The effect of low-level laser therapy on non-surgical periodontal treatment: a randomized controlled, single-blind, split-mouth clinical trial

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.

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.

Clinical effectiveness of adjunctive diode laser on scaling and root planing in the treatment of periodontitis: is there an optimal combination of usage mode and application regimen? A systematic review and meta-analysis

This review aims to evaluate the adjunctive clinical effectiveness of diode laser (DL) to scaling and root planing (SRP) in the treatment of periodontitis, and identify the optimal combination of usage mode and application regimen of DL. Eight electronic databases were searched up to January 2021. Probing pocket depth (PPD), clinical attachment loss (CAL), bleeding on probing (BOP), plaque index (PI), and gingival index (GI) were assessed at short-term (4-6 weeks), 3-month, and 6-month follow-ups. Based on DL usage mode, studies were divided into three groups: inside, outside pocket, and combined modes. As for application regimen, studies in each group were further subdivided into single- and multiple-session subgroups. Thirty randomized controlled trials with 825 participants were included. For inside mode, single-session DL showed significant improvements for PPD (short-term, and 3-month, p < 0.05), CAL (short-term, and 3-month, p < 0.05), PI (3- and 6-month, p < 0.05), and GI (short-term, 3-month, and 6-month, p < 0.05). For outside mode, multiple-session DL showed notable improvements for most clinical outcomes (p < 0.05). The effect of combined mode was still uncertain. Adjunctive DL had additional clinical benefits in the treatment of periodontitis. One session laser treatment is suggested when DL is applied inside pocket in future clinical practice. Meanwhile, more than one session laser treatment presents better outcomes when DL is used outside pocket. PROSPERO: CRD42020156162.

Clinical and biochemical effect of laser as an adjunct to non-surgical treatment of chronic periodontitis

Objectives

To evaluate the clinical and biochemical efficacy of laser therapy as an adjunct to non‐surgical treatment in chronic periodontitis.

Methods

A systematic search was performed through the PubMed, EMBASE, and Cochrane Library for eligible articles published as of May 2, 2020, supplemented by information search in the System for Information on Programme Literature in Europe and a manual literature search. Only randomized controlled trials (RCTs) used to compare the adjunctive use of laser and non‐surgical treatment alone with an observation period of at least 6 months were included.

Results

Sixteen RCTs with a total of 525 subjects were included. Meta‐analysis suggested that the additional use of laser to scaling and root planing (SRP) showed significant superiority over SRP alone among most of clinical parameters involved. Regarding the GCF, although volume in the laser group was lower at week 4 and 12, no significant difference was found regarding the cytokines level. Subgroup analysis revealed that the combined therapy produced no significant difference in PD, CAL and PI at most time points for studies in respect to smokers. No treatment‐related adverse events had been reported in the included studies.

Conclusions

Pooled analysis suggested that laser‐assisted non‐surgical treatment improved clinical outcome to SRP alone in the management of non‐smoking chronic periodontitis patients.

Adjunctive laser or antimicrobial photodynamic therapy to non-surgical mechanical instrumentation in patients with untreated periodontitis: A systematic review and meta-analysis

AIM

To compare the adjunctive effects of lasers or antimicrobial photodynamic therapy (aPDT) to non-surgical mechanical instrumentation alone in untreated periodontitis patients.

MATERIALS AND METHODS

Two focused questions were addressed using the Population, Intervention, Comparison and Outcome criteria as follows: in patients with untreated periodontitis, (a) does laser application provide adjunctive effects on probing pocket depth (PPD) changes compared with non-surgical instrumentation alone? and (b) does application of aPDT provide adjunctive effects on PPD changes compared with non-surgical instrumentation alone? Both randomized controlled clinical trials (RCTs) and controlled clinical trials (CCTs) were included. Results of the meta-analysis are expressed as weighted mean differences (WMD) and reported according to the PRISMA guidelines.

RESULTS

Out of 1,202 records, 10 articles for adjunctive laser and 8 for adjunctive aPDT were included. With respect to PPD changes, 1 meta-analysis including 2 articles (total n = 42; split-mouth design) failed to identify a statistically significant difference (WMD = 0.35 mm; 95%CI: -0.04/0.73; p = .08) in favour of adjunctive aPDT (wavelength range 650-700 nm). In terms of adjunctive laser application, a high variability of clinical outcomes at 6 months was noted. Two articles included patient-reported outcomes and 10 reported on the presence/absence of harms/adverse effects.

CONCLUSIONS

Available evidence on adjunctive therapy with lasers and aPDT is limited by (a) the low number of controlled studies and (b) the heterogeneity of study designs. Patient-reported benefits remain to be demonstrated.

Photobiomodulation Therapy by 820 nm Diode Laser on Nonsurgical Periodontal Treatment of Smoker and Nonsmoker Patients: A Single-Blind Parallel Randomized Clinical Trial

The effect of smoking on nonsurgical periodontal treatment (SRP) is known, but the adjunct use of photobiomodulation (PBMT) to SRP has not been fully investigated in smokers. This study aimed to assess the effect of 820 nm diode laser on SRP in smoker/nonsmoker. Sixty patients (smokers/n = 30, nonsmokers/n = 30) were enrolled in this parallel-arm clinical study. All patients were divided into two main groups: SRP and PBMT + SRP. In PMBT + SRP groups, 7.96 J cm^-2 energy was applied by 820nm diode laser at baseline and first, second and third weeks after SRP. Periodontal pocket depth (PPD), gingival index (GI), plaque index (PI) and clinical attachment level (CAL) were recorded, and also gingival crevicular fluid (GCF) samples were collected at baseline and 6w after SRP. Total antioxidant capacity (TAOC) and total oxidative status (TOS) in GCF were analyzed. PBMT + SRP groups showed a statistically significant decrease in PPD and CAL, not in GI and PI compared with SRP alone. There were no statistically significant differences between smokers and nonsmokers in clinical data at six weeks after treatment. Although TAOC levels were increased in PMBT groups, TOS levels were decreased in all groups at the comparison of baseline and 6w after SRP. Adjunct use of 820 nm diode laser on SRP may improve the clinical parameters in smoker or nonsmoker patient with periodontitis.

Bio-Inspired Systems in Nonsurgical Periodontal Therapy to Reduce Contaminated Aerosol during COVID-19: A Comprehensive and Bibliometric Review

Background: On 30 January 2020, a public health emergency of international concern was declared as a result of the new COVID-19 disease, caused by the SARS-CoV-2 virus. This virus is transmitted by air and, therefore, clinical practices with the production of contaminant aerosols are highly at risk. The purpose of this review was to assess the effectiveness of bio-inspired systems, as adjuvants to nonsurgical periodontal therapy, in order to formulate bio-inspired protocols aimed at restoring optimal condition, reducing bacteremia and aerosols generation. Methods: A comprehensive and bibliometric review of articles published in English. Research of clinical trials (RCTs) were included with participants with chronic or aggressive periodontal disease, that have compared benefits for nonsurgical periodontal therapy (NSPT). Results: Seventy-four articles have been included. For probing depth (PPD) there was a statically significant improvement in laser, probiotic, chlorhexidine groups, such as gain in clinical attachment level (CAL). Bleeding on probing (BOP) reduction was statistically significant only for probiotic and chlorhexidine groups. There were changes in microbiological and immunological parameters. Conclusions: The use of bio-inspired systems in nonsurgical periodontal treatment may be useful in reducing risk of bacteremia and aerosol generation, improving clinical, microbiological and immunological parameters, of fundamental importance in a context of global pandemic, where the reduction of bacterial load in aerosols becomes a pivotal point of clinical practice, but other clinical trials are necessary to achieve statistical validity.

Effectiveness of Photobiomodulation as an Adjunct to Nonsurgical Periodontal Therapy in the Management of Periodontitis- A Systematic Review of in vivo Human Studies

Photobiomodulation therapy (PBMT) has anti-inflammatory, analgesic and regenerative properties. This systematic review aimed to critically appraise the published data of in vivo human randomized clinical trials (RCTs), and present a comprehensive overview of the efficacy of PBMT, as an adjunct to the nonsurgical periodontal therapy (NSPT) in the management of periodontitis. The systematic review protocol is registered in the Prospective Register Of Systematic Reviews (PROSPERO) (www.crd.york.ac.uk/PROSPERO/; ref CRD 42020169108). With the help of the appropriate key words, structured electronic and manual search strategies were applied to gather the relevant published data on in vivo human RCTs based on this topic. Seventeen papers that met the eligibility criteria were included in this review and subjected to a qualitative assessment. Current evidence lacks adequate information regarding the photobiomodulation (PBM) dosimetry, which is fundamental in establishing a standardized and replicable protocol for future researches. Furthermore, substantial discrepancies in the study methodology and a high risk of bias, arising from the majority of the included papers, abet to the inferior quality of these studies. Ultimately, there is an urgent necessity to conduct further well-designed RCTs in order to determine the effectiveness of PBMT, if any, by taking into consideration the abovementioned confounding factors.

Comparison between Antimicrobial Photodynamic Therapy and Low-level laser therapy on non-surgical periodontal treatment: A Clinical Study

BACKGROUND

Alternative antibacterial therapeutic modalities, such as antimicrobial photodynamic therapy (aPDT) and low-level laser therapy (LLLT), have been proposed to improve the effectiveness of periodontal treatment. However, clinical studies evaluating the efficiency of these treatments have been inconclusive, partly due to contradictory results regarding their clinical and microbiological effects. The aim of this study was to evaluate the clinical effects of aPDT and LLLT after a one-stage full-mouth disinfection (OSFMD) protocol during periodontitis treatment.

METHODS

A split-mouth clinical trial was conducted in 20 patients presenting at least two contralateral teeth with a probing pocket depth (PD) ≥ 5 mm and bleeding on probing (BOP) on both sides of the mouth. All patients were submitted to an OSFMD protocol. The selected sites randomly received either (1) aPDT (methylene blue as a photosensitizer activated by red and infrared diode laser) or (2) LLLT (red and infrared diode laser). Clinical parameters were assessed at baseline and at 4 and 12 weeks post-treatment.

RESULTS

Both treatment protocols promoted significant reductions in PD, number of deep pockets and BOP and an increase in clinical attachment level (CAL) after 4 and 12 weeks, but there were no differences between the two groups. There was no change in the gingival level (GL) of either group for all periods of analysis. A decrease in the number of moderate pockets (4-5 mm) was found in the LLLT group (5.15 ± 4.20) when compared to the aPDT group (7.10 ± 5.24), but only after 4 weeks.

CONCLUSIONS

In conclusion, both the aPDT and LLLT therapies promoted improvements in periodontal clinical parameters after the OSFMD protocol; however, in general, there were no distinct differences between the two treatment modalities evaluated in this study.

Is low level laser therapy or ozone therapy more effective for bone healing? Understanding the mechanisms of HIF-1α, RANKL and OPG

Periodontitis is a common chronic infection of dental tissues. Ozone therapy (OT) and low level laser therapy (LLLT) are useful treatments for periodontitis. We investigated the effects of OT and LLLT on periodontal disease-induced bone destruction in rats with experimentally induced periodontitis (EP). We used 30 male Wistar rats divided into three groups: control, OT and LLLT. EP was induced by placing a 3.0 silk suture around the cervix of the left mandibular first molar tooth. OT was performed using an ozone generator at 80% concentration. LLLT was applied using a diode laser. Both OT and LLLT were performed for two weeks at two day intervals. Histomorphometric and immunohistochemical analyses also were performed. Alveolar bone loss was significantly less in the LLLT group compared to the control group. The number of HIF-1α positive cells was significantly less in the LLLT group compared to the control group. We found significantly fewer RANKL-positive cells in the OT group compared to the control group. The number of osteoprotegerin (OPG) positive cells was significantly greater for the LLLT group than for the control group. Although both treatments produced positive effects, LLLT appears to be more effective for increasing alveolar bone formation.

Examination of the Effect of the Combined Use of Nd: YAG Laser Irradiation and Mechanical Force Loading on Bone Metabolism Using Cultured Human Osteoblasts

Introduction: In recent years, laser irradiation in the near-infrared ray (NIR) area has been reported to promote bone healing. There are also reports that laser irradiation accelerates orthodontic tooth movement. In this study, we investigated the effect of NIR laser irradiation and mechanical stimulation on osteoblasts. Methods: We seeded osteoblast-like cells and laser irradiation was performed 24 hours after cell seeding. In addition, a control group not receiving anything, a group receiving only Nd: YAG (neodymium-doped yttrium aluminum garnet) laser irradiation, a group receiving only centrifugal loading, and a group receiving both Nd: YAG laser irradiation and centrifugal force loading were set, and after 24 hours and after 48 hours, cells were collected and quantitative real-time polymerase chain reaction (PCR) was performed. Results: 24 hours after laser irradiation, the gene expression of alkaline phosphatase (ALP), the receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG) was significantly higher in the 2.0 W group than in the control group. In addition, the RANKL/OPG ratio was higher in the 2.0 W group than in the control group. Also, in the group using laser irradiation and centrifugal loading in combination, 24 hours after laser irradiation, ALP and OPG showed significantly higher values than those in the centrifugal load only group. Furthermore, the RANKL/OPG ratio also showed high values. Conclusion: These results suggest that osteoblast-like cells activate genes related to bone metabolism by combining mechanical stimulation and laser irradiation. This helps to elucidate the influence of laser irradiation during tooth movement.

Photobiomodulation in Periodontology and Implant Dentistry: Part 1

(Part 2 of this article can be located at www.liebertpub.com/doi/10.1089/photob.2019.4731.) Objective: Finding evidence-based treatment strategies for low-level light therapy (LLLT) and the correct incorporation of these treatment methods in the clinical practice of periodontics. Background: Photobiomodulation has been shown to have biostimulatory, anti-inflammatory and analgesic effects that can be beneficial in periodontal and dental implant treatment procedures. Methods: In this review we have addressed some clinical questions regarding the potential clinical application of low-level light irradiation and its photobiomodulatory effects in periodontology and implantology. The literature was searched for in vivo (animal or clinical) articles written in English in four electronic databases of PubMed, Scopus, Google Scholar, and Cochrane Library until April 2019. Only studies with low irradiation doses without any thermal effects used only for their photobiomodulatory purposes were included. Results: We were able to find relevant studies for all of our questions, and positive effects for the application of light therapy were reported in most of the studies. However, there is still great deal of heterogeneity in terms of study designs and most importantly in light irradiation devices and the parameters used. Owing to this issue it was not possible to reach specific evidence-based irradiation protocols for the questions addressed in this review. Conclusions: Based on our search results, an obvious positive effect of LLLT on stimulation of healing of periodontal soft and hard tissues and reduction of inflammation can be seen. Future well-designed randomized control studies with the same irradiation settings and systematic reviews evaluating the studies found on the questions mentioned are necessary to reach evidence-based recommendations.

Indicações e tratamentos da laserterapia de baixa intensidade na odontologia: uma revisão sistemática da literatura

Introdução: O laser de baixa intensidade (LLLT – Low Level Laser Therapy) possui efeitos anti-inflamatórios, analgésicos e trófico tecidual, podendo ser aplicado em uma grande variedade de condições clínicas na odontologia. Objetivo: este estudo teve como objetivo revisar as indicações e as possibilidades de tratamento de LLLT nas diversas especialidades odontológicas. Métodos Como estratégia de busca fez-se uma pesquisa bibliográfica nas bases de dados eletrônicas MEDLINE, BSV e SCIELO para identificar estudos relevantes de 2016 a 2018. Uma combinação das seguintes palavras-chaves forai utilizada: low level laser therapy e dentistry. Estas foram combinadas através do operador boleano “AND”. Resultados: foram encontrados 37 artigos com indicação de tratamento com laser de baixa intensidade na periodontia, ortodontia, cirurgia, odontopediatria, DTM, patologia, endodontia e dentística. Conclusão: LLLT é um tratamento seguro, sem efeitos colaterais que pode ser utilizado nas especialidades odontológicas como eficaz tratamento coadjuvante aos convencionais.

Effects of Nd:YAG low-level laser irradiation on cultured human osteoblasts migration and ATP production: in vitro study

Low-level laser therapy has become one of the fastest growing fields of medicine in recent years. Many in vivo and in vitro studies have shown that laser irradiation activates a range of cellular processes in a variety of cell types and can promote tissue repair. However, few in vitro experiments have evaluated the effects of laser irradiation on cells in real time. The purpose of this study was to examine the effects of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser irradiation on the migration of cultured human osteoblasts. A dedicated 96-well plate was used, and confluent cultures of the human osteoblast-like cell line, Saos-2, were injured with a wound maker. The wounded cells were then exposed to the Nd:YAG laser (wavelength of 1064 nm) for 60 s at 0.3 W (10 pps, 30 mJ). The total energy density was about 10.34 J/cm². Images of the wounds were automatically acquired inside the CO₂ incubator by the IncuCyte ZOOM™ software. In addition, after laser irradiation, the production of adenosine triphosphate (ATP) was measured using the CellTiter-Glo™ Luminescent Cell Viability Assay. Migration of cells from the border of the original scratch zone was accelerated by laser irradiation. In addition, compared with the control group, significant enhancement of ATP production was observed in the irradiated group. The present study showed that Nd:YAG laser irradiation (wavelength of 1064 nm, 0.3 W, 10 pps, 30 mJ, 10.34 J/cm², irradiation time 60 s) may contribute to the regeneration of bone tissues owing to enhanced osteoblast cell migration.