Eva Klarić

Silver diamine fluoride/potassium iodide (SDF/KI) Riva Star (SDI) is a tooth desensitizing and anti-caries agent that may be indicated for arresting caries before restoring the tooth in selective caries approach. The aim was to determine the effect of SDF/KI pretreatment on the bonding of SDR Plus Bulk-Fill Flowable (Dentsply) with Clearfil SE Bond 2 (Kuraray) and G-Premio Bond (GC) in self-etch mode on sound dentin. A total of 240 dentin samples were prepared and assigned to 12 groups based on SDF/KI pretreatment (with or without), adhesive type, and testing time (1, 3, and 6 months). The shear bond strength (SBS) was measured using an UltraTester. SBS data were analyzed using three-way factorial model (Adhesive × Pretreatment × Time) and Wald (F) tests, with α = 0.05. Fracture modes were analyzed using χ² and Fisher’s exact test, with α = 0.05. Clearfil performed significantly better than G-Premio at all time points (p < 0.001). Riva Star pretreatment significantly reduced SBS for both adhesives at all time points (p < 0.001). SBS reduction was significantly higher for Clearfil (p < 0.001). The effect of storage was not significant (p = 0.388). Fracture mode distribution differed significantly between adhesives (p < 0.001). Pretreatment × fracture interaction was significant for Clearfil (p = 0.0052). Mixed fractures in G-premio were rare.

Blue diode lasers are alternative curing devices for dental composites. The aim of this study was to investigate the influence of blue diode laser polymerization on shear bond strength of bulk fill composites to human dentin and temperature rise during two types of polymerization. Composite cylinders of SDR Plus(SDR) and Ever X Flow(EX) were bonded to dentin slabs using Adhese Universal and curing devices blue diode laser (449 nm, 1.6 W) and Power Cure LED. For each material and curing device there were two polymerization approaches: 1)conventional: separate curing of adhesive; 2)co-curing: simultaneous adhesive and composite curing. Polymerization modes for each material in conventional and co-curing(c) approach were: blue laser 2000 mW/cm² for 5 s (L5 and L5c); blue laser 1000 mW/cm² for 10 s (L10 and L10c); Power Cure 2000 mW/cm² for 5 s (LED5 and LED5c); Power Cure 1000 mW/cm² for 10 s (LED10 and LED10c). Temeperature was measured using thermal vision camera. For SDR, the highest bond strength was 24.3 MPa in L10c, and the lowest 9.2 MPa in LED5c. EX exhibited the highest bond strength(21.3 MPa) in LED5, and the lowest in L5(7.7 MPa). The highest temperature rise for SDR was in L10 and L5 (7.3 and 7.2 °C), and the lowest in LED5(0.8 °C). For EX, the highest temperature rise was in L5 (13.0 °C), and the lowest in LED5 (0.7 °C). Temperature rise was higher during blue laser polymerization, especially at high intensity and with conventional curing. Preferable blue laser curing mode is co-curing at 1000mW/cm² for 10 s.