Laser technology has been developed rapidly in the last decade. New lasers with a wide range of characteristics are available now which are being used in various branches of dentistry. The application of these new technologies in endodontics has always been challenging. Today more experience and knowledge in applying lasers in operative dentistry and endodontics is available.
The interest in endodontic use of dental laser systems is increasing. There are several studies performed which prove the benefits of using a dental laser for cavity preparation over conventional rotary abrasives. Dental lasers are now set to perform almost every dental procedure which is to be carried out in the field of conservative dentistry and endodontics.
The science of conservative dentistry aims at saving natural teeth that have defects due to dental caries, trauma, abrasion or attrition and esthetic disharmony including developmental anomalies or tooth discoloration, as well as pulpal and or periapical diseases to maintain their inherent masticatory, phonetic and esthetic function and the physiologic integrity in harmonious relationship with the adjacent hard and soft tissues through diagnosis, treatment, post op evaluation and prevention.
One of the most commonly performed procedures in conservative dentistry is cavity preparation which done so that the diseased tooth is rid of all its infection and can receive a suitable restorative material. Cavity preparation is done conventionally by using a rotary abrasive. This results in a cavity form, which is irregular, and it damages the natural morphology of the dental hard tissues. The enamel prisms are destroyed and the dentinal tubules are packed with debris and dentinal muds.
Using a dental laser for this procedure has obvious advantages. The hard tissue dental laser such as the Er:YAG would retain the natural morphology of the dental hard tissues during cavity preparation. The Er:YAG laser radiation appears to be a promising alternative in treating dental hard tissues due to its thermo mechanical ablation properties and the lack o thermal side effects.. The laser cavity preparation results in clean, open and patent dentinal tubules and hence the step of acid-etch which is used in the conventional procedures can be skipped while using a dental laser. As there is absence of smear layer and debris in a laser cavity preparation, it can also be called a sterile cavity preparation as there is almost a 0% possibility of infections.
Acid etching is widely used in clinical dentistry to facilitate the mechanical retention of resin based materials to teeth, in particular enamel surfaces. Several laser systems have been developed with the aim of modifying dental hard tissues and the Er:YAG laser may offer possible alternative to the acid etching technique. Even cementation of resin bonded partial dentures can be facilitated by the use of laser for etching the tooth surface.
The endodontic therapy lasers have been used as treatment coadjuvant with refrence to0 both, low intensity laser therapy and high intensity laser treatment to increase the success rate of the clinical procedure. Low intensity laser therapy has the ability to produce analgesic, anti-inflammatory and biomodulation effects on the irradiated soft tissue thereby improving the wound healing process and giving the patient a better condition of the postoperative experience. High intensity laser irradiation on a soft tissue in a defocused mode could have similar effects to low intensity laser therapy. Depending on the wavelength, high intensity laser irradiation may be used on hard dental tissues such as on the root canal dentin cut surface after apicoectomy to produce structrural morphological changes, to remove the smear layer, to melt and recrystallize dentine or to expose dentinal tubules.
Disinfection of the root canal system:-
While the mechanical and manual challenges of root canal debridement and obturation remain, it has become increasingly clear that the largest proportion of endodontic disease, both pulpal and periradicular, is due to the presence of microorganisms. Therefore, treatment success is related very closely to the ability to remove these irritants and to prevent reinfection.
Application of Er:YAG laser radiation through a flexible waveguide helps to attain antibacterial effect, not only in the root canal walls, but also in the surrounding tissues. Therapeutic doses of laser radiation guarantee one-step disinfection, including of anaerobic microorganisms.