International Journal of Computerized Dentistry, 02/2009

Purpose: In this in vitro study, all-ceramic inlays were subjected to a static strength test. The material used in this case was Vita Mark II® ceramic (Vita-Zahnfabrik, Bad Säckingen, Germany). The goal of the study was to evaluate two different inlay preparations with differently designed ceramic inlays resulting from it, to determine which offered the greatest possible resistance in static fracture loading tests. Materials and Methods: Tooth 36 on the model, provided with a standard preparation with a level floor, served as the test object. Two inserts were produced: one with classical preparation pattern, the other with a modified shape of the cavity floor. In one inlay design, the cavity floor was designed according to the guidelines valid for all-ceramic inlay restorations; in the second inlay design, a differently shaped cavity floor was selected to exclusively meet the requirements of the ceramic material. Impressions were then taken, and inlays were designed and produced by means of CAD/CAM technology. Results: Lower fracture strength with mean fracture load values of ca 66.6 N was shown for traditional inlay preparations with a cavity floor segment designed as box. The mean fracture strength of the inlay design consisting of the same material with a hemispherical cavity floor segment was 84.9 (N), 27.5% greater. Conclusion: The question arises whether it is possible, independently of the ceramic used, to achieve an increase in strength by modifying the design of the inlay. Parole chiave: preparation design, FE analysis, inlay design

For the diagnosis of bone pathology, planning of complex implant-supported prosthetic restorations, and guaranteeing oral surgery that is as safe and free of complications as possible, a three-dimensional radiological display is frequently indicated. Cone beam computed tomography (CBCT), which can cover a large part of the indications of the dental and oral surgical spectrum, represents an alternative to computed tomography. Moreover, the method offers the advantage that it can also be used in the dental practice, taking the existing radiation protection regulations into account. This guarantees optimum patient and user friendliness, because referral to a specialized CT facility is thus no longer necessary in most cases. In the first 12 months of the trials of the Planmeca Promax 3D® at the Department of Dental Surgery and Radiology of the University Clinic for Oral and Maxillofacial Medicine in Graz, the overwhelming majority of referrals for CBCT (almost 90%) was concerned with the field of oral surgery and implantology. Oral surgical questions mainly covered aspects of wisdom tooth anatomy, position of impacted canines, premolars, and mesiodents, as well as cystic lesions. Diagnoses of the maxillary sinuses and the area of tooth preservation represented further indications. Apart from diagnostic purposes, the objective of the referrals was facilitating optimum preparation for the pending operation. In the area of implantology, this was combined frequently with pre- or post-augmentative three-dimensional digital therapy planning. CBCT showed good results in the display of hard tissue structures and can be integrated without difficulty in the daily clinical routine. Parole chiave: CBCT, CT, oral surgery, oral radiology, computerized implant planning, 3-dimensional diagnostics.

L'evoluzione e lo sviluppo di nuove tecniche chirurgiche e protesiche aumentano l'interesse e la richiesta di impianti con carico immediato per i numerosi vantaggi clinici che offre questa modalità di trattamento. Ormai numerose osservazioni cliniche supportate da studi istologici indicano che impianti dentali inseriti in estrazioni fresche con successivo carico immediato esitano in un successo clinico.1 Le metodiche software assistite per la chirurgia protesicamente guidata, possono essere abbinate alle metodiche CAD-CAM per restauri in ceramica integrale nelle riabilitazioni di monoedentulie e pluriedentulie per carichi immediati predicibili e dall'alto valore estetico e funzionale. Gli obiettivi principali consistono nella riduzione dei tempi di trattamento, nel contrastare i processi di riassorbimento ossei post estrattivi, nel preservare le strutture peridontali residue. Le riabilitazioni protesiche su impanti sono ormai forme di trattamento dell'edentulismo parziale o totale molto diffuse, documentati con studi a lungo termine e indagini istologiche sul processo osteointegrativo.1-4 Sono stati proposti ed utilizzati numerosi protocolli con particolare riguardo al numero e distribuzione degli impianti in rapporto alle unità funzionali, rappresentate, nel progetto protesico, da una ceratura diagnostica ed al miglior rapporto assiale delle emergenze protesiche con il carico occlusale.12 La scelta degli impianti come forma e diametro adeguato per applicare un carico funzionale mmediato, deve ricadere su una struttura protesica provvisoria o definitiva, con tutte le potenzialità e caratteristiche atte alla gestione del carico occlusale, ed al condizionamento dei tessuti soffici. La stabilità primaria, la stabilità biologica, l'indice BIC (bone-implant contact), definiscono i parametri di base per l'osteointegrazione, in maniera del tutto analoga ai trattamenti ed ai processi di osteointegrazione ottenibili con impianti a carico differito.6-11 Ripristino dell'elemento dentario completo definitivo in monoedentulia in regione 3.5 13 in un'unica seduta ambulatoriale chair side, tramite il posizionamento di un'impianto conico a carico immediato, abutment in titanio zirconia e corona in ceramica feldspatica definitivi. Atto chirurgico contestuale al restauro coronale. Valutazione degli esiti clinici a distanza. Parole chiave: chirurgia protesicamente guidata, carico immediato, tecnologia CAD-CAM, ceramica integrale

In February 2008, the Lava™ Chairside Oral Scanner C.O.S. (Fig 1) was successfully launched by 3M ESPE (St Paul, MN, USA) in the United States. In German dental practices, the test phase started in October 2008. In Germany, the new intraoral scanner for direct digitization of teeth will be available in April 2009. The method of data capture of the Lava™ C.O.S. is based on the novel 3Din- Motion technology. This technology was developed by Brontes Technologies (Lexington, KY, US), which was founded by former employees of the Massachusetts Institute of Technology (MIT) and acquired by 3M in October 2006. First study results prove the reproducibly high precision of the Lava C.O.S.

Both pressing technology and CAD/CAM methods have proven themselves clinically for the fabrication of allceramic restorations. The advantages of the Cerec technology for the economic fabrication of all-ceramic bridges can be exploited by the use of burn-out blanks of polymer material. The milling process of very hard ceramics in the milling unit, which has some disadvantages, is replaced by the pressing process and makes the IPS e.max press material accessible to CAD/CAM users, primarily for extending the range of indications to splinted crowns and small all-ceramic bridges. Parole chiave: all-ceramic, CAD/CAM technology, pressing technique, lithium disilicate.