The in vitro study presented in this article was performed to evaluate the morphological changes in caries excavated dentin after using three different caries removal methods. These methods include mechanical, chemomechanical (Carisolv™) and Er, Cr: YSGG Laser (Biolase™) by means of scanning electron microscope. Extracted carious human molars were ground to flat surfaces to expose caries surrounded by sound dentin. The caries were then removed with tungsten carbide bur and airotor handpiece (G1), by chemomechanical (Carisolv™) method (G2), and by irradiation with an Er, Cr: YSGG Laser (Biolase™) unit (G3). The samples were then observed under a scanning electron microscope (SEM) with different magnification powers (×800, ×2000 and ×5000). SEM study revealed a considerable difference in the surface characteristics of the dental tissue. The surface which was treated with Er, Cr: YSGG laser (Erbium, Chromium: Yttrium-Scandium-Gallium-Garnet) showed the best result with no residual smear layer followed by surfaces which were chemomechanically excavated with Carisolv™ gel. The treatment with mechanical method resulted in a surface with a smear layer without any micro retention. Thus, from the results obtained, it was concluded that Er, Cr: YSGG laser produced a scaly, irregular and rugged tooth surface without smear layer, which can be of highly retentive nature. Carisolv™ treated dentin showed uneven surfaces with many undermined areas. There were partially patented dentinal tubules and residues of contaminant smear layer. The dentin surfaces prepared using tungsten carbide bur and spoon excavator produced smearing and smear plugs in the tubular orifices.

When the teeth do not erupt at the expected time, it is crucial for the clinician to determine the etiology and formulate an appropriate treatment plan. This case series describes the use of diode lasers in guiding the eruption of unerupted central incisor into occlusion during the mixed dentition stage. Traditional methods of removing fibrotic gingiva overlying unerupted teeth using scalpels or electrosurgery may produce postoperative discomfort and prolonged healing. Lasers provide a simple and safe alternative for children while at the same time reducing the chances of infection, swelling, discomfort, and scaring, besides fear and anxiety, common symptoms related to this specific group in surgical procedures.

Aim: This study was set out to evaluate the antibacterial efficacy of four disinfection techniques namely needle irrigation, diode laser, Photon-induced Photoacoustic Streaming (PIPS) with Er,Cr:YSGG and EndoActivator in minimally instrumented, experimentally infected root canals.Materials and methods: Eighty single-rooted teeth were selected, prepared to an apical size # 20, taper 0.7; the specimens were sterilized and were inoculated with Enterococcus faecalis for 2 weeks. Disinfection was performed with needle irrigation, 940 nm diode laser, PIPS with 2,740 nm Er,Cr:YSGG laser. After disinfection, aerobic sampling was performed and bacterial counts (colony-forming units) and the incidence of positive samples after 24 hours and 7 days were determined.Results: After the two time periods, all four disinfection protocols reduced the bacterial load when compared to the pretreatment load. None of the techniques predictably generated negative samples, but diode laser and PIPS with Er,Cr:YSGG was superior, when compared to needle irrigation and EndoActivator in this aspect. No statistically significant difference was found between needle irrigation and EndoActivator. Conclusion:Diode laser disinfection demonstrated significant elimination of E. faecalis in minimally instrumented canals. PIPS with Er,Cr:YSGG and EndoActivator reduced the bacterial load when compared with needle irrigation.

This ex vivo study investigates the effectiveness of the new design of the tip of Er,Cr:YSGG laser (BIOLASE TM ) in removing the smear layer at the apical third of curved root canals. Eighty one freshly extracted intact single rooted human mandibular premolar teeth with 15° to 30º canal curvature were selected and decoronated at the level of the cementoenamel junction. The roots were divided into three main groups with 27 samples each. Group I-non-lased teeth, group II-teeth lased with plain tip and group III-teeth lased with conical tip. Each group was further divided into three subgroups of nine samples each with 2 ml of 17% (Ethylene diamine tetraacetic acid (EDTA), 2 ml of 2% chlorhexidine (CHX), 2 ml of 3% sodium hypochlorite (NaOCl) respectively. In all the three groups, canals were prepared with rotary nickel-titanium (NiTi) instruments to a working length 1 mm short of the apex to size F3, using ProTaper instruments. The fiber tips were placed into the appropriate irrigant solution in the root canal to a depth of 1 mm short of working length and then activated for 20 seconds. The teeth were split longitudinally and subjected to scanning electron microscopy (SEM) at 1000×. It can be concluded that to ensure complete removal of smear layer from the root canal system it may be prudent to activate EDTA with conical tip design of Er,Cr:YSGG laser during irrigation protocol in the curved root canals.