Enhanced Bone Bonding to Nanotextured Implant Surfaces at a Short Healing Period : A Biomechanical Tensile Testing in the Rat Femur

Purpose: To compare the bone bonding capabilities of 2 different surface treatments at an early healing period. Titanium alloy (Ti6Al4V) custom-made rectangular plates (1.4 x 2.4 x 4 mm) were either dual acid etched (Ti6Al4V-DAE) or nanotextured proprietary processed Ti6Al4V-Ossean (intraLock International, Boca Raton, FL). Materials and Methods: Implants were placed in the distal femurs of 10 Wistar rats and were allowed to heal for 9 days. After euthanasia, the bone immediately proximal and distal to the implant was removed to test the bone bonding force with a universal testing machine. Ultrastructure of the bone/implant interface was assessed by scanning electron microscopy Results: Ti6Al4V-NTB samples exhibited significantly greater bond strength than Ti6Al4V-DAE samples. Morphologically, the Ti6Al4V-Ossean surfaces presented intimate interaction with bone, whereas little interaction between the Ti6Al4V-DAE surface and bone was observed Conclusion: The results of this study indicated a significant increase in bone bonding for the Ossean surface, which is suggested to be the outcome of the nanotexturing

Enhanced Bone Bonding to Nanotextured Implant Surfaces at a Short Healing Period: A Biomechanical Tensile Testing in the Rat Femur

Purpose: To compare the bone bonding capabilities of 2 different surface treatments at an early healing period. Titanium alloy (Ti6Al4V) custom-made rectangular plates (1.4 x 2.4 x 4 mm) were either dual acid etched (Ti6Al4V-DAE) or nanotextured proprietary processed Ti6Al4V-Ossean (intraLock International, Boca Raton, FL)

Monolithic CAD/CAM lithium disilicate versus veneered Y-TZP crowns:comparison of failure modes and reliability after fatigue

Purpose: The aim of this research was to evaluate the fatigue behavior and reliability of monolithic computer-aided design/computer-assisted manufacture (CAD/CAM) lithium disilicate and hand-layer-veneered zirconia all-ceramic crowns. Materials and Methods: A CAD-based mandibular molar crown preparation, fabricated using rapid prototyping, served as the master die. Fully anatomically shaped monolithic lithium disilicate crowns (IPS e.max CAD, n = 19) and hand-layer-veneered zirconia-based crowns (IPS e.max ZirCAD/Ceram, n = 21) were designed and milled using a CAD/CAM system. Crowns were cemented on aged dentinlike composite dies with resin cement. Crowns were exposed to mouth-motion fatigue by sliding a WC-indenter (r = 3.18 mm) 0.7 mm lingually down the distobuccal cusp using three different step-stress profiles until failure occurred. Failure was designated as a large chip or fracture through the crown. If no failures occurred at high loads (> 900 N), the test method was changed to staircase r ratio fatigue. Stress level probability curves and reliability were calculated. Results: Hand-layer-veneered zirconia crowns revealed veneer chipping and had a reliability of < 0.01 (0.03 to 0.00, two-sided 90% confidence bounds) for a mission of 100,000 cycles and a 200-N load. None of the fully anatomically shaped CAD/CAM-fabricated monolithic lithium disilicate crowns failed during step-stress mouth-motion fatigue (180,000 cycles, 900 N). CAD/CAM lithium disilicate crowns also survived r ratio fatigue (1,000,000 cycles, 100 to 1,000 N). There appears to be a threshold for damage/bulk fracture for the lithium disilicate ceramic in the range of 1,100 to 1,200 N. Conclusion: Based on present fatigue findings, the application of CAD/CAM lithium disilicate ceramic in a monolithic/fully anatomical configuration resulted in fatigue-resistant crowns, whereas hand-layer-veneered zirconia crowns revealed a high susceptibility to mouth-motion cyclic loading with early veneer failures. Int J Prosthodont 2010; 23: 434-442.NIDCR[P01 DE01976]Ivoclar Vivaden

Fatigue Reliability of 3 Single-Unit Implant-Abutment Designs

Objectives: Because the mechanical behavior of the implant-abutment system is critical for the longevity of implant-supported reconstructions, this study evaluated the fatigue reliability of different implant-abutment systems used as single-unit crowns and their failure modes. Methods and Materials: Sixty-three Ti-6Al-4V implants were divided in 3 groups: Replace Select (RS); IC-IMP Osseotite; and Unitite were restored with their respective abutments. Anatomically correct central incisor metal crowns were cemented and subjected to separate single load to failure tests and step-stress accelerated life testing (n = 18). A master Weibull curve and reliability for a mission of 50,000 cycles at 200 N were calculated. Polarized-light and scanning electron microscopes were used for failure analyses. Results: The load at failure mean values during step-stress accelerated life testing were 348.14 N for RS, 324.07 N for Osseotite, and 321.29 N for the Unitite systems. No differences in reliability levels were detected between systems, and only the RS system mechanical failures were shown to be accelerated by damage accumulation. Failure modes differed between systems. Conclusions: The 3 evaluated systems did not present significantly different reliability; however, failure modes were different. (Implant Dent 2012;21:67-71)CAPES, Brazil [BEX 2434/09-1