Efficiency of self-adhering flowable resin composite and different surface treatments in composite repair using a universal adhesive
Nigerian Journal of Clinical Practice. 2019;22(12):1675-1679.
ABSTRACT
Aims: The aim of this in vitro investigation was to evaluate the efficiency of self-adhering flowable resin composite (Vertise Flow, Kerr, Orange, CA, USA) and different surface treatments in the repair microtensile bond strength (µTBS) of aged nanofill resin composites using a universal adhesive.
Materials and Methods: Aged substrates (×5000 thermocycling) were prepared using a nanofill (Filtek Ultimate; 3M ESPE) resin composite and randomly assigned to different surface treatments: (1) no treatment (control), (2) acid etching with 37% phosphoric acid, (3) Al2O3 sandblasting, and (4) sandblasting with CoJet (3M ESPE). After surface treatment, specimens were further divided into two groups: no universal adhesive application and universal adhesive application. Vertise Flow was added to the substrates at 2-mm layer increments to a height of 5 mm and light cured. Restored specimens were sectioned to obtain 1.0-mm2 beams for µTBS testing. Data were analyzed with two-way analysis of variance and Tukey's honest significant difference tests (P < 0.05).
Results: The lowest µTBS values were recorded in the control and acid etching groups with no universal adhesive application (P < 0.05). Universal adhesive application significantly increased the repair µTBS values of all surface treatments (P < 0.05), except CoJet treatment. There were no significant differences between Al2O3 sandblasting, CoJet application, and acid etching groups with the universal adhesive application (P > 0.05).
Conclusion: Vertise Flow can be used effectively in the repair of old nanofill resin composites. The usage of universal adhesive with prior acid etching to obtain acceptable repair performance would be the practical choice under clinical conditions.
KEYWORDS
Bond strength · composite repair · resin composites · sandblasting · universal adhesives
STUDY SUMMARY
This in vitro study measured the microtensile bond strength of repairs made with a self-adhering flowable composite to thermally aged nanofill composite, combining four surface treatments with and without a universal adhesive. The lowest values occurred in the untreated and acid-etched groups without the adhesive, and applying the universal adhesive significantly raised bond strength for every treatment except tribochemical silica coating. With the universal adhesive applied, the two sandblasting methods and acid etching did not differ significantly from one another.