Effect of storage and compressive cycles on the bond strength after collagen removal.
This study verified the influence of storage and compressive loads on the microtensile bond strength (microtbs) of an adhesive system when using the conventional technique or collagen removal treatment. Twenty bovine teeth were separated into four groups: G1) adhesive system Prime & Bond NT (PBNT) in accordance with the manufacturer's instructions, G2) PBNT after deproteinization with 10% sodium hypochlorite (NaOCl), G3) PBNT in accordance with the manufacturer's instructions + 50,000 compressive cycles and G4) PBNT after deproteinization + 50,000 compressive cycles. After 24 hours, the teeth were sectioned and half of the specimens were stored in water (37 degrees C) for further evaluation (after 60 days). The failure mode was evaluated by scanning electron microscopy (SEM). The bond strength values were separately submitted to two-way ANOVA for each period and the differences among groups were determined by Tukey's test (p = 0.05). Comparisons between 24 hours and 60 days were determined by multiple paired Student's t-tests (5%). The evaluation at 24 hours revealed that deproteinization did not affect microtbs for the non-cycled groups (G1 = 47.8 +/- 4.7 and G2 = 52.4 +/- 11.32). For the groups tested after the mechanical cycles, deproteinization produced higher microtbs (G3 = 32.7 +/- 9.6 and G4 = 43.3 +/- 16.7). At 60 days, deproteinization produced higher microtbs than the manufacturers' recommendations for the cycled and non-cycled groups (G1 = 31.5 +/- 5.8; G2 = 48.8 +/- 7.7; G3 = 17.1 +/- 7.2 and G4 = 48.8 +/- 12.2). In conclusion, the deproteinized groups were less susceptible to degradation than the groups restored with the conventional technique.
Gonçalves
Luciano de Souza
Lde S
Department of Restorative Dentistry, Dental Materials Division, Piracicaba Dental School, UNICAMP, Brazil. goncalves1976@yahoo.com.br
Consani
Simonides
S
Sinhoreti
Mário Alexandre Coelho
MA
Schneider
Luis Felipe J
LF
Saboia
Vincente de Paulo de Aragāo
Vde P
D000818:Animals; D001696:Biomechanical Phenomena; D002417:Cattle; D003094:Collagen; D019245:Compressive Strength; D001840:Dental Bonding; D003738:Dental Cements; D004356:Drug Storage; D066298:In Vitro Techniques; D008855:Microscopy, Electron, Scanning; D011109:Polymethacrylic Acids; D012973:Sodium Hypochlorite; D013718:Tensile Strength
D003738:Dental Cements; D011109:Polymethacrylic Acids; C425843:Prime and Bond NT; D003094:Collagen; D012973:Sodium Hypochlorite