of an opportunity to apprentice with distinguished master technician, Olivier Tric of Oral Design Chicago. Mr. Tric opened Joshua’s eyes to a whole new world of possibilities. He made the decision to become a master dental technician following the path that Tric had forged. He continued to acquire technical skills by studying in Europe with other mentors and experts in the field such as Klaus Mutertheis. Joshua earned his Masters degree in dental ceramics at the UCLA Center for Esthetic Dentistry under Dr. Edward Mclaren. Joshua Continued his training under Jungo Endo and Hiroaki Okabe at UCLA’s advanced prosthodontics and maxillofacial program working on faculty and residents cases. Joshua currently resides in Cherry Hill, NJ where he is the owner and operator of Niche Dental Studio.