Please activate JavaScript!
Please install Adobe Flash Player, click here for download
ePaper created 2018-03-06, 08:52:14 | version 1.38.0
industry report | Laser-enhanced irrigation Laser energy has been documented to enhance the known effects of NaOCl irrigation through both heating the solution within the canal system and its distant an- tibacterial effects. But not all laser wavelengths have demonstrated to be equal in effectiveness. The best effects are when NaOCl is combined with an Er:YAG la- ser as compared to NaOCl alone or when utilised with other laser types.3 Antibacterial effects were reported to be the best with this combination of irrigant and la- ser.4 The higher wavelength of the Er:YAG compared to the Nd:YAG or diode was more effective in smear layer removal, hence, better at bacterial elimination within the canal system.5 Utilisation of a EDTA as an irrigant alter- nated with NaOCl provides the best debridement of the canal system with enhancement with a Er:YAG laser, as these two solutions have a synergistic effect com- plimenting each other’s effects in the canal anatomy.6 Additionally, the Er:YAG laser (LiteTouch™, AMD LASERS) creates hydrodynamic pressure following cavitation bubble expansion and collapse when the ir- rigation solution is activated in the chamber.7–9 Place- ment of the laser tip does not require entry into the ca- nals to achieve the desired effects and activation of the irrigation solution in the chamber is sufficient to affect the entire canal system. The LiteTouch™ Er:YAG laser energy is set at a sub-ablative power level which al- lows its use without structural changes to the hard tis- sue within the tooth. This eliminates the risks of ledging and perforation of the pulpal floor allowing safe usage within the tooth. When the Er:YAG laser is activated, a heat pulse is generated by the laser radiation delivered via a sap- phire tip into an absorbing liquid (irrigant). This results in tensile stress with cavitation being induced in the liquid in front of the sapphire tip at a distance far below the optical penetration depth of the laser radiation. Bubble expansion and collapse cause the surrounding fluid to flow at a speed of up to 12 m/s travelling throughout the canal system. This causes rapid displacement of in- tracanal fluid via radial and longitudinal pressures suffi- cient to drive irrigants into the canal anatomy and clean the dentinal tubules significantly. This photomechanical activation of the irrigants includes a temperature rise in the irrigant increasing its effectiveness in debride- ment of dentinal walls and its tubules and increases the chemical properties of the irrigants. LiteTouch-Induced Photomechanical Irrigation (LT-IPI) Endodontic treatment is initiated with access to the pulp chamber, which may be performed by traditional methods using burs or by ablation of the enamel and Fig. 2 Fig. 5a Fig. 3 Fig. 5b Fig. 4 Fig. 5c Fig. 2: SEM showing bacteria and pulpal debris in the apical 1/3 that was not removed fully using standard irrigation protocol. Fig. 3: SEM showing com- plete removal of bacteria and pulpal tissue in the apical 1/3 after irrigation using the LT-IPI™ protocol. Fig. 4: SEM cross-section showing complete re- moval of bacteria and pulpal tissue in the apical 1/3 after irrigation using the LT-IPI™ protocol leaving dentine tubules open. (All pictures © Prof. Georgi Tomov, Plovdiv, Bulgaria) Figs. 5a–c: LiteTouch-Induced Photomechanical Irrigation protocol (LT-IPI). dentine with the LiteTouch™ Er:YAG laser. As the la- ser is ineffective in removal of ceramics and metals, such as those used in fixed prosthetics and also amal- gam, carbides and diamonds are needed create ac- cess through these materials. Once dentine has been reached the laser may be utilised to unroof the pulp chamber (hard tissue mode). An additional benefit of the Er:YAG laser to access the pulp chamber is that it provides decontamination and removal of bacterial roots 1 2018 25