TY - JOUR
T1 - Monolithic CAD/CAM laminate veneers
T2 - Reliability and failure modes
AU - Romanini-Junior, José Carlos
AU - Hirata, Ronaldo
AU - Bonfante, Estevam A.
AU - Bordin, Dimorvan
AU - Kumagai, Rose Yakushijin
AU - Fardin, Vinicius P.
AU - Coelho, Paulo G.
AU - Reis, André F.
N1 - Publisher Copyright:
© 2020 The Academy of Dental Materials
PY - 2020/6
Y1 - 2020/6
N2 - Objectives: to evaluate the probability of survival and failure modes of lithium-disilicate, feldspathic-ceramic, and resin-nanoceramic anterior veneers cemented on dentin analog substrates after sliding-contact step-stress accelerated life testing (SSALT). Methods: A virtual incisor tooth preparation was produced with a reduction of 1.5 mm at the incisal edge and of 0.7 mm buccally. A .STL file of the preparation was generated and CAD/CAM based G10 dentin-analog material was used for testing. Laminate veneers were milled in three different materials: lithium-disilicate (LDS, E.max CAD), resin-nanoceramic (RN, Lava Ultimate), and feldspathic-ceramic (FELDS, Vita Blocks). SSALT was employed where a spherical indenter contacted the veneer, slided along its interface with G10 to lift off and start a new cycle at 2 Hz in water. Qualitative fractography was performed. The probability of survival (90% confidence-bounds) was calculated for several load/cycle missions. Results: The probability of survival for a mission of 50,000 cycles decreased from 50 up to 150 N equally for all groups and were not different between them. At 200 N, the probability of survival was significantly lower for FELDS (10%) compared to RN veneers (41%), whereas LDS presented intermediate values (22%). The characteristic strength of RN (247 N) was significantly higher than LDS (149 N), and FELDS (151 N). In FELDS and LDS, hackles, wake hackles and twist hackles indicated the direction of crack propagation. In RN, hackles were observed. Conclusions: Differences in probability of survival were observed only at 180 and 200 N between groups. Failure modes were similar with veneer fracture down to the tooth-analog substrate.
AB - Objectives: to evaluate the probability of survival and failure modes of lithium-disilicate, feldspathic-ceramic, and resin-nanoceramic anterior veneers cemented on dentin analog substrates after sliding-contact step-stress accelerated life testing (SSALT). Methods: A virtual incisor tooth preparation was produced with a reduction of 1.5 mm at the incisal edge and of 0.7 mm buccally. A .STL file of the preparation was generated and CAD/CAM based G10 dentin-analog material was used for testing. Laminate veneers were milled in three different materials: lithium-disilicate (LDS, E.max CAD), resin-nanoceramic (RN, Lava Ultimate), and feldspathic-ceramic (FELDS, Vita Blocks). SSALT was employed where a spherical indenter contacted the veneer, slided along its interface with G10 to lift off and start a new cycle at 2 Hz in water. Qualitative fractography was performed. The probability of survival (90% confidence-bounds) was calculated for several load/cycle missions. Results: The probability of survival for a mission of 50,000 cycles decreased from 50 up to 150 N equally for all groups and were not different between them. At 200 N, the probability of survival was significantly lower for FELDS (10%) compared to RN veneers (41%), whereas LDS presented intermediate values (22%). The characteristic strength of RN (247 N) was significantly higher than LDS (149 N), and FELDS (151 N). In FELDS and LDS, hackles, wake hackles and twist hackles indicated the direction of crack propagation. In RN, hackles were observed. Conclusions: Differences in probability of survival were observed only at 180 and 200 N between groups. Failure modes were similar with veneer fracture down to the tooth-analog substrate.
KW - Ceramics restorations
KW - Fatigue
KW - Mechanical test
KW - Porcelain veneer
KW - Resin restorations
KW - Tooth restorations
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U2 - 10.1016/j.dental.2020.03.004
DO - 10.1016/j.dental.2020.03.004
M3 - Article
C2 - 32359850
AN - SCOPUS:85083861211
SN - 0109-5641
VL - 36
SP - 724
EP - 732
JO - Dental Materials
JF - Dental Materials
IS - 6
ER -