ABSTRACT
This case report presents the treatment of a partially edentulous patient with a clasp-retained removable dental prosthesis (RDP) using both, digital and conventional workflows. Differences were demonstrated in impression taking, bite registration, manufacturing of models, prosthetic set-up, framework design and production; the technical steps for the finish of the RDPs were identical and (currently) still dependent on manual skills. The digitally 3D-printed framework were favored by the patient and the dentist due to the precise fit. The number of manual steps will be continuously reduced applying digital technologies for the treatment with RDPs, resulting in shortened clinical and technical work time and higher precision of the final prosthetic restoration. In addition, the use of intraoral scanners is more patient-friendly than classic impressions with elastomers. Technological advancements are required to eliminate today's limitations and enable a complete digital workflow, even without any physical models. Removable Dental Prosthesis 2.0: yes but not yet completely from A to Z.
Subject(s)
Denture, Partial, Removable , Mouth, Edentulous , Computer-Aided Design , Dental Impression Technique , Dental Prosthesis Design , Humans , WorkflowABSTRACT
BACKGROUND: The required pretreatment of CAD/CAM ceramic materials before resin composite cement application varies among studies. The aim of the present study was to evaluate the effect of hydrofluoric acid concentration and etching time on the shear bond strength (SBS) of two adhesive and two self-adhesive resin composite cements to different CAD/CAM ceramic materials. METHODS: SBS of two adhesive (Panavia V5, Kuraray, [PV5]; Vita Adiva F-Cem, Vita Zahnfabrik, [VAF]) and two self-adhesive (RelyX Unicem 2 Automix, 3 M Espe, [RUN]; Vita Adiva S-Cem, Vita, [VAS]) cements to four different CAD/CAM materials (Vitablocs Mark II, Vita, [VM]; Vita Enamic, Vita, [VE]; e.max CAD, Ivoclar Vivadent, [EC]; Vita Suprinity PC, Vita, [VS]) was measured. The effect of the surface pretreatment by using two different hydrofluoric acid products (HF5% Vita Ceramics Etch, Vita and HF9% buffered, Ultradent Porcelain Etch, Ultradent Products) were assessed at etching times of 0 s, 5 s, 15 s, 30s and 60s for each cement and restorative material combination (n = 10 per group, total n = 1440). RESULTS: Significant effects were found for the etching time and cement for all materials with highest shear bond strength for etching times of 60s = 30s = 15 s ≥ 5 s > 0 s and for RUN>PV5 = VAF > VAS (p < 0.05). Etching with HF5% for 5 s to 15 s resulted in higher SBS values, while no differences were observed between HF5% and HF9% buffered when the substrates were etched for 30s to 60s (p < 0.05). CONCLUSIONS: Within the limitations of this study the recommended surface pretreatment of silicate ceramics is HF etching with concentrations of 5% or 9% for 15 s to 60s to achieve highest shear bond strength while the glassy matrix is sufficiently dissolved. The tested resin composite cements can be applied with all tested materials and suggested for clinical application.
