Does Laser "Revolution" Have Scientific Support?

By David G. Jones

Laser has an array of modern medical and dental applications, but its use is not free of controversy, and utilization of laser in a particular periodontic procedure has stirred debate.

Recent news articles, radio advertisements and television reports have touted the laser as a "revolutionary" procedure for performing subgingival curettage. But some experts say claims associated with use of lasers for that procedure lack the support of scientific evidence.

The controversy revolves around Los Angeles-based media reports featuring advocacy of the use of lasers instead of conventional periodontal procedures. The reports claim that the laser procedure is nearly painless, almost bloodless, and doesn't require sutures, making the laser an attractive alternative for periodontal work.

"These reports were very powerful and broadcast throughout the L.A. viewing area," says Gerald I. Drury, DDS, chairman of the Ethics Committee of the Western Los Angeles Dental Society. "It was very detrimental, and the stations wouldn't let us rebut it.

"There is little scientific evidence, regardless of what these reports claim, supporting the use of lasers for this purpose."

The American Academy of Periodontology's position paper on Lasers in Periodontics supports Drury, stating, "There are no research data that support the use of lasers for subgingival curettage."

A newspaper report said dentists using the procedure saw bone regrowth in 90 percent of their 400 patients, a claim another expert says also has no support from scientific research.

"There has been no referenced research to support these claims, despite research in this area since the late '70s," says Roger K. Rempfer, DMD, chairman of CDA's Council on Dental Care, and a laser user since 1984.

The laser's effective use in soft-tissue surgery has been well-established in research literature, but numerous scientific articles published to date relate to the potential harm lasers may cause to dental root surfaces.

"So while curettage is intended as a soft-tissue procedure, it is impossible not to interface with the root, particularly with the laser. Control is limited with the laser because of scattering of the beam," Rempfer says. "Indeed, significant damage to root surfaces using the pulsed Nd:YAG laser were documented in studies by numerous investigators, such as Cobb, Tarlovich, Morlock, Pippin, Killow, Rapley, Spencer, and others. These studies further demonstrated that subsequent root planing of root surfaces was required to restore the root surface morphology following use of the Nd:YAG laser. So why do two procedures when the literature supports the efficacy of scaling and root planing as a single procedure?"

The Food and Drug Administration recently cleared the pulsed Nd:YAG laser for use in subgingival curettage, a move that would seem to lend credibility to claims made through the media. But another expert questioned the value of the FDA's study after reviewing documents summarizing the agency's research.

"The results of this limited study indicated that both treatment groups (one receiving scaling and root planing alone, and the other scaling and root planing followed by the pulsed Nd:YAG laser curettage) obtained statistically the same result," says Douglas N. Dederich, DDS, an adjunct associate professor of periodontics in the University of Iowa's College of Dentistry. "In other words, the laser made no difference as detected by the clinical indices used. When you then take into consideration the risk of root surface damage and others, but not evaluated in the study, one cannot scientifically recommend laser curettage."

The FDA cleared laser for soft-tissue modalities in 1976, and it boasts several applications being used successfully in periodontics.

"The use of lasers in dental surgery supported by reproducible research includes excisional and ablative soft-tissue procedures, such as frenectomy, gingivectomy, biopsies, and removal of tissue pigmentation," Rempfer says.

Nevertheless, one laser user, who bought equipment in 1986, questions its value.

"I found not much reason to use it over the years when I can use other techniques that don't need as much preparation, don't need anti-reflective instruments, special evacuation systems, and so forth," says Richard Benveniste, DDS, a member of the Enforcement Committee of the state Board of Dental Examiners. "If it could do all the things the manufacturers can say it does, and all the things the marketing people say, it would be great. But there's no research to show this is true."

Even so, the American Academy of Periodontology position paper on Lasers in Periodontics states, in part, "This is an exciting field with many promising possibilities to be investigated, and represents an area that may ultimately prove to be rich with utility in periodontics. . . . Further research on the potential use of laser energy in periodontal therapy is indicated."

UOP Basks in Alumnus' Generosity

Decades of work, good choices and shrewd investments brought the blessings of good fortune to Dr. Arthur A. Molinari, whose dental practice and consistent, dependable presence lent pitch-perfect grace notes to the colorful symphony that is San Francisco.

An institution of sorts, Molinari, 98, practiced dentistry from the time he graduated from the College of Physicians & Surgeons (forerunner of the University of the Pacific School of Dentistry) in 1923 until he retired in 1987. He drove from his Marin County home across the Golden Gate Bridge to his office in the city six days a week until he called it quits -- roughly 15,000 round trips.

He practiced dentistry with a passion and built a family and life with his wife, Ruth Markson Molinari, who died in 1992. He also played the stock market with skill, turning his earnings into a fortune.

Now Molinari has given to UOP School of Dentistry the largest gift the school has ever received and what is thought to be one of the most generous ever given to a dental school in the U.S. Molinari is February gave UOP $5 million. The money has been used to create a $1.5 million endowment to provide scholarships for needy and deserving students, and to create a $3.5 million building fund to support a major addition to the dental school.

"Dr. Molinari's generosity and caring provides the dental school with the resources that will guarantee our continued excellence," says dental school Dean Dr. Arthur A. Dugoni.
Both parts of the gift carry the names of Molinari and his wife, and their daughter, Joan Molinari Mibach.

"It makes me happy to know that dental students who receive a scholarship from our endowment will be reminded that my wife, Ruth Markson, daughter Joan, and I created a legacy for the future of dentistry," says Molinari, who will turn 99 in August. "One of the reasons that I created these funds was to perpetuate the Molinari and Markson family names."

Medical Influence Found in Famous Folks

Celebrities can have a powerful effect on the public's health care choices, according to an article in the March 11 issue of the Journal of the American Medical Association.

Ann Butler Nattinger, MD, MPH, from the Medical College of Wisconsin at Milwaukee, and colleagues, studied the records of 162,287 women with local or regional breast cancer to determine the impact of former first lady Nancy Reagan's decision to undergo mastectomy rather than breast conserving surgery in October 1987.

The researchers found a 25 percent decrease in the number of women choosing breast conserving surgery in the six months following Reagan's surgery compared with women facing a similar decision in the three months before the surgery.

The authors write, "The effect of Mrs. Reagan's surgery was greatest among women who were demographically similar to her, white women aged 50 through 79 years, as opposed to older or younger women or nonwhite women. The effect was more prominent in the central and southern regions of the country, and in counties with lower levels of education and income."

They note that the sharp drop in breast conserving surgery in late 1987 was not associated with publications in the medical literature or lay press that would call into question its effectiveness.

Celebrities are thought to be capable of influencing health care behaviors. That perception has led to celebrity endorsements for promoting safe sex and avoiding illegal drugs. Aside from anecdotal information, there is little data to document that influence, according to the authors.

The authors project nationally that 3,400 fewer women underwent breast conserving surgery in the six months following Reagan's surgery than would have been expected based on previous rates of use.

They conclude that "medical care can be influenced substantially by the behavior of celebrity role models. The influence is strongest among persons who demographically resemble the celebrity, and those of lower income and educational status. One can sympathize with public figures facing difficult personal medical decisions, because they have to deal with the reality that their decision may very well influence the behavior of thousands of others. This study provides support for the concept of targeted celebrity role models as a strategy to influence public health behaviors."

Lead, Decay May Be Linked

A mother's exposure to lead could be a contributing factor to tooth decay in her child, according to an article in the American Dental Hygienists' Association's Access, December 1997. The article cites University of Rochester dental researchers who conclude that exposure to high amounts of lead is likely one cause of the rates of tooth decay found among certain groups, such as children raised in the inner city.

Research suggests lead interferes with tooth development. Higher than normal amounts of lead stored in the bones for decades are released into a pregnant woman's blood and reach the fetus at a time critical to the development of teeth and salivary glands.

Lead is recognized as causing developmental and other problems and may be one reason cavities are still a major problem in some areas of the United States. Inner cities and the Northeast are the areas with the highest lead pollution as well the highest rates of tooth decay. Access reports that although about half of 12-year-olds are now cavity-free, 80 percent of the cavities in this age group are present in just one fifth of the children.

Microcracks Reported With Coarse-Bur Use

Coarse diamond burs may weaken patients' teeth, say scientists at the National Institute of Standards and Technology in Gaithersburg, Md.

In a multicenter study assessing drill-related damage, researchers found that removing enamel with a coarse diamond bur produced subsurface cracks of 50 to 110 microns. Microcracks also occurred, which could combine with the longer cracks to weaken drilled teeth, reports the January NIST Tech Beat.

The study shows, however, that fine diamond burs can remove the areas damaged by coarser burs, which reduces the risk of fracture.

To minimize the risk of fracture in a drilled tooth, researchers suggest dentists use coarse diamond burs for partial drilling and finish the preparation with a fine diamond bur.

Honors

Thomas Schiff, DMD, has been named chair of the Department of Radiology and Emergency Services at the University of Pacific School of Dentistry.
Ernest Newbrun, DMD, PhD, emeritus professor of oral biology and periodontology at the University of California at San Francisco School of Dentistry, has been awarded the honorary degree of Doctor of Dental Science by the University of Sydney, Australia.
Dr. Arthur A. Dugoni, dean of UOP School of Dentistry, has been selected as the 1997 recipient of the Dr. Irving E. Gruber Award. Because of a source error, the name of the award was incorrectly listed in the March 1998 issue of the CDA Journal.

Upcoming Meetings 1998
April 30 - May 2 American Academy of Periodontology's Periodontal and Restorative Conference, Chicago (312) 573-3243
May 6-10 American Association of Endodontists Annual Session, New York (312) 266-7255, Ext. 3006
June 18-21 Infection Control in the Information Age: Access and Integration, Providence, R.I. (800) 298-6727
July 11-17 National Wellness Conference, Stevens Point, Wis. (800) 243-8694
Sept. 11-14 Oral Health 2000 Consortium, San Diego (312) 836-9900
Sept. 13-16 American Academy of Periodontology's Annual Meeting, Boston (312) 573-3210
Sept. 16-19 American College of Prosthodontists Annual Session (800) 378-1260
Oct. 1-3 Annual Scientific Session of the Academy of Surgical Research (612) 927-6707
Oct. 8-12 World Dental Congress, Barcelona, Spain +44 171 935 7852
Oct. 9-13 ADA Annual Session, San Francisco (312) 440-2500
Oct. 31-Nov. 3 Pacific Coast Society of Orthodontists Annual Session (415) 441-2410
Nov. 19-21 International Dental Showcase, NEC Birmingham, U.K. 01722 335599
1999
April 8-11 CDA Scientific Session, Anaheim, Calif. (916) 443-3382, Ext. 4470
April 13-17 International Dental Show, Cologne, Germany, http://www.koelnmesse.de/ids

To have a meeting included on this list, send the information to Upcoming Meetings, CDA Journal, P.O. Box 13749, Sacramento, CA 95853 or fax the information to (916) 443-3382.