Effects of two types of low-level laser wave lengths (850 and 630 nm) on the orthodontic tooth movements in rabbits

In Vitro Effect of Photobiomodulation Therapy with 980 nm Diode Laser on Gene Expression of Key Regulators of Bone Remodeling by Human Periodontal Ligament Cells under Mild Orthodontic Forces

This study investigated the effect of photobiomodulation (PBM) with 980 nm diode laser as monotherapy and in combination with compressive and tensile orthodontic forces on expression of osteoprotegerin (OPG), receptor activator of nuclear factor-κB ligand (RANKL), sclerostin (SOST) and periostin (POSTN), by human periodontal ligament cells. Isolated cells were cultured and subjected to either tensile (10% elongation) or compressive forces (25 g cm-2 ) for 24 and 48 h. Subsequently, the cells received PBM (100 mW power, 3 or 6 J cm-2 energy density) immediately after load cycle. RT-PCR was applied to assess the genes expression. Data were analyzed by one-way ANOVA, followed by post hoc Tukey test (P ≤ 0.05). We found that PBM in combination with orthodontic forces led to upregulation of bone resorption genes (RANKL and SOST) at the pressure side and their downregulation at the tension side. The expression of osteogenic genes (OPG and POSTN) increased at the tension side and decreased at the pressure side. PBM alone did not affect gene expression. In conclusion, these findings suggest that this PBM protocol may be effective in enhancement of the gene expression in favor of bone remodeling acceleration that should be confirmed in future animal and human studies.

Photobiomodulation therapy assisted orthodontic tooth movement: potential implications, challenges, and new perspectives

Over the past decade, dramatic progress has been made in dental research areas involving laser therapy. The photobiomodulatory effect of laser light regulates the behavior of periodontal tissues and promotes damaged tissues to heal faster. Additionally, photobiomodulation therapy (PBMT), a non-invasive treatment, when applied in orthodontics, contributes to alleviating pain and reducing inflammation induced by orthodontic forces, along with improving tissue healing processes. Moreover, PBMT is attracting more attention as a possible approach to prevent the incidence of orthodontically induced inflammatory root resorption (OIIRR) during orthodontic treatment (OT) due to its capacity to modulate inflammatory, apoptotic, and anti-antioxidant responses. However, a systematic review revealed that PBMT has only a moderate grade of evidence-based effectiveness during orthodontic tooth movement (OTM) in relation to OIIRR, casting doubt on its beneficial effects. In PBMT-assisted orthodontics, delivering sufficient energy to the tooth root to achieve optimal stimulation is challenging due to the exponential attenuation of light penetration in periodontal tissues. The penetration of light to the root surface is another crucial unknown factor. Both the penetration depth and distribution of light in periodontal tissues are unknown. Thus, advanced approaches specific to orthodontic application of PBMT need to be established to overcome these limitations. This review explores possibilities for improving the application and effectiveness of PBMT during OTM. The aim was to investigate the current evidence related to the underlying mechanisms of action of PBMT on various periodontal tissues and cells, with a special focus on immunomodulatory effects during OTM.

Effect of low-level laser therapy on orthodontic tooth movement during miniscrew-supported maxillary molar distalization in humans: a single-blind, randomized controlled clinical trial

To investigate the effect of low-level laser therapy (LLLT) on orthodontic tooth movement during maxillary molar distalization over a 12-week observation period. Twenty patients were enrolled in this clinical trial. On the 0th, 3rd, 7th, 14th, 21st, 42nd, and 63rd days following the initial activation of the distalization appliance, laser therapy was applied in a total of 16 different points of the first and second molars for 10 s per point to the randomly determined molar region of the individuals in the intervention group. The amount of molar distalization was measured using digital scans of the three-dimensional (3D) digital models obtained during the 3rd, 6th, 9th, and 12th weeks. The amount of tooth movement on the laser-applied side of subjects in the intervention group was significantly greater than those in the contralateral and control groups at all time intervals (p < 0.001). The amount of tooth movement between the contralateral side of the intervention group and the control group was determined to be statistically insignificant (p > 0.05) at all time intervals. The laser-treated molars of the subjects in the intervention group moved 1.22 times more than the molars in the contralateral side and in the control group in 12 weeks. The rate of tooth movement in the laser, contralateral, and control groups was 0.033, 0.027, and 0.027 mm/day, respectively. Although LLLT was found to be statistically significant in terms of accelerating tooth movement, the effect of LLLT is not considered to be clinically significant. This trial was retrospectively registered (September 22, 2022) at Clinical-Trials.gov (Ref no: NCT05550168).

Predictability of Invisalign® Clear Aligners Using OrthoPulse®: A Retrospective Study

This preliminary retrospective study evaluates how effective the OrthoPulse^® (Biolux Technology, Austria) is in increasing the predictability of orthodontic treatment in patients treated with Invisalign^® clear aligners (Align Technology Inc., Tempe, AZ, USA). A group of 376 patients were treated with Invisalign^® orthodontic clear aligners in association with an OrthoPulse^®. The OrthoPulse^® was prescribed for 10 min a day for the entire duration of the orthodontic treatment. The OrthoPulse^® App remotely tracked the percentage compliance of each patient. The number of aligners planned with the ClinCheck software at the beginning of the treatment and the number of total aligners (including the adjunctive aligners) used to finish the treatment were then considered. After applying inclusion/exclusion criteria, a total of 40 patients remained in the study and were compared with a control group of 40 patients with the same characteristics as the study group. A statistical analysis was carried out to investigate whether using OrthoPulse^® led to a statistical reduction in the number of adjunctive aligners, thus leading to a more accurate prediction of the treatment. The statistical analysis showed that patients who used OrthoPulse^® needed fewer finishing aligners and a greater predictability of the treatment was obtained. In fact, in the treated group the average number of additional aligners represented 66.5% of the initial aligners, whereas in the control group 103.4% of the initially planned aligners were needed. In conclusion, in patients treated with clear aligners, OrthoPulse^® would appear to increase the predictability of orthodontic treatment with clear aligners, thus reducing the number of finishing phase requirements.

The Effect of Photobiomodulation Therapy in Different Doses on Bone Repair of Critical Size Defects in Rats: A Histomorphometric Study

Introduction: 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. Methods: 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%. Results: 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. Conclusion: 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.

Efficacy of Laser Photobiomodulation in Accelerating Orthodontic Tooth Movement in Children: A Systematic Review with Meta-analysis

AIM AND BACKGROUND

This systematic review aimed to investigate the efficacy of laser photobiomodulation (PBM) on the acceleration of orthodontic tooth movement (OTM).

REVIEW METHODS

The study protocol was registered at PROSPERO (CRD42019121465). An extensive electronic search for randomized control trials and clinical control trials via Medline (via PubMed), The Cochrane Controlled Clinical Trials Register, and Scopus up to date 24/02/2019 was done. Hand searching was performed for relevant journals. Reference articles were retrieved and exported to Mendeley Desktop 1.13.3 software. The risk of bias was assessed using the Cochrane risk of the bias assessment tool. Articles were further analyzed using Revman5.3 software.

RESULTS

A total of 14 articles were considered for systematic review and 9 articles were considered for meta-analysis. The results of the meta-analysis showed a significant difference between the laser group and conventional orthodontic treatment with Forest plots showing more tooth movement in the laser group compared to the control group in 2-3 months (mean difference = 1.73; CI: 0.9-2.57; p = 0.00001; I ² = 89 %).

CONCLUSION

Although the analysis of the results shows that laser PBM favors OTM, the results are inconclusive as the heterogeneity across studies was high.

CLINICAL SIGNIFICANCE

Laser PBM may be considered as novel, safe, and noninvasive adjuvant therapy for the acceleration of OTM in children.

HOW TO CITE THIS ARTICLE

Yavagal CM, Matondkar SP, Yavagal PC. Efficacy of Laser Photobiomodulation in Accelerating Orthodontic Tooth Movement in Children: A Systematic Review with Meta-analysis. Int J Clin Pediatr Dent 2021;14(S-1):S94-S100.

Three-dimensional imaging and molecular analysis of the effects of photobiomodulation and mechanical vibration on orthodontic retention treatment in rats : Effects of photobiomodulation and mechanical vibration on orthodontic retention treatment

PURPOSE

We aimed to evaluate and compare effects of photobiomodulation (PBM) and low-magnitude high-frequency mechanical vibration (HFMV) on orthodontic retention.

METHODS

Sixty-four female Wistar albino rats were divided into 9 groups (2 negative and positive controls each, 3 PBM and 2 HFMV groups) and studied for 25 days. In the experimental groups, closed nickel-titanium closed coil springs with a 50 cN force were placed for 10 days between the maxillary incisor and molar. PBM and HFMV were applied daily over long- (15 days) and short-term (7 days) retention periods. The PBM groups received PBM with a single wavelength (650 nm) or higher wavelengths (532, 650, 940 nm) for 9 min per day. HFMV groups received HFMV of 10, 20, and 30 Hz for 10 min per day. Right and left maxilla were assessed using micro-computed tomography imaging and real-time polymerase chain reaction. The amount of tooth movement during the retention period, expression levels of cyclooxygenase‑2 (COX-2), osteoprotegerin (OPG), and receptor activator of nuclear factor-kappa B ligand (RANKL) mRNA gene expression levels, OPG/RANKL ratios, alveolar bone trabecular thickness (Tb.Th), trabecular number (Tb.N), and structure model index were analyzed. Kruskal-Wallis and Mann-Whitney U tests were used for multiple comparisons of the nonparametric distributed data and binary comparisons, respectively.

RESULTS

When using the long-term retention protocol, PBM and HFMV treatment increased Tb.N (p < 0.05) and decreased COX‑2 mRNA gene expression levels (p < 0.05) and Tb.Th (p < 0.05) compared to controls. For short-term retention, PBM and HFMV decreased the amount of relapse tooth movement compared to controls. In addition, Tb.Th (p < 0.05) and the mRNA gene expression levels of COX‑2 and RANKL (p < 0.05) were decreased.

CONCLUSION

PBM and HFMV might be able to support retention after orthodontic tooth movement by reducing bone resorption and increasing bone quality.

Evaluation of the effects of diode laser application on experimental orthodontic tooth movements in rats. Histopathological analysis

Purpose:

To evaluate the effect of diode laser use on experimental orthodontic tooth movements.

Methods:

Thirty Rattus norvegicus albinus Wistar were divided into three equal groups (n = 10), two experimentals and one control. Applying 20 g orthodontic force were attached to the maxillary incisors of the rats in all groups. Low dose laser was applied to the surrounding tissues of the maxillary incisors of the rats in the experimental groups. Two exposure times for laser irradiation were used for seven days: t = 12 min (energy dose = 72 J) and t = 9 min (energy dose = 54 J) by a 0.1 W DEKA brand diode laser with wavelength of 980 nm.

Results:

Osteoclastic activation increased in the 72 J group when compared to control group and decreased in comparison to the 54 J group. Osteoblastic activation was decreased in the 72 J group when compared to the control group and increased in comparison to the 54 J group.

Conclusions:

Applying 54 J laser energy has been found effective to accelerate the orthodontic tooth movement.

Evaluation of Efficacy of Low-Level Laser Therapy

Introduction: Given the inconsistencies in the literature regarding laser performance in non-surgical treatments, this study investigated the available literature to determine the advantages and disadvantages of low-power lasers in treating non-surgical complications and diseases. Methods: Authentic information from articles was extracted and evaluated to assess low-power laser performance for non-surgical treatments. A systematic search of studies on low-level laser therapy (LLLT) for non-surgical treatments was conducted mainly in PubMed and google scholar articles. Results: Four categories of diseases, including brain-related diseases, skin-related diseases, cancers, and bone-related disorders, which were treated by LLLT were identified and introduced. The various types of LLLT regarding the studied diseases were discussed. Conclusion: Positive aspects of LLLT versus a few disadvantages of its application imply more investigation to find better and efficient new methods.

Efficacy of Laser Photobiomodulation in Accelerating Orthodontic Tooth Movement in Children: A Systematic Review with Meta-analysis

AIM AND BACKGROUND

This systematic review aimed to investigate the efficacy of laser photobiomodulation (PBM) on the acceleration of orthodontic tooth movement (OTM).

REVIEW METHODS

The study protocol was registered at PROSPERO (CRD42019121465). An extensive electronic search for randomized control trials and clinical control trials via Medline (via PubMed), The Cochrane Controlled Clinical Trials Register, and Scopus up to date 24/02/2019 was done. Hand searching was performed for relevant journals. Reference articles were retrieved and exported to Mendeley Desktop 1.13.3 software. The risk of bias was assessed using the Cochrane risk of the bias assessment tool. Articles were further analyzed using Revman5.3 software.

RESULTS

A total of 14 articles were considered for systematic review and 9 articles were considered for meta-analysis. The results of the meta-analysis showed a significant difference between the laser group and conventional orthodontic treatment with Forest plots showing more tooth movement in the laser group compared to the control group in 2-3 months (mean difference = 1.73; CI: 0.9-2.57; p = 0.00001; I 2 = 89 %).

CONCLUSION

Although the analysis of the results shows that laser PBM favors OTM, the results are inconclusive as the heterogeneity across studies was high.

CLINICAL SIGNIFICANCE

Laser PBM may be considered as novel, safe, and noninvasive adjuvant therapy for the acceleration of OTM in children.

HOW TO CITE THIS ARTICLE

Yavagal CM, Matondkar SP, Yavagal PC. Efficacy of Laser Photobiomodulation in Accelerating Orthodontic Tooth Movement in Children: A Systematic Review with Meta-analysis. Int J Clin Pediatr Dent 2021;14(S-1):S94-S100.

Efficacy of Laser Photobiomodulation in Accelerating Orthodontic Tooth Movement in Children: A Systematic Review with Meta-analysis

AIM AND BACKGROUND

This systematic review aimed to investigate the efficacy of laser photobiomodulation (PBM) on the acceleration of orthodontic tooth movement (OTM).

REVIEW METHODS

The study protocol was registered at PROSPERO (CRD42019121465). An extensive electronic search for randomized control trials and clinical control trials via Medline (via PubMed), The Cochrane Controlled Clinical Trials Register, and Scopus up to date 24/02/2019 was done. Hand searching was performed for relevant journals. Reference articles were retrieved and exported to Mendeley Desktop 1.13.3 software. The risk of bias was assessed using the Cochrane risk of the bias assessment tool. Articles were further analyzed using Revman5.3 software.

RESULTS

A total of 14 articles were considered for systematic review and 9 articles were considered for meta-analysis. The results of the meta-analysis showed a significant difference between the laser group and conventional orthodontic treatment with Forest plots showing more tooth movement in the laser group compared to the control group in 2-3 months (mean difference = 1.73; CI: 0.9-2.57; p = 0.00001; I 2 = 89 %).

CONCLUSION

Although the analysis of the results shows that laser PBM favors OTM, the results are inconclusive as the heterogeneity across studies was high.

CLINICAL SIGNIFICANCE

Laser PBM may be considered as novel, safe, and noninvasive adjuvant therapy for the acceleration of OTM in children.

HOW TO CITE THIS ARTICLE

Yavagal CM, Matondkar SP, Yavagal PC. Efficacy of Laser Photobiomodulation in Accelerating Orthodontic Tooth Movement in Children: A Systematic Review with Meta-analysis. Int J Clin Pediatr Dent 2021;14(S-1):S94-S100.

Efficacy of Laser Photobiomodulation in Accelerating Orthodontic Tooth Movement in Children: A Systematic Review with Meta-analysis

AIM AND BACKGROUND

This systematic review aimed to investigate the efficacy of laser photobiomodulation (PBM) on the acceleration of orthodontic tooth movement (OTM).

REVIEW METHODS

The study protocol was registered at PROSPERO (CRD42019121465). An extensive electronic search for randomized control trials and clinical control trials via Medline (via PubMed), The Cochrane Controlled Clinical Trials Register, and Scopus up to date 24/02/2019 was done. Hand searching was performed for relevant journals. Reference articles were retrieved and exported to Mendeley Desktop 1.13.3 software. The risk of bias was assessed using the Cochrane risk of the bias assessment tool. Articles were further analyzed using Revman5.3 software.

RESULTS

A total of 14 articles were considered for systematic review and 9 articles were considered for meta-analysis. The results of the meta-analysis showed a significant difference between the laser group and conventional orthodontic treatment with Forest plots showing more tooth movement in the laser group compared to the control group in 2-3 months (mean difference = 1.73; CI: 0.9-2.57; p = 0.00001; I 2 = 89 %).

CONCLUSION

Although the analysis of the results shows that laser PBM favors OTM, the results are inconclusive as the heterogeneity across studies was high.

CLINICAL SIGNIFICANCE

Laser PBM may be considered as novel, safe, and noninvasive adjuvant therapy for the acceleration of OTM in children.

HOW TO CITE THIS ARTICLE

Yavagal CM, Matondkar SP, Yavagal PC. Efficacy of Laser Photobiomodulation in Accelerating Orthodontic Tooth Movement in Children: A Systematic Review with Meta-analysis. Int J Clin Pediatr Dent 2021;14(S-1):S94-S100.

Efficacy of Laser Photobiomodulation in Accelerating Orthodontic Tooth Movement in Children: A Systematic Review with Meta-analysis

AIM AND BACKGROUND

This systematic review aimed to investigate the efficacy of laser photobiomodulation (PBM) on the acceleration of orthodontic tooth movement (OTM).

REVIEW METHODS

The study protocol was registered at PROSPERO (CRD42019121465). An extensive electronic search for randomized control trials and clinical control trials via Medline (via PubMed), The Cochrane Controlled Clinical Trials Register, and Scopus up to date 24/02/2019 was done. Hand searching was performed for relevant journals. Reference articles were retrieved and exported to Mendeley Desktop 1.13.3 software. The risk of bias was assessed using the Cochrane risk of the bias assessment tool. Articles were further analyzed using Revman5.3 software.

RESULTS

A total of 14 articles were considered for systematic review and 9 articles were considered for meta-analysis. The results of the meta-analysis showed a significant difference between the laser group and conventional orthodontic treatment with Forest plots showing more tooth movement in the laser group compared to the control group in 2-3 months (mean difference = 1.73; CI: 0.9-2.57; p = 0.00001; I 2 = 89 %).

CONCLUSION

Although the analysis of the results shows that laser PBM favors OTM, the results are inconclusive as the heterogeneity across studies was high.

CLINICAL SIGNIFICANCE

Laser PBM may be considered as novel, safe, and noninvasive adjuvant therapy for the acceleration of OTM in children.

HOW TO CITE THIS ARTICLE

Yavagal CM, Matondkar SP, Yavagal PC. Efficacy of Laser Photobiomodulation in Accelerating Orthodontic Tooth Movement in Children: A Systematic Review with Meta-analysis. Int J Clin Pediatr Dent 2021;14(S-1):S94-S100.

Efficacy of Laser Photobiomodulation in Accelerating Orthodontic Tooth Movement in Children: A Systematic Review with Meta-analysis

AIM AND BACKGROUND

This systematic review aimed to investigate the efficacy of laser photobiomodulation (PBM) on the acceleration of orthodontic tooth movement (OTM).

REVIEW METHODS

The study protocol was registered at PROSPERO (CRD42019121465). An extensive electronic search for randomized control trials and clinical control trials via Medline (via PubMed), The Cochrane Controlled Clinical Trials Register, and Scopus up to date 24/02/2019 was done. Hand searching was performed for relevant journals. Reference articles were retrieved and exported to Mendeley Desktop 1.13.3 software. The risk of bias was assessed using the Cochrane risk of the bias assessment tool. Articles were further analyzed using Revman5.3 software.

RESULTS

A total of 14 articles were considered for systematic review and 9 articles were considered for meta-analysis. The results of the meta-analysis showed a significant difference between the laser group and conventional orthodontic treatment with Forest plots showing more tooth movement in the laser group compared to the control group in 2-3 months (mean difference = 1.73; CI: 0.9-2.57; p = 0.00001; I 2 = 89 %).

CONCLUSION

Although the analysis of the results shows that laser PBM favors OTM, the results are inconclusive as the heterogeneity across studies was high.

CLINICAL SIGNIFICANCE

Laser PBM may be considered as novel, safe, and noninvasive adjuvant therapy for the acceleration of OTM in children.

HOW TO CITE THIS ARTICLE

Yavagal CM, Matondkar SP, Yavagal PC. Efficacy of Laser Photobiomodulation in Accelerating Orthodontic Tooth Movement in Children: A Systematic Review with Meta-analysis. Int J Clin Pediatr Dent 2021;14(S-1):S94-S100.

Efficacy of Laser Photobiomodulation in Accelerating Orthodontic Tooth Movement in Children: A Systematic Review with Meta-analysis

AIM AND BACKGROUND

This systematic review aimed to investigate the efficacy of laser photobiomodulation (PBM) on the acceleration of orthodontic tooth movement (OTM).

REVIEW METHODS

The study protocol was registered at PROSPERO (CRD42019121465). An extensive electronic search for randomized control trials and clinical control trials via Medline (via PubMed), The Cochrane Controlled Clinical Trials Register, and Scopus up to date 24/02/2019 was done. Hand searching was performed for relevant journals. Reference articles were retrieved and exported to Mendeley Desktop 1.13.3 software. The risk of bias was assessed using the Cochrane risk of the bias assessment tool. Articles were further analyzed using Revman5.3 software.

RESULTS

A total of 14 articles were considered for systematic review and 9 articles were considered for meta-analysis. The results of the meta-analysis showed a significant difference between the laser group and conventional orthodontic treatment with Forest plots showing more tooth movement in the laser group compared to the control group in 2-3 months (mean difference = 1.73; CI: 0.9-2.57; p = 0.00001; I 2 = 89 %).

CONCLUSION

Although the analysis of the results shows that laser PBM favors OTM, the results are inconclusive as the heterogeneity across studies was high.

CLINICAL SIGNIFICANCE

Laser PBM may be considered as novel, safe, and noninvasive adjuvant therapy for the acceleration of OTM in children.

HOW TO CITE THIS ARTICLE

Yavagal CM, Matondkar SP, Yavagal PC. Efficacy of Laser Photobiomodulation in Accelerating Orthodontic Tooth Movement in Children: A Systematic Review with Meta-analysis. Int J Clin Pediatr Dent 2021;14(S-1):S94-S100.

Efficacy of Laser Photobiomodulation in Accelerating Orthodontic Tooth Movement in Children: A Systematic Review with Meta-analysis

AIM AND BACKGROUND

This systematic review aimed to investigate the efficacy of laser photobiomodulation (PBM) on the acceleration of orthodontic tooth movement (OTM).

REVIEW METHODS

The study protocol was registered at PROSPERO (CRD42019121465). An extensive electronic search for randomized control trials and clinical control trials via Medline (via PubMed), The Cochrane Controlled Clinical Trials Register, and Scopus up to date 24/02/2019 was done. Hand searching was performed for relevant journals. Reference articles were retrieved and exported to Mendeley Desktop 1.13.3 software. The risk of bias was assessed using the Cochrane risk of the bias assessment tool. Articles were further analyzed using Revman5.3 software.

RESULTS

A total of 14 articles were considered for systematic review and 9 articles were considered for meta-analysis. The results of the meta-analysis showed a significant difference between the laser group and conventional orthodontic treatment with Forest plots showing more tooth movement in the laser group compared to the control group in 2-3 months (mean difference = 1.73; CI: 0.9-2.57; p = 0.00001; I 2 = 89 %).

CONCLUSION

Although the analysis of the results shows that laser PBM favors OTM, the results are inconclusive as the heterogeneity across studies was high.

CLINICAL SIGNIFICANCE

Laser PBM may be considered as novel, safe, and noninvasive adjuvant therapy for the acceleration of OTM in children.

HOW TO CITE THIS ARTICLE

Yavagal CM, Matondkar SP, Yavagal PC. Efficacy of Laser Photobiomodulation in Accelerating Orthodontic Tooth Movement in Children: A Systematic Review with Meta-analysis. Int J Clin Pediatr Dent 2021;14(S-1):S94-S100.

Effects of 405-, 532-, 650-, and 940-nm wavelengths of low-level laser therapies on orthodontic tooth movement in rats

Background

Investigating the effects of 405-nm, 532-nm, 650-nm, and 950-nm wavelengths of LLLTs (low-level laser therapies) on the orthodontic tooth movement in rats by using histological and immunohistochemical methods. Forty-five Wistar albino rats were randomly divided into 5 groups: control group (positive control: the left maxillary 1st molar side; negative control: the right maxillary 1st molar side), 405 nm LLLT group (Realpoo), 532 nm LLLT group (Realpoo), 650 nm LLLT group (Realpoo), and 940 nm LLLT group (Biolase). The left maxillary 1st molar teeth of all rats were applied mesially 50-g force. Starting from the 1st day, 48 h intervals, LLLT was applied in continuous wave mode and in contact with the tissue. The application area was approximately 1 cm². The lasers were performed for 3 min on each surface (buccal, palatal, mesial), totally 9 min (total dose 54 J/cm²). The amount of the molar mesialization, the bone area between the roots, PDL (periodontal ligament) measurements, TRAP (tartrate-resistant acid phosphatase), and ALP (alkaline phosphatase) immunoreactivity intensity were calculated.

Results

The amount of the molar mesialization was significantly higher in the 650 nm LLLT group (mean 0.878 ± 0.201 mm; 95% CI (confidence interval) 0.724 and 1.032) than in the groups of positive control (mean 0.467 ± 0.357 mm; 95% CI 0.192 and 0.741) and 405 nm LLLT (mean 0.644 ± 0.261 mm; 95% CI 0.443 and 0.845) (p < 0.001). There were significant differences in the PDL-mesial (p = 0.042) and PDL-distal (p = 0.007) regions between the groups. The immunoreactivity intensity for TRAP-mesial was significantly higher in the positive control group (mean 109,420.33 ± 8769.17; 95% CI 100,217.65 and 118,623.02) than in the 405 nm (mean 91,678.83 ± 7313.39; 95% CI 84,003.9 and 99,353.77) and the 650 nm LLLT (mean 87,169.17 ± 4934.65; 95% CI 81,990.56 and 92,347.77) groups (p = 0.002). There was no statistically significant difference between the groups on immunoreactivity intensity with ALP staining.

Conclusions

The results of this study show that LLLT with 650-nm wavelength increases orthodontic tooth movement more than 405-nm, 532-nm, and 940-nm LLLTs. The 940-nm and 650-nm LLLTs also increase the bone area between the roots by more than 405-nm and 532-nm wavelengths.

Outcome of photodynamic therapy on orthodontic leveling and alignment of mandibular anterior segment: A controlled clinical trial

BACKGROUND

Photodynamic therapy (PDT) is a non-invasive approach that has drawn attention to accelerate orthodontic tooth movement (OTM). However, no studies have been published that evaluates the outcome of PDT on orthodontic leveling and alignment. Therefore, the present study aimed to evaluate outcome of PDT on orthodontic leveling and alignment of mandibular anterior segment.

MATERIALS AND METHODS

Thirty patients (18 females and 12 males) were included who had moderate mandibular crowding with average age was 19.23 ± 3.1 years. They were randomly divided into a control group without PDT intervention and a laser group. All patients followed non-extraction approach using one category of fixed appliance and matching NiTi archwire sequence for 3 months. In PDT group, methylene blue mediated gallium aluminum arsenide laser was applied with 635 nm, 6.5 J/cm², for 10 s at 10 points (0.2 J/point) started immediately after first wire then at days 3,7,14 of first month and repeated for additional 2 months. Relief of crowding was assessed by Little`s irregularity index (LII) scores after 4, 8, and 12 weeks through scanned 3-dimensional models via a software.

RESULTS

Both groups showed improvements in mandibular crowding as evidenced by significant decreases (p ≤ 0.001) in LII scores during all observation intervals with no significant differences (p > 0.05). Moreover, the alignment`s rate showed no significant differences between groups.

CONCLUSION

PDT produced a negligible effect concerning alignment of crowded mandibular anterior teeth. Besides, OTM's rate at different observation intervals showed an equivalent pattern either with or without PDT.

Comparison of rate of orthodontic tooth movement in adolescent patients undergoing treatment by first bicuspid extraction and en-mass retraction, associated with low level laser therapy in passive self-ligating and conventional brackets: A randomized controlled trial

BACKGROUND

Low Level Laser Therapy (LLLT) is one of the various interventions to accelerate the rate of Orthodontic Tooth Movement (OTM) in adolescent patients who are undergoing en-mass retraction after all first bicuspid extractions.

OBJECTIVES

To assess the efficacy of LLLT in increasing the rate of OTM.

MATERIALS AND METHODS

Setting and sample population: Institutional Department of Orthodontics and Dentofacial Orthopaedics. Participants, study design and methods: 65 Patients requiring all first premolar extractions were randomly allocated to three groups. Two groups (Comprising of passive self-ligating brackets and conventional brackets) were treated with LLLT and one group served as the control (conventional brackets). The allocation ratio was 1:1:1.32. Eligibility criteria: adolescent patients with sound and healthy permanent dentition with Little's Irregularity Index<5mm.

MAIN OUTCOME

rate of tooth movement in mm/month. Randomization and blinding: computer-generated random allocation sequence; only the data analyser was blinded by coding the digital models. Patients were reviewed once every month till the completion of space closure.

STATISTICS

data normality was checked using Shapiro-Wilks test and Q-Q Plot. Parametric tests were applied for the inferential statistics (ANCOVA) with Dunnett's t test being used for post hoc analysis.

RESULTS

There was a statistically significant enhancement in the rate of OTM in the 2 experimental groups (0.68/0.67mm/month in the right and left side of the maxilla and 0.66/0.65mm/month in the right and left side of the mandible) when compared with the control group (0.48mm/month in the maxilla and 0.48mm/month in the mandible) (P<0.05), but when the 2 experimental groups were compared no difference was observed (P>0.05). No serious harms were reported.

CONCLUSION

A significant increase in the rate of OTM was observed with the application of LLLT. No difference was observed in the rate of OTM when comparing different ligation methods treated with LLLT.

REGISTRATION

National Trial Registry (CTRI No- CTRI/2018/04/013156). Protocol was not published before trial commencement.

Influence of low-level laser (LLL) on interleukin 6 (IL-6) levels in gingival crevicular fluid (GCF) during orthodontic tooth movement of periodontally affected rabbits

AIM

To evaluate the effects of LLL on IL-6 levels in the GCF and the Probing Pocket Depth measurements (PPD) during orthodontic tooth movement in periodontally affected rabbits.

METHODS

Twenty-four rabbits were divided into 3 groups: Group 1(G1), healthy rabbits with orthodontic movement, Group 2(G2) periodontally affected rabbits and orthodontic movement, Group 3(G3) periodontally affected rabbits with orthodontic movement and LLL therapy. A 0.014 stainless steel spring was inserted in the upper central incisors to produce 60gm force. Laser CAT 500 was applied for 3min/day for 2 weeks. PPD measurements were obtained at base line and after 14 days with electronic periodontal probe.

RESULTS

IL-6 levels increased gradually after application of orthodontic force, afterwards the 8^th day, a significant difference in the Il-6 levels between G1 vs. G2 and G2 vs. G3 was observed. PPD measurements showed significant difference between the three groups at base line and after 14 days.

CLINICAL SIGNIFICANCE

LLL application can enhance periodontal ligament regeneration and decrease the periodontal tissue destruction through suppression of IL-6 levels.

Effects of Different Parameters of Diode Laser on Acceleration of Orthodontic Tooth Movement and Its Effect on Relapse: An Experimental Animal Study

AIM:

Recent studies have demonstrated that low-level laser therapy (LLLT) can accelerate orthodontic tooth movement. However, there is still controversy about the optimum parameters that can cause acceleration. The present study was designed to examine two different doses of LLLT in the acceleration of orthodontic tooth movement and their effect on relapse.

METHODS:

An orthodontic appliance was designed to induce tooth movement on lower incisors of rabbits. The in-al-as diode laser was used to radiate different groups of rabbits according to a specific protocol. The amount of tooth movement was measured for 21 days, and then the orthodontic appliance was removed, and the relapse was measured till day 28.

RESULTS:

The amount of tooth movement was significantly greater in the group with irradiation of low dose in comparison with the high dose group and the control group. The relapse was greatest in the group of low dose irradiation and least in the control group.

CONCLUSION:

The findings suggest that LLLT with a low dose accelerate the orthodontic tooth movement while LLLT with a high dose was not able to have the same effect. LLLT had a reverse effect on relapse tendency; an increase in the relapse tendency was seen with low dose irradiation.

The effect of low-level laser therapy on orthodontically induced root resorption: a pilot double blind randomized controlled trial

Background

The effect of low-level laser therapy (LLLT) on accelerating orthodontic tooth movement has been extensively studied; however, there is limited knowledge on the use of LLLT on orthodontic root resorption.

Objective

To investigate the effect of LLLT on orthodontically induced inflammatory root resorption (OIIRR) and to compare the difference between pulsed and continuous LLLT on OIIRR.

Trial design

Double-blind, single-centre 3-arm parallel split-mouth randomized controlled trial.

Participants

Twenty adolescent patients who required bilateral maxillary first premolar (MFP) orthodontic extractions were recruited from the Sydney Dental Hospital between October 2014 and December 2014.

Intervention

All MFPs were tipped buccally for 28 days to induce OIIRR. The experimental premolars (n = 20) received LLLT and the control premolars (n = 20) received placebo-laser on days 0, 1, 2, 3, 7, 14, and 21. Ten experimental premolars received LLLT via continuous delivery and 10 received pulsed delivery.

Laser parameter

AlGaAs diode laser of 808 nm wavelength, 0.18 W power, 1.6 J per point, and duration of 9s for continuous mode and 4.5 s for pulsed mode.

Outcome

The difference in root resorption crater volume between LLLT and placebo-laser and continuous or pulsed laser delivery after 28 days.

Randomization

Randomization was computer-generated, with allocation concealment by opaque sequentially numbered sealed envelopes.

Blinding

The participants and operator were blinded.

Results

Eighty-eight patients were screened and 20 patients were randomized. Forty premolars were analysed. LLLT resulted in 23 per cent less root resorption compared to the placebo (P = 0.026). Pulsed laser delivery resulted in 5 per cent less root resorption than continuous; however, this was not statistically significant (P = 0.823). No harm was observed.

Conclusion

Teeth treated with LLLT had less total root resorption than placebo-laser. Furthermore, there was minimal difference between pulsed or continuous delivery of LLLT.

Trial Registration

Clinical Trials Registry (ACTRN12616000829415).

Protocol

The protocol was not published before trial commencement.

Effect of Low-level Laser Therapy on Orthodontic Movement of Human Canine: a Systematic Review and Meta-analysis of Randomized Clinical Trials

Background:

Low-level Laser Therapy (LLLT) is a noninvasive method of accelerating tooth movement. Herein, this meta-analysis was aimed to assess the efficacy of LLLT in accelerating orthodontic tooth movement of human maxilla or mandible canine.

Methods:

Five databases including Web of Science, Scopus, PubMed, ScienceDirect, and Cochrane Library were used for searching the studies. Studies on LLLT for orthodontic tooth movement of human canine, randomized clinical trial (RCT), and outcome variables such as distance or speed of the tooth movement in treatment duration were considered for the final analysis. RevMan 5.3 was used for calculating the mean difference (MD) and 95% confidence intervals (CIs) on random-effects model.

Results:

Out of 275 studies retrieved from five databases, six RCTs were included and analyzed in this meta-analysis. The results showed that the orthodontic movement of canine was statistically increased in the LLLT group compared with the control group in 21 days (MD: 0.74; 95%CI: 0.17, 1.31; P = 0.01), one month (MD: 0.40; 95%CI: 0.10, 0.69; P = 0.008), 1.5 months (MD: 0.72; 95%CI: 0.51, 0.93; P < 00001), two months (MD: 0.84; 95%CI: 0.23, 1.44; P = 0.006) three months (MD: 0.92; 95%CI: 0.06, 1.78; P = 0.04), and 4.5 months (MD: 1.53; 95%CI: 0.92, 2.14; P < 0.00001).

Conclusion:

The LLLT can speed up the rate of tooth movement of human canine and consequently decrease the treatment time. LLLT represents a proper adjuvant therapy for fixed orthodontic treatment.

A Comparison of the Rate of Retraction with Low-level Laser Therapy and Conventional Retraction Technique

Background and Objectives:

A major concern of orthodontic patients is treatment time. Reducing the treatment time requires increasing the rate of orthodontic tooth movement. Research has proved that bone resorption is the rate-limiting step in tooth movement. Therefore, any procedure that potentiates osteoclastic activity is capable of increasing the rate of orthodontic tooth movement. Low-level laser has been indicated to have the capability to facilitate the differentiation of the osteoclastic and osteoblastic cells, which are responsible for the bone remodeling process. The purpose of this study was to evaluate whether the low-level laser therapy can accelerate orthodontic tooth movement during en masse retraction.

Method:

The study was a split-mouth design. The experimental side was exposed to biostimulation using 810 nm gallium-aluminium-arsenide diode laser. A total of 10 irradiations for 10 s per site were given 5 on the buccal side and 5 on the palatal side of the tooth. The total energy density at each application was 10 J with an interappointment gap of 3 weeks. The retraction was carried using a constant force of 150 gm. A digital vernier caliper measurement was used to measure the distance between the contact points of the maxillary canine and second premolar on 1^st and 84^th day.

Results:

The rate of orthodontic tooth movement was faster on the experimental side, and the difference between the two sides was statistically significant (P < 0.014).

Interpretation and Conclusion:

It was concluded that biostimulation carried out using an 810 nm diode laser is capable of increasing the rate of extraction space closure. Hence, it is capable of increasing the rate of orthodontic tooth movement.

Effect of Photobiomodulation on Maxillary Decrowding and Root Resorption: A Randomized Clinical Trial

Purpose

The effects of low-level laser therapy (LLLT) with light-emitting diode (LED) delivery (Biolux OrthoPulse® device) were tested for no differences from sham-controlled conventional orthodontics in maxillary anterior alignment treatment efficiency and maxillary central incisor root resorption after 6 months of treatment.

Materials and Methods

Two prospective clinical trial samples were matched for pretreatment irregularity index with (n = 14) and without (n = 12) photobiomodulation therapy (850 nm wavelength, 0.065 J/cm2, 5 min per-arch-per-day) and examined every 2 weeks for reduction of irregularity index to <1 mm. The sham control sample was provided with LED devices that did not deliver infrared light. Standardized periapical radiographs of maxillary central incisors were compared at initial and 6 months of treatment.

Results

Photobiomodulation resolved maxillary anterior crowding with 35.2% greater efficiency (41.0 vs. 63.3 days, P = 0.028) at nearly double the tooth movement rate-per-week (1.02 vs. 62 mm/week, P = 0.045). Mean maxillary central incisor root lengths were significantly shorter at the 6-month treatment interval after LLLT (19.63 vs. 20.85 mm, P = 0.021).

Conclusions

LED photobiomodulation therapy at 850 nm wavelength resulted in 1.7X more rapid maxillary anterior alignment.

Histological evaluation of orthodontic tooth movement following low level laser irradiation in rabbits

Background

Reduction of orthodontic treatment time is a major concern for orthodontists. Low level laser therapy (LLL) has been widely used in dentistry and it has been claimed that it could stimulate bone formation.

Objective

The aim of the present study was to evaluate histological effects of LLL on alveolar bone remodeling during experimental tooth movement in rabbits.

Methods

In this experimental study which was performed in the animal lab of Mashhad Dental School in 2016 twenty pre-pubertal female albino rabbits with the mean age of 8±1 weeks were randomly assigned into two groups. All the rabbits were examined by a veterinarian, and underweight or diseased rabbits were excluded from the study. Fifty gram orthodontic force was applied via 0.014 stainless steel spring on central teeth in both groups. In the first group, low level laser KLO3 (wave length: 980 nm, Power: 80mw) was irradiated three minutes from the buccal aspect of central teeth for 21 days. In the second group, rabbits were not exposed to laser irradiation and served as our control group. After this period, the distance between mesial corners of incisors was measured blindly by a caliper calibrated as 0.1mm. All rabbits in both groups were sacrificed by vital perfusion for histological evaluation to determine the number of resorption lacuna and amount of fibrous tissue. Independent sample t-test was used to analyze the data.

Results

The number of resorption lacuna, the rate of tooth movement and fibrous tissue were significantly greater in the lased group (p=0.05).

Conclusion

Low level laser irradiation could accelerate tooth movement in rabbits via increased resorptive activity in alveolar bone.

Effectiveness of Biology-Based Methods for Inhibiting Orthodontic Tooth Movement. A Systematic Review

INTRODUCTION

Several experimental studies in the literature have tested different biology-based methods for inhibiting or decreasing orthodontic tooth movement (OTM) in humans. This systematic review investigated the effects of these interventions on the rate of tooth movement.

STUDY DESIGN

Electronic [MedLine; SCOPUS; Cochrane Library; OpenGrey;Web of Science] and manual searches were conducted up to January 26th, 2016 in order to identify publications of clinical trials that compared the decreasing or inhibiting effects of different biology-based methods over OTM in humans. A primary outcome (rate of OTM deceleration/inhibition) and a number of secondary outcomes were examined (clinical applicability, orthodontic force used, possible side effects). Two reviewers selected the studies complying with the eligibility criteria (PICO format) and assessed risk of bias [Cochrane Collaboration's tool]. Data collection and analysis were performed following the Cochrane recommendations.

RESULTS

From the initial electronic search, 3726 articles were retrieved and 5 studies were finally included. Two types of biology-based techniques used to reduce the rate of OTM in humans were described: pharmacological and low-level laser therapy. In the first group, human Relaxin was compared to a placebo and administered orally. It was described as having no effect on the inhibition of OTM in humans after 32 days, while the drug tenoxicam, injected locally, inhibited the rate of OTM by up to 10% in humans after 42 days. In the second group, no statistically significant differences were reported, compared to placebo, for the rate of inhibition of OTM in humans after 90 days of observation when a 860 nm continuous wave GaAlA slow-level laser was used.

CONCLUSIONS

The currently available data do not allow us to draw definitive conclusions about the use of various pharmacological substances and biology-based therapies in humans able to inhibit or decrease the OTM rate. There is an urgent need for more sound well-designed randomized clinical trials in the field.

Accelerated orthodontic treatment - what's the evidence?

The demand and accessibility of orthodontic care has increased but has also been accompanied by patient requests for shorter treatment times. Longer orthodontic treatment increases the risk of decalcification, gingival recession, and root resorption and so shorter treatment times have multiple advantages as well as appealing to patient's desires. Numerous techniques and materials have been suggested to reduce treatment times but, in most cases, are based upon selected case reports with no prospective clinical trials to validate claims. The present review examines many of the current options purported to accelerate orthodontic tooth movement and the level of evidence presently available. There is some evidence to suggest that low-level laser therapy and a corticotomy involving the raising of a muco-periosteal flap are associated with accelerated orthodontic tooth movement; however, the current level of evidence is low to moderate in quality. For this reason, further research is required before routine application could be recommended.

Laser Surgery of Soft Tissue in Orthodontics: Review of the Clinical Trials

Introduction: Recently, a wide variety of procedures have been done by laser application in orthodontics. Apart from the mentioned range of various treatments, laser has become a tool for many soft tissue surgeries as an alternative to conventional scalpel-based technique during orthodontic treatments in the management of soft tissue. Due to scarce information in the latter subject, this study was designed in order to include clinical trials that included soft tissue ablation by laser in orthodontics. Methods: Literature was searched based on PubMed and Google Scholar databases in 5 years (2010-2015) with English language restriction and clinical trial design. Studies that performed soft tissue application of laser during orthodontic treatment were extracted by the authors. Results: Only eight studies met the inclusion criteria. No significant difference was found between laser ablation and conventional scalpel technique in the matter of treatment outcome. However, few issues remained to clarify the differences in the mentioned procedures. Conclusion: Laser performance can be recommended in case of preceding less bleeding and discomfort during surgical procedure. There are still quandaries among clinical application of scalpel-based surgery in aesthetic region with bracket-bonded teeth. Precaution and knowledge regarding the characteristics of laser beam such as wavelength, frequency, power and timing is extremely needed.

Effectiveness of biologic methods of inhibiting orthodontic tooth movement in animal studies

INTRODUCTION

A number of biologic methods leading to decreased rates of orthodontic tooth movement (OTM) can be found in the recent literature. The aim of this systematic review was to provide an overview of biologic methods and their effects on OTM inhibition.

METHODS

An electronic search was performed up to January 2016. Two researchers independently selected the studies (kappa index, 0.8) using the selection criteria established in the PRISMA statement. The methodologic quality of the articles was assessed objectively according to the Methodological Index for Non-Randomized Studies scale.

RESULTS

We retrieved 861 articles in the initial electronic search, and 57 were finally analyzed. Three biologic techniques were identified as reducing the rate of OTM: chemical methods, low-level laser therapy, and gene therapy. When the experimental objective was to slow down OTM, pharmacologic modulation was the most frequently described method (53 articles). Rats were the most frequent model (38 of 57 articles), followed by mice (9 of 57), rabbits (4 of 57), guinea pigs (2 of 57), dogs (2 of 57), cats (1 of 57), and monkeys (1 of 57). The sample sizes seldom exceeded 25 subjects per group (6 of 57 articles). The application protocols, quality, and effectiveness of the different biologic methods in reducing OTM varied widely.

CONCLUSIONS

OTM inhibition was experimentally tested with various biologic methods that were notably effective at bench scale, although their clinical applicability to humans was rarely tested further. Rigorous randomized clinical trials are therefore needed to allow the orthodontist to improve the effect of translating them from bench to clinic.

Efficacy of adjunctive laser in non-surgical periodontal treatment: a systematic review and meta-analysis

To evaluate the efficacy of the adjunctive laser therapy in conventional non-surgical treatment of chronic periodontitis, an electronic search was performed through the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, MEDLINE, EMBASE, Scopus, Web of Science, China National Knowledge Infrastructure (CNKI), and China Biology Medicine (CBM) Disc, for relevant randomized controlled trials (RCTs) or quasi-RCTs. All the 12 included studies (11 RCTs and 1 quasi-RCT) were qualified for descriptive and quantitative analysis. Outcomes were divided into two groups according to the length of follow-ups (long term and short term). Subgroup analyses were performed based on the mode of laser (inside and outside mode). Among all included researches, reduction in probing depth (PD) and gain in clinical attachment level (CAL) were presented with the mean value and 95 % confidence interval, while bleeding on probing (BOP) was assessed descriptively. Meta-analysis suggested that adjunctive laser therapy reduced PD at 3 months [mean difference (MD) = -0.26, 95 % confidence interval (CI) range = -0.43 to -0.09, p = 0.003] but did not demonstrate significant effect on the CAL at either 3 months (MD = -0.03, 95 % CI range = -0.25 to 0.19, p = 0.79) or 6 months (MD = -0.11, 95 % CI range = -0.38 to 0.16, p = 0.43). Subgroup analyses indicated that laser therapy would be more effective when the probes were set up outside the periodontal pockets.

Combined effect of photobiomodulation with a matrix metalloproteinase inhibitor on the rate of relapse in rats

OBJECTIVE

To investigate combined effect of photobiomodulation with a matrix metalloproteinase (MMP) inhibitor on the relapse rate in relation to MMP expression in rats.

MATERIALS AND METHODS

Fifty-two rats were divided into four groups according to the treatment modality: control group, irradiation group, doxycycline group, and irradiation with doxycycline group. During a relapse period of 5 days after orthodontic movement, maxillary central incisors were treated by low-level laser therapy (LLLT) as a photobiomodulation and/or doxycycline as a synthetic MMP inhibitor. Relapse rate was evaluated in association with MMP expression at the gene and protein levels.

RESULTS

Relapse rates were increased by LLLT (1.57-fold) and decreased by doxycycline (0.83-fold) compared with the control, showing positive correlation with the levels of expression for all MMPs in the periodontal ligament (PDL). LLLT concomitant with doxycycline administration resulted in no significant differences of relapse rate and MMP expression from the control.

CONCLUSIONS

The combined effect of photobiomodulation with an MMP inhibitor around the relapsing teeth proved to be antagonistic to PDL remodeling activity during relapse. This study suggests a basis for developing a novel biologic procedure targeting the MMP-dependent PDL remodeling to control the relapse rate.

Effects of medications and laser on induced tooth movement and associated root resorption: four key points

The following four fundamental points on the use of experimental models will be described to ensure an accurate evaluation of the effects of medication and laser therapy on induced tooth movement and associated root resorption: (1) If the objective is to check the effect on root resorption, the forces experimentally applied must produce a lesion on the cementoblast layer in all specimens; (2) If the objective is to optimize induced tooth movement and reduce treatment time without side effects, the forces experimentally applied should not produce a lesion in the cementoblast layer in any specimen; (3) The laser therapy operator, the person administering medication and the person that places appliances should not know which animals will effectively receive the test treatment, and the control groups should receive placebo treatments; (4) CT and microscopic analysis of the specimens should be random, and the group to which the specimen belongs should not be identified, to ensure that the person reading images and the pathologists are not influenced in their evaluation of phenomena. These measures will ensure that results are more reliable and easier to extrapolate to orthodontic clinical practice.

Lasers in orthodontics

Many types of dental lasers are currently available that can be efficiently used for soft and hard tissue applications in the field of orthodontics. For achieving the desired effects in the target tissue, knowledge of laser characteristics such as power, wavelength and timing, is necessary. Laser therapy is advantageous because it often avoids bleeding, can be pain free, is non-invasive and is relatively quick. The high cost is its primary disadvantage. It is very important to take the necessary precautions to prevent possible tissue damage when using laser dental systems. Here, we reviewed the main types and characteristics of laser systems used in dental practice and discuss the applications of lasers in orthodontics, harmful effects and laser system safety.