Maxillary molar healing after treatment of an uninstrumented canal with a novel root canal procedure: a case report.

A major cause for endodontic failure is the inability to treat all anatomy. Studies report endodontic retreatments contain 42% missed canals. This case illustrates dentin preservation of a molar with an uninstrumented mesiobuccal-3 canal revealed post-GentleWave Procedure. Efficient cleaning and disinfection with maintained healing to 18 months is demonstrated.

Irrigant flow during photon-induced photoacoustic streaming (PIPS) using Particle Image Velocimetry (PIV).

OBJECTIVES: This study aimed to compare fluid movements generated from photon-induced photoacoustic streaming (PIPS) and passive ultrasonic irrigation (PUI). MATERIALS AND METHODS: Particle Image Velocimetry (PIV) was performed using 6-µm melamine spheres in water. Measurement areas were 3-mm-long sections of the canal in the coronal, midroot and apical regions for PIPS (erbium/yttrium-aluminium garnet (Er:YAG) laser set at 15 Hz with 20 mJ), or passive ultrasonic irrigation (PUI, non-cutting insert at 30% unit power) was performed in simulated root canals prepared to an apical size #30/0.04 taper. Fluid movement was analysed directly subjacent to the apical ends of ultrasonic insert or fiber optic tips as well as at midroot and apically. RESULTS: During PUI, measured average velocities were around 0.03 m/s in the immediate vicinity of the sides and tip of the ultrasonic file. Speeds decayed to non-measureable values at a distance of about 2 mm from the sides and tip. During PIPS, typical average speeds were about ten times higher than those measured for PUI, and they were measured throughout the length of the canal, at distances up to 20 mm away. CONCLUSIONS: PIPS caused higher average fluid speeds when compared to PUI, both close and distant from the instrument. The findings of this study could be relevant to the debriding and disinfecting stage of endodontic therapy. CLINICAL RELEVANCE: Irrigation enhancement beyond needle irrigation is relevant to more effectively eradicate microorganisms from root canal systems. PIPS may be an alternative approach due to its ability to create high streaming velocities further away from the activation source compared to ultrasonic activation.

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 LAI's 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) laser's 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.

Enhanced removal of Enterococcus faecalis biofilms in the root canal using sodium hypochlorite plus photon-induced photoacoustic streaming: an in vitro study.

OBJECTIVE: The purpose of this study was to determine the effectiveness of laser-activated irrigation by photon-induced photoacoustic streaming (PIPS) using Er:YAG laser energy in decontaminating heavily colonized root canal systems in vitro. MATERIALS AND METHODS: Extracted single-rooted human teeth (n=60) were mechanically and chemically prepared, sterilized, inoculated with Enterococcus faecalis for 3 weeks, and randomly assigned to four groups (n=15): Group I (control, no decontamination), Group II (PIPS+6% NaOCl), Group III (PIPS+saline), and Group IV (6% NaOCl). PIPS settings were all preset to 50 µsec pulse, 20 mJ, 15 Hz, for an average power of 0.3 W. After decontamination, the remaining live microbes from all specimens were collected and recovered via plate counting of the colony-forming units (CFUs). Randomized root canal surfaces were examined with scanning electron microscopy and confocal laser microscopy. Mean variance and Dunnett's t test (post-hoc test) comparisons were used to compare mean scores for the three groups with the control group. RESULTS: The CFU analysis showed the following measurements (mean±SE): Group I (control), 336.8±1.8; Group II (PIPS+NaOCl), 0.27±0.21; Group III (PIPS+saline), 225.0±21; and Group IV (NaOCl), 46.9±20.29. Group II had significantly lower CFUs than any other groups (p<0.05). Both imaging analyses confirmed levels of remaining bacteria on examined root surfaces. CONCLUSIONS: The use of the PIPS system along with NaOCl showed the most efficient eradication of the bacterial biofilm. It appears that laser-activated irrigation (LAI) utilizing PIPS may enhance the disinfection of the root canal system.

ER:YAG laser for 3-dimensional debridement of canal systems: use of photon-induced photoacoustic streaming.

Laser-activated irrigation at subablative levels has the potential for complete tubular dentin disinfection in endodontics. In spite of the cost of the laser hardware, being able to reach the panacea of bacterial elimination and debris removal is a remarkable achievement and could be a paradigm shift in success rates for endodontic cases. Moreover, with the trend toward more conservative canal preparation and single instrumentation techniques, canal disinfection with an irrigating needle that cannot deliver sufficient volume to the canal terminus, PIPS seems likely to remove the gross canal enlargement impediment. Further investigation into smaller canal preparation sizes are ongoing. Any office that performs soft and hard tissue already understands the benefits of a laser. Adaptation of laser-activated irrigation to endodontics is a simple transition that is already understood by the hundreds of participants already trained in PIPS laser-activated irrigation. Similarly, a protocol for elimination of microbes from periodontal pockets using PIPS has the potential for selective removal of both inflamed and ulcerated epithelial tissues commonly seen in periodontal pathoses. The fact that the PIPS photoacoustic effect does not create thermal damage and will travel 3-dimensionally wherever there is fluid, makes it advantageous as a treatment modality for removing biofilms associated with periodontal pockets that are in difficult to access furcation areas and interproximal vertical defects.

Disinfection of root canals with photon-initiated photoacoustic streaming.

INTRODUCTION: This study set out to compare the efficacy of laser-activated and ultrasonically activated root canal disinfection with conventional irrigation, specifically its ability to remove bacterial film formed on root canal walls. METHODS: Seventy human premolars were shaped to an apical size #20, taper .07, sterilized, and contaminated in situ with oral bacteria for 1 week and incubated for 2 more weeks. Irrigation was done with 6% NaOCl (group 1), NaOCl ultrasonically activated with blunt inserts (group 2), or a pulsed erbium:YAG laser at nonablative settings (group 3) for a total of 60 seconds each. Positive and negative controls were also included. Aerobic bacterial sampling was performed, and the incidence of positive samples after 24 and 48 hours as well as bacterial counts (colony-forming units) were determined. Fixed and demineralized sections 1 mm and 4 mm off the apex were Brown-Brenn stained and assessed for remaining intracanal bacteria/biofilm and dentinal tubule penetration. RESULTS: All 3 canal disinfection protocols significantly reduced bacterial counts (P < .001). None of the 3 techniques predictably generated negative samples, but laser-activated disinfection was superior to the other 2 techniques in this aspect (P < .05). Histologic sections showed variable remaining bacterial presence in dentinal tubules at the 4-mm level and significantly less bacterial biofilm/necrotic tissue remaining at the 1-mm level after laser-activated irrigation (P < .05). CONCLUSIONS: Under the conditions of this combined in situ/in vitro study, activated disinfection did not completely remove bacteria from the apical root canal third and infected dentinal tubules. However, the fact that laser activation generated more negative bacterial samples and left less apical bacteria/biofilm than ultrasonic activation warrants further investigation.

Minimally-invasive, full-mouth rehabilitation using an Er,Cr:YSGG laser and CAD/CAM technology.

The use of erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) lasers and CAD/CAM technology in dentistry is becoming more accepted and prevalent. Using these two technologies together, full-mouth dental reconstruction was attempted to evaluate their effectiveness. The authors prepared all remaining maxillary and mandibular teeth without the use of a dental drill or an anesthetic; fabrication and insertion of the 28 all-ceramic CAD/CAM restorations were completed in two appointments. When used appropriately, practitioners can combine Er,Cr:YSGG losers and CAD/CAM technology to deliver a quality permanent restorative product for their patients.