Sometimes back in 1970s, Low level laser therapy in Melbourne used to differentiate between surgical and therapeutic lasers that applied thermal effects in surgery. Therapeutic lasers by then used low power of not more than 50mW. Non-surgical lasers were those that had power above 50mW and they were referred to as cold lasers. Since there is a wide array of form of lasers, people often get confused about the performance and application. Some of the misconceived ideas are listed below.
- Low Lasers Can’t Burn The Skin:
This is not true in the case of continuous laser of the category 3b. A laser of appropriate intensity used in a particular body part continuously, it is possible for the tissues to burn. The class 3b lasers lack thermal effect. As the tissues absorb the emissions, they gain energy and become hot. Even though the treatment is ‘cold’, it doesn’t mean that a patient experiences cold. Constant waves can easily burn the skin.
- All Lasers in The 4th Category Are Surgical Lasers:
This is a wrong statement. The truth is, all surgical lasers are in the 4th category but there are other lasers in this category which are not surgical lasers. Some ads use class 4 to denote lasers that burn, it doesn’t mean that all lasers in this class can burn. A laser is considered cold depending on the optimal power density. Only the continuous lasers in class 4 burn tissues. These thermal effect lasers are totally safe if they are applied slightly across the body instead of holding them at a particular point for long. Burning risk is reduced through appropriate application and following safety measures.
- The Thermal Effect is a Result of Class 4 Status:
False. Highly powered class 4 lasers can burn the body. Super waves generate more pulses in less than a second and exceed continuous waves. Fast pulsing produces thermal effects so that they act like cold lasers. In other words, class 4 lasers are cold lasers. However, the thermal effect does not solely emanate from this category but rather as a result of energy density. For optimal results, a laser needs to be positioned at a single place. Low energy lasers take long to achieve any biological effect on a tissue but a high-powered laser accomplishes the task quicker.
Some scientists use the term cold laser therapy to refer to lasers of class 3b i.e. those that unction below 500mW. However the best term to use is photo-bio-modulation. Manufacturers on the other hand describe class 4 laser as deep penetration or high power lasers. The best approach is not focusing on thermal power but rather the average power used.
