CAD/CAM vs CAM for precision fit frameworks
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CAM (computer-aided manufacturing) and CAD (computer-aided design)/CAM systems facilitate the use of zirconia substructure materials for all-ceramic fixed partial dentures. An in vitro study, led by Dr Florian Beuer from the Department of Prosthodontics at Ludwig-Maximillians University in Munich, Germany, compared the precision of fit of frameworks milled from semi-sintered zirconia blocks that were designed and machined with two CAD/CAM and one CAM system. Results showed that CAD/CAM systems were more precise than the CAM system. Dr Beuer told Dental Learning Hub more about the study.
Question: Briefly explain the background of your study – have similar studies been conducted elsewhere?
Florian Beuer: Zirconia-based restorations have become very popular in fixed prosthodontics. However, a 5-year study has shown there is evidence that imprecise substructures have cause problems which lead to the removal of many restorations. Other studies have been published on the clinical marginal and internal fit of three-unit zirconia-based fixed dental prostheses (Reich et al. Eur J Oral Sci 2005) and the in vitro fit of posterior fixed dental prostheses frameworks (Bindl et al. Int J Periodontics Restorative Dent 2007).
Question: What factors contributed to the CAD/CAM systems to be more precise than the CAM system?
Florian Beuer: There are two main factors to consider in the fit of restorations produced by the CAM system: The skill of the technician and the accuracy of the scanning process. These two parameters are difficult to standardize and hard to improve.
Question: What trends do you expect to see in the future development of CAD/CAM systems?
Florian Beuer: The next developments will be an intraoral scanning unit that enables the dentist to obtain the data. There will be also improvement and automatization of the veneering process (see Beuer et al. Dent Mater 2008). In 5 to 10 years we can expect alternative fabrication processes, because milling is rather inefficient and wastes material.
Question: Will you conduct further research on this?
Florian Beuer: I am conducting research about alternative fabrications technologies for zirconia restorations. Another area of interest is the simplifying prosthodontic work. We are currently testing the in vitro behaviour of full-contour zirconia crowns
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‘Marginal and internal fits of fixed dental prostheses zirconia retainers’ Dental Materials
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CAM (computer-aided manufacturing) and CAD (computer-aided design)/CAM systems facilitate the use of zirconia substructure materials for all-ceramic fixed partial dentures. An in vitro study, led by Dr Florian Beuer from the Department of Prosthodontics at Ludwig-Maximillians University in Munich, Germany, compared the precision of fit of frameworks milled from semi-sintered zirconia blocks that were designed and machined with two CAD/CAM and one CAM system. Results showed that CAD/CAM systems were more precise than the CAM system. Dr Beuer told Dental Learning Hub more about the study.
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