Shear bond strength of veneering composite to high performance polymers.

High performance polymers like PEEK (polyetheretherketone) and FRC (fiberreinforced composite) could substitute metallic alloys for removable partial dentures. However, these polymers require aesthetic veneering. This study was to determine the bond strength to direct composite. Specimens made of PEEK and FRC were produced and air-abraded (50 µm aluminum-oxide). Specimens were allocated to four experimental groups: Luxatemp Glaze & Bond, Scotchbond Universal, SR Nexco Connect and iBond Universal. Specimens were divided into three subgroups for short-term, long-term and no artificial aging and shear bond strength (SBS) was evaluated. SBS of specimens made of PEEK with no artificial aging showed values between 10.79-14.00 MPa, short-term artificial aging resulted in values between 3.78-13.85 MPa and after long-term artificial aging SBS decreased to 0-8.75 MPa. SBS measurement of FRC specimens resulted in values between 9.83-12.1 MPa without aging, after short-term artificial aging values decreased to 8.36-11.98 MPa and after long-term aging SBS showed a degradation to 4.52-7.82 MPa.

Cold Atmospheric Plasma Improves Shear Bond Strength of Veneering Composite to Zirconia.

Chipping of veneering is the most common clinical complication for zirconia restorations. Veneering composite could be a promising alternative to renew restorations. Zirconia discs (3-YSZ) were prepared with varying surface treatments and bonded to indirect composite as follows: air abrasion and Scotchbond Universal (A/SU); air abrasion and Clearfil Ceramic Primer (A/C); air abrasion and MKZ Primer (A/M); air abrasion and Monobond Plus (A/MP); silica-coating and Scotchbond Universal (S/SU); air abrasion (AP/SU), additional cold atmospheric plasma treatment, and Scotchbond Universal. An indirect composite material was then applied to the zirconia specimens. Specimens were divided into subgroups for short-term (14 days storage at 37 °C and 5000 thermal cycles) and long-term (250 days storage and 37,500 thermal cycles) artificial aging. Shear bond strength measurement (SBS) was performed, and data were analyzed by Kruskal-Wallis-test and multiple comparison testing with Dunn's correction (p ≤ 0.05). The median SBS values (MPa) of short- and long-term artificial aging were: 3.09/1.36 (A/SU); 0.77/1.43 (S/SU); 2.82/2.15 (AP/SU); 1.97/1.80 (A/C); 2.01/1.58 (A/M); and 1.70/1.68 (A/MP). For short-term artificial aging A/SU showed the highest median SBS values, whereas in the long-term trial, AP/SU showed the highest values and the difference was significant. A prolonged artificial aging decreased SBS in all groups, except S/SU. In summary, treatment with CAP can improve SBS in the long-term.