The Morning Drill: October 12, 2011

A collection of dentistry and health related links/comments for your day.

Christensen: Metal crowns of the past are far superior

During a presentation on restoratives at the ADA's Annual Session on Tuesday, Gordon Christensen, DDS, MSD, PhD, didn't hold back.

"One thing I'll look at is the white stuff [nonmetals] in restorative dentistry," he said during the opening of the Christensen Bottom Line 2011. "Does it perform as well as the gold stuff? I'll tell you candidly that it doesn't."

The shift in materials favored for crowns received particular focus during the first part of his talk. Dr. Christensen shared conclusions that his nonprofit product-testing facility in Provo, UT, had reached about many of them.

He had strong words for what he termed "this white crown business." Of them, he said, "metal crowns of the past are far superior."

Nonetheless, dental practitioners continue to embrace the newer materials. According to data from Glidewell Laboratories, "Metal is dying," Dr. Christensen said. Metal has gone from 12% of all crowns placed from 1997 to 2010 to 5.6% in the year 2010. Porcelain-fused-to-metal (PFM) crowns went from 72% to 49% in the same period. Meanwhile, all-ceramic and composites went from 16% to 49.5%.

His skepticism was plain as he deconstructed the reasons all-ceramic restorations are being chosen.

"The strength of some types appears to be better than in the past," Dr. Christensen said. "But I have a whole drawer of broken crowns. I keep them there to keep me humble."

Nearly 5% of PFMs fail after 10 years, he noted, while many ceramic and composites fail after one.

"When you put a restoration on a patient who is 30, it's going to fail," Dr. Christensen said. "You will replace it."

Then he asked who in the audience had had to cut off a full-zirconia crown. With many hands in the air, he quipped, "You still look tired!"

He dismissed most of the burrs designed for cutting zirconia.

"Our research shows you're better off with a $1 diamond," Dr. Christensen said. "A diamond from Microcopy called Neo is one that continues to prove itself." It comprises extremely sharp diamond pieces leftover from the ring-making process, he explained

City of Malibu Adopts Landmark Resolution: Supports Global Phase Out of the Dental Mercury Filling

The Malibu City Council unanimously passed a landmark resolution on Monday, October 10, taking a proactive step by supporting “national and worldwide efforts to reduce anthropogenic sources of mercury,” which is in many products in common use today - including the dental amalgam filling. Dr. and Mrs. James Rota, 30-year Malibu residents, along with Californians for Green Dentistry, contacted the Malibu City Council to express concern regarding awareness of the toxicity of the mercury amalgam "silver" filling.

Mayor John Sibert sponsored the resolution, which was in response to the United Nations Environmental Programme (UNEP) suggestion that cities take an official position in the phase out or global ban of mercury. Malibu is the third city in the United States to do so.

During the City Council Meeting, Mayor Sibert revealed that while conducting environmental studies of soil in Malibu, mercury was found with no apparent source – except that the location in question previously hosted a dental office.

Police: Dentist assaulted

An Idlewood Avenue woman reportedly unhappy with work on her tooth was arraigned Tuesday in Municipal Court on accusations that she pulled her dentist's hair and wouldn't let go.

Cassandra Allen, 21, was arraigned on two counts of assault. Judge Elizabeth Kobly set bond at $10,000, as well as ordering that Allen have no contact with the Small Smile Dental Center on Mahoning Avenue or any of its employees.

Police reports state that Allen went to the office about 9 a.m. Monday, upset over some work done on her tooth. A dentist tried to help her, but several times during the process, Allen complained, the report states.

Allen then jumped the dentist from behind and pulled her hair, reports state.

The dentist yelled and an employee rushed in and tried to get between them. Allen hit the employee with one hand while pulling the dentist's hair with the other, the report states. The employee had several scratches on her arm, reports state.

Another dentist then stepped between Allen and the first dentist, and the dentist and employee ran out of the room, reports state.

The second dentist then fixed Allen's tooth, police said.

The dentist that was attacked told police she had not fixed Allen's tooth in the first place and she spent 30 minutes trying to fix it before she was attacked.

Allen was taken to the Mahoning County Jail, where she was held pending her court appearance. She appeared as if she had been crying when she appeared via video hookup.

Vitamin Supplements Associated With Increased Risk for Death

In women aged 55 to 69 years, several widely used dietary vitamin and mineral supplements, especially supplemental iron, may be associated with increased risk for death, according to new findings from the Iowa Women's Health Study.

Although many vitamin supplements did not appear to be associated with a higher risk for total mortality, several were, including multivitamins, vitamins B6, and folic acid, as well as minerals iron, magnesium, zinc, and copper.

Jaakko Mursu, PhD, from the Department of Health Sciences, Institute of Public Health and Clinical Nutrition at the University of Eastern Finland in Kuopio, Finland, and colleagues reported their findings in the October 10 issue of the Archives of Internal Medicine.

"Supplements are widely used, and further studies regarding their health effects are needed," Dr. Mursu and colleagues write. "Also, little is known about the long-term effects of multivitamin use and less commonly used supplements, such as iron and other minerals."

"In agreement with our hypothesis, most of the supplements studied were not associated with a reduced total mortality rate in older women," Dr. Mursu and colleagues conclude. "In contrast, we found that several commonly used dietary vitamin and mineral supplements, including multivitamins, vitamins B6, and folic acid, as well as minerals iron, magnesium, zinc, and copper, were associated with a higher risk of total mortality."

"Although we cannot rule out benefits of supplements, such as improved quality of life, our study raises a concern regarding their long-term safety," the authors add.

In a related editorial, Goran Bjelakovic, MD, DMSc, and Christian Gluud, MD, DMSc, from the Centre for Clinical Intervention Research, Cochrane Hepato-Biliary Group, Rigshospitalet, Copenhagen University Hospital, Denmark, note that the current study adds "to the growing evidence demonstrating that certain antioxidant supplements, such as vitamin E, vitamin A, and beta-carotene, can be harmful."

"We cannot recommend the use of vitamin and mineral supplements as a preventive measure, at least not in a well-nourished population," they add. "Those supplements do not replace or add to the benefits of eating fruits and vegetables and may cause unwanted health consequences."

Enjoy your morning!