Recent Development of Laser Assisted Dentistry and Clinical Applications

Anshebo Getachew Alemu

Review Article

J Dent App. 2023; 9(1): 1120.

Recent Development of Laser Assisted Dentistry and Clinical Applications

Anshebo Getachew Alemu*

Department of Physics, College of Natural and Computational Science, Samara Unversity, Ethiopia

*Corresponding author: Anshebo Getachew Alemu Department of Physics, College of Natural and Computational Science, Samara Unversity, Ethiopia. Tel: +251-977-413118 E-mail: [email protected]

Received: April 24, 2023 Accepted: May 29, 2023 Published: June 05, 2023

Abstract

Recent advancements in laser applications in clinical and dental medicine have the potential to play a critical role in patient comfort sectors, where laser technology is currently altering human existence. Laser drugs are used in dentistry and clinical therapy to counteract the negative effects of traditional methods, allowing for bloodless surgery with minimal postoperative discomfort and scarring. One of the key goals of laser dentistry is to provide the most comfortable care possible while minimizing risk. The advantages of laser therapy exceed the disadvantages, allowing for straight forward, modern, and safe clinical and dental procedures. This brief study’s main subjects present the current state of the laser in a variety of therapeutic and dental applications

Keywords: Dentistry; Laser; Clinical; Laser safety

Introduction

Due to its many benefits over other conventional current procedures, laser (light amplification by stimulated emission of radiation) applications in dentistry and clinical medicine are now regarded as patient-friendly techniques. Lasers can be employed in a wide range of dental and clinical operations since they are available in a variety of devices and wavelengths [1]. Over the past few years, lasers have increasingly been used in clinical medicine and dentistry [2]. Lasers are recommended for a wide range of treatments due to their various benefits [3-6]. Conventional cavity preparation techniques include low- and high-speed hand pieces, which can be noisy, unpleasant, and stressful for patients [7-10].

Laser Types

Lasers in dental and clinical applications are classified based on a variety of criteria, including the laser's active medium, which can be gas, liquid, solid, or semi-conductor, and the excimer laser beam that will be emitted (Figure 1).

Figure 1: Types of lasers based source material.

    
    
    Figure 1: Types of lasers based source material.

They are invariably classified according to the lasing medium used, as a gas laser or a solid laser. They can also be categorized based on tissue applicability in hard and soft tissue lasers, as well as wavelengths and the danger associated with laser application [11]. In addition, laser classification is based on different criteria such as power, source material (Figure 1), and wave length [12-14]. Another crucial factor in laser classification and treatment is power. Lasers are divided into three classes according to their power, as shown in the Figure 2: Low-power lasers (cold lasers): often less than 250mW cause light stimulation in tissues without having any heat consequences. This process is known as photobiostimulation. High-power lasers (warm or hard lasers) cause heat and improve the flow of energy in tissues to impart their therapeutic effects. The power of high-power lasers, which are usually more than 500mW, has applications in surgery. NdYAG (erbium-doped yttrium aluminum garnet) and Er:YAG (erbium-doped yttrium aluminum garnet) are classified as hard lasers and can be used on both hard and soft tissues, but they have limits due to their high cost and heat harm to the tooth pulp [12-14]. Furthermore, lasers are categorised according to their wavelength range, such as the ultraviolet range (300–400nm) and the visible light range (400–700nm).

Figure 2: Types of lasers based power source.

    
    
    Figure 2: Types of lasers based power source.

Additionally, lasers are divided into groups based on their wavelengths, such as the visible light range (400–700nm) and the ultraviolet range (300–400nm). Figure 3 depicts the NIR (near infrared) spectrum from 700 to 1200nm and the infrared (FIR) region of greater than 1200nm [2,12].

Figure 3: Laser classification based on wavelength range.

    
    
    Figure 3: Laser classification based on wavelength range.

Gas laser: The first gas laser was the helium neon laser, which had a green wavelength and multiple infrared wavelengths. Common examples of gas lasers are carbon dioxide and argon. A particular sort of gas is produced when noble gases such as argon, krypton, and xenon are mixed with reactive gases [15-17].

Although the carbon dioxide laser's bulkiness, high price, and destruction of hard tissue are its drawbacks, it is hydrophilic, has quick soft tissue removal, hemostasis with shallow depth penetration, and has maximal absorbency. Applications of the CO₂ laser in soft tissue surgery are generally accepted. Despite the use of CO₂ lasers for caries prevention, they have not been used in clinical settings as shown in Figure 4. Due to their advantageous optical properties, CO₂ wavelengths of 9,300 and 9,600nm can be used to treat dental hard tissue. Technological advances in software and laser settings will aid in the development of new therapeutic applications and techniques.

Figure 4: CO2 laser [18].

    
    
    Figure 4: CO2 laser [18].

Figure 5: Diode Laser [18].

    
    
    Figure 5: Diode Laser [18].

The availability and demand for CO₂ lasers as hard tissue lasers will both increase for researchers and medical professionals. Since water efficiently absorbs CO₂ lasers, they are absorbed on the surface of soft tissue. The first centimetre of soft tissue is where visible lasers (445–660nm) are most effectively absorbed because pigmented chromophores like melanin and hemoglobin absorb them [15-19].

Liquid laser: A liquid dye is stimulated by liquid lasers to produce light radiation. Most of their "tunable" range is between 550 and 590nm. Their light can be seen. Dye lasers are frequently utilised for vascular reasons, including the treatment of rosacea, spider nevi, and angiomas in children and newborns [20,21]. Other disorders, like psoriasis, where it is beneficial against new lesions, are treated with this type of laser less commonly [22,23].

Solid-state lasers: The medium can be ceramic, glass (neodymium glass), or a crystal (ruby, sapphire, titanium, etc.). There are also laser diodes, such as the ones used in CDs, in a non- exhaustive list.

The erbium laser: The two wavelengths of the erbium laser are the Er:YAG laser and the Er:Cr:YYSGG (yttrium scandium gallium garnet) laser. Because of its high affinity for hydroxyapatite and high water absorption rate, it is the best option for treating both hard and soft tissues that contain a high proportion of water. The erbium laser is a highly flexible laser technology used in dermatology. Because of its ability to be absorbed almost entirely by water, it is an excellent tool for treating a wide range of cutaneous skin problems [24-26]. The Nd:YAG laser is highly absorbed by pigmented tissue and has excellent hemostasis, making it ideal for surgically cutting and coagulating soft tissue.

Diode lasers: The size of laser machines has been significantly decreased thanks to the development of micro-structure diode cells that can produce laser light. The range of spectral emissions is now constrained to a very small band (about 400–1,000nm) due to the limitations of the underlying physics. These lasers only use active media made of solid materials. The active medium is placed between silicon wafers in a diode laser (Figure 4). It is possible to selectively polish the ends of the crystal relative to internal refractive indices to form entirely and partially reflecting surfaces, simulating the optical resonators of larger lasers. This is possible because the active media, such as GaAlAs, is crystalline.

Photons are released from the active medium when current is discharged across the active media from one silicon wafer to the next. Current surgically relevant diode lasers use banks of individual diode "chips" connected in parallel to obtain the needed power capability because individual diode "chips" produce relatively low energy output [27-29].

Semiconductor lasers: The semiconductor laser has found widespread use in the medical professions as a result of its benefits, including its compact size, light weight, long lifespan, and great efficiency. The function mechanism of the semiconductor laser have unique applications in the departments of ophthalmology, surgery, cosmetology, and dentistry are examined [30]. In medical applications, semiconductor lasers have two major mechanisms: bio-stimulation and thermal action. The activation of compensation, nutrition, repair, and other immune defense mechanisms in response to the stimulation response is the mobilisation of compensation, nutrition, repair, and other immune defense systems to remove the pathogenic process. The thermal effect is the most important biological effect because it is present in all laser irradiation. The heat consequences of a high-power semiconductor laser are the major reason for its use. The local irradiation from a laser causes a heated, high-temperature increase in the macro performance of the tissue's molecular absorption of photon energy, vibration, and rotation. Because tissue cells include pigments like melanin, hemoglobin, carotenoids, and other substances that can boost light absorption, the heat effect of lasers is more significant [31-33].

Table 1: Types of Laser.




  
    Gas lasers
    Liquid
    Solid
    Semiconductor
    Excimers
  
  
    
      Argon
      Carbon- dioxide [15-19]
    
    
      Dye lasers [20-23]
    
    
      Er: YAG laser
      Er:Cr:YYSGG
      Nd:YAG laser [24-26]
    
    
      GaAs laser (infrared)
      GaAsP (visible) [34,35]
    
    
      Buffer gas (usually neon or helium),
      Halogen gas (fluorine,chlorine, or bromine),
      noble gas (argon,krypton,or xenon [36,37]



Table 1: Types of Laser.

Table 2: Applications of laser.




  
    Applications
     
    Reference
  
  
    Clinical application
    Laser Application in Hard    Tissues
     
  
  
     
    Caries detection
    [22-37]
  
  
     
    Cavity Preparation
     
  
  
     
    Carious Lesions Prevention
     
  
  
     
    Etching
     
  
  
     
    Fissure Sealant Therapy
     
  
  
     
    Hard Tissue Cutting
     
  
  
     
    Pulp Therapy
     
  
  
     
    Laser Application in Soft    Tissues
     
  
  
     
    Ankyloglossia
     
  
  
     
    Frenectomy
     
  
  
     
    Gingival Remodeling and Gingivectomy
     
  
  
     
    Lesions Removal and Biopsy
     
  
  
     
    Herpetic Lesions
     
  
  
    Dentistry
    Cellulitis and Spasm    treatment
     
  
  
     
    Teeth anesthesia
    [38-44]
  
  
     
    Anterior dental Teeth    Treatment
     
  
  
    Temporomandibular Joint (TMJ)    Treatment
  
  
     
    Surgical Operations and    Injuries
     
  
  
    Biologic process
    Biostimulation
    [45-61]
  
  
     
    Photodynamic therapy (PDT)
     
  
  
     
    Laser-Assisted Microdissection
     
  
  
     
    The Optical Tweezers
     
  
  
     
    The Laser Ablation
     
  
  
     
    The Utilisation in imagery
      
        Laser Coherence Tomography
        Photoacoustic imaging (PAI)
        Surface-enhanced Raman scattering (SERS)



Table 2: Applications of laser.

Table 3: Advantages and disadvantages of laser [62-64].

Advantages of laser
Disadvantages of laser

Less time spent the operator’s chair compared to

similar restorative treatment
Costs associated with purchasing and implementing

technology are rather significant.

Engage with ailing tissues in a precise and selective manner
Laser operations require specialised knowledge and expertise in a range of clinical applications.

Dry operating room and improved visibility
A change in clinical technique is necessary because dental instruments are typically used for both side and end cutting.

Reduced requirement for antibiotics due to tissue surface sterilisation or decontaminating capabilities of the laser and bactericidal qualities on the tissue
Multiple lasers are required for different procedures since no one wavelength can effectively cure all dental problems.

Excellent homeostasis and a decreased need for sutures
Erbium family lasers are unable to remove faulty restorations made of metal and cast porcelain.

. Reduced oedema, scarring, and heat necrosis of surrounding tissue.
A rotary bur is faster at removing hard tissue than a laser.

Reduced use of local anaesthetics for treating soft tissue
Dangerous to skin as well as to eyes, hence the entire professional team needs to wear particular wavelength eye protection.

Reduced post-operative discomfort and accelerated wound healing with a quicker healing response.
There may be a danger of disease transmission through laser-generated aerosol in immune- compromised patients receiving soft tissue therapy

for viral lesions.

Increased acceptance of patients

Little mechanical damage

Compared to electrosurgical tools, lasers induce less thermal necrosis of nearby tissues.

Removal of the high-speed drill and its related

noise, vibrations, smells, and terror

Contouring and removal of ossified tissue



Table 3: Advantages and disadvantages of laser [62-64].

Excimers lasers: A mixture of noble gases and halogens is used as the gain medium in excimer lasers, which are strong ultraviolet lasers as shown in figure6. The power for excimer lasers comes from an electrical current source, like most gas lasers do. A tube that houses the laser medium is filled with three different types of gases, including buffer gas (usually neon or helium), halogen gas (fluorine, chlorine, or bromine), and noble gas (argon, krypton, or xenon). Excimer lasers' main benefit is their ability to generate a very narrow, accurate spot at a very short (UV) wavelength. Due to their ability to accurately obliterate material with minimal to no temperature buildup, excimer lasers are great for removing extra material through laser ablation. Compared to carbon dioxide lasers, which mainly rely on temperature accumulation to "boil off" material during ablation, this is the opposite [34,35].