LASER AND IT’S CLINICAL APPLICATIONS IN DENTISTRY

6 min


Firstly, the term LASER stands for Light Amplification by Stimulated Emission of Radiation. It plays a major role in many fields of medicine and more. It is a device that creates a uniform and coherent light that’s different from other ordinary light sources. However, it has a wide role in modern dentistry. In this article, let’s see the various clinical application.

Stern, Sognnaes and Goldman introduced LASER’s in dentistry in the year 1964.

LASER-TISSUE INTERACTION:

The human tissue has certain optical properties that a LASER interacts with. Meanwhile, based on this four types of interaction can occur when it comes in contact with a tissue. These include,

  • Reflection
  • Transmission
  • Scattering
  • Absorption.

REFLECTION:

In this, the beam simply re-directs without having any effect on the tissue

TRANSMISSION:

In this, the beam passes through the tissue without having any effect on the target tissue.

SCATTERING:

The beam is deflected in different directions which causes the transfer of energy to the tissues adjacent to the surgical site.

ABSORPTION:

The beam energy is absorbed by the target tissues depending on the contents of the tissue. Further, this is a desirable effect. Similarly, this forms the basis of the use of laser.

CHARACTERISTICS OF LASER LIGHT:

  • It’s monochromatic, meaning it has a single wavelength
  • Collimated meaning the beam from the laser is non-divergent
  • Additionally, coherency is the property where all the beams are on the same phase

METHOD OF USE OF LASERS:

There are 2 main methods of usage,

  • CONTACT MODE: There is minimal or light contact with the tissue being worked upon
  • NON-CONTACT MODE: The tip is a few millimeters away from the target tissue.

TYPES OF LASER’S USED IN DENTISTRY:

  • Carbon-dioxide
  • Erbium doped yttrium aluminium garnet (Er:YAG)
  • Neodymium doped yttrium aluminium garnet (Nd:YAG)
  • Diode
  • Argon

The two types of laser application,

  • Hard-tissue applications
  • Soft-tissue application

The wide use of lasers include,

  • Their ability to seal and coagulate minute blood vessels. This gives a bloodless field of surgery increasing effectiveness of performance on part of the surgeon
  • In addition, it provides a sterile surgical field
  • It’s the potential to cut through hard tissues with minimal damage to the adjoining structures.

Different procedures demand different types of lasers.

The soft tissue lasers include Nd: YAG, CO2, Diode and erbium lasers.

DIAGNOSTIC APPLICATIONS:

Some of the applications of LASER in diagnostics include,

  • CHECKING VASCULARITY AND VITALITY:

The laser doppler flowmetry is an accurate method to assess blood flow in micro-vascular structures.

Detecting smooth and occlusal surface caries is through laser fluorescence. The source is a diode laser. It is transferred using a fiber-optic cable that transmits light to a handheld probe. Further, the increased fluorescence indicates a carious state. Consequently, the monitor displays the readings.

HARD TISSUE APPLICATIONS:

Some hard tissue applications of LASER includes the following,

ENDODONTIC APPLICATIONS:

  • Obturation or filling the root canals after a root canal treatment. Thermo plasticized gutta-percha is the most effective method of achieving a fluid-impervious seal. In addition, softening of the gutta-percha can be done with lasers.
  • Apical surgeries: Apex is the root end region of a tooth. Surgeries in this region can be performed using LASERS. Usually, surgeries in this region are performed when a root canal fails, lesions in that region, massive destruction due to infections, or when non-surgical means are inadequate.
  • Meanwhile, removal of first-degree enamel caries. The Nd: YAG can remove pigmented surface carious lesions.
  • Removing fillings, materials like gutta-percha or resin, as an adjunct during a root canal.
  • Preparing cavities, etching of the enamel, enameloplasty (shaping of the pits and fissure of the enamel)
  • Similarly, curing and tooth whitening can be accompanied by lasers. Color changes of several shades are possible when accompanied by at-home tray-based whitening systems, dramatic changes can be obtained.

PERIODONTAL AND SURGICAL APPLICATIONS:

  • Osseous surgeries: Osseous surgeries are procedures that involve the alveolar or basal bone. Bone contouring during flap procedures can be achieved using erbium lasers.
  • Surgical procedures in implant placement: The diode and erbium lasers can be used for second-stage implant exposure.In addition, erbium lasers can be used for implant site preparation. It causes less damage than conventional bur drilling.

SOFT TISSUE APPLICATION:

Some soft tissue applications include,

PAEDIATRIC PURPOSES:

  • Pulpotomy is the surgical procedure of removing the pulp from the pulp chamber. Using Nd: YAG LASER’s for this procedure on primary molars, found 97% success rates clinically and 94.1% radiographically.
  • Above all, exposure of non-erupted or partially erupted tooth for extraction.

ENDODONTIC PURPOSE:

  • Erbium lasers can effectively perform root debridement.
  • Meanwhile, Er: YAG is used for procedures like removal of lipopolysaccharide from root surface without charring, melting for carbonizing the root surface.

PERIODONTAL APPLICATIONS:

Carbon dioxide assisted pulp capping procedures showed significant and superior success rates.

  • It is used in gingival soft tissue procedures like gingivoplasty (alteration of the gingiva), gingivectomy (removal of the gingiva), frenectomy (surgical removal of the frenum), gingival depigmentation (removal of the pigments of the gingiva), second stage exposure of implant and soft tissue crown lengthening procedures.
  • Moreover, Nd: YAG and diode lasers have been used for periodontal pocket debridement. This leads to the complete removal of the pocket epithelium, unlike conventional curettage.
  • Likewise, lasers can achieve an effective reduction of sub-gingival bacterial loads. The bacterial and de-toxifying effects of laser are very advantageous.
  • In addition, surgically, lasers can be used to debride areas with limited access as in deep defects or furcation areas. Erbium lasers are a choice when it comes to the degranulation of bony defects. Carbon dioxide lasers on the other hand might cause carbonization of the bone.
  • Bleaching of soft tissues is accompanied by lasers.
  • Importantly, laser accompanies guided tissue regeneration is very effective.
  • Sulcular debridement to improve gingival health (probing depth, attachment level improvement, tooth mobility, gingival bleeding, etc)

SURGICAL PUPOSE:

  • Pre-prosthetic surgery widely uses a laser. This includes prepping the region adequately for receiving the prosthesis. This improves seating of the prosthesis, improved retention.
  • Resections in case of tumor growths, threatening lesions can be easily removed through lasers. Lesions like fibromas, papilloma, hemangioma, mucoceles, gingival overgrowth, aphthous ulcers, tongue ties, premalignant lesions like oral leukoplakia, and erythroplakia.
  • Similarly, preparing a bed for soft-tissue graft can be done with erbium, CO2, Nd: YAG lasers
  • Likewise, creating incisions, removal of tissue for biopsies, draining the abscess,operculectomy, etc.,
  • Modifying the oral vestibule is accompanied by vestibuloplasty. Meanwhile, it improves denture seating. It is a pre-prosthetic procedure. This is easily accompanied by lasers.
  • Achieving hemostasis in case of profound bleeding.
  • For tissue retraction, while taking an impression.

On the other hand, certain disadvantages of lasers include,

  • Intra-pulpal temperature elevation
  • Enamel surface pitting
  • Crater formation
  • Melting of the root surface

OTHER APPLICATIONS IN DENTISTRY:

Disinfection of the root canals:

Disinfection of the root canals with carbon dioxide and Nd-YAG lasers. Other types of LASER’s that can be employed for this purpose are,

  • XeCl
  • Er: YAG
  • Diode
  • Argon

However, there a lot of limitations with the use of lasers within the canal. The laser beam can only be directed vertically downward in the canal. Sterilization of the lateral parts is difficult. Curvatures in the canal further complicate this.

Treating peri-implantitis:

Firstly, the loss of supporting alveolar bone around the body of the implant is peri-implantitis.

Diode lasers can treat these conditions. However, Nd: YAG and CO2, cannot be used for this purpose. The lasers are preferred for degranulation and implant surface decontamination as they can be used for both hard and soft tissue ablation.

Treating dentinal hypersensitivity:

The Nd: YAG, CO2, erbium, and diode lasers at low power settings can be used to treat dentinal hypersensitivity. Likewise, it acts through the following mechanism.

  1. It closes the dentinal tubules by melting and fusion- Nd: YAG
  2. In addition, it seals and narrows down the dentinal tubules- CO2
  3. Seals dentinal tubules subsequently reducing the movement of dentin fluid- Erbium
  4. Production of sclerotic dentin is promoted which further promotes internal obliteration of dentin tubules reducing sensitivity- Diode lasers.
  5. Meanwhile, lasers showed better results when used along with fluorides and varnishes.

Wound healing:

Firstly, wound healing by laser includes,

  1. Decreased swelling
  2. The scarring is very minimal
  3. Reduction of pain.
  4. Faster healing response
  5. Decreased post-operative pain

It is important to note that lasers should be used at a low-power setting, in a non-contact mode. This promotes wound healing, suppresses inflammation, stimulates cellular ATP.

  • Diode lasers within a wavelength of 635-810 nm
  • Gallium-aluminium-arsenide diode lasers at wavelengths of 906nm, 630-690nm, 830nm.
  • Argon lasers at 488-514nm.

Photo-dynamic antimicrobial therapy:

Mechanism: This procedure is based on the principle that a photosensitizer light binds to the target cell and gets activated by light of a suitable wavelength.

  1. Treating aggressive periodontitis non-surgically
  2. As an adjunct to non-surgical periodontitis
  3. Periodontopathogenic bacteria destruction.

Certain advantages of this therapy include,

  • Thorough elimination of pathogens
  • Anesthesia is not mandatory
  • Additionally, it avoids the risk of bacteremia (Spread of bacteria to the bloodstream)
  • It is a non-invasive procedure.

Laser therapy for relieving pain:

  • Radiotherapy or chemotherapy-induced mucositis can be treated by lasers.
  • Secondly, to relieve post-operative pain and paraesthesia
  • Lasers can relieve pain associated with arthritic conditions of the jaw.

To sum up, the above pointers are only some of the uses of LASER. Also, it plays an inevitable part in dentistry and many other field of medicine. Without doubt, this can form a major part of treatments in the future due to the cost-effectiveness and non-invasiveness.


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Dr Kavitha M

I am an undergraduate degree holder in dentistry. I have a great interest in music and reading. I am a linguaphile. My areas of interest lie in psychology, medical imaging, diagnostics, and oncology. I am a person who focuses more on the emerging areas of forensics.

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