As the laser precisely cuts or "vaporizes" soft tissue, which is called ablation, it coagulates the tissue. This controlled coagulation increases hemostasis and is almost bloodless in many cases. This hemostatic control combines with the bactericidal effect of the laser energy at the surgical site, reduces the discomfort during treatment, and minimizes the risk of infections and the need for antibiotics and sutures.
It also minimizes the inflammatory response, allowing faster and improved healing with less postoperative discomfort. The benefit of laser use for soft tissue treatment and management is that the treatments are often less invasive, more precise, and very conservative, preserving the healthy tissue while treating the diseased site. These benefits greatly reduce discomfort during treatment and minimize the need for local anesthesia for many procedures.
The ability of laser light energy to ablate (vaporize or cut) tissue is dependent on how well the energy is absorbed by that tissue, the amount of energy or power (watts), and the amount of time the energy is being emitted into the tissue. The key to achieving the maximum efficiency for this tissue interaction is to match these variables with the chromophores (absorbers of light) present in the tissue with a laser that emits the proper wavelength.
Using the high peak power with microsecond pulse features on the simple–to–use but more sophisticated lasers allows specific microscopic tissue to be precisely removed with each pulse. It also allows thermal recovery (thermal relaxation) between each pulse, therefore minimizing any collateral tissue damage and postoperative discomfort
With a high powered 980 nm diode laser (greater than 6 watts), this precision can be further enhanced by using water irrigation for convention cooling, allowing the clinician to precisely control his or her clinical options and modes of treatment.
Controlling the amount of energy in each pulse of the laser light and the amount of time that it interacts with the tissue also has a significant impact on the laser's efficiency. There is a linear relationship between the energy in a pulse of light energy and its ablation efficiency. Often this is accomplished by managing the length of time the tissue is energized with laser energy relative to the amount of time it is allowed to relax, enabling the surrounding tissue to cool before the next pulse. The more a laser can control its pulse width and emission/duty cycle, the more effective the laser will be in successfully managing the outcome of the remaining surrounding tissue.
Laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The first laser was built in 1960 by Theodore H. Maiman at Hughes Research Laboratories, based on theoretical work by Charles Hard Townes and Arthur Leonard Schawlow.
A laser can be classified as operating in either continuous or pulsed mode, depending on whether the power output is essentially continuous over time or whether its output takes the form of pulses of light on one or another time scale.
Continuous wave emission mode means the laser is on the whole time it is turned on. In these lasers peak power equals the wattage output displayed.
Superpulsed" lasers are a form of gated lasers with extremely short pulse durations. Free running pulsed lasers are not on constantly but emit photons in powerful bursts of energy measured in millionths of seconds.
Photothermal effects occur when the chromophores absorb the laser energy and heat is generated. This heat is used to perform work such as incising tissue or coagulating blood. Photothermal interactions predominate when most soft tissue procedures are performed with lasers.
Photobiomodulation or Biostimulation refers to lasers ability to speed healing, increase circulation, reduce edema, and minimize pain. Many studies have exhibited effects such as increased collagen synthesis, fibroblast proliferation, increased osteogenesis, enhanced leukocyte phagocytosis, and the like with various wavelengths.
When a laser heats oral tissues certain reversible or irreversible changes can occur:
Irreversible effects such as denaturation and carbonization result in thermal damage that cause inflammation, pain, and edema.