الفهرس 
List of ContentsOnly 14 pages are availabe for public view
 |  | from | 121 |  |  |
| | | from | 121 | | |
Abstract
Abstract : Purpose : To evaluate the influence of micromechanical and chemical conditioning on bonding to machinable composite MZ100 blocks. Materials and methods: A total of 64 machinable composite discs (MZ100 paradigm) were fabricated using CAD/CAM technology according to the desired dimensions (10 mm width and 4 mm thickness). The discs were divided in two main groups (n=32): as milled group (AM) and sandblast group (SB) using Al2O3 (50-μm, 0.2 MPa, and 10s). Each main group was subdivided into two subgroups (n=16) according to method of chemical conditioning : conventional silane (SI) and multipurpose primer (MP, Monobond N). Composite resin discs were fabricated (master fill) according to desired dimensions (4.5 mm width x 3.5 mm thickness). Surface treated MZ100 discs were bonded to the composite resin discs according to the types of adhesive resin cements, multistep adhesive resin cements (MARC, Multilink N) or self-adhesive resin cements (SARC, Rely X U200). One hour after bonding, all specimens were stored in water bath at 37°C for 5 months followed by thermocycling for 10,000 cycles. Following artificial aging all bonded specimens underwent shear bond strength (SBS) testing using universal Instron testing machine. Statistical analysis was performed using a 3-Way ANOVAs, 2-Way ANOVAs and serial 1-Way ANOVAs. Comparison of different test groups was performed using Tukey’s HSD test at (α=0.05). Results: In Three-Way ANOVAs test revealed statistically significant different in SBS between (SB) and (AM) groups {p=0.000} and between different resin cements used {p=0.006}. While there, was no statistically significant different when used different chemical conditioning methods {p=0.132}. The highest SBS was in group (SB+SI) cemented by (SARC) (18.3±2.7), while that the lowest SBS was in group (AM+SI) cemented by (MARC) (6.2±2.9). Conclusions: Sandblasting of the MZ100 paradigm block surface is recommended when luting with the self-adhesive or multistep adhesive resin cements. RelyX U200 outperformed SBS values compared to Multilink N in all groups. The chemical conditioning there was preferable used after sandblasting surface treatment of paradigm MZ100 CAD/CAM block.