**Acknowledgements**

Several studies have been carried out at short- or long- term implantation with PMMA enriched or coated with different materials as base bone cement-osteopal V modified with

hamster oral mucosa irritation and guinea pig skin sensitization and intracutaneous rabbit implantation [106], enriched with CPC in rats [90], scaffolds of electrospinning using polycaprolactone (PCL) implantation in rats [94], no toxic effect or histological findings were observed, even a regeneration was perceived. By contrast, the use of PMMA-PEI nanoparticles injected

Acrylic resin cytotoxicity is associated with the presence of residual monomer in the polymerization process. The monomers change cell morphology and function that can reduce their viability. Since acrylic resins are widely used in dental practice, an acceptable biocompatibility is desirable. Considering that the majority of studies reported acrylic resin toxicity responses, further studies with different assessment methods are necessary for the

In summary, there exist different methods to evaluate acrylic resin cytotoxicity, genotoxicity, and short- or long-term implantation with the MTT method and histological evaluation being the most common tests. In conclusion, there is no non-cytotoxic acrylic resin evidently available in the dental market. Regarding the methods of polymerization, the autopolymerized resin is more cytotoxic and toxic than heat-polymerized resin. The cytotoxic and toxicity effect is dose dependent and is directly correlated with the residual amount of monomer leachable and induce the inflammatory reactions of tissues in contact with the acrylic resin. It is suggested that a water or ethanol bath after polymerization of acrylic resin could decrease the

The particle size differences could influence the roughness surface of PMMA without decreasing their mechanical properties. Furthermore, studies should continue to determine that issue

Ultrasound can be used to process the acrylic resin (Opticryl®) as an alternative technique for PMMA processing with similar results to those obtained using water bath or microwave

The addition of antifungal agents on PMMA surface or into PMMA, such as moieties, metallic or metallic oxide nanoparticles, and antibiotics, could be useful for the inhibition of specific

Residual monomer leach induces cytotoxic and inflammatory reactions of oral cells and tissues in contact with the acrylic resin. It is suggested that water or ethanol bath after polymerization of acrylic resin could decrease the cytotoxic and toxicity activity against oral cells and tissues. But ultrasonic waves are a good option for both, for thermopolymerization of PMMA

) nanoparticles for

castor oil and linoleic acid in rats [86], coating with titanium dioxide (TiO<sup>2</sup>

development of biocompatible materials.

64 Acrylic Polymers in Healthcare

**5. Remarks and perspectives**

processing (control groups).

in detail.

cytotoxic and toxicity activity against oral cells and tissue.

pathogens such as *Candida albicans* for prosthodontic denture.

and at the same time to reduce the residual monomer.

in mice induces significant toxicity by the detection of protein levels in liver tissue.

The authors want to thank PAPIME-DGAPA, UNAM for its financial support through projects PE205916, PE210616, and PAPIIT-DGAPA (IN225526, IA204516). Thanks to José Campos (IER-UNAM), Ana Cecilia Pérez, Neftalí Hernández, Carlos García, and Ma. Elena Calixto (ITESI) for excellent technical support. L. Argueta-Figueroa thanks DGAPA, UNAM for the Postdoctoral scholarship.
