International Journal of Computerized Dentistry, 02/2005

Computer graphics is here to stay and spreading. This article intends to be nothing more than a brief introduction of this new tool in the field of dentistry. We hope that our colleagues will welcome this new development and recognize it as an opportunity to make contact with the basic sciences. Parole chiave: crown preparation, vector graphics, parametric polynomial, interpolation, approximation, C2- continuity

L'insegnamento delle abilità e competenzemanuali è fra gli aspetti che richiedono maggior tempo nell'educazione della salute orale, specialmente quando sono coinvolti gruppi di numerosi studenti. I video sono stati ripetutamente usati come strumenti di educazione, con risultati variabili. Il presente studio aveva lo scopo di valutare l'efficacia di un supporto video basato sull'uso del computer durante il training pratico per l'acquisizione delle abilità manuali e competenze relative al trattamento parodontale. 84 studenti sono stati randomizzati in 9 gruppi: 5 sperimentali e 4 di controllo. I gruppi di controllo hanno ricevuto istruzioni sull'uso degli strumenti per scaling e root planing durante un seminario di 7 ore; inoltre hanno ricevuto 2 ore di pratica manuale. I gruppi sperimentali hanno ricevuto le stesse istruzioni teoriche ma, inoltre, hanno avuto accesso durante le prove pratiche ad un sistema di supporto basato sull'uso del computer, il Visual Training System (VTS). Durante le due ore di pratica, tutti gli studenti si sono esercitati su 21 differenti procedure. Lo svolgimento di questa pratica è stato video registrato e successivamente i video sono stati valutati da un osservatore indipendente. Nel complesso, gli studenti del gruppo sperimentale hanno eseguito le procedure significativamente meglio dei colleghi del gruppo di controllo. Specificamente, i gruppi che hanno utilizzato il video supporto VTS, hanno mostrato una migliore e significativa esecuzione di 9 delle 21 procedure testate. Questi risultati suggeriscono che questo supporto video basato sull'uso di un computer può essere un efficace ausilio nell'insegnamento delle abilità manuali correlate alla salute orale.

In the 1990s, there was great optimism due to the development of devices for measuring tooth shade. The frequently not so simple, visual determination of the shade of a tooth was to be done with the aid of a device which recognizes the shade and describes it accurately by reference to a color chart. However, the skepticism towards such devices was also great. It is known that the color effect frequently differs strongly when comparing a tooth from the shade guide with a metal ceramic crown, despite identical shade designation. Anyone who considers visual shade determination to be inadequate and places his hopes in digital shade matching devices will be disappointed. It is the shade-generating structures of the metal ceramic and frequently of the veneer layers that turn out to be too thin which, despite correct shade selection, cause a different color perception. Such problems have been reduced decisively with the development of fracture- proof hard porcelain caps (Vita In- Ceram) with optical characteristics similar to teeth. In addition, the Vita System 3D-Master tooth shade system developed in 1998 by Vita in cooperation with Dr. Hall from Australia, leads the practitioner to a better understanding of the primary tooth shade characteristics of "brightness (value)", "color intensity (chroma)" and "color (wave length of the visible light, hue)". These two innovations allow a more accurate estimate of the basic shade of a natural tooth (reference tooth) and the imitation in the laboratory of its natural, shade-generating structures. If digital shade measurement supplements the visual shade estimate, then a further improvement can be expected - especially in the recognition of the basic shade. Qualitative descriptions of subjective shade measurement of a natural tooth and of its imitation in the dental laboratory by ceramics can be found frequently in professional journals and publications. With digital tooth shade matching devices, which apart from the color code of the color chart also reproduce exact, colorimetric values, such work processes can be recorded quantitatively and objectively. Reports about this type of controlled shade determination and generation are found rarely in the literature, which is surprising in view of the large number of tooth shade matching devices and dental ceramic systems available. In the present paper, the influence of the individual ceramic layers on color perception is measured and described under standardized conditions. The creation of the basic shade as it results from the composition of the various ceramic layers is traced with a spectrophotometer. The Vita In-Ceram Alumina infiltration ceramic and the VitaVM7 veneer ceramic were selected as the ceramic system. MHTSpectroShade and Vita Easyshade were used as shade matching devices. Parole chiave: In-Ceram, all-ceramic, veneering ceramic, Vita VM7, tooth shades, digital color measurement

It is necessary for orthodontists to collect and analyze the patients' photographic data. By conventional methods, these photo data were commonly saved on film, which were frail and often resulted in data loss. Furthermore, it is not convenient for the orthodontists to consult and study these data during clinical research. A critical problem thus arises in managing these photo data scientifically. The computer technique and picture processing method were employed in the present study to establish the Photo Management System for Orthodontics (PMSO), which makes the administration of patients' photo data more scientific, convenient, and effective than before. This system is characterized as follows: 1. Clinical orthodontists designed and programmed the system, which is "close to clinical reality and serves the clinic". Orthodontists can easily use it without any training course. 2. The images can be imported from many devices, such as digital cameras, scanners, and electronic data storage media such as floppy disks. 3. Even two groups of photos (four images) could be displayed in the same window for comparison and study. This function allows orthodontists to easily observe the differences in the same patient's photos at different stages, which is important to obtain comprehensive knowledge of the patient. 4. The network technique makes it possible for the photos to be shared. The orthodontists can get the patients' photos through the network without going to the radiology department or the imaging room. 5. It is helpful for orthodontic research since the photos can be exported easily in different ways. 6. This is shared software; orthodontists can use it for free. Parole chiave: orthodontics, photo management, image processing, photo grouping, clinical application

An innovative extension of performance in the area of single crown production is presented. Prefabricated crown blanks with color layering are inserted in the row of teeth with specially developed software and adapted apically to the stump with a CAM milling program. Parole chiave: prefabricated crown blanks, semi-finished product, CAD/CAM crown, plastic jacket crown, layering-induced esthetic effect, Cerec, inLab