Its resin matrix may also be constituted by an adhesive
monomer, which comprehends the 4‑methacryloxyethyl
trimellitic anhydride (4‑META), o hydroxyethyl
methacrylate or an organophosphate, which is usually
phosphoric acid 10‑methacriloiloxidecamethylene(MDP).
The system composed with 4‑META, is a liquid adhesive,
which through the inclusion of polymers pearls, obtains
the consistency of cements. Therefore, the is no need for
applying other adhesive systems.[8]