Figure 2. Ca and PO₄ release. (A) Ca ion release and (B) total ionic PO₄ release, from the nano-DCPA-whisker composites vs. filler level and immersion time. The symbols on the x-axis represent the hybrid control (TPH, Caulk/Dentsply) and the unfilled resin that had no Ca or PO₄ release. Each value is the mean ± SD; n = 3. Lines connect the datapoints for visual clarity.