International Journal of Computerized Dentistry, 01/2005

The goal of this study is to present a completely new procedure for automatic occlusal surface reconstruction and to test it in several inlay situations. The starting point is the mathematical analysis of a large number of occlusal surfaces from a tooth library. Learning algorithms used in pattern recognition and image processing were adapted for the special needs of dental morphology. A biogeneric tooth model resulted which can mathematically describeacertain type of tooth only with a few parameters. This model was tested on 40 simulated inlay situations and as an example on two clinical inlay situations. The results show that fully automatic reconstruction was possible except for four cases. In a majority of the cases, no further interactive improvements would have been necessary. Because of the general, theoretically wellfounded approach, fully automatic reconstruction of the occlusal surface can also be extended in the future to full crowns or reduced crown substructures (copings). Keywords: CAD, occlusal, occlusal surface reconstruction, biogeneric, tooth model, inlay, onlay

When previously using Cerec 3D, the occlusal surface could be designed according to morphologically functional aspects with the aid of a bite registration (static and/or dynamic). In addition, different tooth databases could be used for the design of crowns. However, the relevant design suggestion had then to be manually aligned onto the functional registration by the user. The new Cerec 3D software version R 2005 now promises the automatic adjustment of crown proposals in alignment with the corresponding functional registration. In this case, the crown design selected from the tooth databases is adjusted to the morphology of the functional registration and is thereforemodified until light contact points are still present. The procedure of the "selfadjusting crown" is demonstrated by reference to a clinical case. As the name "self-adjusting crown" indicates, this automatic tool is possible only in restorations which have a single-segment preparation margin (crowns). Keywords: crown, occlusal suface, software, FGP, CAD/CAM

Before the introduction of version R1800, only CORRELATION was available to the Cerec user for veneer design, and recourse had to be taken to the earlier Cerec 3 program for constructive veneer production. The software R1800 now alsomakes a tooth database available for veneers and allows copying and free insertion of any acquired tooth forms. With the R2005 version, the editing possibilities for designing veneers were further optimized; copying, mirroring and insertion of crowns were also facilitated. The situation-related selection of the CORRELATION designmethod, DENTAL DATABASE, and REPLICATION are described and assessed by reference to clinical situations. Keywords: CAD/CAM, veneer, Cerec chairside, Veneer Software

Anew device for digitizing model surfaces for dentalCAD/CAMapplications is available with the inEOS scanner. It works according to the principle of stripe light projection. Both rotational scan mode of single prepared teeth and overview scan mode in which a complete model of the jaw can be acquired are possible. Detailed scans can be taken in addition to improve the data quality. The software basis is the proven Cerec inLab 3D program. The virtually produced restorations can bemilled either with the inLab milling unit or transferred to the Infinident milling center for central production. A clinical case which was treated by using the inEOS scanner is presented. Keywords: CAD/CAM systems, surface digitization, full ceramics