How much a dental Crown should last ?

Dental crowns, also called caps, are expensive, from several hundred to several thousand dollars, with insurance typically covering only part of the cost. The dental crown procedure can be temporarily painful and cause localized swelling. The crowns require multiple visits to the dentist. They can break or fall out. When done right, they can protect a smile for decades; when done wrong, they can be a real nightmare.

Take the story told by Jim Faherty, 74, a retired executive in Wellesley, Mass., who went to the dentist a few years ago because of a loose bridge that was replacing three of his upper front teeth.

Faherty said that he was sitting in the chair, expecting the dentist to begin preparation for bridgework, when she suggested crowns instead. He told her that other dentists had said crowns would not work because he had only a residual amount of natural tooth left in the front. But this dentist insisted otherwise.

“Here she is, a professional, graduated from one of the best dental schools, and [she said] crowns are better to keep the area clean,” Faherty said. “She willy-nilly went ahead and did the crowns.

“And they all failed,” he said. What followed, he said in a telephone interview, was a frustrating series of crowns that fell out, new temporary crowns, crooked crowns, surgical root extractions, evaluations, reevaluations, a change of dentist . . . . Two and a half years and more than 50 dental visits later, Faherty has two implants and a new crown — and he’s on a crusade. He’s posted his story on a consumer-complaint site and willingly shares a thick file of his dental records.

He keeps the failed caps in a large saltshaker and rattles them into the phone. “That’s my crowns,” he said.

Faherty’s is an extreme example, but many people are apprehensive about crowns. The more you know as a consumer, the better off you are, so . . . welcome to Dental Crown 101.

Crowns are used to protect weak teeth; to restore misshapen, discolored or broken ones; and to cap implants, root canals and the teeth that anchor either end of a bridge. They are used when a tooth has decayed and there is little natural tooth left to hold a filling. They’re more likely to be needed by people who grind their teeth or clench their jaws, two common activities that lead to fractures and cracks. And in many cases they need to be replaced, sometimes more than once, over the course of a lifetime.

“It is not inevitable that everyone is going to get one,” said Eugene Giannini, a District dentist and spokesman for the D.C. Dental Society. He said it depends on a variety of factors, including general health and lifestyle, genetics and what type of dental care you have received throughout your life.

Among people who do get crowns, the majority get their first in middle age, though sometimes even children need them. The procedure differs patient-by-patient and tooth-by-tooth, Giannini said. First, the dentist must drill away any existing filling and damaged portions of the tooth. Then the remaining tooth material must be reshaped to receive the crown. The amount of tooth that needs to be removed depends in part on the material of the crown.

Crowns made completely of metal are the strongest and require the least amount of tooth removal. They can be made of gold or other alloys including palladium, nickel and chromium.

Porcelain can be fused to metal so that the crown will blend in better with surrounding teeth, though sometimes the metal shows through, especially if the gums are receding. Crowns that are made completely of porcelain can be color-matched the best to surrounding teeth, though they are not as strong as metal models. Crowns made with porcelain require more tooth removal because their strength is dependent on their thickness.

After the drilling, the dentist will make a mold of what is left of the tooth. The mold is sent to a laboratory where the crown is made, and you will get a temporary crown to wear in the meantime. The permanent crown arrives within a few weeks.

But “permanent” is a term for discussion. There are no scientific data on the longevity of crowns, and some patients and insurers say dentists replace crowns more often than necessary.

Insurance plans vary, but in general most won’t reimburse patients for a replacement until a crown is five years old.

And that doesn’t mean every five-year-old crown should be replaced, said Doyle C. Williams, the chief dental officer for DentaQuest, a national dental benefits company.

“Ten to 20 years is the average lifetime of a real crown,” Williams said, noting that he has had one crown in his mouth for 35 years. Williams, who also sits on the board of the National Association of Dental Plans, said he thinks the industry standard should be extended. “It should be changed, because it encourages people to change [a crown] every five years,” he said.

Matthew Messina, a Cleveland dentist and a spokesman for the American Dental Association, disagreed with the assertion that dentists are too quick to replace crowns. “I haven’t seen or heard anything of that sort,” he said. “Based upon what I’m hearing and talking with other colleagues of mine about, there’s nothing we are hearing in the dental association about trends towards that.”

Measures to prevent the need for crowns start in childhood, when sealants can be placed on teeth to cut down on the chance of decay and the need for a large filling. Other measures include making sure your occlusion, or bite, is correct, and wearing a mouth guard when playing contact sports and a night guard to prevent clenching. It’s also not advisable to chew a lot of ice.
And if you can, cut down on jaw-clenching stress. “That’s a thing we see a lot in Washington: Patients are bruxers [teeth-grinders] and clenchers in this town,” said Dennis Milliron, a dentist with a private practice in Foggy Bottom. He likened clenching and grinding to hitting a concrete block with a sledgehammer.

“The first and second time it might not break, but the 20th time? It will break.”

Milliron said a patient’s first crown can be traumatizing, especially for younger people. “It’s the sense of mortality,” Milliron said. “Patients think, ‘Wow, I’m getting old.’ ” He described a professional in her early 30s who received her first crown a few weeks ago.

“She had apprehension, and some of it was about the procedure and some of it was a sense of feeling like she’s falling apart,” Milliron said. The patient, who works in a high-stress government job, had large fillings and a habit of jaw-clenching, he said. “We discussed why it was needed and [that] it wasn’t a reflection of her personally,” he said.