Dental office gets nod for eco-friendly design

Dental office gets nod for eco-friendly design

By DrBicuspid Staff

September 4, 2008 -- The country's first Leadership in Energy and Environmental Design (LEED)-certified dental office recently opened its doors in Portland, OR.

Mint Dental Works' design incorporates environmentally friendly materials. Its custom dental cabinetry, for example, is constructed locally with 100% preconsumer recycled wood fiber particleboard, according to the office Web site. The office is mercury-free and uses digital equipment and natural cleaning products. It is lit with compact fluorescent lighting and occupancy sensors for energy savings.

"We have installed low-flow fixtures, energy star appliances, and sensor-operated faucets. Our dry evacuation system is a new dental technology that uses no water -- a huge savings compared to a traditional system that consumes approximately a gallon a minute," the practice states on its Web site.

"Although it is exciting that our practice will be the first LEED-certified dental office in the [U.S.], what ultimately means the most to me ... is our ability to provide extraordinary comprehensive care for our patients in the healthiest possible environment," Jason McMillan, D.M.D., the practice owner recently told SideKick magazine.

Tylenol and pain management: Know when to say when

Tylenol and pain management: Know when to say when

By Kathy Kincade, Editor in Chief

September 3, 2008 -- One morning last February, 19-year-old Madalyn Byrne woke up with a toothache. So the University of Oklahoma student did what many in her condition would do: she took some Tylenol.

Weeks later, she became ill with flu-like symptoms and within days died from acute liver failure -- all from ingesting too much acetaminophen, according to authorities. Byrne was reportedly taking as many as nine 500-mg Tylenol tablets a day for several weeks, just over the recommended daily maximum of 4,000 mg.

Recommended dosage The recommended dosage of acetaminophen for an adult or teenager is no more than 4,000 mg every 24 hours -- for example, two 325-mg tablets every four hours or two 500-mg tablets every six hours. For children, the maximum daily dose is weight-based: 34 mg/lb of body weight every 24 hours.

Byrne's case is not as unusual as you might think. Acetaminophen, also known as paracetamol and APAP, is one of the most common pharmaceutical agents involved in overdoses, accidental and otherwise, according to the American Association of Poison Control Centers (AAPCC). The FDA estimates that 50,000 people seek emergency room treatment for acetaminophen poisoning each year, and a 2005 study found that acetaminophen poisoning had become the most common cause of acute liver failure in the U.S., with unintentional overdoses accounting for nearly half of all cases (Hepatology, December 2005, Vol. 42:6, pp. 1364-1372).

By 2006, the FDA considered the situation serious enough to warrant new labeling on all over-the-counter products containing acetaminophen. Still, in 2007, 36,230 acetaminophen overdoses occurred in the U.S., according to the AAPCC.

Acetaminophen is considered safer than aspirin for children and teenagers, and better than aspirin and ibuprofen for adults because it avoids such side effects as stomach ulcers and kidney problems. In dentistry, in addition to general pain relief, studies have shown acetaminophen is a safe and effective analgesic for relieving postoperative pain following a number of in-office procedures, including soft-tissue gum surgery and third-molar extractions (Cochrane Database of Systematic Reviews, 2007, Issue 3. Art. No.: CD004487).

Overconfidence in over-the-counter

Experts say the real issue is an overconfidence in the general safety of over-the-counter medication, combined with a lack of understanding about the side effects if recommended dosages are ignored or overlooked.

"Consumers with coughs and colds sometimes don't realize that if they take two Tylenol extra-strength tablets plus multiple over-the-counter cough and cold remedies that also contain a significant amount of APAP, the total amount of APAP may be far in excess of the maximum recommended dose," said Joel Weaver, D.D.S., Ph.D., president of the American Society of Dentist Anesthesiologists.

“People have to be careful, and they definitely can use some guidance from their dentist.”
— Michael Brennan, D.D.S., M.H.S.

For relief of toothache pain, consumers may continue to take more than the maximum dose on the package label because they are in such agony and so desperate for pain relief that they mistakenly believe that "more is better," he added.

"Acetaminophen is very safe when used according to directions to manage acute dental pain until the problem can be diagnosed and treated by a dentist," Dr. Weaver said. "But APAP has a ceiling effect for pain relief, meaning that above the maximum recommended dose, additional drug is not beneficial and may be harmful."

In acetaminophen overdoses, a toxic liver metabolite of APAP known as NAPQI is formed in excess amounts that cannot be neutralized by the body's own defenses. High blood levels of this metabolite can be highly toxic and result in central lobular necrosis of the liver, acute liver failure, and death.

It takes about three days after an overdose for the liver to begin failing. The victim may start feeling some nausea and loss of appetite on the first day following the overdose, and may have abdominal pain and tenderness (particularly below the right ribs) on the second day. If left untreated, the abdominal pain will become increasingly severe and other symptoms will occur: hypoglycemia, coagulation defects, encephalopathy, and, finally, death.

"Fortunately, if the overdose is diagnosed fairly quickly, there is an antidote called N-acetylcysteine that will increase the body's amount of glutathione and inactivate the toxic metabolite [NAPQI]," Dr. Weaver said. If the victim waits too long to seek advice and help, however, the antidote may not be effective.

How can dentists help? By ensuring that they pay attention to the amount of acetaminophen in commonly prescribed pain medications such as Lortab or Vicodin, opioids that combine hydrocodone and acetaminophen, said Michael Brennan, D.D.S., M.H.S., associate chair of oral medicine at the Carolinas Medical Center in Charlotte, NC.

"A common mistake with Lortab prescriptions is they are often 5/500 -- 5 mg of hydrocodone and 500 mg of acetaminophen -- and the prescription is written for one to two tabs every four to five hours, pnr for pain," he said. "But if the patient takes two tabs every four hours, that would be 6,000 mg of acetaminophen, way over the limit of 4,000 mg every 24 hours."

Acetaminophen can also be combined with other nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen or aspirin, but only for short-term usage and within the recommended dosages, he added. In addition, it is important to determine if the patient is already taking aspirin for anticoagulative or anti-inflammatory purposes.

"If you read the literature, there is some suggestion that adding NSAIDs or narcotics to the aspirin could take away some of the anticoagulant properties," Dr. Brennan said. "So you need to ask the patient why they are taking the aspirin. If you tell someone to go off it because 'you're getting enough pain medication already,' that could put them at risk of poor coronary outcomes."

There are other alternatives for short-term pain management, he added.

"A lot of people will start with hydrocodone and acetaminophen, but you could go to a combination of hydrocodone and ibuprofen, although not for more than a week," Dr. Brennan said. "Studies on pain control have shown that you can increase the ibuprofen to 400-600 mg every four to six hours, short-term."

If the patient is still in pain, the amount of hydrocodone could be increased. If that doesn't work, the next step would be Percocet, according to Dr. Brennan. The goal is to make the patient comfortable without putting them at risk.

"At least once a year, we have an acetaminophen overdose case that ends up in the ICU -- a person who had a toothache and took too much Tylenol," Dr. Brennan said. "People have to be careful, and they definitely can use some guidance from their dentist, telling them do not go over this amount. A Tylenol overdose is a very serious thing unless you treat it quickly."

Probiotics companies enlist bacteria to stop decay

Probiotics companies enlist bacteria to stop decay

By Laird Harrison, Senior Editor

September 2, 2008 -- If it takes a thief to catch a thief, maybe it takes bacteria to fight bacteria. That's the logic behind probiotics -- an increasingly popular approach to treating diseases including caries, periodontitis, and halitosis.

“Probiotics is gaining momentum in the U.S., but compared to the rest of the world, we're dramatically behind.”
— Jeffrey Hillman, D.M.D., Ph.D.

Next month, the Florida company ONI BioPharma plans to launch a suite of products that contain three strains of streptococcus native to the human mouth. These bacteria are harmless to humans, but deadly to their relative,Streptococcus mutans, and other disease-causing bacteria, according to Jeffrey Hillman, D.M.D., Ph.D., the company's chief scientific officer.

"Probiotics is gaining momentum in the U.S., but compared to the rest of the world, we're dramatically behind," Dr. Hillman said.

Indeed, companies like BLIS Technologies of New Zealand and BioGaia of Sweden are already marketing probiotic products for oral health around the globe via the Internet. If you haven't gotten questions from your patients -- or a sales call -- you probably will soon. But some oral biologists warn that more research needs to be done before patients start intentionally infecting their mouths with bacteria of any kind.

An ecological disaster

The theory behind probiotics is simple. A normal human body contains more bacteria than human cells. Some cause disease. But over millennia, most of our bacteria evolved along with us; those that killed their hosts were likely to die out; and selective pressure favored harmless freeloaders. Some bacteria even lend a hand -- for example, by helping break down carbohydrates that human intestines can't metabolize on its own.

Others crowd out, or even poison, harmful bacteria and fungi. Researchers are now trying to enlist this last category of bacteria to combat infections. For example, taking antibiotics as medicine sometimes kills the Lactobacillus species that otherwise keep harmful intestinal bacteria and yeast in check, leading to diarrhea, vaginitis, and other symptoms. Several studies have shown promise in treating these problems by reintroducing species ofLactobacillus and beneficial yeast.

"In the GI tract, researchers are starting to make some headway," said John Ruby, D.M.D., Ph.D., an associate professor of dentistry and oral biologist at the University of Alabama at Birmingham School of Dentistry.

In the mouth, Dr. Hillman and others see a similar kind of ecological crisis. They argue that when human beings began to eat more sugar a couple of centuries ago, an imbalance was created favoring S. mutans. These bacteria are highly adapted to converting sugar to lactic acid, which poisons some of its competitors and coincidentally dissolves hydroxyappetite.

Much of the research so far has explored the use of lactobacilli strains already being produced as gastrointestinal treatments. The active ingredient in the BioGaia products, for example, is L. reuteri. The company can cite at least one study in which patients chewing gum impregnated with L. reuteri had slightly less gingivitis than patients chewing a placebo gum (Swedish Dental Journal, 2006, Vol. 30:2, pp. 55-60).

Perhaps the most common form in which such bacteria are found is in yogurt; many common brands contain live lactobacillus cultures, and some research has shown that yogurt reduces the count of S. mutans in the mouth (Archives of Oral Biology, August 2001, Vol. 46:8, pp. 705-712). But it's unclear whether bacteria or some other ingredients in yogurt, such as casein, are responsible.

And researchers such as Dr. Hillman argue that lactobacilli from the intestines aren't likely to stick around long enough on the teeth. "They aren't normal inhabitants of the mouth," he said. "They're gut strains. I'm all in favor of eating yogurt, but I eat it for gastrointestinal health."

Dr. Ruby adds that most lactobacilli also convert sugar to lactic acid. "I don't think they're the answer for treating oral disease because they play a role in causing it," he said.

Instead, Dr. Hillman's ONI BioPharma (formerly known as Oragenics) is developing two types of treatment using organisms native to the human mouth. Probiora 3 contains S. rattus JH145, S. uberis KJ2, and S. oralis KJ3. S. rattus naturally produces less lactic acid but competes against S. mutans, Dr. Hillman said, while the two other bacteria produce hydrogen peroxide that kills the bacteria responsible for periodontal disease.

In fact, he said these organisms help keep the harmful bacteria in check in a healthy person's mouth, so consuming them may restore that balance.

ONI BioPharma will market Probiora 3 to consumers in tablets called Evora Plus and Evora for Children, and in the future will market a similar product directly to dentists, Dr. Hillman said. The company will advise chewing and spitting out a tablet at least once a day to keep re-establishing the beneficial organisms.

In his research, he said, daily swishing with JH145 reduced the levels of S. mutans "six- to sevenfold," with similarly impressive results for the microscopic periodontitis warriors. That research remains unpublished, however.

Where's the proof?

In the meantime, the company is also testing a genetically modified strain of S. mutans, A2JM. Dr. Hillman and his colleagues enhanced the organism's ability to produce an antibiotic that kills other strains of S. mutans, and they deleted a gene that produces lactic acid. He hopes that patients can be inculcated with A2JM -- which will be marketed as SMaRT Replacement -- just once and enjoy protection from S. mutans for life. The organism is now in phase I clinical trials of safety and a few years away from the market.

It's a promising approach, said Jeremy Burton, Ph.D., a University of Otago researcher who now works for BLIS, in an e-mail. "The question is how consumers will accept such organisms."

Rather than a new life form created in a laboratory, consumers might prefer to treat themselves with a different wild strain of oral bacteria, he reasoned, namelyS. salivarius. His company is marketing S. salivarius, found primarily in the back of the tongue, as a treatment for bacterial throat infections such as strep throat. He and his colleagues have also shown that it might knock out some of the bacteria responsible for halitosis (Journal of Applied Microbiology, April 2006, Vol. 100:4, pp. 754-764). So they're selling it as a treatment for "oral health" in general.

BioGaia is even more explicit: "Use regularly for good oral health and when gums are sensitive or bleeding." The German company BASF and the Taiwanese company GenMont Biotech are also reportedly ready to market anticaries probiotics. "The effectiveness has been demonstrated," BASF states on its Web site. And TheraBreath, a Los Angeles company, claims to have gotten good results with a controlled trial using the BLIS organisms in its Aktiv-K12 ProBiotics.

But so far, these claims have not yet stood the gold-standard test: large, randomized, controlled clinical trials conducted in multiple research centers and published in peer-reviewed journals.

Until they do, many independent researchers hesitate to advocate the products. "I think it's not safe to recommend any probiotics, especially for oral health, yet," Leena Näse, D.D.S., M.S., of the University of Helsinki, wrote in an e-mail to DrBicuspid.com -- even though her group found slightly reduced caries in a controlled trial of L. rhamnosus GG in 594 daycare children (Caries Research, November-December 2001, Vol. 35:6, pp. 412-20).

"I would wait for solid evidence before I recommend anything," agreed Dr. Ruby. "To just go out and say this is going to work without the evidence is getting back to the days of elixirs in medicine chests."

So what's his solution to the oral ecology crisis? Eat less sugar.

Dental companies offer aid in wake of Gustav

Dental companies offer aid in wake of Gustav

By DrBicuspid Staff

September 2, 2008 -- Dental product and service providers are stepping up to provide assistance to dentists and their patients in the wake of Hurricane Gustav.

Aetna has temporarily lifted some policy requirements for members affected by Hurricane Gustav, including relief workers traveling to the impacted areas, according to a company press release. For the time being, Aetna members from the hurricane zone who have had to evacuate may temporarily receive in-network benefits for care out of their network in any state, and seek care from providers (including dentists) other than their designated primary care physicians.

In a separate press release, Henry Schein reminded customers about its disaster relief hotline, designed to assist dentists, physicians, and healthcare facilities that may experience operational, logistical, or financial issues as a result of hurricanes or other natural disasters. The toll-free number for all dental, medical, and veterinary customers -- 800-999-9729 -- is being staffed from 7:00 a.m. to 7:00 p.m. Central time, and is monitored 24 hours a day.

"Henry Schein is ready to help support our dental, medical, and veterinary customers whose practices may be adversely affected by natural disasters," said Stanley M. Bergman, chairman and CEO for Henry Schein. "We encourage our customers in areas that may be affected by tropical storms, hurricanes, or other natural disasters this season to call our hotline for assistance."

Prefabricated oral devices not useful for sleep apnea

Prefabricated oral devices not useful for sleep apnea

By Reuters Health

September 1, 2008 -- NEW YORK (Reuters Health), Aug 29 - Prefabricated thermoplastic oral appliances for mandibular advancement are not effective for treating mild sleep apnea, and clinicians should use custom-made devices instead, new research suggests.

The appliances made of thermoplastic material, so-called "boil-and-bite" devices, are meant to provide an individualized fit and to be an alternative to devices made by technicians from dental casts.

"To date, there have been no studies comparing the efficacy of such prefabricated devices with custom-made devices," lead author Dr. Olivier M. Vanderveken, from the University of Antwerp in Belgium, and colleagues point out.

The present findings suggest that not only are the thermoplastic devices poor treatments for sleep apnea, they are not useful in screening patients for response to mandibular advancement therapy, the authors note in the American Journal of Respiratory and Critical Care Medicine for July 15.

The current cross-over trial involved four months of treatment with each type of device separated by a one-month period in 35 patients with mild sleep apnea.

The custom-made devices, created using a plaster cast of the patient's mouth and construction bites, significantly reduced the apnea-hypopnea index, whereas the prefabricated devices did not.

Roughly one-third of patients treated with prefabricated devices had compliance failure, usually due to insufficient retention at night. The total failure rate with such devices was 69%. Sixty-three percent of patients who failed with prefabricated devices, succeeded with custom-made devices.

Eighty-two percent of patients reported a preference for custom-made devices and 9% of subjects indicated no preference (p < 0.0001).

"Our results suggest that the thermoplastic device cannot be recommended as a therapeutic option nor can it be used as a screening tool to find good candidates for mandibular advancement therapy," the authors conclude.

Am J Respir Crit Care Med 2008

Copyright © 2008 Reuters Limited. All rights reserved. Republication or redistribution of Reuters content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. Reuters and the Reuters sphere logo are registered trademarks and trademarks of the Reuters group of companies around the world.

Washington dental board urged to investigate state's death cases

Washington dental board urged to investigate state's death cases

By DrBicuspid Staff

July 18, 2008 -- A top health official in Washington has urged the state's dental board to investigate all patient deaths related to dentistry, according to a seattlepi.com story.

In a recent letter to the Washington State Dental Quality Assurance Commission, Secretary of the Washington State Department of Health Mary Selecky mentioned a recent news story that revealed that the board might have been too soft in some cases.

"In an interview Wednesday, Selecky said the dental board assured her it will re-examine its death investigation process at its next meeting later this month," reportedseattlepi.com.

MedX signs U.S. distributor for Oralase

MedX signs U.S. distributor for Oralase

By DrBicuspid Staff

July 17, 2008 -- MedX Health of Mississauga, Ontario, has signed an exclusive distribution agreement with Technology4Medicine, a newly formed laser company in San Clemente, CA. Technology4Medicine will sell MedX Health's newest laser product, Oralase, in the U.S. once the product receives FDA marketing clearance.

Oralase is a low-level laser therapy (LLLT) device designed to alleviate pain and accelerate tissue repair following dental procedures. MedX has already applied for FDA clearance for Oralase.

"MedX is already well-established in the rehabilitation market, offering innovative laser and light therapy products that have successfully treated pain, sports injuries, and other conditions," said Steve Guillen, president and CEO of MedX Health in a press release. "We believe our products can offer patients with acute and chronic wounds a noninvasive, drug-free solution, and we fully intend to pursue these indications aggressively."

Articaine superior to lidocaine for anesthesia, survey finds

Articaine superior to lidocaine for anesthesia, survey finds

By Rosemary Frei, MSc, DrBicuspid.com contributing writer

July 17, 2008 -- Articaine had more than nine times the anesthetic success than lidocaine for dental anesthesia in a 10-study meta-analysis presented by University of Iowa researchers at the recent International Association for Dental Research (IADR) meeting in Toronto. However, significant differences between the studies cast doubt on the meaning of this result, according to another expert who attended the presentation.

Headed by Kellie Paxton, D.M.D., M.S., the research team searched PubMed (using Medical Subject Headings database search terms) for studies examining the anesthetic efficacy of initial administration of articaine/carticaine and lidocaine in dental applications. The team identified 77 studies but discarded 67 because they had "significant shortcomings," such as not being randomized or not having clearly reported outcomes.

The remaining 10 studies were performed in five different countries and were published between 1991 and 2007. They each used either articaine or lidocaine in a 4% solution 1:100,000 with epinephrine.

The team first summarized the key points in each of the studies with five-page abstraction forms, and an independent evaluator arbitrated disagreements about how to abstract the information. The primary focus was on the proportion of anesthesia administrations achieving pulpal anesthetic success, as measured by an electric pulp test and/or a visual analog scale for intraoperative pain. Secondary analyses were intended to evaluate the length of pulpal anesthesia.

However, a generalized lack of standardization and data made it impossible for the team to perform the secondary analyses, Dr. Paxton said. Two types of randomization were used in the 10 studies: a crossover design in which subjects used one type of treatment followed by the other, and independent sampling in which they were assigned to only one treatment.

"Because two forms of randomization were used in the studies we were analyzing, much heterogeneity was introduced into the meta-analysis," Dr. Paxton noted. "This is because estimation of the treatment effect is dictated by the study's design type."

Individually, two of the 10 studies reported a significantly superior performance of articaine hydrochloride compared to lidocaine hydrochloride, and a third study showed a trend toward such superiority. In four other studies, the observed rate of anesthetic success was greater for articaine but was not statistically significant. The three remaining studies each showed the two agents had similar anesthetic success.

The team then combined the data from the 10 studies and examined them with Fisher's method of combination of probabilities. They found articaine produced statistically significantly more anesthetic success than lidocaine. They also examined the combined data with a random effects model and found that articaine is associated with 9.21 times more anesthetic success than lidocaine (95% confidence interval 2.56-15.85).

However, when the team examined the differences between each of the 10 studies with respect to how the studies were conducted and how the results were reported, they found significant heterogeneity.

The chair of the IADR session, Zakaria Messieha, D.D.S., affirmed these results. "There is too much heterogeneity between the articaine and lidocaine studies to make this meta-analysis conclusive," said Dr. Messieha, an associate professor of clinical anesthesia at the University of Illinois at Chicago and a dental anesthesiologist in private practice in Glen Ellyn, IL.

New fingerprint requirement in California

New fingerprint requirement in California

By DrBicuspid Staff

January 5, 2009 -- All licensed healthcare workers in California -- including dentists -- will have to submit fingerprints within the next two years under a new directive from the state Department of Consumer Affairs.

The order follows news media reports that many healthcare workers are still practicing their professions despite criminal charges.

An article in the Los Angeles Times cited the examples of two dentists who continued practicing, even though one is facing trial on charges of fondling a patient's breasts and the other -- who is now retired -- is a registered sex offender.

The Dental Bureau of California has required dentists to submit fingerprints since 1986, but never collected them for some 16,000 dentists who have been in practice since before that year, the article said, quoting Cathleen Poncabare, the board's executive officer.

In addition to requiring fingerprints, the Department of Consumer Affairs is now ordering dentists and other healthcare workers applying to renew their licenses to disclose any conviction or administrative action against them.

The department will post the text of formal accusations on the Internet. Any healthcare worker whose record suggests a threat to patients can be suspended.

Fiber-reinforced posts win fans

Fiber-reinforced posts win fans

By Monica F. Anderson, DDS, DrBicuspid.com contributing writer

January 5, 2009 -- If fence posts in the Wild West were as reliable as today's endodontic posts, cattle rustlers would have had to find "real" jobs.

It's a challenge just to get your hands around the huge variety of products available for supporting restorations in endodontically treated teeth that have insufficient coronal structure. Recently, though, one type of post -- fiber-reinforced -- has begun to stand out from the others.

For many years, labor-intensive, custom-cast gold posts and cores were the de facto standard in posts. When used with traditional cements such as zinc phosphates, these posts continue to have a high success rate. However, metal posts, whether custom or cast, are more likely to cause root fractures because of their stiffness, which concentrates forces at the end of the posts. Manufacturers have given dentists many choices for simpler custom and prefabricated posts that place less stress on the root.

The 2008 Henry Schein dental catalog contains eight pages of prefabricated post systems ranging from gold-plated composite to titanium, stainless steel, zirconia-enriched, and the increasingly popular fiber-reinforced.

For those who favor custom-made, CAD/CAM fabricated posts are preferred by dentists like Chris Farrugia, D.D.S., a private practitioner in Pensacola, FL, who believes, "For most clinical situations, a custom-fitting ceramic bonded post and core should be considered" (General Dentistry, January/February 2008, Vol. 56:1, pp. 42-50).

With their milliseconds of spare time, doctors must also choose among additional features, such as parallel or tapered, screw-type or passive, flexible or stiff, hollow or solid, tooth-colored or dark, and biocompatible or toxic. A Schein sales representative consulted for guidance on which are bestsellers told DrBicuspid.com, "They all sell well. It just depends on what you like." Such remarks leave one wondering: Does it even matter?

Yes, it does. When posts fail, dentists face time-consuming and expensive retreatment at best and, in the worst cases, catastrophic root fracture.

Custom-made posts may seem to offer a more perfect fit. But they are costly to order from a lab, and making your own requires bulky and expensive equipment. Meanwhile, recent research shows that prefabricated posts bond well to dentin and exhibit high fracture resistance -- especially fiber-reinforced ones.

For example, after comparing glass fiber to zirconia and titanium in their lab, Turkish researchers wrote in the November issue of the Journal of Contemporary Dental Practicethat "Glass fiber posts exhibited a modulus of elasticity much better matched to that of teeth" when used with new-generation adhesives (November 2008, Vol. 9:7, pp. 33-40).

(The researchers recommend self-etching adhesives for cementation because these adhesives contain "self-etching primers and do not require acid etching procedures. Therefore, the risk of overetching the dentin is decreased.")

Excellent aesthetics

Steve Weinberg, D.M.D., a University of Pennsylvania assistant professor who oversees most of the aesthetic dentistry performed in his clinic, agrees that fiber-reinforced posts are an excellent choice for most situations. Glass fiber posts are tooth-colored, which is of great aesthetic importance when using all-ceramic crowns because a dark substructure can show through, he said.

Today, posts can fit passively because of the adhesive system. "The retention is from the bond," he said. "A good adhesive system is more important than the post." Unlike traditional cements, self- or dual-curing resin cements and dual-cure bonding agents create a chemical bond to the dentin that actually "pulls the tooth inward, like an internal splint, so it's fracture-resistant."

Additionally, attention to the little details during preparation and cementation increases the likelihood of success. A ferrule of 1-2 mm on coronal tooth structure allows the crown to reinforce the tooth externally. To get the best bond, the post space must be free of temporary material, gutta-percha, and eugenol. Also, the post space should be at least as long as the crown, but no less than 3-4 mm from the apical seal.

According to Dr. Weinberg, one reason for fiber post failure is "a lot of doctors still don't know that you can't bond a self-cured composite to a light-cured bonding agent. That's why they developed dual-cure bonding agents."

Overall, prefabricated fiber-reinforced polymer posts satisfy the five most important criteria for posts: aesthetics, physical properties similar to tooth structure, excellent adhesion to resin cement, biocompatibility, and easy removal when necessary. (They are easier to remove than metal posts when bonded with resin cement.)

Still, there's plenty of room for individual preference, as long as you can hold down the core without fracturing the root.

Perhaps the day is not far off when an easy-to-use, all-in-one "bondable" file actually shapes, obturates, and serves as the core.

Stay tuned, we'll keep you posted.

Monica "Dr. mOe" Anderson, D.D.S., is a general dentist, writer, and motivational speaker in Austin, TX.

Copyright © 2009 DrBicuspid.com

CA insurers must now provide interpreters

CA insurers must now provide interpreters

By DrBicuspid Staff

January 5, 2009 -- Legislation requiring California medical, dental, and specialty insurers to provide members with interpreters took effect January 1 -- six years after originally being signed into law, the Sacramento Bee reports.

Of the 37 million people living in California, more than 40% speak a language other than English, and one-fifth of the population say they cannot speak English "very well," according to the Bee.

The legislation (AB 853) was signed into law in 2003, but Gov. Arnold Schwarzenegger imposed a moratorium on it when he took office. Insurers had expressed concern about how to balance the need for access to care with cost.

Insurers estimate that the law will cost about $25 million. Many insurers plan to contract out for interpretation services, according to the news story.

Dentist indicted for dumping medical waste

Dentist indicted for dumping medical waste

By DrBicuspid Staff

November 18, 2008 -- Pennsylvania dentist Thomas McFarland Jr. has been indicted by a New Jersey state grand jury on charges that he dumped needles and other medical-type waste that washed up in Avalon during the last week of August, causing several beaches to be closed multiple times, according to a press release by the state attorney general's office.

The Division of Criminal Justice obtained an indictment today charging Dr. McFarland of Wynnewood, PA, with unlawful discharge of a pollutant and unlawful disposal of regulated medical waste, both third-degree crimes.

Dr. McFarland allegedly took a small motor boat into Townsend Inlet at the north end of Avalon on August 22 and dumped a bag of waste from his dental practice in Wynnewood, PA. The waste, which began washing up on Avalon beaches August 23, included 260 "Accuject" dental-type needles, 180 cotton swabs, a number of blue and white plastic capsules used to hold dental filling material, and other items.

Certain information obtained in the first days of the investigation pointed to Dr. McFarland's practice as a potential source of the waste, the press release said.

On September 2, Dr. McFarland went to the Avalon Police Department and admitted dumping the dental waste.

Each of the charges contained in the indictment carries a maximum sentence of five years in state prison. In addition, a fine of up to $75,000 can be imposed for the charge of unlawful discharge of a pollutant, and a fine of up to $50,000 can be imposed for the medical waste charge.

Copyright © 2008 DrBicuspid.com

Dentists, hygienists debate role of 'midlevel provider'

Dentists, hygienists debate role of 'midlevel provider'

By Kathy Kincade, Editor in Chief

November 17, 2008 -- Ten years from now in a remote Arizona town, an unemployed single mother arrives in a clean, bright clinic. An hour later she leaves with her badly decayed tooth removed and her son's cavity filled. It's a scene that could play out today in any dental clinic in the U.S., with one key difference: There is no dentist in this office.

Such visions of the future are tearing U.S. dentistry apart. One side believes the country desperately needs a new class of oral care professional, something between a dentist and hygienist, to help people who don't have access to dental services. The other side believes dentists alone can fill the gap.

In recent weeks, the battle has heated to new intensity. In Minnesota, a government working group is drafting regulations for a new "oral health practitioner." In Texas last month, the ADA House of Delegates approved funding to further the ADA's community dental health coordinator (CDHC) program. And in the Journal of the American Dental Association this month, a researcher presented evidence that dental health aide therapists (DHAT) in Alaska are already doing work on a par with full-fledged dentists.

No one denies that a serious problem exists; the debate centers on how best to fix it. Some believe the answer lies in government programs that make it possible for underinsured populations to afford dental care. Others say the key is to create a new type of provider that can go into underserved areas and perform many of the duties of dentists but without the same training or licensing requirements.

But this notion of the "superhygienist" has become a hot button as -- rather than working together to address the issue -- the ADA, the Academy of General Dentistry (AGD), and the American Dental Hygienists' Association (ADHA) are each developing their own concepts of what these care providers should and shouldn't be allowed to do. The ADHA is a proponent of the advanced dental hygiene practitioner (ADHP), the ADA is putting its muscle behind the CDHC, and the AGD has concerns about both.

Some might call it a turf war.

In an "Access to Care" white paper issued this summer, the AGD argues that "present efforts to institute independent midlevel providers -- lesser educated providers who are not dentists -- to provide unsupervised care to underserved patients are not only economically unfeasible but ... will provide lesser quality care to the poor."

But is this true? In the November JADA article, author Kenneth Anthony Bolin, D.D.S., M.P.H., audited the dental records of patients treated by dentists and DHATs in Alaska, and concluded that "no significant evidence was found to indicate that irreversible dental treatment provided by DHATs differs from similar treatment provided by dentists." He reviewed the records of 640 dental procedures performed in 406 patients in three health corporations and found "no significant differences among the provider groups in the consistency of diagnosis and treatment or postoperative complications" (JADA, November 2008, Vol. 139:11, pp. 1530-1535).

Writing in the same issue of JADA, however, Albert Guay, D.M.D., chief policy adviser for the ADA, questioned Dr. Bolin's findings and methodology. Noting that Dr. Bolin used only postoperative chart review, Dr. Guay argued that "An assessment of the quality and adequacy of clinical treatment requires much more than a chart review" (JADA, November 2008, Vol. 139:11, pp. 1536-1537).

DHAT, ADHP, or CDHC?

For many in the dental community, the issue is not the need for more care providers but how much clinical responsibility and independence they should have. DHATs, for example, are authorized to provide oral exams, preventive dental services, simple restorations, stainless steel crowns, and extractions, plus take x-rays -- all with just a high-school education and two years of training. (The ADA was so concerned about what it sees as potential risks with this model that it sued the Alaska Native Tribal Health Consortium, which oversees the DHAT program, in 2006 to block the program. The ADA lost that lawsuit.)

The ADHA's ADHP is an oral healthcare provider with a master's degree who works independently and is trained to administer the full range of services offered by dental hygienists, plus minimally invasive restorative services, extractions in emergent situations, and some prescriptions. First proposed in 2004, the ADHP initiative takes its cue from midlevel practitioner programs in medicine, particularly nursing.

"We wanted to create a model that we thought would be successful and that addresses the biggest needs in the dental world: restorative and preventive services," said Diann Bomkamp, R.D.H., B.S.D.H., president of the ADHA. "So we looked at this idea of the midlevel provider in dentistry, a model we don't have in U.S. dentistry at all -- although other countries have had midlevel providers for years -- and we felt that dental hygienists, because of our background in dental services, could fill the void."

For the last three years, the ADHA has lobbied at the state and federal levels to gain support and funding for the ADHP program and developed a set of competencies that schools can use in creating curriculums for ADHP programs. According to the ADHA, Fones School of Dental Hygiene in Bridgeport, CT, is now planning an ADHP education program, while Metropolitan State University in St. Paul, MN, has approved the first ADHP master's program and is slated to begin instructing students in mid-2009. Still, this is just the first step; state legislative and licensing issues still need to be addressed.

The ADA's CDHC is designed to take members of underserved communities (similar to the DHAT model) and train them to become part of the dental team, working under a dentist's remote supervision in schools, churches, senior citizen centers, and other community programs. Each CDHC will undergo an 18-month training program that will enable them to promote oral health and provide preventive services, including screenings, fluoride treatments, sealants, temporary fillings, and simple teeth cleanings. They will not excavate caries, although they will be able to place temporary restorations in cavities after removing debris with approval from the supervising dentist.

"CDHCs are community health workers with dental skills who work outside the dental clinic but come from the same community in which they serve," said Robert Brandjord, D.D.S., past president of the ADA and chair of the ADA committee charged with overseeing the CDHC program. "People are more apt to follow through on treatment if they have trust in someone from their own community. We believe this approach has great potential to help underserved populations."

The ADA House of Delegates agrees. At the ADA annual meeting last month, the delegates voted in favor of committing up to $5 million to support the continuation of the CDHC pilot programs and identifying outside sources of funding for three pilot sites. As a result, pilot testing is slated to begin next year in Oklahoma, Montana, and Michigan.

Difference of opinion

Despite such progress, however, the AGD -- which declined to be interviewed for this article -- is adamant that an independent (i.e., unsupervised) midlevel provider will undermine the preventive care model and lead to lesser quality of care. The AGD instead supports the notion of government, healthcare, and community representatives working together to promote oral health literacy, tax credits and other incentives for dentists to practice in underserved areas, and volunteer services.

"Removing the oversight of the dentist removes the one professional who has the overall knowledge and training to coordinate all aspects of treatment that patients might need," the AGD white paper states.

The white paper also emphasizes that midlevel provider models "fail minimum education standards," and it questions the economic realities of such models, noting that "independent midlevel providers will not be immune to the forces of supply and demand" and will likely find it "less economically feasible" to maintain an independent practice in underserved areas.

Dr. Branjord said he is "baffled" by the AGD's position. He noted that in September the AGD posted a video clip on YouTube about the CDHC in which "a lot of the things that were said were not true" (this video has since been removed from YouTube).

For example, "CDHCs are trained to work in clinic relationships, not private practice," he said. "They are not independent. In fact, neither the CDHC nor the ADHP is an independent provider."

However, Bomkamp pointed out that one of the key differences between the CDHC and ADHP is the notion of "direct supervision," which the ADHP model does not require -- something she sees as a clear advantage.

"Dentists are in short supply, and if the new midlevel providers had to work under direct supervision of the dentist, how will that help address the issue of access?" she said. "We're trying to find more places where people can gain entry to oral healthcare services, but if a dentist has to go [into the community] too, what good is that? It's going to cost more to have two providers there, plus it cuts into the time the dentist will have to do more complicated procedures."

Bomkamp added that while she cannot speak for the AGD, "I'm not sure why they are opposed to this. Maybe it's the comfort zone. People get used to working a certain way."

It is difficult not to see these polite differences of opinion masking deeper concerns. One dentist commenting in the DrBicuspid.com Forums discussion groups wrote, "Dentistry will continue to be vilified and ridiculed in the press until we start using legitimate studies as a basis for criticism or opposition to dental therapists. Our constant ranting about poor quality, risks to the public and other completely unfounded claims only makes us look like tradesmen attempting to protect our guild."

Univ. of Iowa receives $1 million grant for dental research

Univ. of Iowa receives $1 million grant for dental research

By DrBicuspid Staff

November 17, 2008 -- Research areas in the University of Iowa's Dental Science Building, home to the university's College of Dentistry, will undergo significant upgrades and modernization, thanks to a $1 million grant from the Roy J. Carver Charitable Trust of Muscatine, IA.

"Improving the college's research area is crucial to facilitating innovative research, retaining leading researchers, and enabling these scholars to do their best work," stated David Johnsen, dean of the College of Dentistry, said in a press release. "It also is vital for recruiting new research faculty, since the college must be able to offer adequate and appropriately equipped laboratory space for incoming investigators.

Clark Stanford, the college's dean for research, noted that since the construction of the Dental Science Building in 1973, the field of oral biomedical research has changed significantly with the growth of cellular, molecular, genetic, and proteomic technologies. He said the Dental Science Building's research area needs laboratories that support these new methods, which are now an intrinsic part of contemporary biomedical research.

Stanford added that the $1 million grant from the Carver trust will allow the college to develop state-of-the-art laboratory facilities for two key research programs: the Molecular Craniofacial Anomalies Research Program and the Biomaterials, Bone, and Tissue Engineering Research Program.

The college's general and specialty dental care clinics receive about 125,000 patient visits each year.

Copyright © 2008 DrBicuspid.com

Adstra offers standalone dental charting

Adstra offers standalone dental charting

By DrBicuspid Staff

October 2, 2008 -- Adstra Systems has announced that its Adstra Charting treatment planning and charting software is now available as a standalone program, after more than six years of being available only as an add-on to Adstra's practice management software.

Adstra Charting software allows users to create and manage odontograms for examinations, completed treatment, and planned treatment. There are four chart views: maxillary, mandibular, buccal, and palatal-lingual. The charting tools are grouped by type: general, periodontal, restorative, and endodontic. Multiple charts can be opened at the same time, and pockets and recessions are represented graphically. A number of reports -- or the whole chart as it's viewed -- can be printed.

Adstra Charting offers an array of tools for charting all kinds of tooth conditions, according to the company. Users can set their own preferences for general chart, periodontal chart, restoration materials, and the connection between procedures and tools. Users can also define exam templates and incorporate them into the patient's chart.

Copyright © 2008 DrBicuspid.com

Court suspends intoxicated dentist's license

Court suspends intoxicated dentist's license

By DrBicuspid Staff

October 2, 2008 -- An Ohio dentist who was found drunk at his practice during a state inspection has lost his license, according to a news story in the Chronicle-Telegram.

The Ninth District Court of Appeals upheld the Ohio State Dental Board's decision to suspend John Brooke's license this week.

"According to the dental board, Brooke was intoxicated when a state inspector showed up to investigate a tip that the dentist was drunk at his office on March 21, 2006," the paper reported. "The investigator said Brooke's eyes were glassy, his face was red, and he was brushing his teeth while he was being questioned."

Brooke had previously been convicted of handling a firearm while intoxicated and a DUI (in 2005 and 2006, respectively), but the board said his efforts to deal with his drinking problem since weren't up to their standards, according to the news story.

United Concordia to offer premium-free dental care to reservists

United Concordia to offer premium-free dental care to reservists

By DrBicuspid Staff

October 1, 2008 -- The U.S. Department of Defense has awarded its Tricare Active Duty Dental Program contract to United Concordia Companies. The contract provides for premium-free dental healthcare services to active duty service members referred from military dental treatment facilities (DTFs) for civilian care and dental coverage for those active duty service members under the Remote Active Duty Dental Program.

Reservists and National Guard members who are on orders to active duty for a period of more than 30 continuous days are considered active duty service members from their initial activation date. In certain circumstances, service members no longer on active duty may also be eligible for coverage when injured while serving on orders.

Many features of the new contract, which is slated to begin services August 1, 2009, are currently handled by the Military Medical Support Office under Tricare Management Activity. Establishing a network of providers is new under the contract.

"Tricare aims to ensure the highest level of beneficiary satisfaction and contractor performance in controlling costs," stated Army Maj. Gen. Elder Granger, Tricare Management Activity deputy director, in a press release. "Network dentists will provide the same dental benefits that are received at military DTFs, to include comprehensive preventive services such as oral cancer screenings."

Riemser buys Curasan's dental business

Riemser buys Curasan's dental business

By DrBicuspid Staff

August 20, 2008 -- German pharmaceutical company Riemser Arzneimittel has acquired the dental business of Curasan.

Curasan had been marketing bone regeneration and membrane products in the U.S. since 2004. Its three leading products include Cerasorb, Epi-Guide, and Revois.

"Given the rapid growth in the U.S. of Cerasorb bone regeneration material and Epi-Guide membrane -- which have doubled in users and sales during each of the past two years -- we are eager to bring additional financial resources to the expansion of these and other dental products," Norman Braun, head of Riemser's dental division, stated in a company press release.

Copyright © 2008 DrBicuspid.com

Dentistry and depression: Part I -- Are dentists more suicidal?

Dentistry and depression: Part I -- Are dentists more suicidal?

By Rochelle Sharpe, DrBicuspid.com contributing writer

August 20, 2008 -- Dentistry has the highest suicide rate of any profession. Or so they say. The perception is so entrenched in the popular culture that it once cropped up in an episode of the TV comedy "Seinfeld."

But researchers from the National Institute for Occupational Safety and Health (NIOSH) are saying it may be a myth. In a recent study, they report that, overall, white male dentists had slightly lower suicide rates than the general working population (Occupational Health, January 2008, Vol. 58:1; pp. 25-29).

So where did the notion get started?

There's no question that dentists struggle with depression. "Dentists are under such horrible pressure," said Dorothea Lack, Ph.D., a San Francisco psychologist who used to work as a dental hygienist. "It's not surprising that they have psychological problems."

In the "Seinfeld" episode, Jerry Seinfeld's Jewish dentist Tim declared, "You have no idea what my people have been through."

"The Jews?" Seinfeld asked.

"No, the dentists," Tim replied.

After Tim states that dentists have the highest suicide rate of any profession, Seinfeld retorted: "Is that why it's so hard to get an appointment?"

The perception may have originated in the 1960s when an Oregon study found that the state's dentists had the highest suicide rate of any professional group. A few other statewide studies showed high rates, too. Washington dentists had the second highest suicide rate in a 1983 analysis (behind sheep herders and wool workers), while California dentists ranked third for suicides in a 1973 inquiry (behind chemists and pharmacists).

Some national studies had similar findings. A 1971 examination of data collected by the U.S. Public Health Service showed that dentists had the third highest suicide rate of 36 occupations (behind managers and police officers). Then, in 1996, Steven Stack, a Wayne State University sociologist, analyzed more recent public health service data, using sophisticated statistical techniques to ensure that the high rate was not due to age, race, gender, or marital status. He concluded that being a dentist increases the risk of suicide by 564%.

Other studies reached completely different conclusions, however, finding that dentists' suicide rates did not differ much from the general working population. Those included a 1985 analysis of North Carolina dentists and at least two national studies in the mid-'70s, one of which was published by the ADA. The ADA even convened a conference on the topic in 1977, with experts declaring that reports of high suicides rates were exaggerated.

Settling the question is not easy. The research is inherently complicated, given that people sometimes won't list suicide as their loved one's cause of death. In addition, not all states collect suicide data by occupation.

The NIOSH researchers wrote that their colleagues have reached conflicting conclusions because they analyzed the data differently. "Only older white male physicians and dentists have elevated suicide rates, which partially explains the varied conclusions in the literature," they wrote.

Overall, they found that dentists older than age 50 had elevated suicide rates. Those between 60 and 64 years, the oldest working dentists studied, had the highest rates: 47.5 of 100,000 dentists committed suicide, compared to 42.6 of 100,000 workers of this age in the general population.

Medical doctors between 60 and 64 years had even higher rates, with 54.8 of 100,000 of these older doctors committing suicide.

But whichever profession is the most stressful, it's clear that many dentists need new ways to cope with the emotional burdens of their jobs.

In part II of this series, we take a look at techniques that psychologists and stressed-out dentists themselves are offering.

New bacteria could help battle tooth decay

New bacteria could help battle tooth decay

By Rabia Mughal, Contributing Editor

August 19, 2008 -- Dentists battle tooth decay and gum disease on a daily basis. Now British researchers have lent them a hand by discovering a new species of bacteria that could be a possible contributor to both.

Identifying and cataloguing new and existing oral bacteria could aid in developing new prevention methods and treatment of oral diseases. However, it is still unclear how relevant these particular new bacteria will be to treating periodontal disease.

The research team, led by William Wade, a professor of oral microbiology from the Dental Institute at King's College London, found three strains of the bacteria in oral mucosal tissue.

The new organism belongs to the Prevotella species, which are part of the normal microbial flora in humans and are associated with various oral diseases and infections in other parts of the body, and has been named Prevotella histicola, from the Latin wordhisticola -- "inhabitant of tissues."

"The healthy human mouth is home to a tremendous variety of microbes, including viruses, fungi, protozoa, and bacteria," Wade stated in a Kings College press release. "The bacteria are the most numerous: there are 100 million in every milliliter of saliva and more than 600 different species in the mouth."

Researchers performed a thorough phenotypic and genotypic characterization of these strains and published the results in the International Journal of Systematic and Evolutionary Microbiology (August 2008, Vol. 58:8, pp. 1788-1791).

The three strains form a homogenous group and are clearly distinct from any species with validly publishable names, the authors noted.

"Cells are saccharolytic and are able to ferment fructose, glucose, lactose, maltose, mannose, raffinose, and sucrose, but not arabinose, cellobiose, mannitol, melezitose, melibiose, rhamnose, ribose, salicin, sorbitol, trehalose, or xylose," they stated. "Major amounts of acetic acid and succinic acid and trace to minor amounts of isovaleric acid and lactic acid are produced as end products of metabolism."

The researchers found the new species living inside both healthy tissue and oral cancer cells.

"This confirms other work showing that oral bacteria can invade both tissues and individual cells," Wade stated.

This discovery is part of a larger goal of describing oral microbiota, Wade told DrBicuspid.com in an e-mail interview. Less than half of oral bacterial species have yet been named, and around half cannot even be cultured in the laboratory, he noted.

"Although we are looking for life on Mars, we are still largely ignorant of the microbial world of our own mouths!" Wade said.

"Very few single discoveries consist of major breakthroughs. In this case, the discovery of a new human oral species of Prevotella (a genus of gram-negative bacteria) is important, but further information will be needed to determine its specific importance related to periodontal diseases," said Chris H. Miller, Ph.D., a professor of oral microbiology at Indiana University. "According to the current NIDCR [National Institute of Dental and Craniofacial Diseases] listing of oral microbial species, there are already five species of oral Prevotella."

Tooth decay and gum disease are not traditional infectious diseases; they result from an imbalance between the human host and its commensal microbiota, influenced by environmental factors, Wade explained.

"To understand the interactions between host and microbiota, we need to fully characterize the microbial communities present," he said.

Wade's team, in collaboration with scientists at the Forsyth Institute in Boston, compiled a list of oral bacterial species earlier this year. That list comprises 600 species and provides descriptions of each species together with tools for analysis of their DNA.

Although most bacteria in the mouth are important for oral health, some can potentially cause disease. This database will help scientists study the role of specific bacteria in human health and disease, according to the college press release.

A better understanding of oral bacteria can also assist in developing new prevention methods and treatment of oral diseases.

"In the case of gum disease, it is clear that individuals who are susceptible display a greater degree of inflammation than those who are not susceptible, to the same level of bacterial challenge," Wade told DrBicuspid.com. "New treatments will be aimed at restoring tolerance to the normal microbiota in susceptible individuals."

Beyond x-rays: Part II -- The glow of demineralization

Beyond x-rays: Part II -- The glow of demineralization

By Kathy Kincade, Editor in Chief

June 26, 2008 -- For years the mineral loss from enamel and dentin has been known to alter the optical properties of teeth. Now some technology developers are hoping to capitalize on this phenomenon with a diagnostic device that uses fluorescence to identify demineralization and thus pinpoint dental caries much earlier than is possible with x-rays or visual examination -- before cavitation begins.

Introducing CEREC® Omnicam.The most perfect CAD/CAM camera ever Slim, elegant design for easier intraoral access, fast photorealistic color imaging, and powderless convenience make the new CEREC Omnicam the most precise, easy-to-use CAD/CAM camera ever.

A series of studies conducted by Swedish researchers in the 1980s demonstrated laser-based autofluorescence of enamel and a direct relationship between the mineral content of the enamel and its optical properties, particularly fluorescence (Journal of Dental Research, July 2004, Vol. 83:Spec Iss C, pp. C84-C88). Subsequent studies utilized this phenomenon -- known as quantitative light fluorescence (QLF) -- to characterize the dental caries process with in vitro, in situ, and in vivo models.

"The only instruments available at present that measure mineral loss use QLF," said George Stookey, Ph.D., distinguished professor emeritus at Indiana University and president and CEO of Therametric Technologies, a company founded to commercialize this technology for dental diagnostics. "This technology is based on using a wavelength of light in conjunction with a filtering system to measure the diffraction of light on the tooth surface. When the mineral content of the enamel changes, so do the optical properties."

Attempts to commercialize this technology have so far met with limited success. Inspektor Research Systems of Amsterdam launched the first QLF system, the Inspektor Pro, in Europe in 2004 (price: $24,000). The system subsequently gained FDA clearance and reportedly was being sold in the U.S. by Omnii Oral Pharmaceuticals; however, that company's Web site indicates it sells only pharmaceuticals, not medical devices. (Efforts to contact both Inspektor and Omnii yielded no response from either company.)

Smaller, less expensive

Therametric is now developing a "next-generation" version of QLF that utilizes a high-intensity halogen lamp as the light source rather than a laser, reducing both the size and cost of the system, according to Stookey. In Therametric's Professional Caries Detection System, a probe relays data and images via a universal serial bus interface to a computer with software that pinpoints sites of impending decay up to two years before these spots could be located using traditional visual and x-ray examination methods, Stookey said.

By catching a potential lesion at such an early stage, dentists should be able to help reverse the demineralization process before cavitation begins, he emphasized. The precavitation portion of caries development involves daily periods of enamel demineralization over two to five years. According to Stookey, it is possible to reverse the caries process through measures that induce and facilitate remineralization of the enamel.

"If you detect a lesion before cavitation, it is reversible chemically," he said. "You can apply fluoride or fluoride gels and get rid of the white spot, although it takes some time. But it takes three to four years for a lesion to develop to the point of cavitation, so at any point you can intercept it prior to this, you can reverse it chemically."

The Professional Caries Detection System by Therametric Technologies.

A study being presented in July at the International Association of Dental Research meeting supports Stookey's claims. Researchers from the Eastman Dental Center in Rochester, NY, used QLF to study the effectiveness of remineralizing agents on early smooth-surface caries. While they found no significant difference between the teeth of those who rinsed twice daily with a combination calcium and fluoride rinse and those who didn't in terms of preventing the progression of caries, they did conclude that QLF could be a useful diagnostic aid in caries management.

Not everyone is convinced that QLF will be that useful, however. According to Allan Farman, B.D.S., Ph.D., M.B.A., D.Sc., a professor of radiology and imaging science at the University of Louisville School of Dentistry, the problem with the QLF technology is that it is largely restricted to evaluating smooth tooth surfaces that are not interproximal.

"As most dental caries occur in regions of stagnation (i.e., pits and fissures on the occlusal surfaces) and interproximally, this technology is not an ideal replacement for traditional radiographic methods for detection of lesions needing restoration as light penetration with the system is around 2 mm at best," Farman stated in an e-mail.

"The technology is acceptable for examining early demineralization in primary teeth without proximal contacts and might be of value for clinical trials into toothpaste, oral rinses, etc.," he added. "The argument that this is a move toward prevention could be made; however, the reimbursements from insurance companies are uncertain for such an approach."

The Therametric product is now undergoing clinical evaluation at several sites and could be on the market by the end of this year, according to Stookey. The price should be "quite competitive with the other instruments that are presently being marketed to assist with caries detection," he noted.

The next generation of dental imaging systems -- notably optical coherence tomography -- promises greater detail than QLF, plus the possibility of 3D. Part III of this series will look at near-infrared imaging and OCT and where they are in commercial development.