Shear bond strength of repaired adhesive filling materials using different repair procedures.
OBJECTIVE
Matrices of adhesive restorative materials and repair procedures may both influence bond strength of repaired adhesive materials. This study examined the bond strength of adhesive filling materials to mature adhesive materials after pretreatment with Co-Jet, Monobond S, and Silibond.


METHODS
A hybrid composite (Tetric Ceram), a polyacid-modified composite resin (Dyract), and an ormocer (Definite) and their corresponding bonding agents were tested in combination with the repair systems. Restorative materials were placed in molds and polymerized. In group A (control), homologous materials were applied on the polymerized surface directly. In group B, homologous filling materials were placed onto the respective material with the corresponding bonding agent. In group C, adhesive repair filling material was applied after solely pretreating with the repair systems. In group D, the restorative material was applied after pretreatment with the repair systems and application of the corresponding bonding agent. Each subgroup consisted of 20 specimens. The shear bond strength of the samples was measured in a universal testing machine according to the test procedure ISO 10477.


RESULTS
The significantly best bond strength of repair filling material on Tetric was achieved by pretreating with Co-Jet followed by application of the corresponding bonding agent (25.5 +/- 5.4 MPa, p < 0.05). A single application of the bonding agent or use of Monobond with bonding agent also yielded bond strengths of 20 MPa or more on Tetric. For Dyract or Definite, bond strengths of 15.5 +/- 5.3 MPa or less were achieved with the different repair procedures.


CONCLUSIONS
Successful pretreatment of hybrid composites for repair can be achieved by application of Co-Jet followed by the corresponding bonding material, whereas sufficient repair of ormocers and polyacid-modified resin composites is limited.
Department of Operative Dentistry, Preventive Dentistry and Periodontology, University of Göttingen, Germany. Christian.hannig@med.uni-goettingen.de
Christian
C
Hannig
Sebastian
S
Laubach
Petra
P
Hahn
Thomas
T
Attin
D000180:Acrylic Resins / Q000737:chemistry; D000269:Adhesives / Q000737:chemistry*; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding / Q000379:methods*; D003738:Dental Cements / Q000737:chemistry*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D011140:Polyurethanes / Q000737:chemistry; D033081:Shear Strength
D000180:Acrylic Resins; D000269:Adhesives; C029012:Composite Dental Resin; D003188:Composite Resins; D003738:Dental Cements; D017220:Dentin-Bonding Agents; C076808:Monobond S; D011140:Polyurethanes