Effect of finishing instrumentation on enamel and composite surface morphology and marginal integrity of resin-based composite restorations Public Deposited

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  • March 22, 2019
Creator
  • Maresca, Cristina
    • Affiliation: School of Dentistry, Department of Operative Dentistry
Abstract
  • This study evaluated the effect of different finishing instruments on enamel and composite surface morphology, and the effects of different finishing instruments on marginal integrity of resin-based composite restorations. Bovine incisors (n=75) embedded in epoxy resin had the facial enamel ground and polished to 1200-grit. A standardized Class V cavity was prepared on each specimen and restored with composite (Z250). Specimens were randomized into fifteen groups (n=5) according to finishing instruments: positive control (coarse diamond), negative control (1200-grit), fine crosscut burs (CC), straight cut burs (StC), spiral cut burs (SpC), and finishing diamonds (FD). StC, SpC, and FD were tested individually as fine, extra-fine, and ultra-fine, and sequentially as a series (cumulative effect). A high-speed, water-cooled handpiece under standardized conditions {(pressure (0.5N) and time (40 s)} was used. Specimens were analyzed for Ra with a mechanical profilometer and observed using scanning electron microscopy (SEM) at x500 magnification for marginal integrity (gap measurement). Data were analyzed using two-way ANOVA and the Duncan test. Statistically significant differences (p<0.05) were detected among the finishing instruments. The positive control surface created by the diamond medium band bur generated the roughest surface, while the negative control surface created with the mechanically polished enamel generated the smoothest surfaces. When compared with the negative control group, StC all series, SpC all series, and FD fine were observed to have a statistically significant difference in surface roughness. These three groups presented higher Ra values when compared with the other groups. For the marginal integrity, there was no statistically significant difference between FD and the negative control. However, the positive control exhibited significantly larger gaps when compared to the other finishing instruments. Intermediate results were observed for CC, StC and SpC. FD (fine, extra-fine and ultra-fine) generated smaller gaps compared to carbides and regular-grit diamonds. Finishing diamonds: fine, extra-fine and ultra-fine, generated smaller gaps compared to carbides and regular-grit diamonds.
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  • In Copyright
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  • "... in partial fulfillment of the requirements for the degree of Master of Science in the Department of Operative dentistry."
Advisor
  • Ritter, Andre
Degree
  • Master of Science
Graduation year
  • 2006
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