**2. Types of laser**

In dental field, lasers can be categorized by different ways: according to the type of the affected tissue, soft tissue and hard tissue lasers; according to the medium of laser used, like solid laser and gas laser; and finally according to wavelength of laser that is being used.

#### **2.1 Neodymium yttrium aluminum garnet laser**

The neodymium yttrium aluminum garnet laser (Nd:YAG) wavelength is strongly absorbed by the pigmented tissue. There has been research on using the Nd:YAG laser for nonsurgical sulcular debridement in periodontal disease control [23]. Neodymium yttrium aluminum garnet laser is a very effective surgical laser for coagulating and cutting periodontal soft tissues, with good hemostasis [24]. In addition Nd:YAG laser is used in laser-assisted new attachment procedure (LANAP) [25].

#### **2.2 Carbon dioxide laser**

The CO2 laser has the advantage of rapid soft tissue elimination and hemostasis with a very shallow depth of penetration, and this advantage is due to its wavelength which has a great affinity for water. Carbon dioxide laser has the highest absorbance of any laser [26], but it is associated with several disadvantages including its high cost, relative large size, and its interactive destruction to the hard tissue.

#### **2.3 Diode laser**

Diode wavelengths are absorbed mainly by hemoglobin and pigmented tissue (melanin). On the other hand, they are poorly absorbed by the enamel and hydroxyapatite. Laser wavelengths, ranging from 810 to 980 nm, are produced from the active medium of the diode laser which is a solid-state semiconductor made of gallium, aluminum, arsenide, and infrequently indium. Diode laser is used in particular procedures including soft tissue crown lengthening, aesthetic gingival (gingivoplasty), removal of inflamed soft tissue, exposure of soft tissue impacted teeth, frenectomies, and photostimulation of the herpetic and aphthous lesions [27].

#### **2.4 Erbium laser**

The erbium wavelengths have the highest absorption of water in any dental laser wavelengths and have a great affinity for hydroxyapatite. Two distinct wavelengths

**147**

*Laser Applications in Periodontology*

proportion of water [29].

*DOI: http://dx.doi.org/10.5772/intechopen.88046*

**3. Laser applications in periodontology**

1.Soft tissue surgical applications

3.Laser root conditioning

**3.1 Soft tissue surgical applications**

ing no topical anesthesia [33].

nective tissues [35, 36].

**3.2 Removal of the pocket epithelium**

4.Bacterial reduction

5.Implant therapy

2.Removal of the pocket epithelium

of erbium lasers had been developed, including Er:YAG (yttrium aluminum garnet) lasers and Er,Cr:YSGG (yttrium scandium gallium garnet) lasers. Because of its great affinity for hydroxyapatite, it is the laser of choice for dealing with dental hard tissues [28], and because of its high absorption of water, erbium lasers can be used for periodontal soft tissue ablation, as dental soft tissue is composed of a high

Lasers such as diode, CO2,Nd:YAG, Er:YAG, and Er,Cr:YSGG are being extensively used in periodontal treatments including gingival soft tissue procedures such as gingivoplasty, gingivectomy, frenectomy, benign tumors or epulis elimination [30], irradiation of aphthous ulcers, gingival depigmentation, coagulation of free graft donor sites, second-stage exposure of dental implants [13], and crown lengthening procedures [30]. This diversity of laser use is due to its superior properties over conventional scalpel procedures which include bacteremia reduction, ease of soft tissue ablation, hemostasis [30], slight wound contraction and slight scarring, immediate sterilization, edema reduction, mechanical trauma reduction, no or little operative and postoperative pain [13, 31, 32], improved patient acceptance [13], more rapid healing, little need for suturing, much easier technique, and necessitat-

The penetration depth of lasers differs, and therefore their performance differs, and lasers possibly cause a hazardous effect on the underlying tissues by thermal injury. Laser light is absorbed in the superficial layers in Er:YAG,CO2 and Er,Cr:YSGG lasers, and hence it has the advantage of being simple and rapidly vaporized from soft tissues, while other type of laser such as diode lasers and deeply penetrating Nd:YAG associate with more thermal influences, which consequently lead to formation of thick coagulation zone on the treated surface [21, 29, 30] and hence used similar to electrosurgical procedures [30]. Finkbeiner [34] has suggested the usefulness of argon laser in soft tissue welding and soldering compared to conventional tissue closure method. Epithelial exclusion using CO2 laser had been suggested to retard its downward growth, and studies have shown effective removal of epithelium from gingival tissues without damaging the underlying con-

Lasers are also used for soft tissue periodontal applications. The Nd:YAG was the first laser wavelength to be compared to the scalpel for treating periodontal

*Laser Applications in Periodontology DOI: http://dx.doi.org/10.5772/intechopen.88046*

*Public Health in Developing Countries - Challenges and Opportunities*

important types of laser used in the India as well as in Iraq.

**2.1 Neodymium yttrium aluminum garnet laser**

**2. Types of laser**

that is being used.

**2.2 Carbon dioxide laser**

**2.3 Diode laser**

**2.4 Erbium laser**

as an adjunct to scaling and root planning (SRP) may provide additional benefits [13]. It had been shown that using lasers in periodontal treatment had a beneficial role in controlling of bacteremia, bacterial reduction, effective subgingival calculus elimination (using Er:YAG lasers), improved eradication of the pocket epithelium in pockets involving teeth, and enhancement of periodontal regeneration in humans and animals without a destructive effect on the neighboring pulp tissues and bone [14–21]. In India the capability of using laser device at laboratories and institutes offers a huge chance to the researchers and scientists concerned in the field of free electron lasers, semiconductor lasers, solid-state lasers, and gas lasers [22]. So because of the importance of the subject and the wide use of laser in India, this chapter focuses on the most

In dental field, lasers can be categorized by different ways: according to the type of the affected tissue, soft tissue and hard tissue lasers; according to the medium of laser used, like solid laser and gas laser; and finally according to wavelength of laser

The neodymium yttrium aluminum garnet laser (Nd:YAG) wavelength is strongly absorbed by the pigmented tissue. There has been research on using the Nd:YAG laser for nonsurgical sulcular debridement in periodontal disease control [23]. Neodymium yttrium aluminum garnet laser is a very effective surgical laser for coagulating and cutting periodontal soft tissues, with good hemostasis [24]. In addition Nd:YAG laser is used in laser-assisted new attachment procedure (LANAP) [25].

The CO2 laser has the advantage of rapid soft tissue elimination and hemostasis with a very shallow depth of penetration, and this advantage is due to its wavelength which has a great affinity for water. Carbon dioxide laser has the highest absorbance of any laser [26], but it is associated with several disadvantages including its high cost, relative large size, and its interactive destruction to the hard tissue.

Diode wavelengths are absorbed mainly by hemoglobin and pigmented tissue (melanin). On the other hand, they are poorly absorbed by the enamel and hydroxyapatite. Laser wavelengths, ranging from 810 to 980 nm, are produced from the active medium of the diode laser which is a solid-state semiconductor made of gallium, aluminum, arsenide, and infrequently indium. Diode laser is used in particular procedures including soft tissue crown lengthening, aesthetic gingival (gingivoplasty), removal of inflamed soft tissue, exposure of soft tissue impacted teeth, frenectomies, and photostimulation of the herpetic and aphthous lesions [27].

The erbium wavelengths have the highest absorption of water in any dental laser wavelengths and have a great affinity for hydroxyapatite. Two distinct wavelengths

**146**

of erbium lasers had been developed, including Er:YAG (yttrium aluminum garnet) lasers and Er,Cr:YSGG (yttrium scandium gallium garnet) lasers. Because of its great affinity for hydroxyapatite, it is the laser of choice for dealing with dental hard tissues [28], and because of its high absorption of water, erbium lasers can be used for periodontal soft tissue ablation, as dental soft tissue is composed of a high proportion of water [29].
