low-level light therapy

This study assessed the effect of low-level laser therapy (LLLT) on the osseointegration of immediately loaded implants with a connective tissue graft (CTG).

This clinical trial was conducted on patients with buccal bone dehiscence requiring dental implants. A CTG was harvested from the palate and placed in the labial side by considering the 2 mm distance between the implant thread and bone. Autogenous bone was harvested from the tuberosity, mixed with the allograft, and implanted at the site. After sufficient torquing of the implant, a customized abutment was fabricated and placed. The patients were randomly assigned to two groups (n = 5) of intervention and control. The patients in the intervention group received LLLT with a 940 nm gallium-aluminum-arsenide laser while those in the control group received placebo irradiation. The primary implant stability was measured before the delivery of customized abutment while the secondary implant stability was measured after 12 weeks by Osstell® and reported as the implant stability quotient (ISQ).

No significant difference was found in secondary ISQ between the laser and control groups (P > 0.05). In the intervention group, a significant difference was found between the primary and secondary ISQ in the buccolingual dimension (P < 0.05) but not in the mesiodistal dimension (P > 0.05). The two groups had no significant difference in gingival thickness or vertical bone gain (P > 0.05). All implants were successful with no complications.

LLLT had a significant positive efficacy for the enhancement of secondary stability of implants in the buccolingual dimension. CTG showed optimal efficacy for the treatment of buccal bone dehiscence.

 Photobiomodulation (PBM) is considered a promising adjunctive approach in regenerative medicine. This study aimed to investigate the proliferation and adhesion of human gingival fibroblast (HGF) cells to a collagen membrane following PBM.

 Cultured HGF cells on a collagen membrane received PBM at wavelengths of 808 nm, 915 nm (2 and 4 J/cm2), and 660 nm (2.1 and 4.2 J/cm2) in interventional groups, while non-irradiated cells served as the control. On days 1 and 3 post-irradiation, cell proliferation was measured by MTT assay and adhesion to the membrane was assessed under the scanning electron microscope (SEM).

 Cell proliferation significantly increased in interventional groups compared to the control, with the most significant increase at 915 nm (4 J/cm2) in both time points. On the first day, the 808 nm and 660 nm lasers demonstrated similar results, significantly lower than the 915 nm laser (2 J/cm²). On day 3, the 660 nm, 808 nm, and 915 nm (2 J/cm²) groups showed comparable results. Qualitative analysis by the SEM identified spindle-shaped cells with multiple extended projections in 915 nm groups, especially at an energy density of 4 J/cm2. Groups of 660 nm and 808 nm (4 J/cm2) showed spindle-shaped cell morphology. No distinct cellular morphology indicative of enhanced adhesion was observed at 808 nm (2 J/cm2).

 The most effective PBM setup for promoting HGF proliferation and adhesion to a collagen membrane was identified at 915 nm (4 J/cm2)

 This study aimed to assess the photobiomodulation effects of blue and red lasers on the proliferation and osteogenic differentiation of periodontal ligament mesenchymal stem cells (PDLMSCs).

 PDLMSCs were cultured and tested in 4 groups. The first two groups were exposed to 445 nm diode laser irradiation (200 mW, 6 and 12 J/cm2), and the third group was exposed to
660 nm diode laser irradiation (50 mW, 4 J/cm2). The fourth group was also considered as the
control group without irradiation. Cell viability/proliferation was assessed by MTT assay. RUNX2, alkaline phosphatase (ALP), collagen type 1 (col1), and osteocalcin (OCN) were evaluated by RTPCR, and Alizarin red was used to evaluate the colonization. The data were analyzed by means of one-way analysis of variance.

 The results of our study showed that cell survival/proliferation in the second group was significantly lower than that in the control group on days 1 and 7 (P<0.05). RT-PCR showed a significant increase in osteogenic genes in all three laser groups compared to the control group (P<0.05). All groups showed a significant increase in calcium content compared to the control group (P<0.05). ALP activity also confirmed the osteoblastic differentiation of cells in laser groups.

 445 nm and 660 nm lasers with the studied parameters showed positive effects on the proliferation and osteoblastic differentiation of PDLMSCs.

Temporomandibular joint disorder with myofascial origin has a high prevalence among other types of this disorder. Two treatments prescribed for Temporomandibular joint disorder would be low-level laser therapy and occlusal splints. The purpose of this review is to compare the effects of LLLT and occlusal splints for the treatment of TMD patients with myofascial pain.The literature search was done by specific terms in Scopus, PubMed, and Web of Science databases and the studies were reviewed by two authors based on inclusion criteria. From 86 articles gained by the search 6 have remained after the evaluation of authors. Based on the reviewed studies and within the diversity of the methods used by the researchers, it could be concluded that both LLLT and occlusal splint would be equally a proper treatment for patients suffering from TMD with myofascial pain.

Statement of the Problem: 

Healing of the inferior alveolar nerve injury during dental procedures is one of the biggest concerns of dentists. There are still debates on different treatment modalities.

This study aimed to compare the effect of 940nm and 810nm diode lasers on the repair of the inferior alveolar sensory nerve.

In this single-blinded randomized clinical trial, 39 patients with inferior alveolar nerve injury were divided into three groups: 1. 810nm laser irradiated, 2. 940nm laser irradiated, and 3. No laser irradiation (control group). All patients were treated in 12 sessions (3 days per week) and evaluated using a complete clinical neurosensory test (CNT), including brushstroke, 2-point discrimination, pinprick nociception, and thermal discrimination before and after treatment.

The mean dysesthesia of the patient treated with 810nm diode laser was sig-nificantly lower than the control group in all sessions (the 1st (p= 0.003), 3rd (p= 0.008), 7th (p= 0.006), and 12th sessions (p= 0.005)). The 810nm laser resulted in more satisfa-ction in patients than the control group in almost all sessions (1st (p< 0.001), 7th (p= 0.028), and 12th (p= 0.006)). More patient satisfaction was seen in the 1st and 3rd sessi-ons in the 810nm laser than in the 980nm laser (p< 0.001 and p= 0.003, respectively).

810nm diode laser can be better than 940nm in repairing inferior alveolar sensory nerve damage.

 Applying autologous growth factors and diode laser in periodontal therapy enhances fibroblast-mediated new attachment and osteoblastic differentiation. Hence, this study compared and evaluated the effectiveness of concentrated growth factor (CGF) alone and with diode laser application in managing intrabony periodontal defects.

 Ten patients with stage III periodontitis were included in this study. All the patients underwent an open flap debridement (OFD) procedure followed by CGF membrane placement in the intrabony defect in site A, whereas, in site B, after OFD, all the patients underwent diode laser irradiation before CGF membrane placement. Plaque and gingival bleeding index (PI & GBI), PPD, and clinical attachment level (CAL) were evaluated at baseline and 3 and 6 months later. Bone fill (BF), BF%, bone crest changes (BCC), and BCC% were assessed radiographically at six months postoperatively.

 Significant reductions in PI and GBI scores, probing pocket depth (PPD), and CAL gain were observed at both sites 3 and 6 months from baseline. A significant reduction in PPD and CAL gain was noted between sites, which were higher in site B than in site A with a mean difference of 0.70±0.05 mm and 1.30±0.18 mm, 0.90±1.89 mm at 3 and 6 months, respectively. Radiographic measurement showed better BF, BF%, BCC, and BCC% at both sites at six months, which were higher at site B than at site A but statistically insignificant.

 The combination of CGF and diode laser application has demonstrated successful and promising results in terms of regeneration, improving the clinical and radiographic parameters.

Sleep bruxism (SB) is a parafunctional oral habit that is frequently related to sleep arousals. The masseter inhibitory reflex (MIR) causes reflex inhibition of voluntary contractions of the elevator muscles induced by intense peri- or intraoral mechanical or electrical stimulations. This study aimed to investigate the changes in MIR of patients with SB, and the effect of different treatment modalities on MIR.

In this case-control study, 100 individuals were randomly assigned to four groups (n=25) of conservative treatment (G1), occlusal splint treatment (G2), low-level laser therapy (LLLT) treatment (G3); and control (G4). The MIR was tested in all participants before and one month after treatment. 

All MIR components of the patients had longer right and left SP1 and right and left SP2 latencies (P=0.017, P=0.043, P<0.001, and P=0.04, respectively), and shorter right and left SP1 and right and left SP2 durations (P=0.021, P=0.021, P<0.001, and P<0.001, respectively) as compared to the control group. The right SP1 and SP2 latencies were prolonged in G3 versus G1 and G2 (P=0.026 and P<0.001, respectively); whereas, the left SP2 latency was prolonged in G2 compared with G1. The right and left SP2 duration was not significantly different among the three treated groups. The left SP1 duration was not significantly different among the three treated groups. Gender had no effect on MIR parameters.

SB patients had an abnormal MIR response. LLLT was the most effective compared to other treatment modalities.

The presence of treatment-resistant microorganisms is known as the main cause of pulpectomy failure in the endodontic treatment of deciduous teeth. The usage of lasers can contribute to reducing these microorganisms. This study aimed to compare the effect of three disinfection methods for deciduous teeth canals using laser diode 810 nm, photodynamic therapy with laser 660 nm and methylene blue, and sodium hypochlorite.

In this experimental study, 58 single-root deciduous teeth with no root resorption were investigated in four groups, including one control group of 10 and three intervention groups of 16. Preparation of the samples was done using manual files up to three numbers after the initial file. After sterilizing the samples in an autoclave, Enterococcus faecalis bacteria were cultured in the canals. In the first group, irrigating with hypochlorite 2.5% was done; in the second group, photodynamic therapy was performed using a laser diode and 0.1 mg/mL methylene solution; and in the third group, high-intensity laser 810 nm direct radiation was done into the canal. Next, samples were taken from all canals. The colony formation unit (CFU) of the bacteria was counted in the blood agar culture medium. The data were analyzed using Kruskal–Wallis and negative binomial a regression test (a =0.05).

The mean CFU differed significantly between the four groups. The rate of incidence of E. faecalis colonies showed a reduction in all three intervention groups compared to the negative control. In the high-intensity laser 810 nm group, there was 68.4%; in the photodynamic therapy with diode 660 nm and methylene blue, there was 88%; and in the hypochlorite group, 98.3% reduction was observed compared to the negative control group.

Based on the results of this study, to compare three disinfection methods of the deciduous teeth canals without preparation of canals, sodium hypochlorite had greater efficiency All three groups of laser, photodynamic therapy, and sodium hypochlorite showed reductions of E. faecalis bacterial colony compared to the control group. The reductive effects of CFU were greater in the hypochlorite sodium group, followed by photodynamic and direct laser radiation groups.

Oral squamous cell carcinoma, which is known as the most common cancer of the oral cavity, is associated with high morbidity and mortality rate. To date, many efforts have been made to find effective methods to stop the growth of cancer cells. One of the emerging methods in this field is the application of low-level lasers.

Human head and neck carcinoma cell lines were prepared and irradiated with four different wavelengths of low-level laser with a density of 1 j/cm2 and a power of 100 mW. The expression of the Bcl-2 and Bax genes and the Bax/Bcl-2 ratio were investigated by real-time PCR.

The highest percentage of Bcl-2 gene expression was related to 660nm wavelength and the highest percentage of Bax gene expression was related to 810 nm infrared wavelength. The lowest level of expression of the Bcl-2 gene related to the 810nm infrared wavelength and the Bax gene related to the 532nm wavelength was obtained. The lowest Bax/Bcl-2 ratio was obtained at the wavelength of 660nm and the highest ratio was obtained at the wavelength of 810nm.

Despite the extensive studies conducted in the field of low-level laser application in oncology, more studies are needed to investigate the effect of this technology on cancer cells.

Considering the positive effects of a low-level laser on new bone formation, we aimed to investigate the effects of a low-level laser in the treatment of patients with class II mandibular deficiency treated with Farmand functional appliance.

Twenty-two growing patients aged 10-14 years were randomly divided into “Farmand” and “Farmand + Laser” groups. All patients were treated with Farmand functional appliance. Patients in the “Farmand + laser” group were exposed to laser irradiation (980 nm, 100 mw, 4 points around temporomandibular joints, 100 seconds each point) weekly for three months after 3-4 weeks of using the appliance. Lateral cephalometry radiographs were taken from all patients before and after the treatment period, and changes in skeletal and dental parameters were measured.

The association of the particular laser irradiation with the functional appliance led to a greater increase in the effective length of the mandible (Co-Gn, P = 0.048), the anterior sagittal position of the mandible (SNB, P = 0.029), and the length of the ramus (Co-Go, P = 0.028), and it showed a further decrease in the discrepancy between the jaws (ANB, P = 0.000) compared with the functional appliance alone.

The application of the laser with the chosen parameters and protocol in conjunction with the functional appliance improved the effects of the functional appliance and reduced the discrepancy between the two jaws.

Temporomandibular disorders (TMDs) are the most prevalent non-dental origin orofacial pain conditions affecting the temporomandibular joints (TMJs) and/or orofacial muscles. Photobiomodulation therapy (PBMT) is a conservative way to improve function and reduce symptoms in TMD patients. This systematic review was conducted to update evidence about the effects of PBMT on pain intensity, TMJ movements, electromyography (EMG) activity, pressure pain threshold (PPT), and TMJ sound in patients with TMDs.

A systematic literature search was conducted in Web of Science, PubMed/Medline, and Scopus databases using appropriate keywords and specific strategies from January 2000 to September 2022. Data extraction was done based on the inclusion/exclusion criteria.

A total of 40 studies were included. All included studies except one provided information on pain intensity; 27 studies showed a reduction in pain intensity in PBMT groups compared to control groups. Seven out of 15 studies, which reported maximum mouth opening (MMO), showed a greater MMO in PBMT groups than in placebo groups. In addition, the figures for passive maximum mouth opening (PMMO) and active maximum mouth opening (AMMO) in all the studies reporting PMMO and AMMO were higher in PBMT groups. In eight out of ten studies, lateral movement (LM) was greater in PBMT groups. Moreover, in three studies out of four, protrusive movement (PM) was reported to be greater in the PBMT group. Four out of nine studies showed a greater PPT in the PBMT group. Reduced TMJ sounds in the PBMT group were reported in two out of five studies. In addition, in most studies, no difference in EMG activity was detected between the two groups.

This updated systematic review showed the promising effects of PBMT on the alleviation of pain and improvement in MMO. Using the infrared diode laser with a wavelength ranging between 780-980 nm, an energy density of < 100 J/ cm2, and an output power of ≤ 500 mW for at least six sessions of treatment seems to be a promising option for treating mentioned TMDs signs and symptoms based on the previously reported findings.

This study investigated the photobiomodulation effect of an 810-nm diode laser in adjunction with topical anesthesia on pain perception during infiltration anesthesia of primary maxillary molars in children.

This double-blind randomized controlled clinical trial was conducted on 64 children (aged 5-9 years) requiring extraction or stainless steel crown for their primary maxillary molars. The patients were randomly allocated into two groups (n = 32) of laser and control. In the laser group, the injection site (buccal and palatal mucosa) was irradiated with an 810-nm laser (200 mW, 5.2 J/cm2) after 20% benzocaine topical anesthetic application, while the control group received a placebo laser following topical anesthesia. The pain intensity experienced by children during needle insertion into the buccal and palatal mucosa was determined using a visual analog scale (VAS) and modified behavioral pain scale (MBPS).

According to the results of the VAS and MBPS, no significant difference was detected in pain scores between the laser and control groups neither in the buccal nor in the palatal mucosa (P > 0.05).

Photobiomodulation therapy with an 810-nm laser with the current setting adjunct to topical anesthesia did not promote significant additional effects on the pain intensity.

 The objective of this study was to assess the effectiveness and safety of photobiomodulation (PBM) in the treatment of male infertility.

 We searched Google Scholar, PubMed, and the reference sections of relevant papers published from January 1, 2000 to September 23, 2022. We retrieved all publications related to the impact of PBM on male infertility. After reviewing the titles, abstracts, and full texts, we included fifteen papers in the research. The studies involved 477 semen samples (in vitro studies) and 70 male participants (randomized clinical trials).

 All 14 in vitro studies that evaluated effectiveness reported that PBM was successful in increasing the proportion of progressive sperms in semen samples. Various methods were used to evaluate the safety. One study with a sample size of 58 concluded that PBM was not a safe treatment, whereas the other ten studies confirmed its safety. Only one clinical trial evaluated the effect of laser acupuncture on male infertility and found improvements in sperm progressive motility without any serious adverse effects.

 All 15 studies evaluating effectiveness reported that the low-level laser was effective for increasing the proportion of progressive sperm in semen samples and that it was safe to use. However, due to the heterogeneity of population characteristics, source characteristics, duration of exposure, sample size, and instruments for measuring safety and efficacy, we cannot conclude that the positive results obtained from the reviewed studies are solely attributable to the low-level laser on the sperm samples.

Dental surgeries are always associated with pain and swelling for several consecutive days. Recent articles have shown conflicting results in the use of new techniques such as low-power lasers to treat postoperative pain and swelling. This study aimed to evaluate the reduction of pain, swelling, and trismus after surgery of the third molar-impacted tooth after the use of a low-power laser.

This study was a randomized, single-blind, split-mouth clinical trial involving patients who were referred to the special clinic of Birjand Dental School from December 2021 to June 2021 and required bilateral removal of the occluded third molars. Immediately after surgery, the patient was given a radiation laser with a wavelength of 780 nm and a power of 70 MW for 30 seconds at a dose or power density of 52.5 j/cm2. The extent of swelling and trismus was assessed by measuring the dimensions of the face and the amount of mouth opening as well as the amount of pain on the second and seventh days after surgery. Statistical analysis was performed using the Wilcoxon and Mann–Whitney U test by SPSS (Version 21) at the significant level of (5 %).

The intensity of pain and swelling decreased significantly over time and the amount of trismus increased significantly during the seventh day compared to the second day (p.value<0.05). The amount of pain on the 7th day after surgery in the group without laser was 1.98±0.26 and the amount of pain in the group with laser was 0.85 ± 0.92 which was not statistically significant between the two groups (value>0.05). The amount of trismus on 7-day was 38.79 ±9.94 and on the side, with laser, it was no significant difference. The distance between the tragus and the corner of the lip on day 7 after surgery was 110.03 ± 5.77 mm and in the laser group was 109.66 ±5.67 mm, no significant difference was observed between the two groups. The distance between the gonium and the outer corner on day 7 after surgery was 98.84 ±7.24 mm in the laser group and 98.21± 6.93 mm in the non-laser group and no significant difference was observed.

The use of low-power laser reduced the pain, reduce postoperative swelling, and trismus caused by surgery but this reduction was not significant. Therefore, it is suggested that the study method should be changed and the sample size must be increased in further studies.

Postoperative management of patients undergoing tonsillectomy is challenging. Photobiomodulation therapy (PBMT) has emerged as a new tool providing therapeutic benefits. However, the contribution of PBMT to the postoperative outcomes of tonsillectomy is still undefined. This systematic review and meta-analysis evaluated the published literature addressing the effects of PBMT on post-tonsillectomy.

Searches in Scopus, PubMed/MEDLINE, Embase, Web of Science, Cochrane Library, and grey literature were carried out for the identification of randomized controlled trials reported up to August/2021. The risk of bias with the Cochrane Collaboration tool and meta-analysis was performed. Outcomes were assessed with the Kaplan-Meier method and the log-rank test.

A total of 1183 articles were retrieved, of which only two were included for qualitative and quantitative analysis. The wavelengths were 685 nm and 980 nm with energy density set at 4 J/cm². The mandibular angle and the surgical wound were the sites of laser irradiation. Individuals who had not undergone PBMT after tonsillectomy were more likely to report pain and odynophagia in the first 24 hours after surgery than individuals who had undergone PBMT after tonsillectomy (P<0.001). Children who received PBMT after tonsillectomy were equally affected by pain and odynophagia in the first seven days after surgery compared to children who had not undergone PBMT after tonsillectomy (P>0.05). However, both studies found a significant association of PBMT with reduced analgesic consumption.

Although PBMT seems promising for the management of individuals undergoing tonsillectomy, a limited number of studies are available in the literature.

This study assessed the effect of low-level laser (LLL) irradiation on the viability of dental pulp stem cells (DPSCs).

In this in vitro experimental study, human DPSCs were purchased from the cell bank of Iranian Genetic Resources and cultured in flasks containing Dulbecco's modified Eagle's medium supplemented with 20% fetal bovine serum (FBS) at 37°C, 5% CO2, and 95% humidity. The cells were stored in semi-confluent form, and the culture medium was refreshed every two days. The cells in the control group were not laser-irradiated, but the cells in the experimental groups were irradiated with 660-nm and 808-nm diode lasers with 4.1 J/cm2 energy density. Cell viability was assessed at baseline and after 24, 48, and 72 hours using the methyl thiazolyl tetrazolium (MTT) assay. The effects of laser irradiation, laser wavelength, and time on the percentage of cell viability were analyzed by two-way ANOVA and Tukey's test.

The effects of laser irradiation and its wavelength (P = 0.04), time of assessment (P < 0.001), and the interaction effect of group and time (P = 0.02) on cell viability were significant. Cell viability in 660-nm and 808-nm laser groups at 48 and 72 hours was higher than that of the control group; however, only the difference in cell viability between the 660-nm laser group and the control group at 72 hours was statistically significant (P = 0.03).

Considering the optimal effect of diode laser irradiation (particularly 660 nm) on the viability of DPSCs, we conclude that it may be suitable for relevant clinical applications.

Impaction of the anterior teeth, which is less frequent in central incisors, can cause serious esthetic and subsequent psychological problems for patients during the mixed dentition period. Traumatic injury to deciduous teeth is the most common etiologic factor. Thus, treatment of maxillary incisor impaction is highly important. Nowadays, application of laser has been suggested in orthodontics and pediatric dentistry for different treatments, such as surgical exposure of impacted teeth and application of low-level laser therapy (LLLT) for acceleration of orthodontic tooth movement. In this paper, the authors present treatment of an impacted and dilacerated maxillary central incisor with laser application for its surgical exposure and LLLT for acceleration of its orthodontic traction and eruption.

Photobiomodulation therapy (PBM) appears to induce osteogenesis and stimulate fracture repair; because of its capacity, it is considered a promising treatment, but the characteristics of response to different radiation doses must be investigated through in vivo studies to establish their safety and effectiveness. Thus, this paper aims to analyze the effects of the PBM at different doses on the repair of critical bone defects through histological and histomorphometric analyses.

Sixty 90-day-old adult rats (Rattus norvegicus, albinus, Wistar) weighing approximately 300 g were used. Critical bone defects of 5 mm in diameter were performed in their calvaria. The animals were randomly separated into 5 groups: C-Blood clot, L15-PBM 15J/cm2, L30-PBM 30 J/cm2, L45-PBM 45 J/cm2, L60-PBM 60 J/cm2. Each group was subdivided according to observation periods of 30 and 60 days with 6 rats in each subgroup. Low-level gallium aluminum arsenide (GaAlAs) lasers were used at a 660 nm wavelength, 30 mW and 0.04 cm2 in area. The PBM was applied over 5 points;4 points of application were distributed on the edges while one point of application was located in the center of the bone defect. PBM occurred right after the procedure. In 30 and 60 days, the animals were euthanized by anesthesia overdose and the analyses were performed. The data were analyzed statistically by the ANOVA, together with the Tukey test, whose significance level was 5%.

As regards the treatment factor, the highest percentage of bone neoformation was achieved by group L45-60. The group with the highest closure, despite not having a statistically significant difference with the other doses, was 45 J with only 0.49 mm between edges.

Thus, the present study allowed concluding that the highest percentage of bone neoformation area was achieved at 45 J/cm2 in 60 days; that is, it was significantly effective in comparison with other doses.

Phototherapy with a light-emitting diode (LED) is used in medicine due to its potential bio-stimulatory effects on the human body. However, controversy still exists regarding the efficacy of low-level laser therapy (LLLT) and phototherapy with LED. This in vivo study aimed to quantitatively and qualitatively assess the newly formed bone following LED phototherapy of the human maxillary sinuses.

This randomized clinical trial (concurrent parallel) was conducted on 44 patients in two groups (n=22) at the Implant Department of Tehran University of Medical Sciences. Randomization was done by a random sequence generator program. The inclusion criteria were absence of chronic sinusitis and chronic bone marrow conditions, no history of surgery at the site, absence of diabetes mellitus, no history of chemotherapy or radiotherapy, maxillary premolar edentulism, and signing informed consent forms. Group A underwent LED phototherapy with 620 ± 2 nm wavelength for 20 minutes daily for a total of 21 days after sinus lift surgery. Group B served as the control group and did not receive phototherapy. After 6 months, the grafted sites were re-opened for implant placement, and bone biopsy samples were obtained using a trephine bur. The samples were stained with hematoxylin and eosin and inspected under a light microscope. The results were statistically analyzed using the Mann-Whitney U test. Both the surgeon and pathologist were blinded to the group allocation of patients.

Forty tissue specimens were analyzed. Insignificant differences existed between the two groups in terms of the degree of inflammation, bone quality, and maturity of collagen. Histological analyses revealed no significant difference in the mineralized areas of bone between the two groups (P>0.05).

The results indicated that LED phototherapy cannot significantly enhance osteogenesis after sinus lift surgery. No side effects were observed in the experimental group.

This study aimed to investigate the effect of low-level laser therapy (LLLT) on the blood cell count when applied to parotid glands of rats irradiated by volumetric modular arc therapy (VMAT).

Thirty-two adult male Wistar rats were used in this study. Samples were randomly assigned to three groups: control group (CG, n = 8), immediate laser group (24 hours) (ILG, n=12), and late laser group (120 hours) (LLG, n=12). The two laser groups were previously subjected to VMAT radiotherapy in a single dose of 12 Gy. LLLT with an AsGaAl laser (660 nm, 100 mW) was applied at three points in the region of the parotid glands, right side, with the energy of 2 J per point (20s, 70 J/cm2) and a spot size of 0.0028 cm2 for 10 consecutive days. In the euthanasia, blood samples were obtained by cardiac puncture. The samples from each group were processed by an automatic method and analyzed for erythrogram, leukogram and platelet count values. The data were analyzed by ANOVA and each LLLT time point was analyzed in relation to the control group, with a significance level less than 0.05.

Groups using LLLT had higher red blood cell counts, being higher in the LLG (p = 0.000). The hematimetric indices MCV (P = 0.002) and MCH (P = 0.009) were lower than the control group, especially when compared to the group using LLLT 120h after radiotherapy (LLG). White blood cell counts were lower in the groups with radiotherapy and immediate use of LLLT (ILG) (P = 0.011), mainly at the expense of lymphocytes (P = 0.002).

The results suggest a potential systemic effect of LLLT, especially on circulating red blood cell counts, regardless of their time of immediate or late use of radiotherapy.