Compiled by Dr Igor Cernavin, Prosthodontist, Honorary Senior Fellow University of Melbourne School of Medicine, Dentistry and Health Sciences, Director and Cofounder of the Asia Pacific Institute of Dental Education and Research (AIDER), Australian representative of World Federation of Laser Dentistry (WFLD).
Tonin et al1 carried out a study to verify the efficacy, in vitro, of two protocols against cultures of periodontal biofilm and Staphylococcus aureus. They concluded that the LLLT and aPDT protocols effectively reduced cultures of periodontal biofilm and S. aureus in vitro, with the superiority of aPDT. The abstract is reproduced in full.
OBJECTIVE: Currently, dental implants are a predictable treatment option for oral rehabilitation; however, complications such as peri-implant diseases are increasing every day. Thus, the aim of this study was to verify the efficacy, in vitro, of two protocols against cultures of periodontal biofilm and Staphylococcus aureus.
MATERIAL AND METHODS: Petri dishes for each of the following groups were used: control groups (C)-plates inoculated with periodontal biofilm (C.B; n = 4) or S. aureus (C.SA; n = 4) without any treatment; laser groups-plates inoculated with periodontal biofilm (low-level laser therapy [LLLT].B; n = 4) or S. aureus (LLLT.SA; n = 4) and treated with LLLT (660 nm, 30 mW, 50 J/cm2, and 47 seconds); antimicrobial photodynamic therapy groups (aPDT)-plates inoculated with periodontal biofilm (aPDT.B; n = 4) or S. aureus (aPDT.SA; n = 4) and treated with aPDT (red laser 660 nm, 30 mW, 50 J/cm2, 47 seconds + toluidine blue O (TBO) 100 g/mL, and 1 minute). After treatments were performed, the contents of all plates were diluted and seeded for counting colony-forming units (CFUs).
STATISTICAL ANALYSIS: Results were analyzed with one-way analysis of variance (ANOVA), Tukey's test, comparison of percentages, and independent t-tests with a 5% significance level.
RESULTS: Both treatments, LLLT and aPDT, significantly reduced the number of CFUs for the two types of culture, LLLT.B (3.69 * 106 ± 0.20), aPDT.B (2.79 * 106 ± 0.13), LLLT.SA (4.10 * 106 ± 0.12), and aPDT.SA (3.23 * 106 ± 0.10) when compared with control groups C.B (5.18 * 106 ± 0.43) and C.SA (5.81 * 106 ± 0.16; p = 0.000). When treatment groups were compared separately, there was also a statistically significant difference (p = 0.000). None of the protocols were able to eliminate cultured microorganisms.
CONCLUSION: The LLLT and aPDT protocols effectively reduced cultures of periodontal biofilm and S. aureus in vitro, with the superiority of aPDT.
Limited studies are available comparing the outcomes of non-surgical periodontal therapy (NSPT) with or without adjunctive Er:YAG laser (ERL) in patients with type 2 diabetes mellitus (T2DM). This study by Feng and coworkers2evaluated the effects of ERL adjunctive NSPT on single-rooted teeth of inadequately controlled T2DM patients with periodontitis. They concluded that Periodontal treatment outcomes in the T2DM patients with inadequate glycemic control were better in the single-rooted teeth received ERL adjunct NSPT.
Yoshida, et al2 examined the effects of aPDT in combination with a plaque-disclosing solution and blue light-emitting diode (LED), which are used for composite resin polymerization and found that aPDT exerts bactericidal effects against P. gingivalis by increasing oxidative stress through the generation of 1O2 (single droplet oxygen) in cells. Periodontal disease may be treated by aPDT using the equipment available in dental offices which eliminates the need to purchase a specific instrument for this.
Del Vecchio and coworkers3 published a literature review examining the effects of laser photobiomodulation in the management of lichen planus and found that PBM is useful in controlling algal sensation and can be used in cases of OLP lesions that are not responsive to conventional therapies or when corticosteroid doses are too high for the patient, resulting in possible side effects.
Zhi et al4 explored the optimal energy density (ED) for relief of orthodontic-related pain by photobiomodulation therapy and concluded that a laser with lower ED (0-10J/cm2) appeared to be more valid than the remaining treatment modalities (laser with higher ED, placebo, and control) for pain reduction in 1, 2, and 3 days after orthodontic procedures were applied. In the future, more high-quality research with consistency in research design is needed for further evaluation.
Hadad and coworkers5 conducted a split-mouth, double-blind, randomized clinical trial in 13 patients with similar bilateral third molars who received intraoral application PBM therapy at 4 points with a diode laser at 810 nm wavelength, 6 J (100 mW, 60 seconds/point) on 1 side (the PBM side); and laser irradiation simulation on the other side (SHAM side. They concluded that PBM therapy resulted in pain and edema reduction after third molar surgery and may be considered as adjuvant therapy after the surgical procedure.
Karveli et al6 published an article on air quality in a dental clinic during Er:YAG laser usage. Given the current COVID situation, the abstract is reproduced in full.
Chemical air pollution in dental clinics consists of the emission of gases and particulate matter (PM), both generated by dental equipment and tooth tissues. One basic application of Erbium Laser devices is cavity preparation on human teeth due to its strong affinity to water and hydroxyapatite. The objective of this study was the evaluation of indoor air quality during the application of an Er:YAG laser, as a dentin removal instrument, in a Dental Clinic. Particulate Matter (PM) was measured using the standard method of EN legislation. In order to measure total Volatile Organic compounds (VOCs), a portable monitor was used. In the first experiment, PM10 and PM2.5 concentrations were increased by approximately 10 and 15 times, respectively. From the second experiment it can be concluded that neither of the measured particle concentrations exceeded the recommended indoor limit values while windows were open, although laser influence was still detectable. Within the limitations applied herein, it was found that Er:YAG laser activity for hard dental tissue removal was associated with high PM and TVOCs concentration values in the working environment, under insufficient or no ventilation. Physical ventilation in the aforementioned setting proved to be an important key factor in improving air quality, as both PM and TVOCs concentrations decreased significantly.
Takanabe7 published an article on dispersion of aerosols generated during dental treatment. Whilst the article has nothing to do with lasers, given the current situation, the abstract is reproduced in full.
The novel coronavirus pandemic has resulted in an urgent need to study the risk of infection from aerosols generated during dental care and to conduct a review of infection controls. However, existing studies on aerosol particles related to dental treatment have mainly evaluated only the scattering range. Few studies have been conducted on the specifics of the generation of aerosol particles in clinical settings, their mechanisms and patterns of distribution throughout open or enclosed spaces, the duration that they remain suspended in air, and the amount and size of particles present. To minimize the influence of background particles, laser lights, a high-sensitivity camera, and particle counters were used in a large super clean laboratory to investigate the dynamics of aerosols generated during the operation of dental micromotors. The results indicate that aerosols tend to scatter upward immediately after generation and then gradually disperse into the surroundings. Most of the particles are less than 5 m in size (only a few are larger), and all particles are widely distributed over the long term. Our research clearly elucidates that aerosols produced in dental care are distributed over a wide area and remain suspended for a considerable time in dental clinics before settling.
REFERENCES
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2. Yoshida, Ayaka; Inaba, Keitaro; (...); Yoshino, Fumihiko. PImpact on Porphyromonas gingivalis of antimicrobial photodynamic therapy with blue light and Rose Bengal in plaque-disclosing solution.hotodiagnosis and photodynamic therapy 2021-Oct-07 | , pp.102576 .
3. Del Vecchio, A; Palaia, G; (...); Romeo, U. Effects of laser photobiomodulation in the management of oral lichen planus: a literature review.. 2021-09-29 | La Clinica terapeutica 172 (5) , pp.467-483.5.
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6. .Karveli, Angeliki; Tzoutzas, Ioannis G; (...); Helmis, Constantinos G. Air Quality in a Dental Clinic during Er:YAG Laser Usage for Cavity Preparation on Human Teeth-An Ex-Vivo Study. 2021-10-17 | International journal of environmental research and public health 18 (20).
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