CEREC-Can You Afford Not to Have One?

 

During the last few years, dentistry has become part of a beauty-enhancing industry, and the timing could not have been planned any better. The dental industry has created numerous technological ad­vancements in dental materials and techniques which assisted the dental professionals by providing better services satisfying patients in terms of function, as well as esthetics. In fact, the ever-growing segment of adults has resulted in a larger pool of well-informed patients who have more disposable income, are more health conscious. On the other hand, the negative impact of "unfair" or "not covered service" insurance reimbursement has also put tremendous pressure on a practice to stay in business.

 

Societal changes, together with the insurance industry policy, have definitely instigated changes in the way we view and practice dentistry. On one side of the fence, some will continue to sit back and practice traditional dentistry. On the other side, others will rush to invest more in training, equipment, and office upgrades. These actions have given rise to the disparity between perceived "low-tech" and "high-tech" dental practices which can be misleading in terms of quality of dental care. Low tech does not necessarily mean "low quality" and high tech does not guarantee "high quality." Nonethe­less, we all should realize that the consumers will most likely equate high quality service with an office that has beautiful décor, high-tech equipment, and an ex­tremely professional staff.

 

With this article, I will attempt to explain how to increase your business, practice better dentistry, and become more accepting to new technology. One piece of new technology that has changed the face of dentistry is the computer-aided de­sign/computer-aided machining (CAD/CAM) system. One of those CAD/CAM systems that turned my practice around is the CEREC (Sirona Dental System). This article will also attempt to show you how to get over the "sticker shock" of the CEREC system and how to turn it into a cost-effective tool, how to profit from it, and use it to create not just a high-tech image with the public, but also high-quality ceramic restorations.

 

Economic Overview
Although costly, the purchase of a CEREC system is alleviated by a significant immediate tax write-off of $100,000 allowed by Section 179. The best way to look at a CEREC is to consider it as an in-house laboratory technician with a salary ($1,900 a month). That means no vacation or sick days, and will work for free after 5 years. Table 1 demonstrates how CEREC can help lower overhead expenses.

 

 

This extra bottom line can be used for your retirement investments and other things. Another benefit to the CEREC system is the elimination of a second visit for cementation. This second visit will not only save you money on chair-time (H = at least $150) assuming 30 minutes allowed for cementation. Therefore, an additional monthly benefit could amount to $4,800 (I = H x B), annualizing $57,600 (J = I x 12). In total, a CEREC system can potentially help you save and generate $103,920 (K = G + J) extra income a year. When the machine is paid off in 5 years, you will also decrease your overhead by $22,800 a year (L = E x 12) (Table 2).

 

Please bear in mind that the above scenario assumes that the cost of CEREC blocks, powder, and milling chamber diamond burs are offset by the cost of impression materials, temporary materials, as well as shipping cost.1 However, a more tangible benefit to having a CEREC unit is consumer confidence, and the capability to deliver high-quality ceramic restorations.2 The high-tech factor never fails to impress a patient and you can bet that he/she will spread the word in the community. The time-saving factor (one appointment technique)3 is a great marketing edge to everyone from the busy business person to a homemaker. Another tangible benefit to having this state-of-the-art technology in a dental office is the boost in both dentist's and the staff's self-image and confidence as a result of positive patient and community image. In addition, I would like to point out the fact that a CEREC provider tends to do less fillings (less profit: $150 vs $800) and more CEREC restorations. More restorations, however, does not mean more crowns. As a matter of fact, ever since I have had a CEREC system (started with CEREC II in 1998), I have been doing less crown buildups and full crowns, but more inlays and onlays, thus practicing more conservative dentistry.

 

Benefits of CEREC Restorations
The benefits of the CEREC sys­tem are:

 

- One appointment visit is a big plus to patients who have a very busy schedule

- Less trauma to the pulp because of the absence of a second visit

- Less trauma to the gingiva and papillae from the absence of an im­pression ste

- Very good ceramic anatomy because this systems' technology can produce a complete range of intracoronal and extracoronal restorations4,5

- This system is capable of generating occlusal pits and fissures of onlays; the contour of ve­neers as well as the outlined form of full-coverage restorations

- The machinable ceramics have a coefficient of thermal expansion that is similar to that of a natural tooth thus minimizing stress on the tooth during thermal changes4

- The ability to deliver high quality restorations5

- Final seating of restorations the same day totally eliminates the fracture risk that could take place with provisional restorations6

- One visit will not only benefit a patient's busy schedule, but also the staff because patients do not have to return and get anesthetized again for the delivery of the final restoration

- No laboratory fee and potential risk of returning restoration to laboratory for shade/marginal fit correction because the CEREC system allows custom shading and marginal fit in the same visit

- With the availability of numerous porcelain blocks and constantly upgraded software, the CEREC system can now provide restorations with strength, durability, wear resistance, and esthetic results comparable to laboratory-fabricated restorations7

 

Disadvantages of CEREC
The disadvantages of the CEREC system are:

 

- Units are expensive

- Learning curve

- Maintenance and future up­grade cost

- Takes up valuable space in operatory

 

Esthetic Capability
Ever since the CEREC CAD/ CAM system was first available in the United States in 1985, tremendous ad­vance­ments have been made in porcelain block materials, bonding material and technique, staining material and technique, hardware and software design, etc. With today's powerful CEREC 3D and the availability of multiple lines of porcelain blocks with extensive shade selections as well as chroma, value, and degree of translucency choices from different manufacturers such as Vident and Ivoclar Vivadent, Inc, highly esthetic single-visit CAD/CAM restorations can be achieved. Indeed, the CEREC restoration should no longer be considered as inferior to a laboratory-fabricated one. Strength, durability, wear, and now, excellent esthetics are all combined in a single system that enables clinicians to provide laboratory-quality restorations in a single-patient visit.⁷

 

Case Presentation

Case No. 1
The patient presented with a defective occlusal amalgam restoration with recurrent decay in tooth No. 30 (Figure 1A). An examination with an explorer revealed open margins and a radiograph showed a large radiolucent area under the amalgam that suggested recurrent decay. Pulp testing was performed and normal response was elicited. Because of the potential unsupported disto-lingual cusp, a CEREC onlay restoration was decided on.

 

The amalgam was then re­moved, all apparent decay was cleaned out, and a caries-detecting chemical was used to confirm complete caries excavation. Just as anticipated, the disto-lingual cusp was severely undermined, and was in­corporated into the preparation. The deep area of the preparation was lined with a layer of Vitrebond (3M ESPE) glass ionomer liner (Figure 1B). Taking into consideration the apparent high translucency of the patient's tooth, a Procad (Ivoclar Vivadent, Inc) esthetic porcelain block was chosen. Following Cerec system protocol, the onlay was designed and fabricated chairside within 20 minutes. After verifying the accuracy and fit, the onlay was then cleaned and etched with hydrofluoric acid (Porcelain Etch, Ultradent Pro­ducts, Inc) for 2 minutes, rinsed, dried, and then painted with a coat of Silane Primer (Kerr Corporation (Figure 1C). The preparation was then cleaned with Tubulicid Red (Global Dental) and etched with 37.5% phosphoric acid (Gel Etchant, Kerr Corporation) for 15 seconds (Figure 1D). A single component adhesive (Optibond Solo Plus, Kerr Corporation) was then applied to the preparation and the internal surface of the ceramic onlay. The onlay was then cemented with luting resin Vitique (Zenith/DMG). After excess ce­ment was removed, the occlusion was checked and adjusted. The adjusted area was then repolished, the onlay margins were reetched with 37.5% phosphoric acid, and adhesive was reapplied to the marginal area, and light-cured again for 40 seconds (Figure 1E). Occlusal pit and grooves stain was not put on the onlay because it would take more valuable clinician's and pa­tient's time, and I have yet to find a patient asking for "dark" occlusal stain on their brand new-high tech porcelain restoration.

 

Case No. 2
The case involved a defective and fractured amalgam on tooth No. 18. The patient's primary complaint was sensitivity when drinking cold beverages. A radiograph showed recurrent decay close to the pulp, but not into it. The tooth responded normally to pulp testing, therefore, a Cerec onlay was recommended to restore the tooth back into function (Figure 2A). After removing the amalgam res­toration, all decay was removed and checked with a caries detector. The deep area of the preparation was lined with a layer of Vitrebond glass ionomer liner, and the preparation was ready for Cerec imaging, onlay design, and milling (Figure 2B). When the onlay was fabricated with a Procad porcelain block, it was tried for fit and accuracy. The onlay was cleaned and etched with hydrofluoric acid (Porcelain Etch) for 2 minutes, rinsed and dried, and silanated with Silane Primer (Figure 2C). The preparation was cleaned with Tubilicid Red and etched with 37.5% phosphoric acid (Gel Etchant) for 15 seconds. After that, an adhesive, (Optibond Solo Plus) was applied onto the preparation and the internal surface of the onlay. The onlay was luted with Vitique luting resin and excess resin was removed. After removing the rubber dam, the occlusion was checked and adjusted. The area was isolated with cotton rolls, the margins were re-etched with 37.5% phosphoric acid for 15 seconds, and a coat of adhesive was reapplied and light-cured for 40 seconds (Figure 2D). Once again, no oc­clusal stain was attempted because there was no good reason to do so.

 

Conclusion
I believe that economic reality will either induce more frustrations and unhappiness in a dental practice, or serve as a driving force to many of us in the profession to reevaluate ourselves, both personally and professionally. When we are able to recognize and isolate the negative factors, we can then look for solutions to better ourselves. I fully believe and have seen that a CEREC system, properly used and marketed, will ultimately result in greater patient satisfaction, more referrals, increased bottom line, better office atmosphere and image, more esthetic case acceptance, additional income for the practice, income to supplement dentist's and staff's continuing education, and, ultimately, more time for family and to enjoy life.

 

 

References
1. Hehn S. The evolution of a chair CAD/CAM system for dental restorations. Compend Contin Educ Dent. 2001;22(6 suppl):4-6.

 

2. Sturdevant JR, Bayne SC, Heymann HO. Margin gap size of ceramic inlays using second-generation CAD/CAM equipment. J Esthet Dent. 1999;11(4): 206-214.

 

3. Morin M. CEREC: the power of technology. Compend Contin Educ Dent. 2001;22(6 suppl): 27-29.

 

4. Jedynakiewicz NM, Martin N. CEREC: science, research, and clinical application. Compend Contin Educ Dent. 2001;22(6 suppl):7-13.

 

5. Sato K, Matsumura H, Atsuta M. Relation between cavity design and marginal adaptation in machine-milled ceramic restorative system. J Oral Rehabil. 2002;29(2):24-27.

 

6. Mehl A, Kunzelmann KH, Folwaczny M, et al. Stabilization effects of CAD/CAM ceramic restorations in extended MOD cavities. J Adhes Dent. 2004;6(3):239-245.

 

7. Masek RT. Achieving high-level esthetics with CEREC. Compend Contin Educ Dent. 2001; 22(6 suppl):19-26.

 

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