Pavinee Padipatvuthikul1, Lawrence H Mair. 1. University of Liverpool, School of Dental Studies, Liverpool Dental School, Pembroke Place, Liverpool L3 5PS, United Kingdom. pavineep@hotmail.com
Abstract
OBJECTIVE: The purpose of this study was to determine the shear bond strength of new composite to water aged composite with and without interfacial surface treatment. METHODS: Two hundred and eighty cylindrical samples were prepared for each of three resin composites (Spectrum, Dentsply; Durafill, Kulzer; Herculite, Kerr). Seventy samples of each material were bonded immediately and the remaining were stored in water. After 1, 4 and 12 weeks 70 samples were removed and the surface treated prior to bonding a second fresh increment. The treatments were: (1) no treatment, (2) abrasion with pumice, (3) a layer of Prime and Bond (Dentsply), (4) abrasion+Prime and Bond, (5) a layer of Optibond Solo Plus (Kerr), (6) abrasion+Optibond and (7) a layer of bis-GMA/TEGDMA. The specimens were loaded to failure in shear mode with a crosshead speed of 50 mm/min until fracture. The fracture surface of a number of specimens were examined in a scanning electron microscope. RESULTS: At all time intervals the treatment that resulted in the highest bond strengths (>20 MPa) was treatment with the dentine bonding agents (DBS) Prime and Bond or Optibond Solobond Plus. No treatment or abrasion alone resulted in very low bond strengths even after 1 week in water. When used in conjunction with DBS's abrasion did not increase the bond strength over the use of the DBS alone. The bis-GMA/TEGDMA was not as effective as the DBS's. SIGNIFICANCE: When bonding new composite to composite that has been underwater it is essential to treat the original composite surface. The results of this study indicated that the application of a dentine bonding agent significantly enhanced the bond. Abrasion alone did not produce an adequate bond.
OBJECTIVE: The purpose of this study was to determine the shear bond strength of new composite to water aged composite with and without interfacial surface treatment. METHODS: Two hundred and eighty cylindrical samples were prepared for each of three resin composites (Spectrum, Dentsply; Durafill, Kulzer; Herculite, Kerr). Seventy samples of each material were bonded immediately and the remaining were stored in water. After 1, 4 and 12 weeks 70 samples were removed and the surface treated prior to bonding a second fresh increment. The treatments were: (1) no treatment, (2) abrasion with pumice, (3) a layer of Prime and Bond (Dentsply), (4) abrasion+Prime and Bond, (5) a layer of Optibond Solo Plus (Kerr), (6) abrasion+Optibond and (7) a layer of bis-GMA/TEGDMA. The specimens were loaded to failure in shear mode with a crosshead speed of 50 mm/min until fracture. The fracture surface of a number of specimens were examined in a scanning electron microscope. RESULTS: At all time intervals the treatment that resulted in the highest bond strengths (>20 MPa) was treatment with the dentine bonding agents (DBS) Prime and Bond or Optibond Solobond Plus. No treatment or abrasion alone resulted in very low bond strengths even after 1 week in water. When used in conjunction with DBS's abrasion did not increase the bond strength over the use of the DBS alone. The bis-GMA/TEGDMA was not as effective as the DBS's. SIGNIFICANCE: When bonding new composite to composite that has been underwater it is essential to treat the original composite surface. The results of this study indicated that the application of a dentine bonding agent significantly enhanced the bond. Abrasion alone did not produce an adequate bond.