Impact of Modified Dentin Bonding Agent Containing Fluorinated TEGDMA on Bond Strength of Composite Resin to Tooth Structure

The bond strength of adhesive resins to tooth structure is a key factor in restoration longevity. This study assessed the impact of substituting TEGDMA with fluorinated TEGDMA (f-TEGDMA) on the shear bond strength of experimental adhesive resins to enamel and dentin. Eight experimental light-cured resins (45 wt% Bis-EMA, 40 wt% TEGDMA/f-TEGDMA, 15 wt% HEMA) were prepared, both filled and unfilled, with f-TEGDMA at 0%, 17%, 24%, and 30 wt% of the monomer base. These were compared to OptiBond Solo Plus (filled) and All-Bond 2 (unfilled). Composite cylinders were bonded to etched enamel and dentin of human molars, stored for 24 h at 37 °C, and tested for shear bond strength. Data were analyzed using one-way ANOVA and Tukey’s test (α = 0.05). Bond strength varied significantly among groups for both substrates (p < 0.001). For enamel, the filled resin without f-TEGDMA matched OptiBond Solo Plus, while any f-TEGDMA concentration reduced filled-resin bond strength (p ≤ 0.013). Unfilled resins were unaffected by f-TEGDMA and were comparable to All-Bond 2. For dentin, only the unfilled resin without f-TEGDMA matched OptiBond Solo Plus; all f-TEGDMA-containing resins were comparable to All-Bond 2 and significantly lower than OptiBond Solo Plus (p < 0.001). f-TEGDMA did not enhance bond strength to either substrate. Dentin bonding was more sensitive to resin composition than enamel bonding.