Allergenicity of gutta-percha and the potential sensitization from latex products : (an animal study)

Abstract

Thesis (M.S.D.)--Boston University, Henry M. Goldman School of Dental Medicine, 2003 (Endodontics).Includes bibliography (leaves 116-130).Introduced in dentistry more than 100 years ago, gutta-percha is the material of choice for root canal obturation, demonstrating minimal toxicity and tissue irritation. With the erupting incidences of latex allergies, there was a concern about the potential for immunoIogical cross-reactivity between gutta-percha and natural rubber latex. Gutta-percha is a rubber-like hydrocarbon derived from the sap of Payena and Palaquium gutta trees that are of the same botanical family as the Havea Brasiliensis trees that produce natural rubber latex. Gutta-percha is an isoprene polymer of a trans-arrangement, whose chemical composition is similar to the cis-polyisoprene of latex. One aim of this study was to test for this cross-reactivity. A total of twenty-two (22) female Dunkin-Hartley guinea pigs were divided into seven (7) groups. Two groups received latex implants subcutaneously, with one group getting a latex patch and the other getting a gutta-percha patch. Two groups received gutta-percha implants subcutaneously, with one group getting a latex patch and the other getting a gutta-percha patch. The remaining three groups were control groups. Two were negative controls, one receiving latex patches and the other receiving gutta-percha patches. The last group was the positive group receiving latex protein injected subcutaneously and latex paint on the skin of the animal. The implanted materials were left for fourteen (14) days before the patches were applied. The patches were placed for three (3) days before the animals were euthanised. Blood samples were drawn on days 1 and 14 (before placing the patches), day 14 six hours after placing the patches, and on day 15 and 16. After the animals were euthanised, tissue samples were obtained where the patches were applied and where the materials were implanted. H&E stained slides were prepared. The blood samples were analyzed by Western blot assay. The clinical, histological and immunological results indicated that there was no cross-reactivity between latex and gutta-percha. No detectable allerginicity for gutta-percha was observed however inflammatory reaction in tissue around implanted latex and gutta-percha was detected. It was concluded that the commercial gutta-percha tested did not contain the extractable proteins that can cross-react with latex. However if gutta-balata is added to the manufactured gutta-percha, caution should be considered when using this product to obturate root canals in latex-allergic patients