| dc.description.abstract | Statement of problem. Additively manufacturing (AM) is gaining popularity in dentistry, including the use for interim implant supported fixed dental prostheses. However, evidence regarding the bonding protocols of AM interim crowns on ti-base abutments is lacking.
Purpose. The purpose of the present in vitro study was to compare the effect of different surface treatments and bonding protocols on the retentive bonding strengths of implant-supported AM interim crowns on Ti-bases.
Material- and methods. A total of 50 AM fabricated interim crowns were cemented on Ti-bases. Five subgroups (n=10) were established testing different surface pre-treatments including Group C = no surface pre-treatment, Group AP = crown air-abraded with 50μm Al₂O₃, Group AMP = crown air-abraded with 50μm Al₂O₃ and silanized, Group MP = crown silanized, and Group CMP = crown air-abraded with 30μm silica-coated Al₂O₃ (CoJet) and silanized. The specimens were cemented using a resin cement and stored in distilled water for 24 hours. Following, the specimens underwent retention testing with a Universal Instron machine at 2mm/minute crosshead speed. Pull-out forces (N) and modes of failure were registered. Statistical analysis was performed using Mann-Whitney U tests with Bonferroni corrections for multiple tests (a=.05).
Results. The median retention force values were 233.27 ±79.28 N for Group Control, 398.59
±68.59 N for Group MP, 303.21 ±116.80 N for Group AMP, 349.31 ±167.73 N for Group CMP,
and 219.85 ± 55.88 N for Group AP. The pull-off forces were significantly greater for Group MP, while the differences between the remaining groups were not significant. (P<.05). Group AP showed the lowest retention values.
Conclusions. The surface pre-treatment of the intaglio AM crown significantly influenced the bonding strength on Ti-bases. Pretreatment with an MDP-containing silane significantly improved the bonding strength, whereas pretreatment with 50μm Al₂O₃ air-abrasion alone is not recommended prior to cementation on a Ti-base abutment. | |
