NANO-ZR

Klinische Performanz von CAD/CAM-gefertigten Kronen und Brücken auf Gerüstbasis von Ce-TZP/Al2O3

15/11/2011 to 17/06/2016

More and more patients request an All-Ceramic Restoration due to its biocompatibility (no corrosion of metal ions) and aesthetic benefit (no metal margins at the gingiva). The great strides of Dental Technology are based on progress within computerization. Especially high-performance computers are affordable and construction-software is easy to handle, now. The manual veneering of the CAD-CAM manufactured frameworks have still to be done by dental technicians. The clinical goodness of Zirconia-based restorations is mostly affected by fractures of this veneering ceramic. Small fractures are called “chip-offs”. If present, the patient reports a roughness at the affected tooth-surface. But, these areas can be polished easily by the dentist. Bigger veneering fractures, which are accompanied with the loss of tooth’s anatomical shape, are observered rarely. Perhaps, a reparation or even renewal of the complete restoration is necessary. Such “big defects” stand mostly a chain of events with unpolished (i.e. not noticed by patient nor dentist) “chip-off”. By analyses it could be shown, that the veneering gets more and more chapped underneath a rough area. These cracks from within time through the ceramic (crack-propagation). That is why, chip-offs heighten the risk of veneering fracture, simultaneously. Therefore, every flaw signifies necessity for intervention by the dentist (polish, reparatory, renewal), independent from the size!
This debits the cost-benefit of the restoration compared to classical solutions (same veneering ceramic on metal frameworks). For insurances and dentists as well as patients an All-Ceramic restoration which is aesthetic and durable. Therefore it is only allowed to show very few flaws.
Answer to the question: “How often is a reconstruction affected by which flaws?” can only be told by continuous long-term follow-ups. A significant lower risk of complication is promised and reported for NANOZR-based reconstructions within the current literature.
The planed treatment and follow-up shall generate a cohort which is comparable to former ones in literature. Cohorts with comparable All-Ceramic-restorations and similar evaluation methods will be benchmark to the findings of this study.
Furthermore it will be set in comparison with conventional metal-based crowns and fixed-partial-dentures.
The follow-up examination within the study is a scientifically based routine dental check-up. Systematically data will be compiled about changes or adverse events at restorations, teeth or soft-tissues. Therefore findings of a visual check are documented in this study. This kind of investigation and evaluation is done at our department for years; regularly especially for All-Ceramic restoration in kinds of quality assurance. Thus, investigators are trained and experienced. Dental- and Hygiene-status are part of the regular dental check-up. These thorough examinations can only be offered to patients with All-Ceramic Restorations (Quality assurance).
Leading indicator is the quality evaluation by means of modified “CDA-Ratings” (scale of point values by the Californian Dental Association), beside routine findings.
Flaws (i.e. cracks, fractures) are gathered in the course of this evaluation. Decisive is for the most, documentation of non-occurrence of such complications.