Ying Zhao

We investigated how two equal-average-power thulium fiber laser (TFL) regimens differ in vapor-bubble development. Regimens combining measured tip energies of 25 mJ at 100 Hz with a 1000 μs set duration (S1) and 10 mJ at 250 Hz with a 400 μs set duration (S2), both 2.5 W, were compared as whole regimens using 200, 275, 365 and 550 μm fibers. Shadowgraphy at 200,000 frames/s with 0.25 μs exposure captured 192 events from 64 independent recordings. Full-contour measurements with recording-specific calibration characterized area, timing, shape and directional expansion. Recording-level Welch tests and heteroscedastic interaction models used Holm-adjusted families. Maximum-area S2/S1 ratios were 0.917, 0.730, 0.749 and 0.639 (adjusted p < 0.001 at the three larger diameters). S2 reached maximum area earlier with smaller maximum axial extents at every diameter and higher mean-positive transverse extent rates at 200–365 μm over the full measurable event window. Circularity and solidity at maximum area and peak-positive axial extent rate depended on fiber diameter (Holm-adjusted interaction p = 0.0168, 0.0086 and 0.0135). Equal-average-power TFL excitation produced different bubble timing and directional growth—a matched-power description of the vapor source underlying laser-activated irrigation. Because pulse energy, repetition frequency and duration differed together, the findings describe whole-regimen responses, not single-parameter effects.

Purpose: Root-canal anatomy can limit irrigant access. Bubble dynamics in distilled water were examined for plasma-mediated 1064-nm Nd: YAG laser-induced optical breakdown (LIOB) and thermally driven 2940-nm Er: YAG laser-activated irrigation (LAI) to guide confined-model testing. Methods: LIOB was tested at 100, 200 and 300 mJ/pulse and LAI at 10, 15 and 20 mJ/pulse. Ten independent bubble events per setting were imaged at 50,000 frames/s. Projected size, lifetime, frame-averaged apparent expansion rates, aspect ratio and first rebound were compared using Kruskal–Wallis and Holm-adjusted Mann–Whitney U tests. Results: Chain-like plasma luminescence preceded LIOB bubble formation. Median primary equivalent diameters were 3.21, 4.39 and 4.72 mm in LIOB and 2.24, 2.60 and 2.89 mm in LAI. The LIOB increment was smaller at 200–300 mJ than at 100–200 mJ. Axial apparent expansion was lower and transverse expansion generally higher with LIOB. Rebound-to-primary ratios were 0.65–0.74 for LAI and 0.57–0.61 for LIOB, while absolute rebounds were larger with 200/300-mJ LIOB. Conclusion: Under the tested, non-energy-matched configurations, LIOB and LAI produced different bubble sequences and growth patterns. The results provide a free-water benchmark for confined-model experiments, but do not establish pressure safety, cleaning efficacy or superiority.

Background: The present study aimed to investigate the differential photobiomodulation (PBM) effects of diode laser with low-level laser and high-level laser on orthodontic tooth movement (OTM) and alveolar bone remodeling on the compression zone. Methodology: A split-mouth design OTM model of rats was established. By varying the irradiation duration of a diode laser, wavelength of 650 nm, one accelerating OTM group with five different energy densities subgroups and one inhibiting OTM group with five different subgroups were obtained, respectively. The best accelerating/inhibiting efficacy of OTM was achieved by comparing the OTM distance of different subgroups with micro-CT. The osteoclastic level on the compression zone in the best accelerating/inhibiting subgroup was observed by Hematoxylin-eosin (HE) and tartrate-resistant acid phosphatase (TRAP) staining, while the expression levels of receptor activator of nuclear factor kappa-B ligand (RANKL), osteoprotegerin (OPG), alkaline phosphatase (ALP), runt-related transcription factor 2 (RUNX2), and osteocalcin (OCN) were individually explored by real-time PCR and immunohistochemical staining. Results: The maximum accelerating efficiency of OTM in the 6.7 J/cm ² subgroup was 36.7%, in which the lacunae and osteoclasts of the compression side were increased on 7d,14d (P< 0.05), and the expressions of RANKL, ALP, RUNX2, and OCN were` upregulated and the expression of OPG was downregulated. The optimal inhibiting efficiency of OTM in the 106.7 J/cm² subgroup was 34.9%, in which the lacunae and osteoclasts of the compression zone were reduced on 7d, 14d (P< 0.05), and the expressions of RANKL, ALP, RUNX2, and OCN were downregulated and the expression of OPG was upregulated. Vertical alveolar bone height loss and orthodontic teeth loosening was observed in the subgroups with energy density over 123.3J/cm² (P<0.01). Conclusions: Differential energy density laser exerted a biphasic effect on OTM which optimal parameters of 6.7 J/cm² could accelerate OTM of 36.7%, and 106.7 J/cm² could decelerate OTM of 34.9%, respectively. The osteoclast/osteoblast activity on the compression zone was promoted /inhibited.

To investigate the effect of photobiomodulation (PBM) on orthodontically induced root resorption (OIRR) while accelerating orthodontic tooth movement (OTM), and explore the possible role of periodontal ligament stem cells (PDLSCs) during this process. Thirty rats were randomly divided into 5 groups (A1-A5). The right upper first molars (UM1s) were assigned as PBM side (P), receiving different energy densities of PBM: A1-P (3.3 J/cm²); A2-P (5 J/cm²); A3-P (6.7 J/cm²); A4-P (8.3 J/cm²); A5-P (10 J/cm²). A diode laser (650 nm, 30 mW) with 0.09 cm² beam area was used to irradiate right UM1s at three points (the mesial, buccal and palatal sides) over the root and the irradiation time per point was 10 s in group A1, 15 s in group A2, 20 s in group A3, 25 s in group A4 and 30 s in group A5. The left UM1s were split-mouth control side. Bilateral UM1s were moved mesially by 50 g force for 14 days. The amount of OTM, root length (RL), total root resorption volume (T-RRV), RRV of compression zone (RRV-CZ) and RRV of tension zone (RRV-TZ) were evaluated by micro-CT, and CAP expression level of PDLSCs was analyzed by IHC staining. Groups of 5 and 6.7 J/cm² achieved significant accelerated orthodontic tooth movement (AOTM). There was no significant difference of RL, T-RRV and RRV-CZ between PBM and control sides. PBM irradiation at 5-10 J/cm² significantly reduced RRV-TZ. Moreover, the 6.7 J/cm² group achieved the largest AOTM efficiency and showed the highest reduction rate in decreasing RRV-TZ. The expression level of CAP was significantly higher on PBM side than that on control side in both compression and tension zones. Diode laser (650 nm, 30 mW) of 5-10 J/cm² had a protective effect on orthodontic tooth root by upregulating the cementoblastic differentiation of PDLSCs. Particularly, diode laser of 6.7 J/cm² exhibited the best efficiency in preventing OIRR of tension zone while accelerating OTM.

Aim: To investigate the role of lipopolysaccharide (LPS) from Porphyromonas gingivalis and miR‐155‐5p‐enriched exosomes in the formation of foam cells and the occurrence of carotid atherosclerosis (CAS). Methods: The CAS tissue samples and plasma from the healthy control group or patients undergoing periodontitis without CAS and with CAS were collected at the Xuanwu Hospital, Capital Medical University. The expression level of miR‐155‐5p was evaluated by immunofluorescent analysis and qRT‐PCR. Oil red O staining and lipid accumulation assays were performed to explore the effects of LPS and miR‐155‐5p on mouse macrophage Raw264.7 and human monocytes THP‐1. The expression levels of lipid‐regulated genes were detected by qRT‐PCR. Dual‐luciferase reporter gene assay and DET1 overexpressed or inhibited Raw264.7 cells were used to verify the target gene of exosomal miR‐155‐5p. ApoE ^−/− mice were used to confirm the auxo‐action of atherosclerosis from exosomal miR‐155‐5p in vivo, and LAL assay was used to detect the LPS content. Results: miR‐155‐5p was higher in patients with periodontitis and CAS plasma exosomes than those in patients without CAS. The expression of miR‐155‐5p was significantly increased in CAS tissues compared with Normal tissues, and the expression level of miR‐155‐5p was associated with lipid‐regulated genes in CAS tissues. MiR‐155‐5p‐enriched exosomes accelerated lipid accumulation in macrophage‐like cells and promoted the activity of lipid‐accumulation genes by targeting DET1 . In ApoE ^−/− mice, circulating miR‐155‐5p‐enriched exosomes captured LPS, and the LPS‐laden exosomes conferred plasma access for LPS, triggering the formation of foam cells and the occurrence of CAS. Conclusion: miR‐155‐5p enriched exosomes capture and escort LPS to the atherosclerotic sites, licensing the formation of foam cells and thus promoting CAS.

Periodontitis is a significant independent risk factor for atherosclerosis. Yet, the exact mechanism of action is still not fully understood. In this study, we investigated the effect of exosomes‐miR‐155‐5p derived from periodontal endothelial cells on atherosclerosis in vitro and in vivo. Higher expression of miR‐155‐5p was detected in the plasma exosomes of patients with chronic periodontitis (CP) and carotid atherosclerosis (CAS) compared to patients with CP. Also, the expression level of miR‐155‐5p was associated with the severity of CP. miR‐155‐5p‐enriched exosomes from HUVECs increased the angiogenesis and permeability of HAECs and promoted the expression of angiogenesis, permeability, and inflammation genes. Along with the overexpression or inhibition of miR‐155‐5p, the biological effect of HUVECs‐derived exosomes on HAECs changed correspondingly. In ApoE−/− mouse models, miR‐155‐5p‐enriched exosomes promoted the occurrence of carotid atherosclerosis by increasing permeable and angiogenic activity. Collectively, these findings highlight a molecular mechanism of periodontitis in CAS, uncovering exosomal miR‐155‐5p derived periodontitis affecting carotid endothelial cells in an ‘exosomecrine’ manner. Exosomal miR‐155‐5p may be used as a biomarker and target for clinical intervention to control this intractable disease in future, and the graphic abstract was shown in Figure .

Photobiomodulation therapy (PBMT) is the application of a low‐level laser device to generate physiological changes and provide therapeutic effects. Till now, the effects of PBMT on the neural differentiation of mesenchymal stem cells have been rarely reported. Herein, the potential effect and mechanism of PBMT on the neural differentiation of dental pulp stem cells (DPSCs) were preliminarily investigated in our research. The optimal dose of 3.75 J/cm² was first screened for use in the following neural‐inducing studies. Then, DPSCs were cultured in neural induction medium and treated with laser irradiation for 7 days. From the results of morphology and immunofluorescence, we found that irradiation promoted the formation of neural stem cell‐like spheroids derived from DPSCs and enhanced potential neural differentiation. Furthermore, neural differentiation gene expressions of Nestin, microtubule‐associated protein‐2, and neural cell adhesion molecule were increased after PBMT irradiation. The protein expressions of class III β‐tubulin and neurogenic differentiation factor 1 were also improved. Meanwhile, the involvement of extracellular signal‐regulated kinase (ERK1/2) was investigated by western blot. Our study showed that the neural differentiation of DPSCs was promoted by PBMT, and the underlying mechanism in this process was associated with activating the ERK1/2 signaling pathway.