Histocompatibility of polyvinyl acetate, an ingredient of chewing gum

The histocompatibility of polyvinyl acetate (PVA), an ingredient of chewing gum, was evaluated from both a direct irritant (toxic reaction) and an allergic (antigen-antibody) standpoint. Subcutaneous injections in rats and topical application of hamster pouches were utilized. Polyvinyl acetate was shown to cause a moderate to severe inflammatory reaction when injected subcutaneously, which peaked at day 7 and was minimal at day 42. The histologic appearance of the hamster cheek pouch was not significantly altered by the PVA. Although PVA has been used as a plasticizer in chewing gum, it was not possible to induce any histologic changes in tissues which resembled the specific changes present in atypical gingivostomatitis (plasma-cell gingivostomatitis).