You don’t see class actions going to trial very often, but that is what happened in Patricia A. Murray Dental Corp. v. Dentsply International, Inc., and the defendant device manufacturer came away with a defense verdict that binds the class. The California Court of Appeal’s opinion affirming that result is the topic of today’s post, and it is a nice bookend to a Pennsylvania case we wrote on just a few months ago, Center City Periodontists v. Dentsply International, Inc. Both are class actions alleging that Cavitron ultrasonic dental scalers are not worth what dentists paid for them.

Same devices. Similar allegations. Somewhat different outcomes. The Pennsylvania class action bit the dust when the court denied class certification, a result we lauded here. The California plaintiffs met a similar fate on their first try, but the California Court of Appeal reversed the order denying class certification and remanded for further proceedings. So the plaintiffs returned to the trial court and got their class certified. They probably wish now that they had ended it there, or at least accepted whatever class settlement the defendant might have offered.

Why? Because they took their certified class action to trial and lost.

Here is what happened. The class representatives alleged that the Cavitron’s directions say it can be used in “[p]eriodontal debridement for all types of periodontal diseases,” but in fact they cannot because the devices accumulate biofilm in their waterlines and are incapable of delivering sterile water during surgical procedures. According to the plaintiffs, this was a deceptive business practice under a California consumer statute and a breach of express warranty. Patricia A. Murray Dental Corp. v. Dentsply International, Inc., No. A141377, 2018 WL 345049, at *1 (Cal. Ct. App. Jan. 10, 2018).

Let’s focus on these allegations. Dentists have widely used Cavitron ultrasonic scalers for more than 40 years, and the statement that they can be used in “debridement for all types of periodontal diseases” is likely to deceive consumers only if dentists do not already know that biofilms can accumulate and that the systems cannot dispense sterile water. That is one of the reasons why the certification of this class was questionable in the first place: Surely each dentist’s knowledge regarding biofilms and his or her clinical judgment on when to use sterile versus nonsterile water is unique to each class member.

But plaintiffs also surely argued on class certification that all dentists are the same, so the trial court and Court of Appeal hoisted plaintiffs on their own petard. If dentists are all the same, they are the same in that they are all highly trained and already understand that biofilms and related water quality issues are dental facts of life. For the Court of Appeal, the dentists’ knowledge base was a critical consideration. That is to say, the Cavitron’s directions as presented “to the general public, could be viewed as representing that the Cavitron is suitable for surgical use. However, the fatal flaw in this reasoning is that the targeted consumers of this product are licensed dental professionals.Id. at *8.

As the Court further explained, the “knowledge base of the targeted consumer” is relevant in determining whether the allegedly deceptive conduct or advertising is “likely to deceive,” which is the standard under California’s statute. Id. On that score, the evidence was overwhelming that the Cavitron’s directions were not likely to deceive a significant portion of licensed dentists because they already knew about biofilms and water quality. Biofilm contamination of dental unit waterlines was first documented in the 1960s, and as early as 1978 the American Dental Association was suggesting countermeasures. Id. at *3. The ADA has issued publications on the topic, including a “Statement on Dental Unit Waterlines” in 1995 (and don’t you wish you had that scintillating article to read over a cup of coffee). California dentists are required to take continuing education classes on infection control every two years. The plaintiffs’ expert admitted that water quality was a “hot subject” starting in the mid-1990s. The CDC released recommendations, and then updated them. The Dental Board of California adopted minimum standards. Id. at **4-6.

You can read the opinion to get the details, but the gist is clear—dentists knew about this stuff and were not “likely to be deceived.” As the California Court of Appeal put it:

Plaintiffs already knew the facts they contend should have been disclosed. They know all dental waterlines contain biofilm and that Cavitrons do not deliver sterile water. [¶] In sum, plaintiffs failed to carry their burden of proof.

Id. at *10 (emphasis added). This disposed of the deceptive practices claim and also breach of warranty because “[u]nlike the state of the evidence during class certification, the record on appeal establishes substantial evidence that plaintiffs were aware of the biofilm risk posed by Cavitron usage, but they purchased and used it anyway.” Id. (emphasis added). That’s what it came down to: The dentists knew, but purchased and used the devices anyway. They got what they paid for, with their eyes wide open.