Lasers in Medical Science最新文献

Introduction: Photodynamic therapy (PDT) offers broad-spectrum antifungal effects with lower resistance in some studies. This study evaluates the effectiveness of two PDT protocols, using a 660 nm diode laser with methylene blue (MB) compared to an 810 nm diode laser with indocyanine green (ICG), in reducing colony counts of Candida albicans, C. glabrata, C. tropicalis, and C. krusei.

Methods: This experimental laboratory study tested 4 standard Candida species in seven groups (2 PDT, 2 photosensitizers alone, 2 lasers wavelength with saline, 1 control with saline) each containing five replicates per species. PDT was performed using MB with a 660 nm diode laser and ICG with an 810 nm diode laser. Laser exposure setting was 100 mW, 10 J/cm², 100 s. CFUs were quantified, and statistical analysis was performed using SPSS version 26, with significance set at P < 0.05.

Results: PDT had better efficacy for colony count reduction of C. tropicalis, and C. krusei. PDT with an 810 nm diode laser and ICG had better efficacy than PDT with 660 nm diode laser and MB but difference was not significant (P > 0.05). For some candida species there was no significant difference between PDT with laser alone for colony reduction but there was significant difference between them with each photosensitizer and saline alone (P < 0.05).

Conclusion: Both PDT had better efficacy for colony count reduction of C. tropicalis, and C. krusei compare to other two species. PDT with diode 810 nm and ICG seems better than PDT with diode 660 nm and MB, but the difference was not statistical between two methods.

The aim of this randomized controlled clinical study is to compare the effect of intracanal cryotherapy and intraoral Low-Level LASER Therapy (LLLT) applications on postoperative pain and quality of life in patients following endodontic treatment for symptomatic apical periodontitis. After ethical clearance and registering the trial at clinical trial registry of India, a randomized, parallel-controlled clinical study with 2 test arms and 1 control arm was conducted. 90 subjects diagnosed with acute apical periodontitis in molar teeth meeting the inclusion and exclusion criteria, were enrolled in the current trial. After obtaining written informed consent, first researcher randomly allocated the subjects into 3 arms: intracanal cryotherapy, intraoral Low-Level LASER Therapy (LLLT) and control. Preoperative pain scores were marked on the Heft- Parker visual analog scale (HP-VAS) by the second researcher. Preoperative quality of life was marked by the subjects on the Oral Health Impact Profile-17 (OHIP-17) questionnaire. Root canal treatment was performed for all the subjects enrolled in the study and the interventions were performed accordingly, by a single operator. The patients were instructed to record their postoperative pain levels and analgesics intake at 24 h, 48 h, the third day, fifth day, and seventh day. On the seventh day postoperative quality of life questionnaire was recorded by the subjects. The data were tabulated in MS Excel and statistically analyzed using the EPI-INFO software. After 24 h, postoperative pain reduced significantly in the cryotherapy arm when compared with the LLLT arm. However, no statistically significant differences in postoperative pain were found between the two test arms at 48 h, the third day, fifth day, and seventh day. Subjects in the control arm were relieved of postoperative pain after the fifth day. Subjects in the cryotherapy arm required fewer analgesics, with intake limited to the first 24 h postoperatively. Conversely, participants in the LLLT arm needed analgesics for the initial 48 h postoperatively. In contrast, subjects in the control arm had the longest duration of analgesic use, up to the fifth day. The quality of life for all the subjects was found to improve postoperatively after seven days, irrespective of additional interventions. Application of cryotherapy and Low-Level LASER Therapy was found to be effective at 24 h and 48 h respectively, in the management of postoperative endodontic pain. The findings highlight the potential benefits of cryotherapy and LLLT compared to standard postoperative care alone. Henceforth, cryotherapy and Low-Level LASER Therapy could be utilized, as they are simple and innocuous modalities to manage post-endodontic pain.

This pilot case series aimed to investigate the feasibility and preliminary efficacy of photobiomodulation (PBM; also known as low-level laser therapy [LLLT]) applied to specific acupuncture points (PC6 and CV24) in managing the gag reflex during posterior single-tooth extraction. Participants with moderate-to-severe gag reflex (n = 20) were selected based on Gagging Severity Index (GSI) scores ≥ 3 during clinical examination. Gag reflex severity was measured using both the GSI and the Predictive Gagging Survey (PGS) before and after the procedure. LLLT (976 nm diode laser, 100 mW, 4 J/cm² per point, continuous-wave, 20 s per point, 8-mm diameter tip [spot area ≈ 0.50 cm²]) was administered immediately prior to extraction. Preoperative GSI scores (3.3 ± 0.6) underwent a significant decrease postoperatively (1.3 ± 0.5; P < 0.001). Concurrently, PGS scores showed a moderate positive correlation with baseline GSI. LLLT was found to be an effective method of controlling the gag reflex during posterior tooth extraction, thereby facilitating the procedure. In this pilot study, LLLT was associated with reduced gag reflex during posterior tooth extraction. However, the absence of a control group should be acknowledged as a limitation, and the findings should be interpreted with caution. Controlled trials are needed to confirm these preliminary results.

Laser acupuncture (LA) has been increasingly investigated as a non-invasive therapy for knee osteoarthritis (KOA), yet its clinical efficacy remains uncertain. To evaluate the effectiveness and safety of LA for pain, function, and mobility in KOA through a systematic review and meta-analysis. Randomized controlled trials (RCTs) comparing LA with sham, placebo, electroacupuncture, or standard care were identified from major databases. Outcomes included pain (VAS, WOMAC-Pain, NPRS, PI), function (WOMAC-Function), and range of motion (flexion). Risk of bias was assessed using RoB 2, and heterogeneity explored through subgroup analyses. Thirteen RCTs of 611 participants were included. LA did not significantly improve WOMAC pain (SMD 0.04; 95% CI - 0.36 to 0.45), pVAS (SMD 0.12; 95% CI - 0.91 to 1.15), or NPRS (SMD - 0.23; 95% CI - 0.58 to 0.12). Function showed a nonsignificant trend toward improvement (SMD - 0.32; 95% CI - 0.94 to 0.30), and knee flexion outcomes were also nonsignificant (SMD 0.10; 95% CI - 0.39 to 0.59). Substantial heterogeneity (I² > 70%) was observed across studies, likely related to differences in wavelength (650-904 nm), dosage, and acupoint protocols. Funnel plots did not suggest marked publication bias. Current evidence does not demonstrate statistically significant benefits of LA over comparators for pain, function, or flexion in KOA. Considerable heterogeneity and variability in laser parameters limit firm conclusions. Large, standardized RCTs with optimized parameters are needed to confirm efficacy and guide clinical application.Clinical trial number: Not applicable.

Purpose: Infrared low-level laser therapy (LLLT) has shown great promise in promoting cell proliferation and viability, making it a valuable tool in regenerative medicine. This study investigated how the interval between sessions shapes the response to 970 nm LLLT in murine osteoblast cultures by delivering three 10 J/cm² sessions separated by 24-48 h and measuring proliferation, reactive oxygen species (ROS), cytotoxicity, and apoptosis, with the goal of informing protocol design for bone regeneration.

Methods: Two osteoblast cultures were used, one control and the other LLL-treated group. The latter consisted of three irradiation sessions (10 J/cm² each) applied at 24, 48, and 96 h.

Results: The experimental results showed a significant increase in cell proliferation after two and three sessions (p < 0.05), while ROS levels progressively accumulated, peaking after the third session (p < 0.001). Cell viability remained above 90% in both groups during the first 48 h; however, a slight but significant reduction was observed in the LLLT group at 96 h. Apoptosis levels were lower in LLLT-treated cells during early phases (24-48 h), suggesting a transient cytoprotective effect that diminished after the third session. These findings indicate that infrared LLLT promotes cell proliferation without inducing cytotoxicity or programmed cell death.

Conclusion: The results demonstrate that applying three infrared LLLT sessions of 10 J/cm² applied at 24, 48, and 96 h promotes osteoblastic proliferation and viability without inducing cytotoxicity or apoptosis. The proposed protocol, defined by energy dose and irradiation timing, provides a safe and effective strategy for bone tissue engineering.

Purpose: Transoral robotic surgery (TORS) is an established surgical approach for oropharyngeal squamous cell carcinoma (OPSCC). Carbon dioxide (CO₂) laser offers high cutting precision and minimal collateral thermal injury, yet its use in TORS remains underreported. The purpose of this study is therefore to describe the first UK case series detailing the use of CO₂ laser via hollow waveguide in TORS.

Methods: Eight patients (six male, two female; mean age 60 years) presenting with either left tonsillar (seven cases) or right tongue base (one case) OPSCC underwent primary TORS resection with CO₂ laser at a tertiary UK head and neck centre between October 2020 and May 2024. Cases were selected based on tumour stage, anatomical suitability and patient preference. The CO₂ laser (SmartXide Trio, 3-10 W, ultra-pulse mode) was delivered via hollow waveguide mounted on one of the arms of the Da Vinci robotic system. Outcome measures included histological margin status, peri- and postoperative complications, swallowing function, and hospital length of stay.

Results: All tumours were completely excised; two of the eight had close margins on the primary specimen but were clear on additional sampling. No intraoperative complications occurred, and all procedures were completed without conversion. All patients resumed oral intake without nasogastric feeding. Mean hospital stay was 2.75 days, with no airway compromise, catastrophic bleeding, or significant swallowing dysfunction.

Conclusion: CO₂ laser dissection in TORS for OPSCC represents a viable surgical approach with acceptable postoperative functional outcomes and may possibly demonstrate reduced thermal injury compared with monopolar electrocautery.