Network integrity of bulk-fill composites: Thermal stability, post-curing hardness development and acidic softening
This study investigated the thermal stability and top-to-bottom hardness ratio of six bulk-fill composites (STARK<sup>®</sup> Bulk Fill Composite, Filtek™ One Bulk Fill Restorative, SDR<sup>®</sup> Plus Bulk Fill Flowable, Tetric<sup>®</sup> N-Ceram Bulk Fill, X-tra fil, and Beautifil-Bulk Restorative) following acidic softening. Discs-shaped specimens were fabricated and photo-cured for 20 s. Vickers hardness was sequentially measured, immediately after irradiation (VH<sub>0</sub>), after 24 h of dry storage (VH<sub>dry</sub>) and after 24 h of acidic storage (VH<sub>acidic</sub>) at 37°C. Network integrity was assessed by comparing the relative hardness decrease (VH<sub>RD</sub>) after acidic softening with the initial maximum rate temperature (IRT) of mass loss. Compared to VH<sub>0</sub>, VH<sub>dry</sub> significantly increased, whereas VH<sub>acidic</sub> significantly decreased. The VH<sub>RD</sub> of top surface ranged from 16.62% for FBF to 62.84% for SDR. IRT primarily reflects resin composition and residue is a filler-based value. Relative network integrity estimated by IRT revealed a negative correlation with VH<sub>RD</sub>. Consequently, acidic erosion hardness development can be indirectly employed to assess network integrity in bulk-fill composites.
Authors
- Waseem Sharaf Saeed (ORCID: https://orcid.org/0000-0002-5254-5665)
- Rawaiz Khan
- Ali Alrahlah (ORCID: https://orcid.org/0000-0002-0385-8817)
- Abdel-Basit Al-Odayni (ORCID: https://orcid.org/0000-0002-7652-093X)
- Mohammed Aldhafyan (ORCID: https://orcid.org/0000-0003-2804-3929)
Institutions
- King Saud University (SA)
Publication Details
- Journal
- Dental Materials Journal
- Published
- 2025-02-13
- DOI
- https://doi.org/10.4012/dmj.2024-247
- Citations
- 2
- Primary Topic
- Dental materials and restorations
- Type
- article
- Field-Weighted Citation Impact
- 3.35
Funders
- King Saud University