Fabrication of complete dentures (CDs) utilizing computer-aided design and computer-aided manufacturing (CAD/CAM) methods has attracted a lot of attention. The purpose of this paper was to summarize current knowledge about digital CDs and the relevant technology, and to present the application of the new technology in a dental geriatrics case. Initially, some of the challenges regarding digitization of the oral mucosa as a supporting surface of the CDs’ intaglio surface are listed. Next, a brief introduction of the CAD software capabilities regarding CDs is presented. The latest CAM additive and subtractive techniques for CDs are following. Subsequently, the consecutive steps for the construction of a digital CD as part of the prosthodontic treatment of a 90-year-old ambulative female patient are presented. Finally, some considerations about the digital workflow in CD manufacturing are discussed. In conclusion, the new digital technology has clear advantages; however, implementation requires careful planning. The digital workflow is applicable and versatile.

One of the key arguments in favor of digitally produced complete dentures (CDs) is the requirement for less patient visits in comparison to the conventional workflow. However, it is not yet clear if this argument is accurate; nor, if indeed the insertion of the complete dentures is achieved in fewer appointments, how many are required. The purpose of this literature review was to investigate the reported number of required patient visits for the production of digitally fabricated CDs. An electronic search was performed in PubMed/MEDLINE using three groups of keywords: “complete dentures”, “CAD/CAM”, and “Appointments” with their alternative forms. Out of the initial 157 results, 36 articles were automatically selected utilizing exclusion keywords. After consensus between the two examiners, eight articles were finally analyzed and presented in a table. The majority (75%) of the reports came from institutions, and the average number of appointments up to complete denture insertion was 4.1, not always including try-in dentures. In this study, it can be concluded that, with a digital workflow, the insertion appointment is reached in fewer visits than the conventional five-visit procedure which is commonly taught in dental schools.

Introduction The production procedures, including impressions, introduce errors affecting the passivity of fit. A completely digital workflow is possible nowadays because of the intraoral scanners (IOS). This study aimed to evaluate the effect of the impression technique (conventional versus digital) and the screw tightening sequence on the marginal discrepancy (MD) of implant-supported bars. Methodology This laboratory study was conducted on a simulated Kennedy class II edentulous maxilla with three parallel implants in the edentulous quartile. The closed tray technique with a-silicon (CTM) and the intraoral scanning with the I-Tero™ system (IOS) were compared and three bars were manufactured from each technique. Depending on the screw tightening sequence (A11 and A17) 4 groups were created with 6 samples each. The MD was examined implementing 24 negative replicas, which were sectioned and studied under a stereomicroscope. The Horizontal Discrepancy (BHD), Vertical Discrepancy (BVD) and Conical Discrepancy (BCD) of the bar were calculated on the means of the measurements of the horizontal, the vertical and the conical MD respectively. The descriptive statistics, normality tests, one-way ANOVA (a=.05) and post-hoc Tukey’s tests were run and the graphs were draw with SPSS. Results There was a significant effect (P<.05) of the impression technique combined with the screw tightening sequence on all variables. The post-hoc Tukey’s tests revealed significant differences between all groups except from those of the same impression technique only for the BHD (P<.05). Conclusion In this study all groups resulted in marginal discrepancies. The closed tray impression technique gave better results.

Background The replica technique with its modifications (negative replica) has been used for the assessment of marginal fit (MF). However, identification of the boundaries between prosthesis, cement, and abutment is challenging. The recently developed Digital Image Analysis Sequence (DIAS) addresses this limitation. Although DIAS is applicable, its reliability has not yet been proven. The purpose of this study was to verify the DIAS as an acceptable method for the quantitative assessment of MF at cemented crowns, by conducting statistical tests of agreement between different examiners. Methods One hundred fifty-one implant-supported experimental crowns were cemented. Equal negative replicas were produced from the assemblies. Each replica was sectioned in six parts, which were photographed under an optical microscope. From the 906 standardized digital photomicrographs (0.65 μm/pixel), 130 were randomly selected for analysis. DIAS included tracing the profile of the crown and the abutment and marking the margin definition points before cementation. Next, the traced and marked outlines were superimposed on each digital image, highlighting the components’ boundaries and enabling MF measurements. One researcher ran the analysis twice and three others once, independently. Five groups of 130 measurements were formed. Intra- and interobserver reliability was evaluated with intraclass correlation coefficient (ICC). Agreement was estimated with the standard error of measurement (SEM), the smallest detectable change at the 95% confidence level (SDC95%), and the Bland and Altman method of limits of agreement (LoA). Results Measured MF ranged between 22.83 and 286.58 pixels. Both the intra- and interobserver reliability were excellent, ICC = 1 at 95% confidence level. The intra- and interobserver SEM and SDC95% were less than 1 and 3 pixels, respectively. The Bland–Altman analysis presented graphically high level of agreement between the mean measurement of the first observer and each of the three other observers’ measurements. Differences between observers were normally distributed. In all three cases, the mean difference was less than 1 pixel and within ± 3 pixels LoA laid at least 95% of differences. T tests of the differences did not reveal any fixed bias (P > .05, not significant). Conclusion The DIAS is an objective and reliable method able to detect and quantify MF at ranges observed in clinical practice.

Η επιφάνεια της εκτεθειμένης κονίας στο όριο της επιεμφυτευματικής αποκατάστασης είναι δύσκολα διαχειρίσιμη και αποτελεί επιβαρυντικό παράγοντα για τους περιεμφυτευματικούς ιστούς. Σκοπός της εργαστηριακής αυτής έρευνας είναι να εξετάσει ποσοτικά την επίδραση του συνδυασμού τριών παραγόντων στην επιφάνειας της εκτεθειμένης κονίας. Οι υπό μελέτη παράγοντες είναι το επίπεδο αρχικής εφαρμογής στο όριο της προσθετικής εργασίας (MD), ο τύπος της κονίας (CT) και η τεχνική απομάκρυνσης των περισσιών κονίας (FT).Αρχικά, με ένα πιλοτικό πείραμα αναπτύχθηκε η μέθοδος. Για την κυρίως μελέτη σχεδιάστηκε ένα 2^3 full factorial, πλήρως τυχαιοποιημένο πείραμα, με 15 επαναλήψεις. Χρησιμοποιήθηκαν 120 πανομοιότυπα δοκίμια. Κάθε δοκίμιο προετοιμάστηκε με τυποποιημένες διαδικασίες συνδυάζοντας τους τρεις παράγοντες (MD, CT, FT) δύο επιπέδων έκαστος. Από κάθε δοκίμιο κατασκευάστηκε αρνητικό αντίγραφο, που μετά από χρώση διατμήθηκε σε έξι τμήματα κάθετα ως προς το όριο της αποκατάστασης. Με ένα στερεομικροσκόπιο τα τμήματα φωτογραφήθηκαν ψηφιακά και οι φωτογραφίες επεξεργάστηκαν και αξιολογήθηκαν. Μετρήθηκε η μέση αναλογία της πραγματικής αύξησης του μήκους της κατατομής της επιφάνειας της κονίας σε σύγκριση με το ιδανικό μήκος της για το κάθε δοκίμιο (SaCPIR).Τα αποτελέσματα αποκάλυψαν σημαντικές διαφορές μεταξύ των οκτώ συνδυασμών που ελέγχθηκαν (n=14) (ANOVA, α=0,05). Δοκίμια και από τα δύο επίπεδα εφαρμογής, που είχαν συγκολληθεί με ρητινώδη κονία και η περίσσεια είχε αφαιρεθεί μετά την πήξη, είχαν χαμηλότερες τιμές SaCPIR (P<.05). Οι στατιστικές δοκιμασίες ανάλυσης παραγόντων έδειξαν ότι η μεταβλητή SaCPIR επηρεάζεται κυρίως από το αρχικό επίπεδο εφαρμογής (P<.0001) και από την τεχνική αφαίρεσης της περίσσειας (P<.0001). Συνεπώς, αυξημένα επίπεδα αρχικής διαφοράς στο όριο της αποκατάστασης, εντός των κλινικώς αποδεκτών τιμών, και αφαίρεση της περίσσειας μετά την πήξη με πλαστικό ξέστρο, οδήγησαν γενικώς σε χαμηλότερες τιμές SaCPIR. Επιπλέον, αποκαλύφθηκαν αλληλεπιδράσεις μεταξύ των παραγόντων (P<.05).Συμπερασματικά, η επιφάνεια της εκτεθειμένης κονίας σε στεφάνες με αποδεκτά όρια, που συγκολλήθηκαν με ρητινώδη κονία και οι περίσσειες αφαιρέθηκαν μετά την πήξη, διακυμάνθηκε πλησιέστερα στην ιδανικά συγκολλημένη αποκατάσταση. Επιπλέον, σε αυτή τη μελέτη αποσαφηνίστηκε η πολυπλοκότητα με την οποία αλληλεπιδρούν τρεις παράγοντες κατά τη διάρκεια της διαδικασίας συγκόλλησης και επηρεάζουν χαρακτηριστικά της εκτεθειμένης επιφάνειας κονίας στο όριο της αποκατάστασης.