« March 2006 | Main | May 2006 »

Up Front with Dr. Jack Hahn

Dr. Jack Hahn was recently interviewed by the Cincinatti Enquirer. What follows are some brief excerpts from this interesting history provided by Dr. Hahn.

For those who may not know, Hahn is one of the pioneers of modern dental implantology. He invented the "Replace Select" dental implant system - a system for replacing missing teeth with artificial ones that have tapered ends and are anchored in the gums or jawbone.

"Hahn invented his system nearly three decades ago after a female patient walked into his North Avondale office and inspired him to develop his own substitute for dentures. The patient brought with her 17 sets of dentures in a box, none of which fit correctly. Hahn remembers her as a "dental cripple." "She had no quality of life," he said. "She couldn't go to restaurants. She couldn't go to parties." Hahn couldn't do implant work then because he didn't have the training. So he referred the patient to a doctor in New York for implants, and upon her return Hahn realized her life had been transformed. That was the impetus for Hahn to learn about implants by studying from the same doctor that performed the surgery."

"Though modern implants date to the 1970s, Hahn's system simplified the process so that more dentists can perform them. His patented system works much like a step-by-step "paint by number" kit. Color-coded implants make placement easier, the tips are tapered to be less invasive, and temporary tooth surfaces allow for immediate use. Once the tapered root forms have bonded to bone, patients get permanent surfaces."

"There are 44 million denture wearers in the U.S.," Hahn said. "People sneeze them out, they swallow them, the dog eats them. Dentures may irritate gums and many wearers have trouble eating."

Advances in implant surface techniques also allow for quicker healing and immediate function have helped boost the number of implant surgeries, he said. Hahn says implants are less expensive than bridges and dentures in the long run because they are more durable.

Note: To read the full interview, conducted by ANNA GUIDO, you can visit the Enquirer online by clicking here.

April 25, 2006 in Dental Implant News | Permalink | Comments (6)

Dental Implant Trauma Case

Dr. Blair asks us:

I have a young man (28) that needs his upper two centrals removed due to trauma and we plan dental implants.

The adjacent teeth are virgin and do not need to be restored. Comfortable and esthetic provisionals are always a struggle for cases  like this. I have used the Essix type of appliance as well as a removable flipper. Any other great ideas? Thanks in advance.

April 25, 2006 in Techniques and Procedures | Permalink | Comments (11)

Placement of Dental Implants in Grafted Sites

Dr. Dawson asks us:

Can anyone inform me of the latest thinking regarding dental implant placement in grafted sites, whether it be autogenous or otherwise......3/12, 6/12?? I seem to find conflicting evidence at every turn. Many thanks

April 25, 2006 in Treatment Planning & Complications | Permalink | Comments (11)

Mini Dental Implants: Soft-Hard Reline Material

Has anybody tried the new soft-hard reline material that replaces the need for O-rings or attachments with mini dental implants?

Its main indication is in the mandibular anterior.  You place your mini dental implants between the mental foramen nerves and then reline the overdenture with this material instead of using a ball or O-ring type of attachment.  I have seen advertisements for this and wonder about how well it works.  It certainly sounds a lot easier than doing an attachment pick up in the mouth with the danger of the acrylic locking around a dental implant.  I wonder if this can also get locked down. Any comments?

April 17, 2006 in Mini Dental Implants, Overdentures, Restoration of Dental Implants | Permalink | Comments (6)

Mini Dental Implants on 3 Tooth Bridge

Armando, a dental implant patient asks us:

Is it possible to use mini  dental implants to attach a 3 tooth bridge?

I had a bridge in that place with 2 regular dental implants that only lasted 5 years at which time one of the dental implants came loose. I did not want to go throught the experience and do dental implants again, but I would consider mini dental implants if it was feasible. Thanks for any advice.

April 17, 2006 in Treatment Planning & Complications | Permalink | Comments (3)

Fosamax Drug Could Be Merck's Next Woe

Even the Wall Street Journal is beginning to comment on the Fosamax debate. This past week the newspaper commented: "Echoing claims made in Vioxx lawsuits, Pensacola, Fla.-based law firm Levin Papantonio Thomas Mitchell Echsner & Proctor earlier this week filed a suit against Merck in U.S. District Court in Fort Myers seeking class-action status. The suit claims that Merck sold and heavily marketed Fosamax, the company's second-best-selling product, as safe despite knowing about its dangerous side effect. Another law firm, Knoxville, Tenn.-based Threadgill, filed a similar suit against Merck last fall." 

With Fosamax, attorneys are closely following the Vioxx playbook while claiming that they have more powerful cases because the link between Fosamax and the disease is easier to establish.

"With Vioxx, Merck can get away with saying, 'Hey, a lot of people have heart attacks for a number of reasons that have nothing to do with our product," says Tim O'Brien, a lawyer with Levin Papantonio. "But this is a very unique condition that isn't caused by cigarette-smoking or eating cheeseburgers."

Merck says most of the reported cases of osteonecrosis in patients taking bisphosphonates -- the class of drugs Fosamax belongs to -- have been cancer patients injected with more-powerful intravenous forms, and that a direct link to Fosamax isn't so easily drawn.

"The cause of osteonecrosis of the jaw (ONJ) is not well understood and is likely to include a number of conditions," the company says in a statement.

Oral surgeons and dentists began noticing the link between jaw decay and bisphosphonates five years ago. At first they thought that only the potent, intravenous versions of the drugs, such as those administered to cancer patients to stop cancer cells from dissolving bone, posed a risk.

In the past two years, some oral surgeons have become convinced that oral bisphosphonates such as Fosamax can also cause jawbone death when taken for a long period of time. Last month, the American Association of Endodontists issued a position statement recommending that dental surgeons should check whether patients are on bisphosphonates and consider those taking the drug to be at some risk for ONJ.

Merck counters that "in all of our controlled clinical trials, including the 10-year data with Fosamax, which have included more than 17,000 patients, we have not had reports of osteonecrosis of the jaw occurring in patients taking Fosamax."

The Whitehouse Station, N.J., drug maker also points out that it inserted two paragraphs in the "precautions" section of the Fosamax prescribing information for doctors in July 2005 after the Food and Drug Administration requested it amend Fosamax's label.

Salvatore Ruggiero, chief of oral surgery at the Long Island Jewish Medical Center in New York, says of the 155 ONJ cases he has come across, 22 involve patients who were taking Fosamax and other oral bisphosphonates. Some of these patients took Fosamax for seven or eight years, he says. "With the oral drugs like Fosamax, exposure time is the key," Dr. Ruggiero says.

Plaintiffs' attorneys have seized on such findings to allege that Merck engaged in the same deceptive behavior with Fosamax as it did with Vioxx. Like Vioxx, Merck has marketed Fosamax aggressively and today has more than $3 billion in annual sales from the drug. Doctors wrote 22.4 million prescriptions for Fosamax in the U.S. last year, according to IMS Health.

Henry Bone, director of the Michigan Bone & Mineral Clinic in Detroit, says the link between oral bisphosphonates like Fosamax and jaw decay is overblown. Fosamax "and other bisphosphonates are very important drugs for the treatment of osteoporosis," he says. "Rare reports of the 'osteonecrosis of the jaw' syndrome do not outweigh the benefits of these valuable medications." Dr. Bone has received research funding from Merck and once worked as a paid consultant for the company.

David Tundell, a 61-year-old former aircraft maintenance officer in the Air Force and a plaintiff in the Florida suit, says the Fosamax he took for a year helped alleviate the osteoporosis in his hips. But he believes it also landed him in the emergency room earlier this year when his jaw swelled to the point where he could no longer eat. During a three-day hospitalization, all his teeth were taken out and part of his jaw was shaved off to remove dead bone. He says his doctor recommended he stop taking Fosamax.

The prevalence of ONJ is hard to determine. The National Osteonecrosis Foundation says there are 20,000 Americans a year who are diagnosed with osteonecrosis, but it doesn't break out the number of jaw cases. The foundation says anecdotal evidence suggests there has been a surge in jaw cases of late.

Yesterday, a jury in Atlantic City, N.J. awarded $9 million in punitive damages to a 77-year-old man who had a heart attack while taking Vioxx, bringing total damages awarded to him and his wife to $13.5 million. It was the second Vioxx case Merck has lost.

"Certainly, they're hoping for spillover" from the Vioxx cases, says John Brenner, a partner with McCarter & English in Newark, N.J., which isn't involved in cases with either drug. "They'll try to paint it as a matter of pattern and practice on Merck's part. But you're going to be hard-pressed in a trial to introduce Vioxx in a Fosamax case."

Mr. O'Brien, the lawyer with Levin Papantonio, argues that Fosamax could become a bigger problem for Merck than Vioxx because ONJ is a so-called "signature" disease that is rare among patients who haven't taken bisphosphonates. He notes that dentists now refer to the condition as "fossy jaw" in a play on the middle syllable of the word "bisphosphonate." Levin Papantonio, which is also involved in the national litigation over Vioxx, is representing 200 patients in its Fosamax lawsuit and expects that number to rise.

Other pharmaceutical companies make oral bisphosphonates for osteoporosis. French drug maker Sanofi-Aventis SA makes Actonel and Swiss drug maker Roche AG makes Boniva. Mr. O'Brien says his firm decided to target Fosamax because data from the FDA's bisphosphonate safety review showed a much higher rate of ONJ with Merck's drug than with the others. "We'll take on any big pharmaceutical company," he says. "We're not doing this just because it's Merck."

In the complaint it filed Monday, Levin Papantonio alleges that the FDA's drug-safety office concluded that Merck and other bisphosphonate makers should change their labels to reflect the risk of ONJ as early as August 2004, 11 months before Merck changed the Fosamax label.

Merck counters that it submitted a draft revised label for Fosamax to the agency in March 2005. An FDA spokeswoman says it isn't "at liberty to discuss details of internal labeling negotiations between the agency and a company." She adds that the current Fosamax label "adequately conveys what is known about ONJ-bisphosphonates."

Source: JOHN CARREYROU, for the Wall Street Journal

April 16, 2006 in Dental Implant News | Permalink | Comments (4)

Fosamax Osteonecrosis Lawsuit Filed

The oral bisphosphonate (e.g. Fosamax) / osteonecrosis story continues to heat up.  This past week Linda Secrest and her husband, Frank Secrest, filed a personal injury and product liability lawsuit against Merck & Co., the manufacturer of Fosamax. Class-action status will be pursued for similarly injured victims, O'Brien, her lawyer said. The lawsuit was filed in federal court in Fort Myers.

As described by Secrest, six or seven months after she started on Fosamax, Secrest underwent a root canal in September 2000. She had no inkling the medication can lead to infection and tissue loss after invasive dental procedures, including having cavities filled.

Secrest fell victim to a painful infection with swelling. The infection refused to heal and led to a jawbone tissue disease, called osteonecrosis of the jaw, referred to as ONJ, where tissue doesn't heal and becomes exposed after a minor trauma, such as invasive dental work.

"We have over 200 clients all over the U.S., but the majority are in Florida," Tim O'Brien, of the national firm Ennis & Ennis, said.

His law firm is among others nationwide working on negligence claims against Merck regarding Fosamax, following a similar course as the 9,000 lawsuits logged against the drug manufacturer for failure to warn of potentially deadly side effects from its painkiller Vioxx.

"Merck's problem is bigger here than with Vioxx," O'Brien said, adding that there is a clear link the jawbone tissue disease and Fosamax. "It is not that (the jaw tissue disease) is so uncommon. It is just that the causes are so few."

A top seller for Merck, bringing in more than $3 billion in sales, Fosamax was first approved by the Food and Drug Administration for osteoporosis in September 1995. The medication belongs to a class of drugs known as bisphosphonates, used for treating bone conditions and as chemotherapy for cancer patients.

During the late 1990s and later, cases were surfacing where cancer patients on bisphosphonates, namely intravenous drugs Aredia and Zometa, had developed jawbone deterioration.

In 2004 after seeing an increase of jawbone necrosis in patients on bisphosphonates, a group of oral surgeons published an article in the Journal of Oral and Maxillofacial Surgery relating their findings involving 63 patient cases. Novartis, the manufacturer of Aredia and Zometa, responded by issuing a warning to doctors in November 2004.

On the other hand, Merck did not take such action, although the company knew or should have known that Fosamax, as part of same class of drugs as the chemotherapy agents, inhibit blood flow and tissue growth, according to the lawsuit. That's despite the FDA recommendation that Merck should amend its labeling for Fosamax to specifically warn of the risk of the jawbone disease.

"As a result, a minor injury or disease can turn into a nonhealing wound," according to the lawsuit. "That in turn can progress to widespread necrosis (bone death) and osteomyelitis (inflammation of bone marrow)."

Merck did not undertake any further clinical studies on Fosamax to examine the risk of jawbone loss, and the pharmaceutical company did not warn the medical community or consumers of the risks, according to the lawsuit.

Merck spokesman Chris Loder issued a prepared statement in response to the lawsuit:

"The cause of osteonecrosis of the jaw (ONJ) is not well understood and is likely to include a number of conditions. In all of our controlled clinical trials, including the 10-year data with Fosamax, we have not had reports of osteonecrosis of the jaw occurring in patients taking Fosamax. Merck has received post-marketing reports described as osteonecrosis of the jaw occurring in patients taking Fosomax. Post-marketing reports do not necessarily indicate causality."

On Jan. 31, 2005, Merck received a request for data from the FDA to update the label for Fosamax to include bisphosphonate class labeling for the jawbone tissue disease, according to the statement.

"Merck submitted a draft to FDA on March 1, 2005," according to the statement. "FDA comments on this draft revised label were received in June 2005 and the new label was made publicly available in July, 2005."

Dr. Salvatore Ruggiero, lead author of the 2004 article that linked the class of drugs to jawbone necrosis, said Merck likely would not have known that Fosamax can lead to jawbone necrosis.

"The problem is the complications with the drugs, especially the oral form, will take many years to manifest, so you won't see it in phase one, phase two or phase three (clinical) trials," Ruggiero, chief of oral and maxillofacial surgery at Long Island Jewish Medical Center, said. "So I'm not surprised they did not know of this complication. When Merck became aware of the problem? I don't know."

The FDA did issue a broad warning covering the entire class of the drugs but he does not recall when that occurred and when Merck acted.

"The timing of it is what the lawyers are going nuts over," he said, adding that his focus was making oncologists, dentists and primary physicians aware of the medical complication.

The predicament now is that no studies are under way to further show the connection, although his clinic is following 155 patients with jawbone necrosis.

"Do we all think it is happening? Absolutely, but we need prospective studies," he said. "The association is very strong."

His theory is that the longer an individual is on this class of medications, the risk of jawbone necrosis increases following invasive dental work.

Dr. James Green, an oral surgeon with the University of Florida's College of Dentistry, said the dental community became aware of the incidence of jawbone death with bisphosphonates five or six years ago.

"My experience runs about three or four years," he said. "I don't know why we are seeing it now, all of a sudden we are seeing these cases now."

At the same time, Fosamax is responsible for many fewer cases of jawbone death than the chemotherapy medications of the same class of drugs.

"Fosamax is a little player, about 4 percent of the cases," Green said, adding that it is confusing why Fosamax is facing the personal injury attention unless Merck did not reveal the risks.

O'Brien, the plaintiff's attorney, said the reason for the focus on Fosamax is that it is prescribed for a noncritical condition, whereas the chemotherapy drugs aim to save a patient's life.

Secrest, the Naples plaintiff, and other defendants will need coninuing medical monitoring that goes beyond normal medical care, according to the lawsuit.

In Secrest's case, her non-healing infection led to teeth having to be removed and an attempt with dental implants which didn't take, O'Brien said. The couple have declined to comment about the lawsuit.

She had 60 treatments in a hyperbaric chamber, which stimulates blood vessel growth for tissue healing, to no avail.

"They were not much help," her attorney said. "She now has exposed jawbone, she has significant bone loss. It's very, very trying on her. If you look at her, you will see a ravaged mouth. It is very trying because there is no fix."

Source:  Liz Freeman, NapleNews.com

April 16, 2006 in Dental Implant News | Permalink | Comments (7)

Improving Bone Grafts

A new technology for dental implants that may improve construction or repair of bones in the face, skull and jaw, has been developed by researchers from the American Dental Association Foundation (ADAF) and the National Institute of Standards and Technology (NIST).

The new technology, which is described in journal articles(1, 2,3), provides a method for making scaffolds for bone tissue. The scaffold is seeded with a patient's own cells and is formed with a cement paste made of minerals also found in natural bone. The paste is mixed with beads of a natural polymer (made from seaweed) filled with bone cells. The paste is shaped or injected into a bone cavity and then allowed to harden with the encapsulated cells dispersed throughout the structure. The natural polymer beads gradually dissolve when exposed to the body's fluids, creating a scaffold that is filled by the now released bone cells.

The cement, a calcium phosphate material, is strengthened by adding chitosan, a biopolymer extracted from crustacean shells. The implant is further reinforced to about the same strength as spongy natural bone by covering it with several layers of a biodegradable fiber mesh already used in clinical practice.

"Bone cells are very smart," says Hockin Xu, of the ADAF and principal investigator for the project. "They can tell the difference between materials that are bioactive compared to bioinert polymers. Our material is designed to be similar to mineral in bone so that cells readily attach to the scaffold."

The researchers used mouse bone cells in their experiments, but in practice surgeons would use cells cultured from patient samples. In addition to creating pores in the hardened cement, the natural polymer beads protect the cells during the 30 minutes required for the cement to harden. Future experiments will develop methods for improving the material's mechanical properties by using smaller encapsulating beads that biodegrade at a predictable rate.

Source: MedicalNewsToday.com

1. E.F. Burgera, H.H.K. Xu and M.D. Weir. Injectable and rapid-setting calcium phosphate bone cement with dicalcium phosphate dihydrate. Journal of Biomedical Materials Research B. April 2006.

2. H.H.K. Xu, M.D. Weir, E.F. Burguera and A.M. Fraser. Injectable and macroporous calcium phosphate cement scaffold. Biomaterials. In press.

3. M.D. Weir, H.H.K. Xu, and C.G. Simon, Jr. Strong calcium phosphate cement-chitosan-mesh construct containing cell-encapsulating hydrogel beads for bone tissue engineering, Journal of Biomedical Materials Research A. In press.

April 14, 2006 in Dental Implant News | Permalink | Comments (3)

Jaw Decay Linked to Fosamax

Source: By Linda Marsa, Special to The LA Times

Sue Piervin never suspected the pills she took to strengthen her bones could severely damage her jaw. Twelve years ago, a routine X-ray revealed her bones were thinning, so her doctor prescribed a drug to help stop the erosion of bone density. Then, in 1999, Piervin developed a painful bone spur in her jaw that had decayed to such an extent that it had to be surgically removed.

April 11, 2006 in Dental Implant News | Permalink | Comments (5)

Mitral Valve Prolapse

I have started treatment planning a dental implant rehabilitation for a patient with mitral valve prolapse with regurgitation. 

She will be receiving multiple dental implants and two dental implant supported bridges.  She routinely
takes an antibiotic premedication (amoxicillin) for dental treatment that involves gingival bleeding, surgery, etc.  A periodontist will be placing the dental implants and I will be restoring them.  When should I have her take the amoxicillin?  Every time I try in the abutments and bridge components? Any thoughts or comments would be appreciated.

April 10, 2006 in Treatment Planning & Complications | Permalink | Comments (9)