Effects of low-level laser therapy on soft and hard tissue healing after endodontic surgery

The specificities, influencing factors, and medical implications of bone circadian rhythms

Physiological processes within the human body are regulated in approximately 24-h cycles known as circadian rhythms, serving to adapt to environmental changes. Bone rhythms play pivotal roles in bone development, metabolism, mineralization, and remodeling processes. Bone rhythms exhibit cell specificity, and different cells in bone display various expressions of clock genes. Multiple environmental factors, including light, feeding, exercise, and temperature, affect bone diurnal rhythms through the sympathetic nervous system and various hormones. Disruptions in bone diurnal rhythms contribute to the onset of skeletal disorders such as osteoporosis, osteoarthritis and skeletal hypoplasia. Conversely, these bone diseases can be effectively treated when aimed at the circadian clock in bone cells, including the rhythmic expressions of clock genes and drug targets. In this review, we describe the unique circadian rhythms in physiological activities of various bone cells. Then we summarize the factors synchronizing the diurnal rhythms of bone with the underlying mechanisms. Based on the review, we aim to build an overall understanding of the diurnal rhythms in bone and summarize the new preventive and therapeutic strategies for bone disorders.

Can diode laser 810 nm decrease post endodontic pain in patients with asymptomatic necrotic maxillary incisors? A four-arm randomized controlled trial

AIM

To find the best method for applying the diode laser 810 nm to relieve post-endodontic pain on necrotic maxillary incisors with periapical lesions within a single-visit treatment.

METHODS

Eighty patients with a necrotic incisor, diagnosed with asymptomatic apical periodontitis, received standardized cleaning and shaping procedures, then divided randomly with a 1:1:1:1 allocation ratio into four groups: Group 1: control group with no laser application, Group 2: applying the diode laser as an irrigation activation system (IAS), Group 3: applying the diode laser from the buccal and palatal mucosa, Group 4: applying the diode laser as an IAS and from buccal and palatal mucosa. The postoperative pain was assessed using the visual analog scale (VAS) 1, 3, 7, and 14 days after the treatment. The mean values of the VAS score were statistically analyzed used Kruskal-Walis and Mann-Whitney U tests. The level of significance was set at a = 0.05.

RESULTS

During 14 days after treatment, there was a statistically significant difference between mean values of VAS scores in the four groups (P value < 0.05); Group 1 scored the highest score, whereas Group 4 showed the lowest one. Moreover, Group 4 showed favorable outcomes compared with Group 2 and Group 3 during the first three days after treatment.

CONCLUSION

Diode laser reduced postoperative pain after necrotic teeth with large-sized apical lesion treatment, whereas using diode laser either as an IAS or LLLT reduced the postoperative pain compared with the control group. Moreover, the usage of a diode laser in both previous techniques represents the best protocol for postoperative pain relief during 14 days of treatment.

CLINICAL RELEVANCE

The clinical significance of this study is to investigate the best method to reduce postoperative pain using diode lasers 810 nm; where the results of this study indicated that the more diode laser exposer in LLLT and IAS, the less postoperative pain after endodontic procedures.

Effect of Laser Photobiomodulation on Postoperative Pain in Endodontics: A Systematic Review

Objective: Photobiomodulation therapy has proven benefits in various dental treatments. The current systematic review aims to explore the role of laser photobiomodulation in modulating postoperative pain followed by endodontic treatment. Methods: In this systematic review, randomized controlled clinical trials on low-level laser therapy/photobiomodulation in endodontic therapy were analyzed. Database search was performed in PubMed/Medline, Web of Science, Scopus, and Cochrane Library, followed by literature search in Google Scholar. Results: A total of 12 studies were included as per the set criteria. The included studies utilized diode laser (808-970 nm) and indium gallium aluminum. All the included studies evaluated postendodontic pain after root canal therapy and endodontic surgery. A majority of the included studies showed significant benefits of photobiomodulation in postoperative pain management in endodontic therapy.Heterogeneity of the laser parameters and lack of power calculations for sampling among the included studies preclude solid recommendation of use of photobiomodulation therapy (PBMT) for postendodontic pain management. Conclusions: Although PBMT has proven potential benefits being a possible adjunct in postoperative pain management in endodontic therapy, it requires robust standardized randomized control trials to confirm the results of the systematic review.

Application of Low-Level Laser Therapy in Endodontics: A Narrative Review

Low-level laser therapy (LLLT) stands out in the realm of dentistry for its unique attributes that set it apart from traditional therapeutic approaches. This non-invasive and painless modality harnesses the power of low-intensity lasers, offering a distinct advantage in terms of safety and patient comfort. Unlike many conventional methods, LLLT does not rely on pharmaceutical interventions or invasive procedures, making it a gentle yet effective option for various dental applications. Its non-thermal, photobiomodulatory effects on cellular and tissue functions mark a notable departure from the more aggressive treatment modalities commonly associated with dentistry. This article provides an extensive exploration of LLLT's applications in dentistry, focusing on its mechanisms of action and biological effects, and emphasizes the uniqueness of LLLT as a transformative tool in modern dental care.

Nd:YAG laser therapy on postoperative pain, swelling, and trismus after mandibular third molar surgery: a randomized double-blinded clinical study

This study aims to evaluate the effect of Nd:YAG laser therapy (NdLT) on postoperative pain, swelling, and trismus after mandibular third molar (M3) surgery. Three hundred patients were randomly divided into the Nd group (n = 100), medication group (n = 100), and Nd+medication (Nd+m) group (n = 100). The WHARFE classification system was used to assess surgical difficulty. After surgery, the Nd group was irradiated by the Nd:YAG laser in very long-pulsed mode (VLP, pulse duration 1 ms, 20 Hz, 4 W, R21-C3) in 6 regions of the extraction socket with a total energy of 300 J. For the medication group, dexamethasone 0.75 mg and loxoprofen 60 mg were prescribed immediately and every 12 h thereafter for 3 days. The Nd+m group received both treatments mentioned above. Pain assessment was performed at 6, 24, 48, and 72 h postoperatively using the visual analog scale (VAS). Swelling was evaluated by changes in the distance from (1) the tragus to the labial commissure, (2) the tragus to the pogonion, and (3) the mandibular angle to the lateral canthus preoperatively and 72 h postoperatively. Trismus was assessed by the change in maximum mouth opening. Groups Nd and Nd+m had lower VAS scores at 6 h, 24 h, and 48 h (F = 13.80, p = 0.00), but the difference between the two groups was not significant (F = 1.34, p = 0.11). However, no significant difference was observed at 72 h (p = 0.10). There was no significant difference in swelling or trismus among the three groups (p > 0.05). NdLT is an effective approach to improve complications after M3 surgery.

Endodontic Flare-Ups: An Update

Root canal treatment deals with mechanical and chemical cleaning followed by obturation that promotes healing and repair of periradicular tissues. Flare-ups can occur in between or some days after endodontic therapy leading to unscheduled visit by the patient. This complication is characterized by severe pain and/ or swelling. There is a correlation between number of appointments, intracanal medicament used and flare-ups. However, there is no sure procedure that can avoid this complication. Therefore, this review article has discussed about causes and some procedures to prevent and treat flare-ups.

Effects of Photobiomodulation Using Low-Level Laser Therapy on Alveolar Bone Repair

Alveolar bone repair is a complex and extremely important process, so that functions such as the mastication, occlusion and osseointegration of implants can be properly reestablished. Therefore, in order to optimize this process, many procedures have been used, such as grafting with biomaterials and the application of platelet-rich fibrin (PRF). Another method that has been studied is the use of photobiomodulation (PBM) with the use of low-level laser therapy (LLLT), which, through the absorption of photons by the tissue, triggers photochemical mechanisms in the cells so that they start to act in the search for homeostasis of the affected region. Therefore, the objective of this review was to analyze the use of LLLT as a possible auxiliary tool in the alveolar bone repair process. A search was carried out in scientific databases (PubMed/MEDLINE, Web of Science, Scopus and Cochrane) regarding the following descriptors: “low-level laser therapy AND alveolar bone repair” and “photobiomodulation AND alveolar bone repair”. Eighteen studies were selected for detailed analysis, after excluding duplicates and articles that did not meet predetermined inclusion or non-inclusion criteria. According to the studies, it has been seen that LLLT promotes the acceleration of alveolar repair due to the stimulation of ATP production, activation of transcription and growth factors, attenuation of the inflammatory process and induction of angiogenesis. These factors depend on the laser application protocol, and the Gallium Aluminum Arsenide—GaAlAs laser, with a wavelength of 830 nm, was the most used and, when applications of different energy densities were compared, the highest dosages showed themselves to be more efficient. Thus, it was possible to conclude that PBM with LLLT has beneficial effects on the alveolar bone repair process due to its ability to reduce pain, the inflammatory process, induce vascular sprouting and, consequently, accelerate the formation of a new bone matrix, favoring the maintenance or increase in height and/or thickness of the alveolar bone ridge.

Photobiomodulation Therapy and Pulp-Regenerative Endodontics: A Narrative Review

Regenerative endodontic procedures (REPs) were used to recover the dental pulp’s vitality in order to avoid the undesirable outcomes of conventional endodontic treatment and to promote dentinal formation, especially for immature permanent teeth. Photobiomodulation therapy (PBMT) exhibits photobiological and photochemical effects for improving the root canal’s environmental conditions by compensating for oxidative stress and increasing the blood supply to implanted stem cells and improving their survival. Basic research has revealed that PBMT can modulate human dental pulp stem cells’ (hDPSCs) differentiation, proliferation, and activity, and subsequent tissue activation. However, many unclear points still remain regarding the mechanisms of action induced by PBMT in REPs. Therefore, in this review, we present the applications of laser and PBMT irradiation to the procedures of REPs and in endodontics. In addition, the effects of PBMT on the regenerative processes of hDPSCs are reviewed from biochemical and cytological perspectives on the basis of the available literature. Furthermore, we consider the feasibility of treatment in which PBMT irradiation is applied to stem cells, including dental pulp stem cells, and we discuss research that has reported on its effect.

Low intensity near-infrared light promotes bone regeneration via circadian clock protein cryptochrome 1

Bone regeneration remains a great clinical challenge. Low intensity near-infrared (NIR) light showed strong potential to promote tissue regeneration, offering a promising strategy for bone defect regeneration. However, the effect and underlying mechanism of NIR on bone regeneration remain unclear. We demonstrated that bone regeneration in the rat skull defect model was significantly accelerated with low-intensity NIR stimulation. In vitro studies showed that NIR stimulation could promote the osteoblast differentiation in bone mesenchymal stem cells (BMSCs) and MC3T3-E1 cells, which was associated with increased ubiquitination of the core circadian clock protein Cryptochrome 1 (CRY1) in the nucleus. We found that the reduction of CRY1 induced by NIR light activated the bone morphogenetic protein (BMP) signaling pathways, promoting SMAD1/5/9 phosphorylation and increasing the expression levels of Runx2 and Osterix. NIR light treatment may act through sodium voltage-gated channel Scn4a, which may be a potential responder of NIR light to accelerate bone regeneration. Together, these findings suggest that low-intensity NIR light may promote in situ bone regeneration in a CRY1-dependent manner, providing a novel, efficient and non-invasive strategy to promote bone regeneration for clinical bone defects.

Efficacy of low-level laser therapy in oral mucosal surgical wound healing: a systematic review and meta-analysis

Aim: Wound healing is a complex phenomenon with various biological changes in tissue integrity, low-level laser therapy (LLLT) has acquired several unique components to help into accelerating tissue reconstruction and eventually wound healing. Thus, in the present systematic review and meta-analysis study, the role of LLLT in oral mucosal wound healing following surgical interventions was investigated. Methods: The study databases, including PubMed, Web of Knowledge, Google Scholar, Scopus, and Cochrane, were searched by two blinded investigators considering eligible studies based on the following keywords: “Wound Healing”, “Oral Mucosal Wound Healing”, “Laser therapy”, “Low-level laser therapy”, “Oral Surgery”, “Photobiomodulation therapy”, among 88 screened, only 12 articles were eligible for the final analysis. Results: There was a significant difference between control and laser group in all mentioned studies in the case of wound epithelialization in gingiva, with weighted mean difference (MD) of –0.28, [95% confidence interval (CI): –0.37, –0.19, P < 0.001], periodontium 1 day postoperative, with weighted MD of –0.56 (95% CI: –0.84, –0.27, P < 0.001) and 7 days postoperative, with weighted MD of –0.73 (95% CI: –0.97, –0.49, P < 0.001). In the cases of postoperative pain, LLLT has significantly declined pain in comparison with control group with weighted MD of –0.47 (95% CI: –0.69, –0.24, P < 0.001) for 7 days postoperative and –0.55 (95% CI: –0.96, –0.13, P = 0.005) 14 days postoperatively. Conclusions: LLLT can be used as a promising tool in oral surgeries because of its inevitable capability in accelerating wound healing and reducing intraoperative pain.

Implementation of Low-Level Laser Therapy in Dentistry: A Review

A type of light therapy known as low-level laser therapy (LLLT) uses only one wavelength of light. Low-level lasers (LLL) do not have a warming effect on the tissues; instead, they have an effect called photobiostimulation. LLL do not evaporate the tissue. The use of LLL to manage a range of illnesses is known as LLLT. Helium-neon lasers are an illustration of an LLLT product. Gallium arsenide, the infrared semiconductor made of gallium aluminum arsenide, is also an example. The performance powers range from 50 to 500 mW with electromagnetic spectrum wavelengths in the red and near-infrared region spanning from 630 to 980 nm and pulsed or continuous-wave emission. In periodontics, LLLT has gained prominence for several applications, including wound healing and pain relief after non-surgical and surgical procedures.

PROMs Following Root Canal Treatment and Surgical Endodontic Treatment

The FDI is currently working on developing a tool to encompass patient-reported outcome measures (PROMs) within the overall assessment of outcomes of endodontic treatment. The outcome of endodontic treatment has traditionally been determined by various clinical and radiographic criteria. However, these parameters do not address the impact of treatment on a patient's oral health-related quality of life (OHRQoL). OHRQoL, a crucial PROM, can be used to understand treatment outcome from a patient-centred perspective, thus improving clinician-patient communication whilst guiding decision-making. This focussed review aims to recount the OHRQoL of patients following nonsurgical root canal treatment and surgical endodontic treatment, with a specific focus on the minimal important difference (MID; the minimum score changes of an outcome instrument for a patient to register a clinically significant change in their OHRQoL and/or oral condition) and the methods used to determine it. The current evidence indicates that the OHRQoL of patients requiring root canal treatment is poorer than those without such need. Accordingly, the literature suggests that OHRQoL improves following nonsurgical or surgical endodontic treatment. However, study methodologies vary widely, and conclusions cannot be drawn with high confidence, nor can MID recommendations be provided. Well-designed clinical studies with baseline measurements and appropriate follow-up time frames are therefore needed. Despite that the literature is rife with outcome studies, research on PROMs is an area that deserves greater attention, particularly in relation to the MID. Determining the MID will facilitate the understanding of changes in outcome scores from the patients' perspective, thus allowing for more informed decision-making in clinical practice.

An Evaluation of the Effects of Photobiomodulation Therapy on the Peri-Implant Bone Healing of Implants with Different Surfaces: An In Vivo Study

(1) Background: This study evaluates the effects of photobiomodulation (PBM) therapy on the peri-implant bone healing of implants with a machined surface (MS) and treated surface (TS). (2) Methods: Topographic characterization of the surfaces (scanning electron microscopy [SEM]- energy dispersive X-ray spectroscopy [EDX]) was performed before and after implant removal. Twenty rabbits were randomly divided into four groups: MS and TS groups (without PBM therapy) and LMS and LTS groups (with PBM therapy). After implant placement, the stability coefficient (ISQ) was measured. In the periods of 21 and 42 days, the ISQ was measured again, followed by biomechanical analysis. (3) Results: The surfaces of the TS implants showed topographic differences compared with MS implants. The ISQ values of the LMS were statistically significant when compared with those of the MS at 42 days (p < 0.001). The removal torque values of the LMS were statistically significant when compared with those of the MS at 21 days (p = 0.023) and 42 days (p = 0.023). For SEM, in general, the LMS, TS and LTS presented high bone tissue coverage when compared to MS. (4) Conclusions: The PBM therapy modulated the osseointegration process and was evidenced mainly on the machined surface.

Effect of Ultrasonic and Diode Laser Irrigation Activation on Post-operative Pain and Microbial Reduction in Single Visit Endodontic Treatment of Necrotic Mandibular Molars

Aim: To clinically evaluate the effect of continuous ultrasonic and diode laser 810 wave length irrigation activation techniques on postoperative pain and bacterial reduction in single visit endodontic treatment of mandibular molars. Material and methods: Forty patients requiring root canal treatment therapy for necrotic mandibular molars teeth were included in this study with age ranges between 20 and 45 years. In all cases, single visit endodontic treatment was carried out using Revo-S rotary file system in crown down sequence. NaOCl 2.5% irrigation solution was used during treatment. Patients were randomly and equally assigned into two groups according to irrigation technique. Group (1): conventional syringe irrigation and group (2): continuous ultrasonic irrigation. Each group was subdivided into two sub groups (n = 10); subgroup 1A (conventional syringe irrigation with no laser), subgroup 1B (conventional syringe irrigation with diode laser), subgroup 2A (continuous ultrasonic irrigation with no laser) and subgroup 2B (continuous ultrasonic irrigation with diode laser). Postoperative pain evaluation was done using Visual Analogue Scale (VAS) at 6, 12, 24, 36, 48 hours and 7 days postoperatively. Microbiological detection of bacterial reduction was done by taking Samples (S1 and S2) for bacterial cultures. S1 after finishing access cavity and before mechanical preparation and S2 after finishing mechanical preparation and irrigation activation and before obturation. Samples were cultured on blood agar and determined as colony forming units (CFU/mL). Microbiological bacterial reduction was calculated accordingly.  Statistical analyses were analyzed using the Mann-Whitney U test.  The significance level was set at p < 0.05. Results: In all sub groups, postoperative pain decreased by time in all time intervals but pain was significantly lower in subgroup (2B) (continuous ultrasonic irrigation with diode laser) than subgroup (1A) (conventional syringe irrigation with no laser) in all time interval. Microbiological results showed the highest bacterial reduction was in subgroup (2B) (continuous ultrasonic irrigation with diode laser) and least bacterial reduction was in subgroup (1A) (conventional syringe irrigation with no laser). Conclusion: Using diode laser and continuous ultrasonic irrigation activation techniques as adjunctive methods showed improvement in postoperative pain records and enhanced bacterial reduction in root canal therapy. Keywords: Continuous ultrasonic irrigation, diode laser 810, post-operative pain, bacterial reduction, single visit endodontic treatment.

In vivo efficacy of low-level laser therapy on bone regeneration

PURPOSE

In clinical use of low-level laser therapy for bone regeneration (LLLT), application protocol (dose, duration, and repetitions) has not been established. This study aimed to depict a reliable dosage of LLLT by evaluating the efficacy of different dosing of LLLT (diode) on the healing of rabbit cranial defects.

METHODS

Critical size defects were prepared in calvarias of 26 New Zealand White Rabbits in such each animal containing both test and control groups. Test groups were irradiated with 4 Joule/cm² (j/cm²), 6 j/cm², and 8 j/cm². The rabbits were subjected to six times of laser treatments in 10 days. At the end of the second week, 5 rabbits were sacrificed for histopathological and immunohistochemical analyses. At the 4th and 8th weeks, 20 rabbits (10 each) were sacrificed for micro-CT and histopathological analyses.

RESULTS

Micro-CT evaluation revealed improved new bone formation in all test groups compared to the control group. 6 j/cm² group demonstrated the highest bone formation. The highest bone morphogenic protein -2 levels were found in the 4 j/cm² group. Osteocalcin expression was significantly higher in 4 j/cm² group.

CONCLUSIONS

Our findings indicate that LLLT have a positive effect on new bone formation. The high efficacy of doses of 4 j/cm² and 6 j/cm² is promising to promote early bone healing.

The effect of photodynamic therapy on postoperative pain in teeth with primary endodontic infection

INTRODUCTION

The objective of this study was to investigate the action of photodynamic therapy on pain control after endodontic treatment in asymptomatic teeth with a primary infection, within a single visit.

METHODS

Sixty (60) single-rooted teeth with pulp necrosis and periapical lesions were selected and randomly divided into two (2) groups (n=30), according to the protocol; a control group (CG) and a group using photodynamic therapy (aPDT). The canals were instrumented with Reciproc files # 25 up to 40 along the entire length of the canal, using 2% chlorhexidine gel as the auxiliary chemical substance, followed by irrigation with sterile saline. The canals were filled with Endomethasone N cement, 0.005% methylene blue, using AsGaAl diode laser, 660 nm wavelength, 100 mW of power and 9 J of energy, using optical fibers with 365 µm in diameter.

RESULTS

Pain intensity was assessed at 8, 12, 24, 48, 72 hours and 1 week after endodontic treatment using a visual analogue scale. The level of pain was classified as none (0), mild (1-3), moderate (4-7) or severe (8-10). The data were at a significance level of 5%. There was a statistically significant difference (p<0.05) in the periods of 8, 12, 24, 48 and 72 hours between the control group and the aPDT group. After 1 week, there was no statistically significant difference.

CONCLUSIONS

It is concluded that photodynamic therapy had a significant effect on decreasing post-endodontic treatment pain in teeth with necrotic pulp and asymptomatic periapical lesions.

Endodontic postoperative flare-up: An update

Endodontic treatment corresponds to a combined chemical and mechanical approach, followed by a three dimensional hermetic obturation, that eliminate the pulpal and periradiculare disease and boost healing and repair of periradiculare tissue. Despite the advances in the endodontic field, the inter-appointment flare up remains a true nightmare that encounters every dentist. This complication commences a few hours or days after root canal procedures and it is characterized by the development of pain and/or swelling, requiring an unscheduled appointment for emergency treatment. Different studies showed that flare-ups represent a multifactorial phenomenon including mechanical, chemical and microbial factors. In addition, a correlation was found between flare-up and age, gender, tooth type, presence of preoperative pain, tooth condition before treatment, irrigation techniques, number of visits as well as intracanal medication. Moreover, some medicine intake was proved to be efficient in controlling this postoperative pain. However, a clear procedure to avoid its occurrence is yet to be established. In this review, we summarize knowledge about the etiology of flare-up and its related factors. This could be effective in helping dentists to adapt some strategies to prevent it.

Plasma Rich in Growth Factors in the Treatment of Endodontic Periapical Lesions in Adult Patients: A Narrative Review

Platelet concentrates have been widely used in regenerative medicine, including endodontics. The aim of this manuscript was to assess critically the efficacy of PRF in the treatment of endodontic periapical lesions in adult patients on the basis of the literature. The PICO approach was used to properly develop literature search strategies. The PubMed database was analyzed with the keywords: "((PRP) OR (PRF) OR (PRGF) OR (CGF)) AND (endodontic) AND ((treatment) OR (therapy))". After screening of 155 results, 14 articles were included in this review. Different types of platelet concentrates are able to stimulate the processes of proliferation and differentiation of mesenchymal stem cells. Platelet rich fibrin (PRF) releases growth factors for at least 7 days at the application site. Growth factors and released cytokines stimulate the activity of osteoblasts. Moreover, the release of growth factors accelerates tissue regeneration by increasing the migration of fibroblasts. It was not possible to assess the efficacy of PRF supplementation in the treatment of endodontic periapical lesions in permanent, mature teeth with closed apexes, due to the lack of well-designed scientific research. Further studies are needed to analyze the effect of PRF on the healing processes in the periapical region.

Radiographic analysis of the management of tooth extractions in head and neck-irradiated patients: a case series

Tooth extraction after head and neck radiotherapy exposes patients to an increased risk for osteoradionecrosis of the jaw. This study reports the results of a radiographic analysis of bone neoformation after tooth extraction in a case series of patients who underwent radiation therapy. No patients developed osteoradionecrosis within a follow-up of 1 year. Complete mucosal repair was observed 30 days after surgery, while no sign of bone formation was observed 2 months after the dental extractions. Pixel intensity and fractal dimension image analyses only showed significant bone formation 12 months after the tooth extractions. These surgical procedures must follow a strict protocol that includes antibiotic prophylaxis and therapy and complete wound closure, since bone formation at the alveolar socket occurs at a slower pace in patients who have undergone head and neck radiotherapy.

Effect of low-level laser therapy on postoperative pain after single-visit root canal retreatment of mandibular molars: A randomized controlled clinical trial

AIM

To compare the effect of low-level laser therapy (LLLT) on postoperative pain after single-visit root canal retreatment on mandibular molars.

METHODOLOGY

This randomized controlled clinical trial included 36 patients referred to the Department of Endodontics, Islamic Azad University, Tehran, Iran. Healthy patients who required root canal retreatment on symptomatic first or second mandibular molars, with a PAI index score of 2 or 3, preoperative tooth and percussion pain of <56 mm on a 170-mm visual analogue scale (VAS) were included. After local anaesthesia using inferior alveolar nerve block followed by rubber dam isolation and access cavity preparation, the D RaCe retreatment system was used to remove the existing root filling material, and after canal negotiation and gaining patency, working length was determined with an apex locator. Further canal enlargement was carried out with size 35, 0.04 taper, and size 40, 0.04 taper RaCe rotary instruments and then canals were filled using laterally compacted gutta-percha points and AH Plus sealer. The patients were randomly assigned to treatment groups: In the LLLT group, a 980-nm diode laser set at 6.89 W/cm² energy density, 0.5 W power, and a tip diameter of 10 mm were activated from the buccal side on the mesial and distal root apices for 15 s. In the sham group, the laser handpiece was placed inside the patient's mouth at the same location, but the laser was not activated. Then patients were instructed to record their postoperative pain levels at 4, 8, 12 and 24 h and 2, 3 and 7 days after treatment on separate VAS scales. For data analysis, the independent sample t and the Mann-Whitney U tests were used. Nominal variables were analysed by using the chi-square test.

RESULTS

In the LLLT group, the most intense pain was reported 24 and 48 h post-treatment [mean (SD) = 0.22 (0.54) for both], whereas in the sham group, the most intense pain level was observed 4 h post-treatment [mean (SD) = 0.78 (0.80)]. At the 4-h interval, pain intensity was significantly lower in the LLLT group (p = .016).

CONCLUSIONS

Low-level laser therapy reduced postoperative pain after single-visit root canal retreatment of mandibular molars only four hours following the procedure.

The Effects of Photobiomodulation on Leukocyte and Platelet-Rich Fibrin as Barrier Membrane on Bone Regeneration: An Experimental Animal Study

Objective: To compare the effects of leukocyte and platelet-rich fibrin (L-PRF) and photobiomodulation therapy (PBMT)-applied L-PRF (PBMT/L-PRF) as barrier membranes on new bone formation (BV/TV) for the treatment of critical-sized bone defects. Materials and methods: The right iliac crests of five sheep were used in this experimental animal study. Eight critical-sized defects were surgically created in each sheep and a total of 40 defects were obtained. A deproteinized bovine bone graft was placed in all defects, and the defects were divided into four groups to be covered with L-PRF membrane, PBMT/L-PRF membrane, collagen membrane, or left uncovered as controls. Animals were sacrificed at 1 month. The sections obtained were histomorphometrically analyzed. Results: The results showed that the collagen group presented significantly higher values for main bone healing parameters (BV/TV, bone volume, and bone surface; p < 0.05). The PBMT/L-PRF group presented higher values than the L-PRF group and controls for these parameters though not statistically significant (p > 0.05). Conclusions: The findings show that PBMT may provide additional regenerative properties to L-PRF when used as barrier membranes. However, these results did not reach the collagen membranes, which warrants further studies for adapting the laser parameters to increase regenerative capacity of L-PRF.

Effect of low-level laser therapy on postoperative endodontic pain: An updated systematic review

OBJECTIVE

To evaluate the influence of low-level laser therapy (LLLT) on postoperative pain after endodontic treatment.

METHODS

The PICOS strategy was used to identify randomized clinical trials comparing low-level laser therapy and mock laser therapy to manage postoperative pain after endodontic treatment, retreatment, and endodontic surgery. An electronic search was performed in MEDLINE through PubMed, Web of Science, LILACS, Scopus and Cochrane Library, OpenGrey and Google Scholar. Quality assessment was performed using the Cochrane Collaboration's tool for assessing the risk of bias. The quality of evidence was rated on the basis of the GRADE approach.

RESULTS

Twelve studies were included in the qualitative synthesis. Within the 12 studies, 7 articles were classified as "low risk of bias," 4 studies were considered "unclear risk of bias" and 1 study was considered "high risk of bias." Six studies evaluated the postoperative pain after primary root canal treatment, two studies after root canal retreatment and four after periapical surgery. Most of the studies reported significantly less postoperative pain after LLLT in different time periods; two studies found no differences. The certainty of evidence was classified as low and very low to treatment / retreatment and endodontic surgery, respectively.

CONCLUSIONS

Based on the limited quality evidence, most of the included studies reported significantly less postoperative pain after LLLT. However, the lack of standardization in laser parameters, use of medications and the certainty of evidence classified as low and very low indicate the need for further studies.

B.P.F.C.® Bio-Plasma® with Pure Growth Factors (BioPlasma®) Used for the Treatment of a Persistent Great Periapical Lesion of an Endodontically Treated Tooth: A New Therapeutic Option

The aim of this case report was to evaluate the efficacy of a new platelet-rich plasma preparation and its regenerative capacity of bone periapical tissue for the treatment of a very compromised endodontic treated tooth, with a periapical lesion of 1.5 cm in diameter, using a pure platelet concentrate. This is made without the use of anticoagulant or any type of activator, e.g., bovine thrombin, calcium chloride. For this reason, it has been called "Pure"; it is the B.P.F.C.® Bio-Plasma® with Pure Growth Factors (BioPlasma®) designed and developed by Dr. Raffaello Viganò. The patient has read and signed a written consent form. The study protocol was approved by the Ethics Committee for Human Studies, University of Varese. X-ray at 2 and 6 months and 4 years after endodontic surgery demonstrated the success of the treatment.

Effectiveness of kinesio taping on postoperative morbidity after impacted mandibular third molar surgery: a prospective, randomized, placebo-controlled clinical study

Objective

Our study seeks to investigate the effectiveness of kinesio taping (KT) on postoperative morbidity compared to placebo and control groups after impacted third molar surgery.

Methodology

Sixty patients with impacted mandibular third molar were included in this prospective, randomized, placebo-controlled clinical study. After surgical extraction of the impacted tooth, patients were allocated into three groups (20 patients each): group 1 received KT (kinesio), group 2 received placebo taping (placebo), and group 3 received no taping (control). The groups were compared regarding facial swelling, pain and trismus. Swelling was evaluated using a tape measuring method. Pain was assessed by a visual analog scale and the number of analgesic tablets taken. Trismus was determined by measuring maximum mouth opening.

Results

In the KT group, all parameters reduced significantly on 2^nd and 4^th postoperative days compared to other groups; however, placebo and control groups revealed comparable outcomes. On 7^th day, all groups showed comparable results.

Conclusions

The KT application is an effective method for reducing morbidity after impacted mandibular third molar surgery. However, placebo taping is not as effective as proper taping. Placebo taping shows similar results compared to no taping regarding facial swelling percentage, pain and trismus.

Does occlusal reduction reduce post-endodontic pain? A systematic review and meta-analysis

OBJECTIVES

Pain management during endodontic therapy is an important issue in clinical practice. The objective of this systematic review and meta-analysis was to evaluate the efficacy of occlusal reduction to control the post-operative endodontic pain in adults undergoing root canal therapy.

MATERIALS AND METHODS

Electronic database and manual searches of English papers were conducted up to August 2019 to identify randomised placebo-controlled trials. The MeSH terms used were (endodontics OR root canal therapy) AND (postoperative pain) AND (occlusal reduction). The primary outcome measure was the post-operative pain intensity up to 72 hours. Pooled standardised mean differences (SMDs) and 95% confidence intervals (CIs) were calculated using random-effects inverse variance method. The statistical heterogeneity was assessed using the Cochrane Q test. The significance level was set at P < .05.

RESULTS

In total, six randomised controlled trials including 344 participants were included. Our meta-analyses showed that relief of occlusal surface did not significantly reduce the pain intensity scores at 12- (SMD = -0.46; 95% CI = -1.24, 0.30; P = .239), 24- (SMD = -0.17; 95% CI = -0.73, 0.38; P = .533) and 48- (SMD = -0.67; 95% CI = -1.38, 0.03; P = .063) when compared to placebo. However, at 72 hours, patients received intervention showed significant more pain reduction than placebo groups (SMD = -1.07; 95% CI = -1.81, -0.32; P = .005).

CONCLUSION

Based on this meta-analysis, the efficacy of occlusal reduction in post-endodontic pain control for up to 2 days is not supported. However, on day three, it had a positive influence on the control of post-endodontic pain.

Photobiomodulation in Endodontic, Restorative, and Prosthetic Dentistry: A Review of the Literature

Objective: To provide a review of the literature about the photobiomodulation therapy (PBMT) dental treatment protocols in endodontic, restorative, and prosthetic dentistry based on validated clinical studies published so far. More specifically, this study was carried out to carefully review therapeutic protocol of PBMT in clinical studies and their conclusions. Background data: The importance of using low-power lasers and photobiomodulation (PBM) is increasing in dentistry mainly due to their painless and noninvasive function. However, lack of sufficient clinical studies has led to unclear results regarding PBMT in dentistry, and also lack of an available precise protocol for clinicians. Moreover, scarcity of clinical studies in this area has made conduction of a precise systematic review study difficult. Methods: In our study, published clinical studies up to April 2019 were reviewed from library sources, Google Scholar, PubMed and Medline, Elsevier, Embase, Cochrane, Scopus, and Web of science (ISI). Inclusion criteria included those presented in clinical trials and case report/case series, language (English), and studies available in full text. Exclusion criterion was in vitro studies. Results: In general, findings of clinical studies have shown that PBMT can have a significant role in reducing postoperative dental pain, increasing depth of anesthesia, improving tooth hypersensitivity, reducing inflammation of the tissue, and helping wound healing. Conclusions: A review of clinical studies showed that the use of alternative or adjunctive PBMT is of great importance in controlling postoperative pain after endodontic treatments. In addition, evidence suggests that different parameters of light can be efficient in the treatment of tooth hypersensitivity. Nevertheless, lack of sufficient clinical studies and reliable results do not allow introducing a precise treatment protocol.

Effects of Pulsed 810 nm Al-Ga-As Diode Laser on Wound Healing Under Immunosuppression: A Molecular Insight

BACKGROUND AND OBJECTIVES

Dysregulated inflammation is one of the major contributing factors for the prevalence of non-healing chronic wound in immunosuppressed subjects. Photobiomodulation (PBM) has emerged as a potential non-thermal, light-based therapeutic healing intervention for the treatment of impaired wounds.

STUDY DESIGN/MATERIALS AND METHODS

The present study delineates the underlying molecular mechanisms of PBM 810 nm laser-induced full-thickness cutaneous wound repair in immunosuppressed rats at continuous and pulsed wave-mode with power-density of 40 mW/cm ² , fluence 22.6 J/cm ² for 10 minutes daily for 7 post-wounding days. Molecular markers were assessed using biochemical, enzyme-linked immunosorbent assay quantification, enzyme kinetics and immunoblots analyses pertaining to inflammation, oxidative stress, cell survival, calcium signaling, and proliferation cascades.

RESULTS

Results distinctly revealed that pulsed 810 nm (10 Hz) PBM potentially influenced the cell survival and proliferation signaling pathway by significantly upregulated phospho-protein kinase B(phospho-Akt), phospho-extracellular-signal-regulated kinase 1 (ERK1), transient receptor potential vanilloid-3 (TRPV3), Ca²⁺ , calmodulin, transforming growth factor-β1 (TGF-β1), TGF-βR3, and Na ⁺ /K ⁺ -ATPase pump levels. PBM treatment resulted in reduction of exaggerated inflammatory responses evident by significantly repressed levels of interleukin-1β (IL-1β), IL-6, cyclooxygenase 2 (COX-2), and substance-P receptor (SPR), as well as inhibited apoptotic cell death by decreasing p53, cytochrome C, and caspase 3 levels (P < 0.05), which, in turn, effectively augment the wound repair in immunosuppressed rats. PBM treatment also lowered 4-hydroxynoneal (HNE) adduct level and NADP/NADPH ratio and upregulated the GRP78 expression, which might culminate into reduced oxidative stress and maintained the redox homeostasis.

CONCLUSIONS

Taken together, these findings would be helpful in better understanding of the molecular aspects involved in pulsed 810 nm laser-mediated dermal wound healing in immunosuppressed rats through regulation of cell survival and proliferation via Ca²⁺ -calmodulin, Akt, ERK, and redox signaling. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.