Determination of the effect of Nd:YAG laser irradiation through dentinal tubules on several oral pathogens

Efficacy of Laser-Activated Irrigation Versus Ultrasonic-Activated Irrigation: A Systematic Review

This study aimed to conduct a systematic review and critical analysis of the evidence pertaining to the efficacy of laser-activated irrigation (LAI) versus ultrasonic-activated irrigation (UAI) in mature permanent teeth. A comprehensive literature search was performed using PubMed and Google Scholar. Additionally, a hand search was performed to identify relevant studies related to UAI and LAI. The search covered all articles published from January 1997 to December 2021. The identified studies were screened for eligibility using the inclusion and exclusion criteria. The included articles were then subjected to data extraction and analysis. The search yielded 1,637 results. Of these, 23 articles were included in this systematic review. All included articles were assessed for the outcomes of antimicrobial efficacy, smear layer, and dentin debris removal. The majority of the articles reported the superiority of LAI over UAI. Within the confines of this systematic review, the current evidence mandates that LAI has superior efficacy over UAI in the elimination of microorganisms, dentin debris, and smear layer from the root canal system.

The Efficacy of a Diode Laser on Titanium Implants for the Reduction of Microorganisms That Cause Periimplantitis

The paper presents the optimisation of a safe diode laser irradiation process applied to the surface of titanium implants in order to reduce microbial numbers in the treatment of inflammation classified as periimplantitis. The study comprised isolation and identification of microorganisms inhabiting surfaces of dental implants, crowns, teeth and saliva from patients with fully symptomatic periimplantitis. Microorganisms were detected by a culture-dependent method and identified with the use of MALDI-TOF mass spectrometry. The isolated microorganisms were inoculated on the surface of a new implant and then irradiated by a diode laser (wavelength of 810 ± 10 nm) in one, two or three repetitions and biocidal efficacy was assessed. To evaluate impact of laser irradiation on roughness, morphology and structure of the implant surface, optical profilometry, scanning electron microscopy and optical microscopy were used. Examination of the tested surfaces and saliva revealed the presence of Gram-positive and Gram-negative bacteria and one fungal species. In all patients, cultures from the endosseous part of the implant revealed the presence of the pathogenic and pyogenic bacterium Streptococcus constellatus. In 13 out of 20 samples laser-irradiated in duplicate and triplicate, all microorganisms were eliminated. The irradiation used did not cause any changes in the properties of the implant surface.

The effect of ultrasonically activated irrigation and laser based root canal irrigation methods on debris removal

PURPOSE

To test the efficacy of debris removal of 5 in vitro irrigation protocols: conventional irrigation, irrigation activated by ultrasound, Er:YAG laser with photon-induced photoacoustic streaming (PIPS) tip, and 2 diode laser techniques.

METHODS

The root canals of 75 extracted human canine teeth were enlarged and bisected longitudinally. Standardized grooves were prepared 2-6 mm from the root apex and filled with 0.5 mm of dentine debris. The teeth were reassembled and irrigated using 1 of the following techniques (n = 15/technique): (1) conventional irrigation, (2) diode laser irrigation - tip placed 2 mm from working length, (3) diode laser irrigation - tip placed at root canal orifice, (4) Er:YAG laser - PIPS, and (5) ultrasonically activated irrigation. The root segments were disassembled, and the amount of remaining debris was evaluated by 3 examiners under a stereomicroscope at ×20 magnification using a 4-grade scoring system. The data were statistically analyzed using Kruskal-Wallis and Dunn's multiple comparison tests, with a 95% confidence level (p = 0.05). Cohen's kappa test was used to evaluate inter-observer and intra-observer agreement.

RESULTS

Ultrasonically activated irrigation removed significantly more dentinal debris than conventional irrigation (p = 0.016), but there were no significant differences between the other groups.

CONCLUSIONS

Ultrasonically activated irrigation was more effective than conventional irrigation in the removal of apically placed dentine debris.