Sargenti paste. Root canal may be able to save a tooth by replacing the pulp with a substitute material, ideally, one that is inert and easy to handle. Standard root canal uses gutta percha, a tropical tree sap. In the 1950s sargenti began filling roots with a paste that contained paraformaldehyde, which forms formaldehyde when contacted w water. The paste can damage surrounding tissues if it leaks from root.
Let me explain. Developed in the 1940s and 1950s by angelo sargenti, d.M.D., a swiss dentist who died in 1999, and introduced in the U.S. At the 1958 ada meeting, the sargenti technique gained popularity in the 1970s. But it just as quickly became the object of complaints about its side effects, with patients claiming they suffered permanent jaw damage and developed osteomyelitis following root canal procedures.