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Infection Control for Dentists Part 6: Dentists Sought Class Action Certification against Dentsply for Cavitron Defects and Lost

By August 10, 2017June 27th, 2023Practice Management

So Centre City Periodontists, PC v. Dentstply International, Inc [2017] US District Court, ED Pennsylvania is an interesting and recent case worth mentioning. In that case, Centre City Periodontists, PC and dentists residing in Pennsylvania and New Jersey sued Dentsply International, Inc. in a class action for breach of express warranty. They claimed alleged deficiencies in the design and labeling of various models of the Cavitron ultrasonic scaler.

The crux of the dentists’ claim was that the Cavitron isn’t safe or suitable “for its indicated uses because the internal walls of the device’s waterlines naturally accumulate biofilm, exposing patients and dental staff to potentially hazardous bacteria levels in excess of safe water standards, even when operated and maintained in a manner consisted with the Directions for Use and related materials”.

According to the dentists, this inherent defect constituted a breach of the Cavitron’s express warranty against defects in materials or workmanship. Together with Dentsply’s failure to disclose this defect, this amounted to a breach of an express warranty of safety and suitable contained in the Directions for Use and related materials.


By way of background, a Cavitron is a device used to deliver high pressure, pulsating water stream into a patient’s mouth through a hand piece at the end of a flexible tube that is connected to the device’s main body. The water stream keeps the working area cool and frees up debris during non-surgical procedures. Only certain quality of water should be used because of the potential for pathogenic microorganisms to be transmitted through the water.

The U.S. Centers for Disease Control and Prevents established guidelines in 2003 to advise health professionals to use adaptive devices or closed water systems combined with chemical flushing and other measures in consultation with manufacturers to achieve no more than 500 colony forming units per milliliter (the regulatory standard for portable water established by the US Environmental Protection Agency). In other words: water flushing isn’t enough on its own. Even the American Dental Association was recommending to its members in 1996 that biolfilm formation in waterlines should be managed using a combination of strategies such as chemical treatment and independent reservoirs.

Now, because the Directions for Use and related materials HAD NOT required the installation of of a closed water system or chemical flushing AND HAD NOT warned buyers of the biofilm problem, the dentists who launched the class action purportedly believed that the Cavitrons would deliver potable water consistent with safe water standards for its indicated uses when installed on an OPEN water source and FLUSHED only with water in accordance with the Directions for Use. Over time, these dentists noticed that, when left untreated, the Cavitron’s waterlines naturally accumulated potentially hazardous levels of biofilm.


So the dentists sued Dentsply in 2010 and alleged that Dentsply had allegedly breached an express warranty, negligently designed the Cavitrons and violated New Jersey’s Consumer Fraud Act. For the class to be certified as a class action to proceed under the rules of civil procedure, there number be (1) a numerous class that joinder of all members is impracticable, (2) common questions, (3) typical claims, and (4) adequate representation. Let’s look at each of these requirements, shall we?


The plaintiff dentists were unable to prove that the class was so numerous that having them individually sue is impractical.   Yes, the plaintiff dentists pointed to the number of dentists practicing in New Jersey and Pennsylvania who COULD be included in the class of dentists who bought Cavitrons and also connected them to an open water source. But the Court could not “assume”, “speculate” or defer to “common sense” with respect to how many class members existed. The plaintiff dentists must produce evidence, direct or circumstantial, specific to the products, problems, parties, and geographic areas actually covered by the proposed class definition to allow a court to make a FACTUAL finding. And there was insufficient evidence here.   While the plaintiffs failed at this point and the whole case could be dismissed as a result, the Court went to to assess the other components of having a class action certified.


This is the only component of certifying a class action that the plaintiff dentists were able to establish – namely, whether Dentsply’s conduct was common as to all members of the class. The plaintiff dentists argued that the breach of warranty claims all share as a common issue that Dentsply represented in the Directions for Use that the Cavitrons were suitable for its indicated dental uses if purchasers followed Dentsply’s installation and maintenance instructions. The Court agreed that these types of questions will result in common answers that apply across the board to all members of the class.


Importantly, the common issues must be typical among the class. The claims of the class representative must be generally the same as those of the class in terms of the legal theory advanced and the factual circumstances underlying that theory. Also, the class representative must not be subject to a defence that is both inapplicable to many class members and likely to become a major focus of the litigation. Finally, the interests and incentives of the representatives must be sufficiently aligned with those of the class.

On these issues of typicality, the plaintiff dentists failed to satisfy this requirement. First, some plaintiff dentists bought their Cavitrons at a discount from an UNAUTHORIZED dealer (this could defeat that plaintiff dentist’s claim since the warranty covers only products purchased from an AUTHORIZED Dentsply dealer). Second, some plaintiff dentists acknowledged that they hadn’t necessarily read (or recall having read) all of the relevant provisions of the Cavitron’s Directions for Use; but not being aware of the content CANNOT be typical representatives of a class that was allegedly misled and damaged by Dentsply’s representations in those same Directions for Use! For these and other reasons, the Court held that the plaintiff dentists’ claims are not sufficiently typical to warrant certification of the class action.


Because some of the plaintiff dentists had specific issues that diverged the interests and the incentives between them and the class members, which meant that they could not fairly and adequately represent the class. For example, some of the plaintiff dentists had untimely claims because they bought Cavitrons too early on and could be barred from bringing claims based on the statute of limitations.   And this fight to have these particular plaintiff dentists involved involved in the class action might create intra-class conflict because the plaintiffs may be incentivized to spend resources to save their less valuable claims without any obvious benefit to class members with more valuable, timely claims.

Another problem with adequacy is the fact that a plaintiff dentist and one of the their lawyers had been friends for twenty-five years and still regularly kept in touch despite living on opposite coasts. The plaintiff dentists treated that solicitor’s family members. And the plaintiff dentist replied that he available to help when approached by the solicitor about the lawsuit. All of this raised serious concerns as to the plaintiff dentist’s adequacy to represent the class.


For these and other reasons (including finding that a class action was not superior to other available methods for adjudicating this controversy), the Court refused to certify the class.

The Content of this post is provided for informational purposes only. It is not intended to be legal, financial, tax, or other professional advice of any kind. You are advised to contact DMC (or other counsel) to seek specific legal advice concerning your individual situation.