TY - JOUR
T1 - Fracture strength of Zirconia and alumina ceramic crowns supported by implants
AU - Traini, Tonin
AU - Sorrentino, Robert
AU - Gherlone, Enric
AU - Perfetti, Federic
AU - Bollero, Patrizi
AU - Zarone, Ferdinand
PY - 2015/7/1
Y1 - 2015/7/1
N2 - Due to the brittleness and limited tensile strength of the veneering glass-ceramic materials, the methods that combine strong core material (as zirconia or alumina) are still under debate. The present study aims to evaluate the fracture strength and the mechanism of failure through fractographic analysis of single all-ceramic crowns supported by implants. Forty premolar cores were fabricated with CAD/ CAM technology using alumina (n = 20) and zirconia (n = 20). The specimens were veneered with glass-ceramic, cemented on titanium abutments, and subjected to loading test until fracture. SEM fractographic analysis was also performed. The fracture load was 1165 (6509) N for alumina and 1638 (6662) N for zirconia with a statistically significant difference between the two groups (P =0.026). Fractographic analysis of alumina-glass-ceramic crowns, showed the presence of catastrophic cracks through the entire thickness of the alumina core; for the zirconia-glass-ceramic crowns, the cracks involved mainly the thickness of the ceramic veneering layer. The sandblast procedure of the zirconia core influenced crack path deflection. Few samples (n = 3) showed limited microcracks of the zirconia core. Zirconia showed a significantly higher fracture strength value in implant-supported restorations, indicating the role played by the high resistant cores for premolar crowns.
AB - Due to the brittleness and limited tensile strength of the veneering glass-ceramic materials, the methods that combine strong core material (as zirconia or alumina) are still under debate. The present study aims to evaluate the fracture strength and the mechanism of failure through fractographic analysis of single all-ceramic crowns supported by implants. Forty premolar cores were fabricated with CAD/ CAM technology using alumina (n = 20) and zirconia (n = 20). The specimens were veneered with glass-ceramic, cemented on titanium abutments, and subjected to loading test until fracture. SEM fractographic analysis was also performed. The fracture load was 1165 (6509) N for alumina and 1638 (6662) N for zirconia with a statistically significant difference between the two groups (P =0.026). Fractographic analysis of alumina-glass-ceramic crowns, showed the presence of catastrophic cracks through the entire thickness of the alumina core; for the zirconia-glass-ceramic crowns, the cracks involved mainly the thickness of the ceramic veneering layer. The sandblast procedure of the zirconia core influenced crack path deflection. Few samples (n = 3) showed limited microcracks of the zirconia core. Zirconia showed a significantly higher fracture strength value in implant-supported restorations, indicating the role played by the high resistant cores for premolar crowns.
KW - Alumina
KW - Fracture
KW - Implant-Supported Prostheses
KW - Strength
KW - Zirconia
UR - http://www.scopus.com/inward/record.url?scp=84938596197&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84938596197&partnerID=8YFLogxK
U2 - 10.1563/AAID-JOI-D-13-00142
DO - 10.1563/AAID-JOI-D-13-00142
M3 - Article
C2 - 24779915
AN - SCOPUS:84938596197
VL - 41
SP - 352
EP - 359
JO - Journal of Oral Implantology
JF - Journal of Oral Implantology
SN - 0160-6972
ER -