SHEAR BOND STRENGTHS OF 2 COMMERCIALLY AVAILABLE DENTIN-AMALGAM BONDING SYSTEMS

Objectives: The purpose of this in vitro study was to determine the sh ear bond strengths (SBS) of amalgam to dentine treated with the Amalga mbond Plus System (AM) and All-bond 2 System (AL) after storage period s in physiological saline for up to 48 weeks. Methods: The occlusal su perficial dentine surfaces of 150 extracted human molars were exposed by wet grinding on 600-grit silicon carbide and the bonding area demar cated with a perforated adhesive tape. Freshly mixed Tytin amalgam was transferred to the opening in a split Teflon mold on the demarcated d entine surfaces treated with either AM or AL as directed by the manufa cturers. The SBS of AM after 24 h (A), 4 weeks (B), 12 weeks (C), 24 w eeks (D), and 48 weeks (E), and of AL after 24 h (F), 4 weeks (G), 12 weeks (H), 24 weeks (I), and 48 weeks (J), were determined with a knif e-edged rod at a crosshead speed of 0.5 mm/min and expressed in megapa scal (MPa). The data were analyzed by ANOVA and Student's t-test. Resu lts: The mean +/-SD of SBS in MPa were: A: 14.6+/-4.0; B: 14.5+/-3.6; C: 15.3+/-4.8; D: 14.6+/-4.6; E: 13.9+/-4.0; F: 9.5+/-4.7; G: 12.1+/-1 .7; H: 10.2+/-3.5; I: 12.0+/-3.9; J: 11.9+/-3.5. The SBS of the five g roups treated with AM (A, B, C, D and E) were not significantly differ ent (P > 0.05) and the SBS of the five groups treated with AL (F, G, H , I and J) were not significantly different (P > 0.05). The SBS of A v s. F, B vs. G, ad C vs. H, were significantly different (P < 0.05), bu t D vs. I and E vs. J were not significantly different (P > 0.05). Con clusion: The SBS of amalgam to dentine treated with AM and AL were not adversely affected by the duration of storage. Copyright (C) 1996 Els evier Science Ltd.