Dental laser

Soft tissue lasers

Diode lasers wavelengths in the 810–1,100 nm range are poorly absorbed by the soft tissues such as the gingivae, and cannot be used for soft tissue cutting or ablation. Instead, the distal end of diode’s glass fiber is charred (by burned ink or by burned corkwood, etc.) and the char is heated by the 810-1,100 nm laser beam, which in turn heats up the glass fiber’ tip. The soft tissue is cut, on contact, by the hot charred glass tip and not by the laser beam.

Similarly ND:YAG lasers are used for soft tissue surgeries in the oral cavity, such as gingivectomy, periodontal sulcular debridement, LANAP, frenectomy, biopsy, and coagulation of graft donor sites. The Nd:YAG laser wavelength are partially absorbed by pigment in the tissue such as hemoglobin and melanin. These lasers are often used for debridement and disinfection of periodontal pockets. Their coagulative ability to form fibrin allows them to seal treated pockets.

The CO₂ laser remains the best surgical laser for the soft tissue where both cutting and hemostasis is achieved photo-thermally (radiantly).

Soft and hard tissue lasers

Erbium lasers are both hard and soft tissue capable. They can be used for a host of dental procedures, and allow for more procedures to be done without local anesthesia. Erbium lasers can be used for hard tissue procedures like bone cutting and create minimal thermal and mechanical trauma to adjacent tissues. These procedures show an excellent healing response. Soft tissue applications with erbium lasers feature less hemostasis and coagulation abilities relative to the CO₂ lasers. The new CO₂ laser operating at 9,300 nm features strong absorption in both soft and hard tissue and is the newest alternative to erbium lasers.

Dental caries removal

In September 2016 the Cochrane collaboration published a systematic review of the current evidence comparing the use of lasers for caries removal, in both deciduous and adult teeth, with the standard dental drill. Nine trials were reviewed, published between 1998 and 2014, with 662 participants in total. These included three different types of laser: Er:YAG; Er,Cr:YSGG; and Nd:YAG. Overall the quality of evidence available was found to be low, and the authors were unable to recommend one method of caries removal over the other. There was no evidence of a difference between the marginal integrity or durability of the restorations placed. However, there was some evidence that the laser produced less pain and required less anaesthesia than the drill. The authors concluded that more research is required.

Cost of lasers

Use of the dental laser remains limited, with cost and effectiveness being the primary barriers. The cost of a dental laser ranges from $4,000 to $130,000, where a pneumatic dental drill costs between $200 and $500. The lasers are also incapable of performing some routine dental operations.

Benefits of lasers

Dental lasers are not without their benefits, though, as the use of a laser can decrease morbidity after surgery, and reduces the need for anesthetics. Because of the cauterization of tissue there will be little bleeding following soft tissue procedures, and some of the risks of alternative electrosurgery procedures are avoided.

History

Sailesh Kumar R made the first CO₂ laser in 1964, in the same year the Nd:YAG Laser was invented at Bell Labs.