Kylie Jones, 4, was having a first cavity filled and her mom was a little nervous.

"In our family, none of us had ever had a filling," said Lisa. "I didn't know what to expect."

But all Kylie had to do was watch a movie and open wide while the dentist aimed a tiny red light from a laser handpiece to illuminate the exact spot of her cavity.

The dentist then used laser energy mixed with water molecules to remove the decay. The little girl's experience with high-tech dentistry still is uncommon. But it's also a sign of choices to come.

A growing number of dentists are offering patients the laser instead of the drill or scalpel as a way to lessen anxiety and pain, trauma to tissue and healing time.

The laser's virtues also supposedly enable dentists to perform more procedures and, thus, make more money.

"It works wonderfully on pediatric patients," says Dr. Rhonda Newton, the Sammamish dentist who treated Kylie.

Newton also has used it on adults for crown lengthening. That's when the tooth breaks off too far below the gum line. The laser reduces the level of bone and gum to expose more of the tooth's top, called the crown.

"It's a lot less invasive than traditional periodontal surgery," said Newton.

After Newton started using the laser, her husband bought stock in the manufacturer.

The laser has been approved for use in dentistry for years but was slow to catch on. That's because it's expensive, takes time to master — and even then doesn't always eliminate the need for anesthetic or a drill, say dentists.

Among the 157,000 dentists in the U.S., the American Dental Association estimates about 3.5 percent use surgical lasers. At least 50 or more dentists in Western Washington have lasers, according to one manufacturer.

But that is starting to change thanks to recent advances in design as well as aggressive marketing by manufacturers.

"It's going to be the way to go. I can't believe more people aren't doing it," said Dr. Dean Burnett, a Bellevue endodontist who started using the laser in January.

In the recent past, dentists predominantly used lasers to perform different kinds of soft-tissue procedures, such as gum surgery.

But new state-of-the-art lasers can cut both hard tissue like tooth enamel and soft tissue as well as bone.

In 2000, a laser called the Waterlase was the first to win Food and Drug Administration approval for use on all oral tissues. In the subsequent years, the dental laser's range of applications has expanded.

Today the Waterlase and other such lasers can ablate or remove small to medium-sized cavities and contour bone; sterilize and enlarge root canals, remove canker sores and lesions — in many cases with no anesthetic, no drilling or cutting and little blood loss or swelling.

Laser devices work by creating a focused beam of light that produces heat at a certain wavelength. Different laser wavelengths react uniquely with different kinds of materials.

The Waterlase uses a unique wavelength and a patented combination of laser energy, water and air that makes a rat-a-tat-tat popping sound.

The action of the Waterlase on hard tissue — using energized water molecules to cut — is "like taking little stones and throwing them on the surface to chip away," said Dr. Tar-Chee Aw, associate professor of restorative dentistry at the University of Washington.

The laser handpiece never touches the surface during a hard-tissue procedure such as removing a cavity.

The laser also causes a temporary analgesic effect on the tooth, according to Keith Bateman, an executive with Biolase Technology, which makes the Waterlase.

On soft tissue, the laser uses only heat to cut and the water to cool as the tip gently touches the tissue. The heat causes bleeding to stop and blood to clot.

Fees more expensive

The technology does come with cautions for consumers.

Most lasers are pricey, between $40,000 and $50,000. The newest version of the Waterlase is $70,000. Some dentists may boost their fees for procedures performed with lasers.

Dental-insurance companies reimburse by procedure — gum surgery, for example — not by the technique used. So patients could get stuck paying the extra cost.

Before patients agree to a laser procedure, they should make sure their dentist knows what he or she is doing.

"It's always important for a consumer to ask about a dentist's experience with the type of procedure they're having done," said Dr. Ronald Inge, dental director and vice president with insurer Washington Dental Service. "If they've been using the laser for some time, that's a good thing. If it's the first time, that's a cautionary concern."

In the past year, patient Dennis Staab, 57, has had two crown preparations with the laser, both with no anesthetic or drill. The first time, he felt a "little sting" during the procedure and afterward a dull ache that seemed to last a couple days longer than usual.

His dentist, who still was new to using the laser, decided to reduce the power with the second crown. That time, Staab felt no discomfort at all.

"It's like anything else. The more you use it, the better you get," said Staab, who plans now to always ask for the laser.

Sometimes, there is no better medical tool than the laser, said dentist Dr. Robert Pick, a spokesman for the American Dental Association and a pioneer in laser dentistry. For example, Pick says, the laser should always be used to remove the "frenum," a piece of tissue found in several places in the mouth that attaches to the inside of the cheek or underside of the lip or tongue.

Sometimes, the frenum that attaches the gum to the upper lip can pull the gum away from the teeth and cause gum recession. Using a scalpel would cause bleeding and be a disservice to the patient, said Pick.

Pros and cons

Despite its growing popularity, the laser still has a long way to go before gaining mainstream acceptance.

It's slower than the drill and won't cut through metal. So millions of baby boomers can't rely on the laser to get rid of their old mercury fillings.

The laser also doesn't provide the kind of tactile feedback that dentists are accustomed to with the drill, so they must rely solely on sight. That can mean constantly checking to make sure too much tooth isn't removed.

"They would like to think it's going to be the device to replace the drill," said Aw at the UW who is researching the laser's effectiveness on preparing teeth for fillings. "But it's not yet the magical revolution they think it is."

Kylie Jones was less reserved.

In 15 minutes, the laser had removed the decay and prepared the surface of the tooth for a filling with no stinging needle and no whining drill, only the whoosh of water and a sound like popcorn popping. "I hope I have another one," Kylie said brightly after it was all over.

"No. No. We don't want another cavity," her mom, Lisa, replied with relief and surprise.

Marsha King: 206-464-2232 or mking@seattletimes.com