Dentists in Georgia and Texas sued 3M Co. this week for allegedly making defective dental crowns that came apart in patients’ mouths and cost the dentists thousands to replace.

The lawsuit, filed Monday in the U.S. District Court in Minneapolis, was brought by three dentists and two dental practices seeking class-action status from the courts.

The suit accuses 3M Co. and its 3M ESPE dental subsidiary of producing defective “Lava Ultimate” dental crown materials that allegedly de-bonded inside the patients’ mouths at least 50 percent of the time.

“Dentists have been forced to cover the cost of replacing the crowns,” the lawsuit said. Replacements cost the dentists as much as $1,000 per crown, the court document said.

The lawsuit said 3M pulled its Lava Ultimate crown products from the market last summer “and admitted that the product was “de-bonding at a higher than anticipated rate.”

The suit accused 3M of marketing a product that it knew early on was defective and not able to stand up to its own warranty. Plaintiffs claim that 3M settled many complaints privately.

3M spokeswoman Lori Anderson said in an e-mail that the company “is currently reviewing the complaint and does not have any comment on the pending litigation.”

The lawsuit was filed by plaintiffs: Vikram Bhatia from Georgia; Jeffrey Chen from Georgia; Bruce Sherrill from Texas; Johns Creek Dental Associates in Johns Creek, Ga.; and Brookhaven Dental Associates in Atlanta.