Objectives: To measure retention of CAD-CAM e.max (Ivoclar Vivadent) and Lava (3M-ESPE) crowns using three resin luting agents with and without surface priming.
Methods: Extracted molars (n=10) were embedded in PVC cylinders with acrylic resin and placed into a lathe to produce a uniform crown preparation (20�-taper). Following the orientation groove placement(69L bur), preparations were scanned using CEREC 3D/Sirona (e.max crowns) and LAVA COS/3M ESPE (LAVA crowns).� A CAD-CAM Milling Machine produced crowns. Preparations were imaged with digital microscope (Keyence/VHX-600) at 20X magnification and the surface area of each preparation calculated.� The bonding area was used to calculate bond strength by dividing the failure load with bonded surface area. Crowns were cemented using temporary cement (RelyX TempE/3M ESPE), stored (distilled water/37�C/7days), cleaned, sandblasted (Al2O3 /50�/35psi/10sec),primed and cemented(table). Specimens were stored (distilled water/37�C/24h) before debonding in tension at a cross-head speed of 5mm/min (INSTRON Model/5565). Data were compared with 2-way ANOVA and Tukey-Kramer post-hoc test(p=0.05).
Results: (Mean�SD)
Experimental Groups Parkell | e.max | Zirconia(LAVA) | ||||
����� Force(N) | Stress(MPa) | ����� Force(N) | Stress(MPa) | |||
C&B Metabond
| Primer | ��649.9�270 | 5.4�2 | 479.6�150 | � 3.93�1.2 | |
No-Primer | 183.3�66 | 1.8�0.6 | � 397.7�181 | 3.47�1 | ||
Metal-Primer |
|
| 423.1�143 | 3.36�1 | ||
SEcure
| Primer | � 459.6�155 | 3.8�1 | 353.79�166 | 2.63�1 | |
No-Primer | 194.9�91 | 1.70�0.8 | 350.37�151 | 2.56�1 | ||
Metal-Primer |
|
| �390.71�184 | 3.11�1 | ||
Brush&Bond/Secure
| Primer | � 441.7�181 | 3.9�2 | 556.64�177 | 4.16�1 | |
No-Primer | 163.3�70 | 1.4�0.6 | �505.69�201 | 3.91�1 | ||
Metal-Primer |
|
| 509.19�222 | 3.71�1 | ||
Brush&Bond/Hyperfil | Primer | � 485.7�140 | 4�1 | 541.46�137 | 3.98�1 | |
No-Primer | 138.5�77 | 1.3�0.7 | 267.09�124 | 1.90�0.7 | ||
Metal-Primer |
|
| 359.25�159 | 2.49�0.9 | ||
Conclusion:
e.max: Groups bonded with primer produced higher retention compared to no primer groups (p<.05).
Zirconia(LAVA):
Load Failure: No significant difference (p>0.05) was observed among groups except Brush&Bond/Hyperfil/(No Primer and Metal Primer), Brush&Bond/(Hyperfil/No Primer and Secure /Metal Primer), Brush&Bond/(Hyperfil/No Primer and Secure/Primer).
Stress: No significant difference (p>0.05) was observed among groups except C&B Metabond/(No Primer;Primer) and Brush&Bond/Hyperfil/No primer, Brush&Bond/Hyperfil/(No Primer and Primer), Brush&Bond/(Hyperfil and Secure)/(No Primer and Primer) showed significance. Supported in part �by a grant from Parkell.
Keywords: Adhesion, Biomaterials, CAD/CAM, Cements and Ceramics
See more of: Dental Materials 1: Adhesion - Bond Strength Testing and Mechanisms