Do resin-based composite CAD/CAM blocks release monomers?

Abstract

The present study aimed to identify and quantify the elution of monomers of five different resin-based CAD/CAM blocks (RCBs) using HPLC. Five different RCBs were used in the study: GC Cerasmart (CS), Voco Grandio blocs (GR), 3M Lava Ultimate (LU), Shofu Block (SB), and Vita Enamic (VE). Fifteen samples from each material were prepared using a low-speed precision diamond saw (ISOMET Buehler, Lake Bluff, IL, USA) at 5 × 5 × 4mm size. After the preparation of samples, an extraction solution was mixed with %75/%25 ethanol/water. The samples were stored in the amber-colored bottles during three different immersed periods as 1h, 24h, and 90days (n = 5). After immersion, 0.5ml solutions were taken from each bottle and analyzed using HPLC. A total of 16.7μg/ml of monomers from SB, 13.4μg/ml of monomers from GR, 13.2μg/ml of monomers from CS, and 6.7μg/ml of monomers from LU were found after 3-m immersion. TEGDMA after 3-m of immersion was only released from the SB group, and also BisEMA was released from the CS group. Among the specimens immersed for 1h, UDMA was released the least from the LU group and the most from the GR group (p < 0.05). Correspondingly, 24h and 3m after immersion, the highest release of monomers was found in the GR (p < 0.05). When the monomer release from RCBs was evaluated, it was shown that these materials released methacrylate-based monomers except VE, especially if they were kept in a solvent solution for a long time such as 3m. The novel resin-based CAD/CAM blocks might monomer release, which may cause cytotoxic effects. But, the detected amount of monomer release is below the estimated daily limit.