Effects of Low-Level Laser Therapy in Orthodontic Patients on Immediate Inflammatory Response After Mini-Implants Insertion: A Preliminary Report

Low-level laser therapy combined with scleral graft transplantation in the treatment of contracted socket: a clinical study

OBJECTIVE

To analyse the efficacy of the therapeutic use of low-level laser therapy (LLLT) on the tissue repair process of allogeneic scleral grafts in patients with contracted sockets by analysing the speed of graft vascularisation and fornice depth of contraction percentage.

METHODS

A retrospective chart review was performed from April 2015 to April 2021 including 39patients with socket contraction. Allogeneic scleral grafts were used to repair the sockets in all patients. They were randomly enrolled into two groups. The laser group included 18 patients treated with LLLT after the surgery, whereas the control group included 21 patients without LLLT after the surgery who healed naturally. The LLLT equipment used in the research had a wavelength of 650 nm, 10 mW power, and 3.8 J/cm2 dosimetry, and the procedure was performed once daily for 5 min over 7 days, beginning 1 week postoperatively. All patients were followed up over 6 months to examine the changes in the size of the area of the non-vascularised graft and upper and inferior fornice depth.

RESULTS

The laser group presented a significantly increased speed of conjunctival vascularisation compared with the control group (P = 0.003). The fornice depth of contraction percentage was more apparent in the control group than that in the laser group (P = 0.000).

CONCLUSION

LLLT accelerates conjunctival vascularisation, stimulates conjunctival incision healing within a short period, shortens the tissue repair process, reduces the local inflammatory response, and causes no significant shrinkage of the conjunctival sac.

The Influence of Low-Level Laser Therapy on CBCT Radiographic and Biochemical Profiles of Type II Controlled Diabetic Patients After Dental Implant Insertion: A Randomized Case-Control Study

Background Low-level laser treatment (LLLT) was thought to increase bone quality during osseointegration when combined with dental implants. However, there is no sufficient information on its impact on dental implants in diabetics. Osteoprotegerin (OPG) has been described as a marker for bone turnover to determine implant prognosis. The current research aims to evaluate the effect of low-level laser therapy (LLLT) on bone density (BD) and osteoprotegerin levels in peri-implant crevicular fluid (PICF) in type II diabetic patients. Methods This study comprised 40 individuals with type II diabetes mellitus (T2DM). Implants were randomly placed in 20 non-lasered T2DM patients (control) and 20 lasered T2DM patients (LLLT group). At the follow-up stages, BD and OPG levels in the PICF were evaluated in both groups. Results Significant variations were shown among control and LLLT groups concerning OPG level and BD (p≤0.001). OPG was significantly decreasing with follow-up points (p≤0.001). There was a significant decrease in OPG with time in both groups with a higher decrease in the control group. Conclusion LLLT is promising in controlled T2DM patients due to its outstanding influence on BD and estimated crevicular levels of OPG. Regarding its clinical significance, LLLT significantly improved bone quality during osseointegration on dental implants in T2DM. LLLT is considered potentially important for T2DM patients during implant placement. Trial registration The study was registered on ClinicalTrial.gov under registration number NCT05279911 (registration date: March 15, 2022) (https://clinicaltrials.gov/ct2/show/NCT05279911).

The Effect of Photobiomodulation Therapy on the Stability of Orthodontic Mini-implants in Human and Animal Studies: A Systematic Review and Meta-analysis

Introduction: The present study aimed to systematically explore available literature on the possible impact of photobiomodulation (PBM) therapy on the stability and success of orthodontic mini-implants. Methods: A comprehensive electronic search was conducted in PubMed, ISI Web of Science, Scopus, Cochrane and Embase databases for human and animal studies published until July 2021. Two independent researchers reviewed the studies based on specific eligibility criteria. Results: 15 studies were included in the systematic review after a comprehensive search. Ten studies were included in the meta-analysis. Four were human RCT studies that evaluated the stability with Preriotest. Three other human RCT studies and two animal studies had evaluated the Implant stability quotient (ISQ). Two human RCTs that had evaluated displacement of mini-implants were also analyzed. The analysis of Periotest stability results showed a positive effect of PBM on mini-implant stability at 30 and 60 days after implantation (P<0.05). In human studies using the ISQ method, a slight improvement was seen in the PBM groups; however, this was not statistically significant (CI=-1.92-2.70, SMD=0.39). In studies that examined the displacement of mini-implants, no statistically significant difference was observed between irradiated and non-irradiated groups (CI=-1.92-2.70, SMD=0.03). According to the results of animal studies, which had used the ISQ method, the use of laser was statistically effective in increasing the stability of mini-implants (SMD=1.43, CI=1.00-1.85). Conclusion: PBM therapy can be suggested as an adjunctive clinical method to improve the stability of mini-implant treatment. Further well-designed clinical studies can help establish evidence-based dosing and irradiation protocols.

Buccal bone thickness of posterior mandible for microscrews implantation in molar distalization

BACKGROUND

This study explored the inter-radicular space and buccal bone thickness of the posterior mandibular region to provide an appropriate miniscrew insertion site for lower dentition distalization.

METHODS

The cone-beam computed tomographic (CBCT) records of 63 subjects were collected. Buccal bone thickness (BBT) was measured at four sections: (I) the root of the second premolar(P₁); (II) the mesial root of the first molar(P₂); (III) the distal root of the first molar(P₃); (IV) the mesial root of the second molar(P₄). The narrowest inter-radicular space of the four sections was also detected. Both BBT and inter-radicular space were measured at 4 height levels, 2, 4, 6 and 8mm from the alveolar ridge.

RESULTS

The largest BBT was observed at the mesial root of the second molar at 6 and 8mm, demonstrating a thickness of 6.77±2.50mm and 7.46±1.94mm, respectively. It provided sufficient coverage for mini-implants inserted 10°-30° oblique to the root. Therefore, during distalization of the mandibular dentition, roots have sufficient space to bypass the inclined mini-implants on the lingual side, avoiding miniscrew-root contact. The width between the mesiodistal roots of the first molar was the smallest, showing 1.53±0.69mm and 2.13±0.65mm at 4 and 6mm. Miniscrews implanted in this region had an increased risk of root proximity.

CONCLUSIONS

The most appropriate insertion site at the mandibular buccal shelf was the mesial point of the second molar at 6-8mm from the alveolar ridge, and an insertion angle of 10°-30° was recommended to avoid miniscrew-root contact. CBCT analysis is recommended before implantation due to individual differences.

Micro-CT analysis of the mandibular bone microarchitecture of rats after radiotherapy and low-power laser therapy

To investigate whether low-level laser therapy (LLLT), at different times of application (immediate and late) in the region of the parotid glands, has a distance effect on the microarchitecture of the trabecular bone in mandible of rats irradiated by volumetric modular arc therapy (VMAT). Thirty adult Wistar rats were randomly divided into placebo control groups (CG, n = 2), only radiotherapy (RG, n = 2), only LPLT (LG, n = 2), and two other groups using LLLT in the immediate time (24 h) (ILG, n = 12) and late (120 h) (LLG, n = 12) to radiotherapy by VMAT in a single dose of 12 Gy. LLLT with AsGaAl laser (660 nm, 100 mW), a spot size of 0.0028 cm², was applied in three points in the region of the right parotid gland, with energy of 2 J/cm², 20 s per point, for 10 consecutive days. After euthanasia, the right hemimandibles of each animal were dissected, prepared, and analyzed by computerized microtomography (micro-CT) and histomorphometry. The different groups were analyzed by the Tukey and Bonferroni multiple comparison tests. The micro-CT analysis found statistically significant differences between the groups, especially in the LLG, which had the highest average bone volume compared to the CG (p = 0.001) and ILG (p = 0.002) and a greater number of trabeculae than the CG (p = 0.000) and ILG (p = 0.031). The ILG also had a higher number of trabeculae than the CG (p = 0.005). Trabecula separation (Tb.Sp) was lower in the LLG (p = 0.000) and ILG (p = 0.002) when compared to the CG. In the histomorphometry, there was no statistical difference between the groups in relation to all the analyzed variables. Micro-CT analysis showed that the LLLT, even applied at a distance, both in the immediate and late VMAT times, has an effect on the mandibular bone microarchitecture by increasing the volume and number of trabeculae and decreasing the spaces between them.

Effect of photobiomodulation therapy on mini-implant stability: a systematic review and meta-analysis

The study aimed to assess trials investigating the effect of PBMT on mini-implant stability. Electronic searches of seven databases and manual search were conducted up to May 2020. Randomized controlled trials and controlled clinical trials evaluating the effect of PBMT on mini-implant stability were included. The risks of bias of individual studies were performed using ROB 2.0 and ROBINS-I-tool based on different study design. Meta-analysis was conducted to compare mini-implant stability exposed to PBMT with control ones at different time points after implantation. Among the 518 records initially identified, seven studies were included in this study. Six studies investigated low-level laser therapy (LLLT) and one study evaluated light-emitting diode (LED) therapy. Two studies were eligible for meta-analysis, which showed that LLLT significantly improved mini-implant stability 60 days after initial implantation (MD - 3.01, 95% CI range [- 4.68, - 1.35], p = 0.0004). High energy density of LLLT began to show beneficial effect on mini-implant stability as early as 3 days after implantation, while the significant effect of low energy density displayed later than 30 days after insertion. LED therapy could improve mini-implant stability after 2 months post-insertion. In conclusion, PBMT appears to be beneficial in ameliorating mini-implant stability. High energy density of LLLT might exert more rapid effect than low energy density. More high-quality clinical trials are needed to further demonstrate PBMT' effects on orthodontic mini-implants.

Effect of Low-Level Laser Therapy on Peri-Miniscrew Fluid Prostaglandin E2 and Substance P Levels: A Controlled Clinical Trial

Objective

This study aims to evaluate the effect of low-level laser therapy on peri-miniscrew fluid prostaglandin E2 (PGE2) and substance P (SP) levels during orthodontic treatment.

Methods

A total of 15 individuals were included in this study. Miniscrews were inserted to the inter-radicular region of the maxillary right and left second premolar and the first molar teeth, and diode lasers were randomly applied to the right or left side. Irradiation was performed at 940 nm wavelength using a gallium-aluminum-arsenide diode laser with 100 mW power output, 0.125 cm2 spectral area, 8 J/cm2 energy density, and 10 seconds of exposure time. Peri-miniscrew fluid samples were collected on the 1st, 3rd, and 7th days, and PGE2 and SP levels were assessed. For statistical comparison, two-way (factors) analysis of variance with repeated measurements on one-factor levels was used at statistical significance (p) of <0.05.

Results

PGE2 levels on the 1st, 3rd, and 7th days were 160.64±10.05, 135.17±37.18, and 98.57±22.94, respectively, in the control group and 150.75±9.08, 87.17±40.67, and 78.10±16.50, respectively, in the laser group. SP levels on the 1st, 3rd, and 7th days were 79.90±12.05, 64.61±10.05, and 70.05±9.10, respectively, in the control group and 76.32±11.39, 60.25±9.08, and 65.71±5.59, respectively, in the laser group. The differences in PGE2 and SP levels between the laser and control groups were not statistically significant at all time intervals.

Conclusion

Low-level laser therapy cannot be recommended as a clinical adjunct therapy to reduce inflammation and pain around the miniscrews.

Effects of low-level laser therapy on the orthodontic mini-implants stability: a systematic review and meta-analysis

Objectives

The aim of this systematic review and meta-analysis was to assess the effects of low-level laser therapy (LLLT) on the orthodontic mini-implants (OMI) stability.

Materials and methods

An unrestricted electronic database search in PubMed, Science Direct, Embase, Scopus, Web of Science, Cochrane Library, LILACS, Google Scholar, and ClinicalTrials.gov and a hand search were performed up to December 2020. Randomized clinical trials (RCTs) or non-randomized clinical trials (Non-RCTs) that assessed the effects of LLLT on the OMI stability were included. Data regarding the general information, LLLT characteristics, and outcomes were extracted. The authors performed risk of bias assessment with Cochrane Collaboration’s or ROBINS-I tool. Meta-analysis was also conducted.

Results

Five RCTs and one Non-RCT were included and 108 patients were evaluated. The LLLT characteristics presented different wavelength, power, energy density, irradiation time, and protocol duration. Five RCTs had a low risk of selection bias. Two RCTs had a low risk of performance and detection bias. All RCTs had a low risk of attrition bias, reporting bias and other bias. The Non-RCT presented a low risk of bias for all criteria, except for the bias in selection of participants. The meta-analysis revealed that LLLT significantly increased the OMI stability (p < 0.001, Cohen’s d = 0.67) and the highest clinical benefit was showed after 1 (p < 0.001, Cohen’s d = 0.75), 2 (p < 0.001, Cohen’s d = 1.21), and 3 (p < 0.001, Cohen’s d = 1.51) months of OMI placement.

Conclusions

LLLT shows positive effects on the OMI stability.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40510-021-00350-y.

Effect of 808 nm Semiconductor Laser on the Stability of Orthodontic Micro-Implants: A Split-Mouth Study

BACKGROUND

To evaluate the effect of photobiomodulation (PBM) on orthodontic micro-implants (n = 44; 14 women, 8 men).

METHODS

PBM with 808 nm diode laser was applied immediately, 3, 6, 9, 12, 15, and 30 days post the implantation. Results were assessed within same time frames and additionally after 60 days to check for implants stability using the Periotest device. Patients pain experiences following the first day post-treatment and potential loss of micro-implants after 60 days were recorded. The procedure involved insertion of mini-implants in the maxilla for the laser group (L, n = 22) and negative control group (C, n = 22). Irradiation was carried buccally and palatally with respect to the maxillary ridge (2 points). The energy per point was 4 J (8 J/cm2), total dose was 56 J.

RESULTS

Patients did not report significant differences in terms of pain experiences comparing the L and C groups (p = 0.499). At 30 days post-treatment, higher secondary stability of implants was observed in the laser group (Periotest Test Value, PTV 6.32 ± 3.62), in contrast to the controls (PTV 11.34 ± 5.76) (p = 0.004). At 60 days post-treatment, significantly higher stability was recorded in the laser group (PTV 6.55 ± 4.66) compared with the controls, PTV (10.95 ± 4.77) (p = 0.009). Conclusions: Application of the 808 nm diode laser increased secondary micro-implant stability.

Clinical Efficacy of Photobiomodulation on Dental Implant Osseointegration: A Systematic Review

Background:

Photobiomodulation (PBM) has been shown to have a positive effect on dental implant osseointegration and stability in in vitro and animal studies; however, its usefulness in dental implant clinical practice is yet unclear.

Objective:

The objective was to assess the clinical effectiveness of PBM on dental implants’ osseointegration.

Methods:

Two reviewers independently conducted a comprehensive electronic search of articles published from inception up to January 10, 2020, in PubMed, Cochrane Library and Embase databases following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Randomized clinical trials (RCTs) and nonrandomized clinical studies that compared the effect of PBM on dental implant stability with control groups were included. Animals and in vitro studies studies as well as studies with confounders such as application of orthodontic were excluded. Risk of bias (using Cochrane Risk of Bias tool for RCTs and Risk of Bias in Non-Randomized Studies of Interventions tool for nonrandomized studies) was assessed by both authors. Owing to substantial heterogeneity, only a narrative synthesis of the included studies is presented.

Results:

Seven relevant clinical studies were included, and they used a variety of PBM parameters and devices. The posterior region of the jaw was found to be more frequently evaluated. For assessing the effect of PBM on implant stability, five studies used resonance frequency analysis and two used periotest; three studies additionally used biomarkers for assessment. Four studies found that PBM has a potential positive effect on the outcome of dental implant stability, whereas three studies reported that PBM has no effect on implant stability.

Conclusion:

The findings of this systematic review suggest that postoperative application of PBM may potentially have some positive effect on dental implant’s osseointegration and stability. However, additional studies are required with uniformity in methods to provide a more robust assessment of this effect.

Fluorescence image and microbiological analysis of biofilm retained around healthy and inflamed orthodontic miniscrews

INTRODUCTION

Peri-miniscrew inflammation is one of the causes of orthodontic miniscrew failure.

OBJECTIVE

The aim of this study was to correlate and quantify throughout autofluorescence images, PCR and microbiologic count of biofilm retained around orthodontic miniscrew and the presence of Porphyromonas gingivalis.

MATERIALS AND METHODS

Forty miniscrews used for orthodontic treatment were evaluated during orthodontic treatment, collected from patients and divided into two groups: healthy and inflamed miniscrews. To be considered inflamed, the samples should present: loss of stability checked by periotest®, clinical presence of mucositis, red aspect of the gum or bleeding around the miniscrew. Immediately after removal of the miniscrews, they were photographed using a macro 100 lens and a Pentax camera coupled to a fluorescent equipment - Qscan (AioBio - Korea) with 405 nm excitation wavelength and a blue band filter. A microbiologic sample was collected with a sterile microbrush scrubbed around the miniscrew tread. Fluorescent images were analyzed with ImageJ software to quantify fluorescent intensity and fluorescent area and microbiological samples were submitted to CFU count for total contamination and q-PCR assay to quantify Porphyromonas gingivalis.

RESULTS

The results showed a good correlation between CFU count and fluorescent intensity and PCR/fluorescent area. The healthy miniscrews presented less fluorescent intensity and lower CFU count when compared to inflamed miniscrews. q-PCR analysis showed a higher number of P. gingivalis contamination around inflamed miniscrews.

CONCLUSION

Quantification of biofilm retained by miniscrew by images of autofluorescence is a simple and reliable method with great potential for clinical use to monitory inflammation around miniscrew and risk of loss.

Photobiomodulation in Periodontology and Implant Dentistry: Part 2

(Part 1 of this article can be located at www.liebertpub.com/doi/10.1089/photob.2019.4710.) Objective: Finding evidence-based treatment strategies for low-level light therapy 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 photobobiomodulatory 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 a great deal of heterogeneity in terms of study designs and most importantly in light irradiation devices and the parameters used. Due 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 low-level light therapy 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.

Photobiomodulation increases intrusion tooth movement and modulates IL-6, IL-8 and IL-1β expression during orthodontically bone remodeling

This study investigated the effects of photobiomodulation (PBM) on upper molar intrusion movement, regarding acceleration of orthodontic movement and its molecular effects. The sample consisted of 30 patients with indication of tooth intrusion for oral rehabilitation. Teeth were divided into three different groups: G1 (n = 10) pre-molars without force or laser application (control); G2 (n = 10) upper molar intrusion; and G3 (n = 10) upper molar intrusion and PBM. On PBM treated molars, the teeth were irradiated with a low-power diode laser (808 nm, 100 mW), receiving 1 J per point, density of 25 J/cm² , with application of 10 s per point, 10 points (5 per vestibular and 5 per palatal region). Orthodontic force of intrusion applied every 30 days and PBM was performed immediately, 3 and 7 days after force application for 3 months. Gingival crevicular fluid was collected at the same time periods as the laser applications and interleukins (IL) 1-β, -6 and -8 were evaluated by enzyme-linked immunosorbent assay. Clinical measures were performed monthly to verify the amount of intrusion. The levels of IL-6, IL-8 and IL-1β increased under orthodontic force (G2 and G3) when compared to control group (G1), however, the cytokines levels were significantly higher after PBM (G3). The mean intrusion velocity was 0.26 mm/month in the irradiated group (G3), average duration of 8 months vs 0.17 mm/month for the non-irradiated group (G2), average duration of 12 months. This study suggests that PBM accelerates tooth movement during molar intrusion, due to modulation of IL-6, IL-8 and IL-1β during bone remodeling.

Effect of photobiomodulation on the stability and displacement of orthodontic mini-implants submitted to immediate and delayed loading: a clinical study

The aim of this study was to evaluate the effect of photobiomodulation (PBM) on the stability and displacement of orthodontic mini-implants (MIs) submitted to loading. Forty-eight and 35 mini-implants (1.5 × 8 × 1 mm) were assessed for stability and displacement, respectively (19 patients). MIs were allocated according to the intervention in 1-PBM + immediate loading (IL), 2-PBM + delayed loading (DL) (four weeks after implantation), 3-IL only, and 4-DL only. PBM (Therapy XT, DCM) was implemented using a red emission (660 nm, 4 J/cm², 0.1 W, 20 s) immediately after implantation (day 0) and infrared emissions (808 nm; 8 J/cm², 0.1 W, 40 s) in the following appointments every 48-72 h during two weeks (days 2, 4, 7, 9, 11, and 14). Loading of 150 gF was applied during three months for all MIs. The stability was assessed by resonance frequency analysis (Osstell ISQ), and images from Cone beam computed tomography were evaluated to determine the amount of the displacement of the MI's head. MIs from the PBM groups presented lower loss of stability (P = 0.0372). When the analysis considered the loading protocol as an additional variable, group two showed the lowest loss of stability, being significantly different from groups that did not receive PBM (P = 0.0161). There was no difference between groups two and four during the period without loading (P > 0.05). DL groups presented lower loss when the effective period of loading was assessed, independently of the application of PBM (P < 0.0001). All groups showed displacement of the MIs head without significant differences (P > 0.05). DL potentiated the effect of PBM, decreasing the loss of stability.