6-8 After five years, the survival probability was 95% and after seven years, the Kaplan-Meier curve dropped to 91.6%. Reiss and Walther published a series of papers between 19 on 1,011 CEREC restorations placed in 299 patients in a private practice that they monitored for up to 18 years. 5 The Kaplan- Meier survival probability was 97.4% at five years and 95.5% at nine years. 4 Posselt and Kerschbaum reported on 2,328 CEREC 1 and CEREC 2 inlays and onlays placed in 794 patients in one private practice. Otto and De Nisco reported a Kaplan-Meier survival probability of 90.4% after 10 years for 200 restorations placed in 108 patients in a Swiss private practice. 2,3 Similar to other porcelain restorations, porcelain fracture and tooth fracture are the two primary modes of failure for CEREC restorations. The primary function of the Milling Chamber is to mill the designed restoration from blanks of ceramic or composite restorative material as directed by the CEREC 3D program on the Acquisition Unit.Ī significant number of clinical studies have been published on CEREC restorations over the past 20 years. It consists of two milling arms containing diamond instruments as well as a water reservoir for irrigation of the diamonds during the milling process. The second piece of hardare is the Milling Chamber. The primary functions of the Acquisition Unit are to optically record a digital image of the cavity preparation to the computer and design the restoration with the CEREC 3D software program. The Acquisition Unit consists of an intraoral camera, computer, color LCD monitor, keyboard, and trackball assembled in a mobile unit. The CEREC 3 System is designed for dental operatory use and consists of two separate hardware pieces. Since then, the system has evolved through a series of hardware and software upgrades to expand the restorative capabilities of the CEREC 3 system to include posterior inlays, onlays, and crowns, as well as anterior crowns and veneers.
1 The initial CEREC 1 unit was used to deliver a ceramic inlay for the first time in 1985. The CEREC System was initially developed in the early 1980s specifically to deliver ceramic restorations by a dentist during a single appointment. The CEREC System (Sirona Dental Systems) is one such digital system that applies CAD/CAM technology for restorative dentistry that has undergone a number of recent innovations. A number of digital systems have been introduced that offer dentists the opportunity to deliver restorative treatment without the need for impressions and stone casts. Computer Assisted Design/Computer Assisted Machining (CAD/CAM) is a technological innovation for dentistry that has significantly affected materials and processes in both the dental laboratory and clinic. Advances in technology continually challenge dentists to re-evaluate their current techniques for patient treatment.
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