Effectiveness of Low-Level Laser Therapy with a 915 Nm Wavelength Diode Laser on the Healing of Intraoral Mucosal Wound: An Animal Study and a Double-Blind Randomized Clinical Trial

The effect of preoperative low-level laser therapy on pain, swelling, and trismus associated with mandibular third molar extraction

OBJECTIVE

This study aimed to evaluate the effect of low-level laser therapy (LLLT) applied before mandibular third molar extractions on postoperative pain, swelling, and trismus.

MATERIALS AND METHODS

The study included 28 patients aged 18-45 years with bilaterally impacted mandibular third molars in similar positions, indicated for extraction based on clinical and radiographic examinations. Patients were divided into two groups: Group 1 received LLLT 10 min before surgery, while Group 2 (control group) underwent routine impacted tooth extraction after applying blue LED light. Measurements were taken preoperatively and at 24 h (T0), 48 h (T1), and 7 days (T2) postoperatively to assess the effects of LLLT on pain, swelling, and trismus. Statistical analysis was performed using the Jamovi 2.2.5 software. Due to the non-normal data distribution, the Friedman test was used for repeated measures within groups, while the Mann-Whitney U test was employed to compare the laser and control groups.

RESULTS

The study included 23 female (82.14%) and 5 male (17.86%) patients, with a mean age of 21.34 ± 4.37 years. No statistically significant differences were observed between the laser and control groups concerning pain, trismus, and swelling at T0, T1, and T2 (p > 0.05).

CONCLUSION

Within the limitations of this study, preoperative LLLT showed clinically acceptable effects on postoperative pain, swelling, and trismus. Further clinical studies are needed to evaluate the long-term success of LLLT.

Effect of fenugreek oil on healing of experimentally induced buccal mucosal ulcer by immunohistochemical evaluation of Ki-67 expression

Wound healing involves multiple populations of cells, the extracellular matrix, and soluble mediators' actions like growth factors and cytokines. Wound care was the target of many research, utilizing new therapy techniques and the progression of acute and chronic wound treatments with techniques involving plants to improve healing and decrease the side effects of drugs. When fenugreek is applied to an ulcer, its anti-inflammatory components are released, reducing unnecessary inflammation and accelerating the healing process. Healing is controlled by growth factors that naturally activate and boost the proliferation of cells, such as Ki-67, which is associated with the growth fraction and represents the cell's ability to proliferate. The current study aims to assess the expression of Ki-67 in rat mucosal ulcers treated with fenugreek leave oil. Twenty-four male Wistar albino rats of 350-450 gm weight were used. The rats were grouped as follows; normal group (normal tissue without ulcer induction), control group (tissue with surgical ulcer induction on the right side), and study group (ulcer treated with fenugreek leave oil on the left side), and had been sacrificed at 3- and 7-day healing durations. Thereafter, the tissue specimens were used for immunohistochemical analysis of Ki-67. The obtained outcomes showed that expression of Ki-67 increased in groups where ulcers were induced, with significant differences between control and study groups on the 3rd day. It was concluded that the application of fenugreek oil had an accelerating effect on the healing process of mucosal ulcers, as indicated by the elevated expression level of Ki-67.

Piezoelectric Surgery, Er:YAG Laser Surgery and Nd:YAG Laser Photobiomodulation: A Combined Approach to Treat Medication-Related Osteonecrosis of the Jaws (MRONJ)

Medication-related osteonecrosis of the jaw (MRONJ) is a drug complication that can occur in patients taking antiresorptive or antiangiogenic drugs. Although it is a well-documented disease, there is no widely accepted treatment. However, several therapeutic approaches have been proposed. The surgical approach in many advanced cases appears inevitable; however, the results are not yet defined and predictable. This study aimed to propose a combined surgical approach with a piezoelectric device and laser (Er:YAG for bone ablation and Nd:YAG laser for photobiomodulation) in a young patient with breast cancer and bone metastasis under denosumab treatment, affected by spontaneous stage 3 MRONJ with maxillary sinus involvement. The patient under study reported no post-operative discomfort, with painkiller intake limited to the day after surgery. Total mucosal healing was observed without recurrences for more than 4 years after surgery. According to the results of our preliminary study, a combined surgical approach using a piezoelectric device and laser therapy is effective in managing patients affected by MRONJ, leveraging the clinical and biological advantages of these different techniques.

The effect of photobiomodulation therapy in common maxillofacial injuries: Current status

The use of photobiomodulation therapy (PBMT) may be used for treating trauma to the maxillofacial region. The effects of PBMT on maxillofacial injuries were discussed in this review article. The electronic databases Pubmed, Scopus, and Web of Science were thoroughly searched. This review included in vitro, in vivo, and clinical studies describing how PBMT can be used in maxillofacial tissue engineering and regenerative medicine. Some studies suggest that PBMT may offer a promising therapy for traumatic maxillofacial injuries because it can stimulate the differentiation and proliferation of various cells, including dental pulp cells and mesenchymal stem cells, enhancing bone regeneration and osseointegration. PBMT reduces pain and swelling after oral surgery and tooth extraction in human and animal models of maxillofacial injuries. Patients with temporomandibular disorders also benefit from PBMT in terms of reduced inflammation and symptoms. PBMT still has some limitations, such as the need for standardizing parameters. PBMT must also be evaluated further in randomized controlled trials in various maxillofacial injuries. As a result, PBMT offers a safe and noninvasive treatment option for patients suffering from traumatic maxillofacial injuries. PBMT still requires further research to establish its efficacy in clinical practice and determine the optimal parameters.

Low-level laser therapy alleviates periodontal age-related inflammation in diabetic mice via the GLUT1/mTOR pathway

Diabetes mellitus (DM) is a chronic age-related disease that was recently found as a secondary aging pattern regulated by the senescence associated secretory phenotype (SASP). The purpose of this study is to detect the potential efficacy and the specific mechanisms of low-level laser therapy (LLLT) healing of age-related inflammation (known as inflammaging) in diabetic periodontitis. Diabetic periodontitis (DP) mice were established by intraperitoneal streptozotocin (STZ) injection and oral P. gingivalis inoculation. Low-level laser irradiation (810 nm, 0.1 W, 398 mW/cm2, 4 J/cm2, 10 s) was applied locally around the periodontal lesions every 3 days for 2 consecutive weeks. Micro-CT and hematoxylin-eosin (HE) stain was analyzed for periodontal soft tissue and alveolar bone. Western blots, immunohistochemistry, and immunofluorescence staining were used to evaluate the protein expression changes on SASP and GLUT1/mTOR pathway. The expression of aging-related factors and SASP including tumor necrosis factor-α, interleukin (IL)-1β, and IL-6 were reduced in periodontal tissue of diabetic mice. The inhibitory effect of LLLT on GLUT1/mTOR pathway was observed by detecting the related factors mTOR, p-mTOR, GLUT1, and PKM2. COX, an intracytoplasmic photoreceptor, is a key component of the anti-inflammatory effects of LLLT. After LLLT treatment a significant increase in COX was observed in macrophages in the periodontal lesion. Our findings suggest that LLLT may regulate chronic low-grade inflammation by modulating the GLUT1/mTOR senescence-related pathway, thereby offering a potential treatment for diabetic periodontal diseases.

Histologic Evaluation of Effect of Three Wavelengths of Diode Laser on Human Gingival Margins

Introduction: Available evidence suggests that the response of the intervened tissue is directly linked to the effects generated by the cutting instrument used. To determine the histological findings in gingival tissue margins excised through gingivectomies performed using 450 nm, 940 nm, and 980 nm diode lasers. The present study aimed to determine the histological findings in gingival tissue margins excised through gingivectomies performed using 450 nm, 940 nm, and 980 nm diode lasers. Methods: Gingival tissue samples were collected from 30 patients who had undergone gingivectomy procedures. Each study group comprised 10 patients who willingly provided their samples after providing informed consent. The visualization of histological findings was facilitated through Hematoxylin-Eosin staining. Additionally, variables related to pain and hemostasis were assessed during the intraoperative period. Results: The incision quality was categorized as irregular across all three wavelengths. Histological examination of the epithelial tissue revealed the absence of carbonization and the preservation of cell morphology in over 50% of the resection margin in samples obtained with the 450 nm and 940 nm wavelengths. In the connective tissue, observations included carbonization, collagen coagulation, and basophilia, with the 980 nm wavelength demonstrating the highest percentage of samples displaying collagen coagulation in more than 50% of the resection margin. Conversely, the 450 nm wavelength exhibited the highest degree of preservation of the fibroblast structure. Conclusion: Based on a comprehensive analysis of the study results, it can be inferred that the 450nm and 940nm wavelength lasers tend to produce less thermal damage and better cell preservation when compared to the 980nm wavelength.

A Review of Applications and Intracellular Mechanisms of Intense Pulsed Light in Eyelid Inflammatory Diseases

Objective: To evaluate relevant clinical outcomes and conclude possible mechanisms of intense pulsed light (IPL) in eyelid inflammation. Background: IPL devices were primarily applied in cutaneous vascular malformations and have been used in ocular diseases for about 20 years, mostly including meibomian gland dysfunction (MGD), blepharitis, and ocular rosacea. Recent findings: Seventy-two original clinical researches were included, 57 for MGD, 4 for blepharitis or blepharitis-related keratoconjunctivitis, and 11 for rosacea. Dry eye symptoms, (tear) break-up time (BUT), and meibomian structure and/or functions were improved in most patients, but production of reactive oxygen species is an important link in the photobiomodulation mediated by IPL, which can influence numerous signal pathways to achieve anti-inflammatory, anti-infective, and prodifferentiation effects. Conclusions: The evidence suggests that IPL is an effective therapeutic tool for most patients with MGD, but more clinical evidence is needed for other indications.

Comparison of clinical outcomes of non-surgical adjunctive use of the 980-nm diode laser to conventional periodontal flap procedure-a randomised controlled split-mouth clinical trial

Lasers have been found to be effective as an adjunctive in periodontal therapy. The objective of the study was to compare the outcomes of non-surgical adjunctive use of 980-nm diode laser to that of conventional flap surgery in terms of clinical outcome measures and radiographic osseous defect depths. This study was designed as a double-blinded split-mouth randomised controlled clinical trial. A total of fifteen patients (30 quadrants) with generalised periodontitis stage III grade B were randomly assigned test group (diode laser) and control group (conventional flap surgery). Both test and control groups had 15 quadrants each. At 3 months, the probing pocket depth (PPD) was 3.46 ± 0.19 mm (test) and 4.20 ± 0.20 mm (control), with a statistically significant difference between the groups (p = 0.01). Similarly, at 6 months re-evaluation, PPD was 1.46 ± 0.12 mm (test) and 2.33 ± 0.13 mm (control) with a highly significant statistical difference (p = 0.001). Plaque index showed a difference between both test and control groups at baseline, 3 months and 6 months (p = 0.001) while gingival index, modified sulcular bleeding index and radiographic osseous defect depth showed a difference at 3 months and 6 months (p = 0.001). Within the study's limitations, 980-nm diode laser can result in significant improvements in the clinical and radiographic parameters and is very well tolerated by the subjects.

Effect of Photobiomodulation Therapy with 915 nm Diode Laser on Pain Perception During Local Anesthesia of Maxillary Incisors: A Randomized Controlled Trial

This study aimed to evaluate the effect of photobiomodulation therapy (PBMT) with 915 nm wavelength on pain reduction during maxillary incisors' local infiltration in a randomized clinical trial study. A prospective triple-blinded split mouth clinical trial was designed to assess pain perception during needle insertion and local anesthetic injection in 32 healthy patients required operative caries management on contralateral maxillary incisors. After laser treatment (915nm, power of1.5 W, duty cycle of 60% and energy density of 72 J/cm² ) in active group and no irradiation in sham group, the injection was performed. Patients' perception of pain was immediately assessed using numerical rating scale (NRS) for pain. Washout period between two appointments was one week. Wilcoxon signed rank and Pearson correlation statistical analysis were used to assess for comparison of pain score between two appointments and the effect of anxiety level of previous dental injections. The mean scores of pain for the active laser and sham laser groups were 2.5±2.19 and 4.34± 2.52, respectively with a statistically significant higher NRS in the sham laser group (P˂0.05). In this study's condition, diode PBMT reduced pain during infiltration on maxillary incisors. Anxiety experience of dental injection had no significant effect on pain perception scale (P˃0.05).

Pulpal and periapical tissue response after direct pulp capping with endosequence root repair material and low-level laser application

Background

The study aims to investigate the pulp and periapical reaction and healing after capping with EndoSequence Root Repair Material (ERRM) combined with low-level laser application.

Methods

In 6 rabbits, pulps were exposed via class V, half of the samples received a low-level diode laser at 980 nm. Thereafter, cavities were capped with regular-set ERRM. The specimens were processed for histomorphological examination after 2 weeks and two months.

Results

After 2 weeks, images show mild inflammation and organized odontoblasts in lased group. The non-lased group shows more severe inflammation. The predentin thickness was thicker in the lased group with statistical significance (p < 0.05). After 2 months, inflammatory cells were sparse in both lased and non-lased groups. In the periapical area, group one showed dilated blood vessels and thick fibrous connective tissues. In group two, there were more numerous maturations of PDL fibers with scattered inflammatory cells and congested blood vessel.

Conclusions

Using low-level laser therapy in combination with ERRM for pulp capping shortens the inflammatory phase and enhances healing.

The effect of low-level laser on the quality of dentin barrier after capping with bioceramic material: A histomorphometric analysis

The study aims to investigate the quality of dentin barriers and pulp reaction to EndoSequence Root Repair Material (ERRM) combined with low-level laser application. In eight dogs, pulps were exposed via class V, half of the samples received low-level diode laser at 870 nm. Thereafter, cavities were capped with fast-set or regular-set ERRM. The specimens were processed for histomorphological and immunohistochemical examination after 2 weeks and 2 months. Dentin bridges were observed in all samples, and 87.5% were complete. The low-level laser group had significantly more reparative dentin area than the non-lased group (p < 0.05). The dentin bridges were found to have an unprecedented tubularity of 43%-89%. Tiny dentin island formation was observed within the material particles. Initial mild-to-moderate inflammatory reactions were observed, which subsided after 2 months. RUNX2 and osteocalcin staining were evident for all samples at both time intervals. Low-level laser combined with bioactive ERRM is effective in inducing reparative dentin formation.

Low-level laser therapy is effective in controlling postoperative pain in lower third molar extractions: a systematic review and meta-analysis

This systematic review aimed to evaluate the effectiveness of low-level laser therapy in controlling postoperative pain in lower third molar extractions. A search was carried out in MEDLINE/PubMed, Web of Science and Cochrane Library (CENTRAL) databases, using the "low-level laser therapy", "photobiomodulation therapy", "impacted mandibular third molar", "mandibular third molar", "third molar extraction" descriptors and 2625 studies were found, including only randomized clinical trials published until July 2020, with no restrictions on language and country of study. Selected studies were submitted to initial screening based on the reading of titles, abstracts and full article, and duplicate studies were excluded. Overall, 2562 articles were found, of which only 15 randomized clinical trials were included in this review. A total of 648 patients (16-44 years) who received low-level laser therapy as an intervention and placebo in their control group were evaluated. The pain evaluation criterion was the Visual Analog Scale (VAS) on the second and seventh days after surgery. Photobiomodulation with low-level laser showed statistically significant reduction in postoperative pain in lower third molar extractions, both on the second (MD: - 0.59; CI: - 0.92, - 0.27) and seventh day after surgery (MD: - 0.76; CI: - 1.21, - 0.32).

Effect of Different Energy Densities of 915 nm Low Power Laser on The Biological Behavior of Human Gingival Fibroblast Cells in-vitro

Photobiomodulation is recognized as an effective method for adjunct therapy in periodontal treatments. our purpose in this study was to investigate the effects of different energy densities of 915nm diode laser on the viability and viability capacity of human gingival fibroblast cells. cell samples were examined in 5 groups, including 4 irradiation groups with low-level diode laser 915nm, 1,2,3,4 J/cm² , and a control group (no Laser irradiation). Cell viability and viability were measured 1, 3 and 5 days after irradiation by MTT and DAPI assay. Statistical differences between groups at any time were analyzed by one-way ANOVA and a post hoc Turkey's test. The cell viability and viability capacity increased on the third day at an energy density of 3 J/cm² ; (P-value = 0.007) and the fifth day at energy densities of 2,3 and 4 J/cm² was recorded compared to the control group (P-value =0.000). Also, a significant decrease in the viability and viability of irradiated cells with an energy density of 1 J/cm² was found. (P-value =0.033). according to our results, Photobiomodulation with 915nm diode laser has a positive stimulating effect on the viability and viability capacity of human gingival fibroblast cells.

Comparison between the Effect of 810 nm and 940 nm Diode Laser Irradiation on Histopathological Changes in Iatrogenic Oral Ulcers: an Animal Study

STATEMENT OF THE PROBLEM

Considering the relatively high prevalence of oral mucosal ulcers, their fast healing is of significance.

PURPOSE

This study aimed to histopathologically compare the effects of 810 nm and 940 nm diode laser on the healing of iatrogenic oral ulcers in rabbits.

MATERIALS AND METHOD

In this single-blind experimental study, mucosal ulcers measuring 3mm in diameter and 1mm in depth were bilaterally created in the buccal mucosa of 18 rabbits using a biopsy punch. The defects were irradiated with 810 nm diode laser on the right side and 940 nm diode laser on the left side. Biopsy samples of the same depth were obtained from the ulcers on days 3 and 7 followed by histopathological analysis. The intensity of inflammation was determined on hematoxylin-eosin-stained sections using a four-point scale. Data were analyzed employing the Wilcoxon signed rank test.

RESULTS

The degree of inflammation was not significantly different between the 810nm and 940nm diode laser groups on day 3; but on day 7, animals receiving 810 nm experienced a significantly lower degree of inflammation compared to those treated with 940 nm laser (p= 0.028).

CONCLUSION

When comparing 810- and 940-nm diode lasers, 810 nm irradiation significantly decreased the severity of inflammation in oral wounds created on the buccal mucosa of rabbits in a time-dependent manner.

Complementarity of Photo-Biomodulation, Surgical Treatment, and Antibiotherapy for Medication-Related Osteonecrosis of the Jaws (MRONJ)

Background and Objectives: Antiresorptive or anti-angiogenic agents may induce medication-related osteonecrosis of the jaws (MRONJ), which represents a challenge for clinicians. The aim of this study is to design and apply a composed and stage-approach therapy combining antibiotherapy, surgical treatment, and photo-biomodulation (PBM) for the prevention or treatment of MRONJ lesions. Materials and Methods: The proposed treatment protocol was carried out in the Department of Oral & Maxillofacial Surgery of the “Victor Babes” University of Medicine and Farmacy of Timisoara, in 2018–2020. A total of 241 patients who were previously exposed to antiresorptive or anti-angiogenic therapy, as well as patients already diagnosed with MRONJ at different stages of the disease were treated. A preventive protocol was applied for patients in an “at risk” stage. Patients in more advanced stages received a complex treatment. Results: The healing proved to be complete, with spontaneous bone coverage in all the n = 84 cases placed in an “at risk” stage. For the n = 49 patients belonging to stage 0, pain reductions and decreases of mucosal inflammations were also obtained in all cases. For the n = 108 patients proposed for surgery (i.e., in stages 1, 2, or 3 of MRONJ), a total healing rate of 91.66% was obtained after the first surgery, while considering the downscaling to stage 1 as a treatment “success”, only one “failure” was reported. This brings the overall “success” rate to 96.68% for a complete healing, and to 99.59% when downscaling to stage 1 is included in the healing rate. Conclusions: Therefore, the clinical outcome of the present study indicates that patients with MRONJ in almost all stages of the disease can benefit from such a proposed association of methods, with superior clinical results compared to classical therapies.

The effect of laser-activated bleaching with 445 nm and 915 nm diode lasers on enamel micro-hardness; an in vitro study

BACKGROUND

The appearance of the teeth is of great importance to patients, particularly tooth color. In recent years, tooth whitening has been one of the most popular ways to restore tooth color. Bleaching gels can be affected by heat, light or laser, which can improve its effects. This study intends to examine the effects of two different wavelengths of diode laser (445 & 915 nm) after the bleaching process, on the enamel micro-hardness.

METHODS

A total of 65 caries-free humans third molars were randomly divided into five groups (N = 13): first group: bleaching gel activated with 915 nm diode laser (1.5 W), second: bleaching gel activated with 915-nm (2.5 W), third: bleaching gel activated with 445-nm (1 W), fourth: bleaching gel activated with 445-nm (1.5 W), fifth (control group): bleaching gel without laser activation. Micro-hardness test (Vickers test) was performed before and after the treatment. The data were submitted to repeated measurement ANOVA and Tukey's HSD post hoc test (α = 0.05).

RESULTS

Enamel micro-hardness did not change significantly in groups 3 and 4 but decreased in groups 1 and 2. Group 2 showed the most reduction in micro-hardness. There were no significant changes in the control group.

CONCLUSION

According to the results of this study, 445 nm Diode laser did not reduce enamel micro-hardness, making it suitable for bleaching treatments. However, more studies are required to consider other factors, such as color changes and pulp temperature.