Influence of different dentin etching times and concentrations and air-abrasion technique on dentin microtensile bond strength.
OBJECTIVE
To determine the influence of different dentin treatments on the microtensile bond strengths of adhesive resins to dentin.


METHODS
Fifteen human molars were ground to 600-grit to obtain flat root-dentin surfaces. Five different dentin treatments were evaluated: Group 1--10% phosphoric acid for 30 seconds; Group 2--37% phosphoric acid for 15 seconds; Group 3--air-abrasion for 10 seconds followed by 10% phosphoric acid for 30 seconds; Group 4--air-abasion for 10 seconds followed by 37% phosphoric acid for 15 seconds. The dental adhesive (OptiBond Solo Plus) was applied according to manufacturer's instructions and followed by composite (Z100) application to provide sufficient bulk for microtensile bond testing. All samples were placed in distilled water for 24 hours at 37 degrees C, thermocycled for 500 cycles in distilled water at 10 degrees C and 50 degrees C, and serially sliced perpendicular to the adhesive surface and subjected to tensile forces (0.5 mm/minute). Additional samples were prepared for SEM to observe the adhesive interface.


RESULTS
Group 2 exhibited significantly (P < 0.05) lower bond strength values than all other treatments. The bond strengths of the different conditions were (in MPa): Group 1: 43.0 +/- 16.1; Group 2: 29.2 +/- 8.3; Group 3: 48.1 +/- 14.2; Group 4: 41.0 +/- 9.3. The dentin treated with phosphoric acid 37% for 15 seconds showed the lowest values of microtensile bond strength. The results obtained with Groups 1, 3 and 4 were statistically similar.
Ahid
Fernando
F
School of Dentistry of Araraquara, UNESP, Brazil.
Andrade
Marcelo F
MF
Campos
Edson A
EA
Luscino
Fabrício
F
Vaz
Luis G
LG
D000134:Acid Etching, Dental / Q000379:methods*; D020906:Air Abrasion, Dental; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006801:Humans; D008855:Microscopy, Electron, Scanning; D010756:Phosphoric Acids / Q000008:administration & dosage / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013499:Surface Properties; D013718:Tensile Strength; D013997:Time Factors; D014092:Tooth Root / Q000648:ultrastructure; D014867:Water / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry
D003188:Composite Resins; D017220:Dentin-Bonding Agents; C451600:OptiBond Solo Plus; D010756:Phosphoric Acids; D019279:Resin Cements; C083568:Z100 composite resin; D014867:Water; D012822:Silicon Dioxide; D015040:Zirconium