Česká Stomatologie a Praktické Zubní Lékařství (Jun 2012)

The Effect of Surface Treatment on Composite Repair Bond Strength Longevity

  • L. Comba,
  • P. Bradna,
  • M. Dudek,
  • V. Fialová,
  • J. Dušková,
  • D. Houšová

DOI
https://doi.org/10.51479/cspzl.2012.007
Journal volume & issue
Vol. 112, no. 2
pp. 36 – 46

Abstract

Read online

Introduction: Composite restorations undergo degradation in the oral cavity, which may compromise their aesthetic and functional properties, cause failure of marginal integrity, increased abrasion or even partial fracture of the filling. Instead of complete removal of such restorations, they can be repaired. Aim: To study the bond strength of a new composite resin to an aged composite substrate after a 4-month storage in distilled water or sodium laurylsulphate solution (SLS). Two various surface treatments and two different adhesive systems were tested. Materials and methods: Light cured specimens of a micro-hybrid composite (Filtek Z250, shade A2) were aged in distilled water (37 °C) for 5 months. Composite surface was prepared either by grinding (SiC paper P320, mean grain size 46 µm, equivalent to red diamond bur) or by air abrasion (Rondoflex; Al2O3 50 µm; 3.2 bar; 60 s). Composite build-ups were made from the same composite material using two adhesive systems (Optibond FL, Gluma Comfort Bond). The microtensile bond strength (n = 13-16) was measured after a 4-month storage of specimens at 37 °C in distilled water or in a solution of sodium lauryl sulfate (1.5 wt. %). Control specimens were stored in distilled water for 24 hours (37 °C). Results: A decrease of the bond strength compared to the control group on the ground surface after the 4-month storage in distilled water or SLS was found to be adhesive system- dependant. The bond strength for Optibond FL decreased by 52% in SLS only (p < 0.001), but for Gluma Comfort Bond it decreased by 45% in distilled water (p < 0.001) and by 61% in SLS (p < 0,001). On the air-abraded surface the bond strength decreased only for Optibond FL in SLS (p < 0.01), by 31%. Conclusion: Long-term durability of composite repair can be maintained by preparing the original composite surface using air abrasion. The effect of the adhesive system on the bond strength was not significant.

Keywords