IADR Abstract Archives
Ten-year Clinical Outcome of Posterior Metal-ceramic Crowns Fabricated With Laser-sintering Technology
Objectives: To evaluate the long-term clinical outcome of posterior metal-ceramic crowns fabricated with CAD/CAM-based laser-sintering technology (BEGO Medical, Bremen, Germany).
Methods: Sixty crowns, restoring 16 premolars and 44 molars, were placed in 39 patients between 2004 and 2006. After tooth preparation, impression taking and model casting, the stone dies were scanned to create STL data. Software (Softshape, BEGO Medical) was used to construct digitally the metal frameworks, followed by manufacturing of copings with laser-sintering technology, in which an ytterbium-fiber laser beam directly fuses a 20 micron layer of metal powder (BEGO Medifacturing, BEGO Medical). A base metal alloy (CoCr) and a precious alloy (AuPt) were used in this study with 30 restorations each. All frameworks were veneered with feldspar ceramic (IPS d.Sign, Ivoclar-Vivadent), and cemented with glass-ionomer cement (Ketac Cem, 3M Espe). Patients were recalled after 6-12 months and then annually.
Results: Six patients with 10 crowns were regarded as dropouts, because they did not attend the recall program for more than 24 months. The mean observation time was 90.3 ± 32.9 months. The 10-year cumulative survival rate using the Kaplan-Meier method was 85.6% and 91.7 % for AuPt group and CoCr group, respectively. The overall 10-year survival rate for all crowns was 87.5%. Two abutment teeth had to be extracted; one due to endodontic complication and the other one due to a deep caries. Another two crowns were removed because of new treatment plan. Secondary caries were reported in 2 patients with 3 crowns, while one abutment tooth had to be endodontically treated. Nevertheless, the latter complications did not affect the clinical function of the involved crowns. No technical complications such as chipping of the veneering ceramic were detected in the current study.
Conclusions: The long-term clinical outcome of posterior metal-ceramic crowns fabricated with CAD/CAM-based laser-sintering technology after 10 years is very promising, so that this novel technique could replace the traditional lost wax casting process.
Methods: Sixty crowns, restoring 16 premolars and 44 molars, were placed in 39 patients between 2004 and 2006. After tooth preparation, impression taking and model casting, the stone dies were scanned to create STL data. Software (Softshape, BEGO Medical) was used to construct digitally the metal frameworks, followed by manufacturing of copings with laser-sintering technology, in which an ytterbium-fiber laser beam directly fuses a 20 micron layer of metal powder (BEGO Medifacturing, BEGO Medical). A base metal alloy (CoCr) and a precious alloy (AuPt) were used in this study with 30 restorations each. All frameworks were veneered with feldspar ceramic (IPS d.Sign, Ivoclar-Vivadent), and cemented with glass-ionomer cement (Ketac Cem, 3M Espe). Patients were recalled after 6-12 months and then annually.
Results: Six patients with 10 crowns were regarded as dropouts, because they did not attend the recall program for more than 24 months. The mean observation time was 90.3 ± 32.9 months. The 10-year cumulative survival rate using the Kaplan-Meier method was 85.6% and 91.7 % for AuPt group and CoCr group, respectively. The overall 10-year survival rate for all crowns was 87.5%. Two abutment teeth had to be extracted; one due to endodontic complication and the other one due to a deep caries. Another two crowns were removed because of new treatment plan. Secondary caries were reported in 2 patients with 3 crowns, while one abutment tooth had to be endodontically treated. Nevertheless, the latter complications did not affect the clinical function of the involved crowns. No technical complications such as chipping of the veneering ceramic were detected in the current study.
Conclusions: The long-term clinical outcome of posterior metal-ceramic crowns fabricated with CAD/CAM-based laser-sintering technology after 10 years is very promising, so that this novel technique could replace the traditional lost wax casting process.