Micro-computed tomographic evaluation of the effects of pre-heating and sonic delivery on the internal void formation of bulk-fill composites

Dent Mater J. 2021 Mar 31;40(2):525-531. doi: 10.4012/dmj.2020-071. Epub 2020 Dec 2.


The aim of this study was to compare the effects of conventional, sonic or pre-heating insertion techniques on internal void formation of bulk-fill composites with micro-computed tomography. Standardized cylindrical cavities were prepared in 160 human third molars. Four groups received different paste-like bulk-fill composites: SonicFill 2 (SF2); VisCalor Bulk (VCB); Filtek One Bulk-fill restorative (FBF); Tetric EvoCeram Bulk Fill (TEB); and a conventional posterior composite, Clearfil Majesty Posterior (CMP). A hybrid CAD/CAM block was selected as a control (n=10). Composite restorations were built according to each resin composite type and insertion technique (n=10). Micro-CT was used to assess internal void rates. Data was analyzed with two-way ANOVA and Tukey's multiple comparisons test (α=0.05). CAD/CAM blocks were free of voids. For each composite, the highest void rates were observed for the sonic delivery method (p<0.05) except for SF2. SF2 was not affected by insertion techniques (p>0.05). Other composites showed the lowest void rates with pre-heating technique.

Keywords: Composite placement; Internal void; Micro-computed tomography; Pre-heating; Sonic activation.

MeSH terms

  • Composite Resins
  • Dental Caries*
  • Dental Restoration, Permanent
  • Heating*
  • Humans
  • Materials Testing
  • X-Ray Microtomography


  • Composite Resins