Effect of composite resin placement techniques on the microleakage of two self-etching dentin-bonding agents.
OBJECTIVE
To evaluate microleakage of Class V resin-based composites (RBC) bonded with two self-etching dentin adhesive systems. Class V cavities were restored with either one or three increments of RBC to determine whether the restorative method affected microleakage.


METHODS
60 extracted human premolars and molars were randomly assigned to 6 groups for bonding with Clearfil Liner Bond 2V or Etch & Prime 3.0 or Prime & Bond NT. The latter, using a total-etch technique, was used as a control. Cavities were cut in both the buccal and lingual surfaces. Half of each preparation was in enamel and half was in cementum/dentin. The teeth were thermocycled and the restorations examined microscopically for leakage using Procion Brilliant Red as a marker. SEM microphotographs were prepared from dye-labeled and non dye-labeled areas to illustrate the micromorphology of the systems.


RESULTS
None of the groups showed microleakage at the enamel margins. All groups showed microleakage at the gingival margins. At the gingival margin, there was no significant difference between the groups irrespective of the bonding material (Kruskal-Wallis: ANOVA P=0.2113). No significant difference was observed with each material when the bulk filling (one increment) technique was compared with the three-increment technique. SEM showed that the self-etching materials produced a shallower depth of etch, and a less abundant resin tag complex than the material using a separate phosphoric acid gel. In dye-labeled areas, debonding was predominantly cohesive in resin.


CONCLUSIONS
Gingival margin microleakage is not prevented  by either restoring cavities with self-etching materials of the control using a total-etch technique.
Santini
A
A
University of Edinburgh, Scotland, UK. ariosantini@hotmail.com
Plasschaert
A J
AJ
Mitchell
S
S
D000134:Acid Etching, Dental / Q000379:methods; D000268:Adhesiveness; D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D002648:Child; D004396:Coloring Agents; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003737:Dental Cavity Preparation / Q000145:classification; D003739:Dental Cementum / Q000648:ultrastructure; D003743:Dental Enamel / Q000648:ultrastructure; D003763:Dental Leakage / Q000145:classification*; D003793:Dental Restoration, Permanent / Q000145:classification; D003804:Dentin / Q000648:ultrastructure; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D011756:Diphosphates / Q000737:chemistry; D000431:Ethanol / Q000737:chemistry; D006801:Humans; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D010756:Phosphoric Acids / Q000008:administration & dosage; D011109:Polymethacrylic Acids / Q000737:chemistry; D018709:Statistics, Nonparametric; D013499:Surface Properties; D013696:Temperature; D013816:Thermodynamics; D014227:Triazines; D014867:Water
C112274:Clearfil Liner Bond 2; D004396:Coloring Agents; D003188:Composite Resins; D017220:Dentin-Bonding Agents; D011756:Diphosphates; C121187:Etch&Prime; D008689:Methacrylates; D010756:Phosphoric Acids; D011109:Polymethacrylic Acids; C103500:Prime & Bond; D014227:Triazines; D014867:Water; C026429:Procion Brilliant Red H8-BS; D000431:Ethanol; D017438:Bisphenol A-Glycidyl Methacrylate