A Pennsylvania state court excluded plaintiffs’ expert testimony offered in coordinated cases alleging a denture adhesive caused personal injuries. See In re: Denture Adhesive Cream Litigation, No. 090604534 (Phila, Ct. Common Pleas)(J.New).
In 2009 the court had created the mass tort docket for these product cases. Defendants include manufacturers and retailers. Defendants moved to exclude under the Frye test the plaintiffs’ four main general causation experts, who opined that the product’s zinc conduct led to neurological complications; the court heard live testimony and oral argument.
The court had considered some of the issues before, excluding the general causation opinions because they were based on inadequate data, including with regard to how much zinc is absorbed in the body. Plaintiffs then submitted supplemental information which they alleged filled in the various analytical gaps. One item involved a publish Scottish study of 22 patients to which one of the experts applied a further analysis he termed a “cohort study”, and another was a study by one of the experts of 24 subjects using denture products over a 30 day period.
The court concluded that the opinions involved “novel” science because the alleged link between zinc and neuropathy is reported in literature only in the past few years. In analyzing the new data, the court stressed that the issue was not just the alleged link between zinc exposures and neuropathy, but the ability of a specific product to cause specific injuries. Not all zinc-containing dental creams are equal, said the court.
The so-called cohort study did not describe the actual exposure dose of each subject. It didn’t describe the type of adhesive used, the frequency it was used, or the duration between use and symptoms. Thus it is based on a method that is not generally accepted. Furthermore, it was not published and subject to peer review.
The experts alleged that zinc in the denture adhesive had blocked the users’ bodies from being able to absorb copper, causing copper deficiency myeloneuropathy. The second study, at best, linked product use to a short-term reduction in copper. It did not say anything about severe copper deficiency or allegedly resultant neurological symptoms. The court found it to be a “blatant, litigation driven attempt to remediate” the deficiencies in the prior expert testimony.
In sum, even with the “new” data, plaintiffs had failed to provide a sound and generally accepted methodology linking the product to the alleged injury. Expert opinions excluded.