Giovanni Olivi

Disinfection efficacy of photon-induced photoacoustic streaming on root canals infected with Enterococcus faecalis: an ex vivo study.

BACKGROUND In 2010, one of the authors proposed that lasers could be used to enhance the decontaminating action of sodium hypochlorite (NaOCl). The authors conducted a study to compare the disinfection efficacy of laser-activated irrigation (LAI) by using a photon-induced photoacoustic streaming (PIPS) tip with conventional irrigation and specifically LAIs ability to remove bacterial film formed on root canal walls. METHODS The authors shaped 26 human anterior teeth to a master apical file size of International Organization for Standardization 25/06 (size 25 tip and size .06 taper) and then sterilized the teeth, infected them with Enterococcus faecalis and incubated them for four weeks. The authors used two irrigation protocols. Group A received two cycles of 30 seconds each of 5 percent NaOCl laser activation and one cycle of 30 seconds with laser activation involving the use of 17 percent ethylenediaminetetraacetic acid (EDTA). The erbium:yttrium-aluminum-garnet (Er:YAG) lasers settings were 20 millijoules, 15 hertz, 50-microsecond pulse duration, and it had a 600-micrometer PIPS tip. Group B received two cycles of 30 seconds each of 5 percent NaOCl and 17 percent EDTA irrigation alone, delivered via a syringe with a 25-gauge needle. RESULTS The authors found that group A had significantly better disinfection compared with group B (P < .05). The results of cultures obtained after 48 hours showed that disinfection was maintained better in group A compared with group B (P < .0001). Scanning electron microscopic images showed absence of bacterial biofilm remaining after LAI using PIPS. CONCLUSIONS Er:YAG laser activation of 5 percent NaOCl and 17 percent EDTA was more effective than conventional irrigation for eradicating E. faecalis and preventing new bacterial growth ex vivo. Additional clinical studies are needed to clarify the effect on endodontic treatment outcomes. PRACTICAL IMPLICATIONS PIPS appears to be effective in enhancing the effect of the irrigants commonly used in endodontics.

Advanced Laser-Activated Irrigation: PIPSTM Technique and Clinical Protocols

PIPSTM is an advanced laser-activated irrigation process by which photons of light are emitted in very low energy levels and with short microsecond pulse duration. PIPSTM utilizes a unique tapered and stripped tip design that allows for lateral dispersion and propagation of the generated shock wave in liquids at subablative levels, via photoacoustic and photomechanical events avoiding the possibility of thermal damage and allowing for effective three-dimensional streaming of fluids when the correct specific parameters and protocols are used. By virtue of lower energy and high peak power, unique tip design, and its positioning far from the apex, PIPSTM provides safe and effective activation for exchange of irrigants. The tip is kept stationary in the coronal aspect of the access preparation only thus offering effective irrigation with a minimally invasive instrumentation optimizing the conservation of the dentin structure and thus avoiding the possibility of laser thermal damage to dentin walls. The use of NaOCl and EDTA along the correct protocol improves the cleaning and decontaminating effect for root canals when compared to conventional methods.

Disinfection efficacy of photon-induced photoacoustic streaming on root canals infected with Enterococcus faecalis

BACKGROUND In 2010, one of the authors proposed that lasers could be used to enhance the decontaminating action of sodium hypochlorite (NaOCl). The authors conducted a study to compare the disinfection efficacy of laser-activated irrigation (LAI) by using a photon-induced photoacoustic streaming (PIPS) tip with conventional irrigation and specifically LAIs ability to remove bacterial film formed on root canal walls. METHODS The authors shaped 26 human anterior teeth to a master apical file size of International Organization for Standardization 25/06 (size 25 tip and size .06 taper) and then sterilized the teeth, infected them with Enterococcus faecalis and incubated them for four weeks. The authors used two irrigation protocols. Group A received two cycles of 30 seconds each of 5 percent NaOCl laser activation and one cycle of 30 seconds with laser activation involving the use of 17 percent ethylenediaminetetraacetic acid (EDTA). The erbium:yttrium-aluminum-garnet (Er:YAG) lasers settings were 20 millijoules, 15 hertz, 50-microsecond pulse duration, and it had a 600-micrometer PIPS tip. Group B received two cycles of 30 seconds each of 5 percent NaOCl and 17 percent EDTA irrigation alone, delivered via a syringe with a 25-gauge needle. RESULTS The authors found that group A had significantly better disinfection compared with group B (P < .05). The results of cultures obtained after 48 hours showed that disinfection was maintained better in group A compared with group B (P < .0001). Scanning electron microscopic images showed absence of bacterial biofilm remaining after LAI using PIPS. CONCLUSIONS Er:YAG laser activation of 5 percent NaOCl and 17 percent EDTA was more effective than conventional irrigation for eradicating E. faecalis and preventing new bacterial growth ex vivo. Additional clinical studies are needed to clarify the effect on endodontic treatment outcomes. PRACTICAL IMPLICATIONS PIPS appears to be effective in enhancing the effect of the irrigants commonly used in endodontics.

Laser-Activated Irrigation (LAI)

The complex anatomy of the root canal system and the limited penetration depth of the commonly used irrigants into the dentine limit the ability to clean, debride and disinfect three-dimensionally and completely the root canal system. Erbium family lasers represent the cutting-edge technology for the activation of irrigants in endodontics. LAI is introduced here, emphasising all the different techniques proposed. The mechanism of LAI and all the conditions that influence LAI efficiency and safety are described including the wavelength to use, the energy, the pulse duration and pulse frequency, tip design and tip position into the canal or in the pulp chamber. Studies on applications of LAI for smear layer removal and canal decontamination are fully debated.

Laser Application for Dental Bleaching/Whitening

The esthetics of the smile has nowadays an increased demand in clinical dental practice. The color of teeth depends on the quantity and quality of reflected light, the quantity of the incident light, the thickness of the enamel, and the quantity and quality of dentin reflecting the light. The classification of discolorations includes intrinsic and extrinsic dyschromia; dyschromia can be isolated to one or more elements or generalized, so extended to many elements. While extrinsic dyschromia can be easily treated at home by the patient with toothpaste or by professional polishing techniques, air-flow polishing, the intrinsic dyschromia requires professional bleaching treatments or esthetic dentistry treatments (composite resins, veneers, crowns). Among the side effects of dental bleaching, over-bleaching represents a serious risk that can be easily avoided using laser with proper parameters and time of application. Research demonstrated the presence of damage to the enamel surface when the time of application of the bleaching gel lasts more than 20 min. Different wavelengths and protocols are proposed, all having a safe total time of application within 20 min.

Disinfection efficacy of photon induced photoacoustic streaming (PIPS) in root canals infected with Enterococcus faecalis: an ex vivo study

BACKGROUND In 2010, one of the authors proposed that lasers could be used to enhance the decontaminating action of sodium hypochlorite (NaOCl). The authors conducted a study to compare the disinfection efficacy of laser-activated irrigation (LAI) by using a photon-induced photoacoustic streaming (PIPS) tip with conventional irrigation and specifically LAIs ability to remove bacterial film formed on root canal walls. METHODS The authors shaped 26 human anterior teeth to a master apical file size of International Organization for Standardization 25/06 (size 25 tip and size .06 taper) and then sterilized the teeth, infected them with Enterococcus faecalis and incubated them for four weeks. The authors used two irrigation protocols. Group A received two cycles of 30 seconds each of 5 percent NaOCl laser activation and one cycle of 30 seconds with laser activation involving the use of 17 percent ethylenediaminetetraacetic acid (EDTA). The erbium:yttrium-aluminum-garnet (Er:YAG) lasers settings were 20 millijoules, 15 hertz, 50-microsecond pulse duration, and it had a 600-micrometer PIPS tip. Group B received two cycles of 30 seconds each of 5 percent NaOCl and 17 percent EDTA irrigation alone, delivered via a syringe with a 25-gauge needle. RESULTS The authors found that group A had significantly better disinfection compared with group B (P < .05). The results of cultures obtained after 48 hours showed that disinfection was maintained better in group A compared with group B (P < .0001). Scanning electron microscopic images showed absence of bacterial biofilm remaining after LAI using PIPS. CONCLUSIONS Er:YAG laser activation of 5 percent NaOCl and 17 percent EDTA was more effective than conventional irrigation for eradicating E. faecalis and preventing new bacterial growth ex vivo. Additional clinical studies are needed to clarify the effect on endodontic treatment outcomes. PRACTICAL IMPLICATIONS PIPS appears to be effective in enhancing the effect of the irrigants commonly used in endodontics.