LASERS IN DENTISTRY

LASER TREATMENTS IN DENTISTRY:

 

 

 

 

 

 

 

The term LASER is an acronym for ‘Light Amplification by the Stimulated Emission of Radiation’.

As its first application in dentistry by Miaman, in 1960, the laser has seen various hard and soft tissue applications.

In the last two decades, there has been an explosion of research studies in laser application.

In hard tissue application, the laser is used for caries prevention, bleaching, restorative removal and curing, cavity preparation, dentinal hypersensitivity, growth modulation and for diagnostic purposes.

whereas soft tissue application includes wound healing, removal of hyperplastic tissue to uncovering of impacted or partially erupted tooth, photodynamic therapy for malignancies, photostimulation of herpetic lesion.

Use of the laser proved to be an effective tool to increase

efficiency, specificity, ease, and cost and comfort of the dental treatment.

There are two scenarios, on the one hand there are hard lasers, such as, Carbon dioxide (CO2), Neodymium Yttrium Aluminum Garnet (Nd: YAG), and Er:YAG, which offer both hard tissue and soft tissue applications, but have limitations due to high costs and a potential for thermal injury to tooth pulp.

whereas, on the other hand in cold or soft lasers, based on the semiconductor diode devices, which are compact, low-cost devices used predominantly for applications, are broadly termed as low-level laser therapy (LLLT) or ‘biostimulation’.

Why are dentists currently using lasers for?

These devices have been proven to help in the detection and treatment of oral diseases.

They can be used for treating gum disease, detecting cancer, and pinpointing tooth decay in its early stages.

They can precisely remove tissue, seal painful ulcerations like canker sores, and even treat small cavities.

In the future, dental laser technology will undoubtedly find even more applications.

How Do Lasers Work

Lasers take advantage of the quantum behavior of electrons, tiny particles inside atoms.

By stimulating atoms with pulses of energy, and then using a method of optical amplification, they cause the atoms to produce a beam of coherent light.

Essentially, that means that they emit light which has a great deal of energy, yet can be precisely controlled. It's the combination of high energy and precision that make lasers so useful.

Where Are Lasers Being Used

At present, the use of lasers in dentistry falls into three general categories: disease detection, soft tissue treatments, and hard tissue treatments.

There are many ways lasers can aid in diagnosis.

Laser light of specific wavelength, for example, can detect tiny pits and fissures in the biting surfaces of the tooth that a traditional dental tool can't find.

This enables a defect that's too small to be treated at present to be carefully monitored.

Lasers can also help locate dental calculus (tartar) beneath the surface of the gums, and can even aid in the detection of oral cancer in its early stages, accurately showing where healthy tissue ends and diseased tissue begins.

For the treatment of soft tissue problems, lasers have many advantages.

They are minimally invasive tools that generally involve taking away less tissue than conventional methods.

Used in gum surgery, for example, lasers can treat gum disease by killing harmful bacteria deep in pockets below the gum line, and removing the diseased tissue without harming the healthy tissue.

They can also remove the thin layer of cells that inhibits reattachment of the gum and bone tissues to the tooth, while sealing off the adjacent blood vessels. This type of procedure generally results in less bleeding and pain.

Lasers are also effective in treating ulcers and sores on the lips or gums.

Lasers are even finding increasing use for hard-tissue procedures, like the treatment of dental caries and cavities.

Not only are they more exact in the amount of material they remove, but they eliminate the noise and vibration of the dental drill, which is uncomfortable for some patients.

As lasers become more common in the dental office, these high-tech tools will be integrated into routine dental practice.

This promising technology already offers some real benefits, and is sure to find increasing use in the near future.

Dental Lasers Filling:

Hard tissue dental procedures include all work done on the teeth themselves, such as filling cavities.

Dental lasers can be used in cavity fillings by taking the place of a traditional dental drill when preparing the tooth for the filling.

Lasers can remove the tooth decay in a tooth and help shape the tooth to receive the filling.

They are also used to harden composite resin fillings. Because no drill is involved, using a laser for tooth fillings may eliminate the need for anesthesia, which is a great benefit for patients with sensitive teeth or phobias involving dental work.

Lasers can also be used to help patients with hot-cold sensitivity. By sealing tiny tubes located on the root of the tooth, dental lasers can help sensitive patients enjoy hot and cold beverages again.

Dental Lasers Gum Treatment:

It is estimated that about 6% of all general dentists use a dental laser for procedures involving soft tissues.

Soft tissue dentistry typically refers to treatment of the gums. Lasers are used to reshape the gums for a number of procedures, including root canals and crown lengthening.

Lasers can also be used to reshape gum tissue to improve the appearance of patients’ smiles.

Dentists may also use a laser to help contour the gum lines for denture wearers, to provide a more comfortable fit.

When used in soft tissue procedures, lasers are able to focus on a very specific area, reducing damage to surrounding tissues. Because the light beam of a laser helps blood to clot faster, lasers reduce bleeding during soft tissue procedures.

For the same reason, many soft tissue dental procedures performed with lasers do not require stitches.

Additionally, lasers sterilize the tissue as they go, leading to fewer infections.

All of these benefits add up to greatly increased healing time and fewer return trips to the dentist because of complications after the patient returns home.

CARBON DIOXIDE LASER:

The CO2 laser wavelength has a very high affinity for water, resulting in rapid soft tissue removal and hemostasis with a very shallow depth of penetration.

Although it possesses the highest absorbance of any laser, disadvantages of the CO2 laser are its relative large size and high cost and hard tissue destructive interactions.

NEODYMIUM YTTRIUM ALUMINUM GARNET LASER:

The Nd: YAG wavelength is highly absorbed by the pigmented tissue, making it a very effective surgical laser for cutting and coagulating dental soft tissues, with good hemostasis.

In addition to its surgical applications,there has been research on using the Nd: YAG laser for nonsurgical sulcular debridement in periodontal disease control and the Laser Assisted New Attachment Procedure (LANAP).

ERBIUM LASER:

The erbium ‘family’ of lasers has two distinct wavelengths, Er, Cr: YSGG (yttrium scandium gallium garnet) lasers and Er: YAG (yttrium aluminum garnet) lasers.

The erbium wavelengths have a high affinity for hydroxyapatite and the highest absorption of water in any dental laser wavelengths. Consequently, it is the laser of choice for treatment of dental hard tissues.

In addition to hard tissue procedures, erbium lasers can also be used for soft tissue ablation, because the dental soft tissue also contains a high percentage of water.

DIODE LASER:

The active medium of the diode laser is a solid state semiconductor made of aluminum, gallium, arsenide, and occasionally indium, which produces laser wavelengths, ranging from approximately 810 nm to 980 nm.

All diode wavelengths are absorbed primarily by tissue pigment (melanin) and hemoglobin. Conversely, they are poorly absorbed by the hydroxyapatite and water present in the enamel.

Specific procedures include aesthetic gingival re-contouring, soft tissue crown lengthening, exposure of soft tissue impacted teeth, removal of inflamed and hypertrophic tissue, frenectomies, and photostimulation of the apthous and herpetic lesions.

MECHANISM OF LASER ACTION:

Laser light is a monochromatic light and consists of a single wavelength of light.

It consists of three principal parts: An energy source, an active lasing medium, and two or more mirrors that form an optical cavity or resonator.

For amplification to occur, energy is supplied to the laser system by a pumping mechanism, such as, a flash-lamp strobe device, an electrical current, or an electrical coil.

This energy is pumped into an active medium contained within an optical resonator, producing a spontaneous emission of photons.

Subsequently, amplification by stimulated emission takes place as the photons are reflected back and forth through the medium by the highly reflective surfaces of the optical resonator, prior to their exit from the cavity via the output coupler.

In dental lasers, the laser light is delivered from the laser to the target tissue via a fiberoptic cable, hollow waveguide, or articulated arm.

Focusing lenses, a cooling system, and other controls complete the system.

The wavelength and other properties of the laser are determined primarily by the composition of an active medium, which can be a gas, a crystal, or a solid-state semiconductor.

Laser safety:

While most dental lasers are relatively simple to use, certain precautions should be taken to ensure their safe and effective operation.

First and foremost is protective eyewear by anyone in the vicinity of the laser, while it is in use.

This includes the doctor, chairside assistants, patient, and any observers such as family or friends.

It is critical that all protective eyewear worn is wavelength-specific.

Additionally, accidental exposure to the non-target tissue can be prevented through the use of warning signs posted outside the nominal hazard zone, limiting access to the surgical environment, minimizing the reflective surfaces, and ensuring that the laser is in good working order, with all manufacturer safeguards in place.

With regard to prevention of possible exposure to infectious pathogens, high volume suction should be used to evacuate any vapor plume created during tissue ablation, and normal infection protocols should be followed.

Each dental office should have a designated Laser Safety Officer to supervise the proper use of the laser, coordinate staff training, oversee the use of protective eyewear, and be familiar with the pertinent regulations.

Medicolegal considerations:

Conservative soft tissue surgery with a dental laser is considered within the scope of accepted dental practice and typically considered a covered procedure under most professional liability insurance policies designed for dental specialists.

Informed consent must be routine and is best handled as part of the general consent form that all patients read and sign prior to the initiation of dental treatment.

NOTE: It is highly recommended that each clinician take a course from a reputable provider.

IN CONCLUSION:

Laser technology for hard tissue application and soft tissue surgery is at a high state of refinement, having had several decades of development, up to the present time, and further improvements can occur.

The field of laser-based photochemical reactions holds great promise for additional applications, particularly for targeting specific cells, pathogens, or molecules.

A further area of future growth is expected to be a combination of diagnostic and therapeutic laser techniques.

Looking to the future, it is expected that specific laser technologies will become essential components of contemporary dental practice over the next coming years.