Mechanical properties and dentin bonding of semi-direct restorations produced with a diatomite-based resin composite

Abstract

Diatomite is a silica that may be used as a resin composite filler. However, mechanical properties and dentin bonding behavior of semi-direct restorations produced with a diatomite-based resin composite are still unknown. PurposeThe study aimed to evaluate the bottom/top microhardness ratio (B/T), bond strength (BS), failure mode (FM), flexural strength (FS), and elastic modulus (EM) of semi-direct restorations with a diatomite-based resin composite. MethodsBovine incisors were used to produce dentin cavities (n = 136), which were restored with resin composites [Filtek One Bulk Fill (BF), Filtek Z250 XT (Z250), Filtek Z350 XT (Z350), and Zirconfill (ZF), which contains diatomite] through semi-direct technique. The BT, BS and FM were evaluated in the same restorations. Standardized sticks (10 mm × 1 mm x 2 mm) were fabricated (n = 10) for FS and EM analyses. All specimens were water stored in an incubator at 37 °C for 24 h or 6-month, except B/T that was stored and evaluated only after 24 h water storage. ResultsThere were no statistically significant differences among the resin composites for B/T. At 24 h, ZF provided values statistically higher than Z250 and BF. For Z350, 6-month aging was statistically higher values than 24-h. Mixed failures were predominant for all resin composites at both time points. For FS, only Z250 provided a lower value at 6-months analysis and no increase at six months. The diatomite-based resin composite showed similar mechanical properties and dentin bonding to traditional resin composites using semi-direct restorations. Clinical significanceThe proper mechanical performance of a new diatomite-based resin composite, whose raw material is available in nature, shows a promising alternative for the dental market.