There are two type of lasers
- 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,
- 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.
TYPES OF LASERS
- Lasers used in dental practice can be classified by various methods:
- According to the lasing medium used, such as, gas laser and solid laser;
- according to tissue applicability, hard tissue and soft tissue lasers;
- according to the range of wavelength. Some of the diffrent lasers are:
1.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.
2.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)
LASER APPLICATION FOR DIFFERENT PURPOSES
- At low doses (e.g., 2 J/cm2), laser application stimulates proliferation, while at high doses (e.g. 16 J/cm2) it is suppressive It affects fibroblast maturation and locomotion and this in turn may contribute to the higher tensile strengths reported for healed wounds
- Low-level laser treatment (LLLT) of gingival fibroblasts in the culture has been shown to induce transformation in myofibroblasts (useful in wound contraction) as early as 24 hours after laser treatment
- The positive effects of LLLT on the healing of lesions of recurrent aphthous stomatitis in humans have also been recorded There are some positive data, which indicate that LLLT promotes healing and dentinogenesis following pulpotomy as also the healing of mucositis and oropharyngeal ulcerations in patients undergoing radiotherapy for head and neck cancer.
2. Aesthetic gingival re-contouring and crown lengthening
With the advent of the diode laser, many clinicians are choosing to include optimization of gingival aesthetics as part of the comprehensive orthodontic treatment whereas, conventional gingivectomy is associated with pain, discomfort, and bleeding.
3. Exposure of unerupted and partially erupted teeth
An impacted or partially erupted tooth can be exposed for bonding by conservative tissue removal, allowing for reasonable positioning of a bracket or button. It has the advantage of no bleeding, and an attachment can be placed immediately, and moreover.
4. Removal of inflamed, hypertrophic tissue, and miscellaneous tissue removal
HARD TISSUE APPLICATIONS :
- Photochemical effects
- Laser fluorescence
- Cavity preparation, caries, and restorative removal