{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,20]],"date-time":"2026-06-20T02:41:11Z","timestamp":1781923271226,"version":"3.54.5"},"reference-count":56,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2025,4,22]],"date-time":"2025-04-22T00:00:00Z","timestamp":1745280000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Dentistry Journal"],"abstract":"<jats:p>Background: During the initiation of routine orthodontic treatment with fixed appliances, placing elastic separators (ESs) may lead to the patient experiencing considerable pain. Earlier studies evaluating the effects of low-level laser therapy (LLLT) on reducing pain caused by orthodontic ESs have reported contradictory results. The aim of our study was to evaluate the effect of a single application of LLLT on the experience of pain following ES placement. Methods: A double-blind, placebo-controlled randomized controlled trial was performed\u2014with implementation of the split-mouth technique\u2014where n = 33 volunteers (12 male and 21 female; aged between 19 and 36 years) were enrolled. ESs were placed at the mesial and distal surfaces of the first permanent molars in the upper or lower jaws. Jaws were divided into two quadrants; the treatment group received LLLT (using a GaAlAs diode laser, at a 980 nm wavelength, with 100 mW producing 6 J of energy; continuous wave), while the other quadrant served as the placebo side receiving a similar treatment, but without laser irradiation, immediately after separation. A questionnaire with a visual analogue scale (VAS; 0\u2013100) was used for the assessment of pain (spontaneous pain and pain on mastication) scored for each first permanent molar directly after separation and after 6, 24, 48 and 72 h of both laser and placebo treatment application. Results: Mean VAS values were lower, but not significantly different, between the treatment vs. placebo groups for spontaneous pain at either measurement point (p &gt; 0.05). Mean VAS values were significantly lower in the treatment groups for pain on mastication at the 6 (9.29 \u00b1 12.65 vs. 19.07 \u00b1 20.99; p = 0.025), 24 (21.96 \u00b1 21.11 vs. 37.19 \u00b1 26.35; p = 0.012) and 48 h (28.01 \u00b1 21.40 vs. 42.60 \u00b1 26.29; p = 0.016) measurement points. The analgetic effect of LLLT was most effective after 6 h, both in the resting position (\u221249% decrease) and during mastication (\u221251% decrease). Conclusions: A single application of LLLT with 6 J of energy may have beneficial effects on reducing the pain caused by orthodontic ESs used at the initiation of treatment with fixed appliances, especially during mastication, after 6\u201348 h following the separation procedure. Trial\u00a0registration: clinicaltrials.gov ID NCT06816537 (date of registration: 7 February 2025, retrospectively registered).<\/jats:p>","DOI":"10.3390\/dj13050181","type":"journal-article","created":{"date-parts":[[2025,4,22]],"date-time":"2025-04-22T20:11:48Z","timestamp":1745352708000},"page":"181","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["The Effect of Low-Level Laser Therapy to Reduce Pain Caused by Orthodontic Separators: A Randomized, Double-Blind Placebo-Controlled, Split-Mouth Study"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4864-9493","authenticated-orcid":false,"given":"Alireza Khandan","family":"Dezfully","sequence":"first","affiliation":[{"name":"Department of Orthodontics and Pediatric Dentistry, Faculty of Dentistry, University of Szeged, Tisza Lajos krt. 64-66., 6720 Szeged, Hungary"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1270-0365","authenticated-orcid":false,"given":"M\u00e1ri\u00f3","family":"Gajd\u00e1cs","sequence":"additional","affiliation":[{"name":"Department of Oral Biology and Experimental Dental Research, Faculty of Dentistry, University of Szeged, Tisza Lajos krt. 64-66., 6720 Szeged, Hungary"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Aliz Eperke","family":"Pat\u00f3","sequence":"additional","affiliation":[{"name":"Department of Orthodontics and Pediatric Dentistry, Faculty of Dentistry, University of Szeged, Tisza Lajos krt. 64-66., 6720 Szeged, Hungary"},{"name":"Department of Oral Biology and Experimental Dental Research, Faculty of Dentistry, University of Szeged, Tisza Lajos krt. 64-66., 6720 Szeged, Hungary"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Krisztina","family":"K\u00e1rp\u00e1ti","sequence":"additional","affiliation":[{"name":"Department of Orthodontics and Pediatric Dentistry, Faculty of Dentistry, University of Szeged, Tisza Lajos krt. 64-66., 6720 Szeged, Hungary"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Melinda","family":"Madl\u00e9na","sequence":"additional","affiliation":[{"name":"Department of Oral Biology and Experimental Dental Research, Faculty of Dentistry, University of Szeged, Tisza Lajos krt. 64-66., 6720 Szeged, Hungary"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,4,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"170","DOI":"10.1093\/ejo\/cjl081","article-title":"Orthodontic pain: From causes to management\u2014A review","volume":"29","author":"Krishnan","year":"2007","journal-title":"Eur. J. Orthod."},{"key":"ref_2","first-page":"210","article-title":"Pain control during fixed orthodontic appliance therapy","volume":"75","author":"Polat","year":"2005","journal-title":"Angle Orthod."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"125","DOI":"10.1007\/BF01300354","article-title":"Pain in orthodontics","volume":"61","author":"Bergius","year":"2000","journal-title":"J. Orofac. Orthop."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"292","DOI":"10.1053\/j.sodo.2007.08.010","article-title":"Pain and discomfort after orthodontic appointments","volume":"13","author":"Polat","year":"2007","journal-title":"Semin. Orthod."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"349","DOI":"10.1016\/0889-5406(91)70073-6","article-title":"The pain experience and psychological adjustment to orthodontic treatment of preadolescents, adolescents, and adults","volume":"100","author":"Brown","year":"1991","journal-title":"Am. J. Orthod. Dentofacial. Orthop."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"580","DOI":"10.1177\/0022034512444446","article-title":"Cognitive behavioral therapy for orthodontic pain control: A randomized trial","volume":"91","author":"Wang","year":"2012","journal-title":"J. Dent. Res."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"169","DOI":"10.1016\/j.ajodo.2011.06.042","article-title":"Pain reduction after initial archwire placement in orthodontic patients: A randomized clinical trial","volume":"141","author":"Farzanegan","year":"2012","journal-title":"Am. J. Orthod. Dentofacial Orthop."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"71","DOI":"10.1111\/j.1601-6343.2012.01542.x","article-title":"Pharmacological management of pain during orthodontic treatment: A meta-analysis","volume":"15","author":"Angelopoulou","year":"2012","journal-title":"Orthod. Craniofac. Res."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"531","DOI":"10.1093\/ejo\/cjq173","article-title":"Non-steroidal and steroidal anti-inflammatory use in the context of orthodontic movement","volume":"34","author":"Knop","year":"2012","journal-title":"Eur. J. Orthod."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Inchingolo, F., Inchingolo, A.M., Latini, G., Del Vecchio, G., Trilli, I., Ferrante, L., Dipalma, G., Palermo, A., and Inchingolo, A.D. (2023). Low-Level Light Therapy in Orthodontic Treatment: A Systematic Review. Appl Sci., 13.","DOI":"10.3390\/app131810393"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"S119","DOI":"10.4103\/1305-7456.119089","article-title":"Lasers in orthodontics","volume":"7","author":"Nalcaci","year":"2013","journal-title":"Eur. J. Dent."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"e166","DOI":"10.1007\/s10103-023-03827-w","article-title":"High-intensity laser therapy in low back pain management: A systematic review with meta-analysis","volume":"38","author":"Abdildin","year":"2023","journal-title":"Lasers Med. Sci."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"99","DOI":"10.1590\/2177-6709.22.6.099-109.sar","article-title":"High-intensity laser application in orthodontics","volume":"22","author":"Nojima","year":"2017","journal-title":"Dental Press J. Orthod."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"277","DOI":"10.1089\/clm.1991.9.277","article-title":"Biomolecular mechanism of laser biostimulation","volume":"8","author":"Harris","year":"1991","journal-title":"J. Clin. Laser Med. Surg."},{"key":"ref_15","first-page":"291","article-title":"Soft laser irradiation effects on pain reduction in orthodontic treatment","volume":"38","author":"Harazaki","year":"1997","journal-title":"Bull. Tokyo Dent. Coll."},{"key":"ref_16","first-page":"199","article-title":"The evaluation of laser irradiated pain reductive effect by occlusal force measurement","volume":"61","author":"Fukui","year":"2002","journal-title":"Orthod. Waves"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"614","DOI":"10.1016\/S0889-5406(95)70007-2","article-title":"A clinical investigation of the efficacy of low level laser therapy in reducing orthodontic postadjustment pain","volume":"108","author":"Lim","year":"1995","journal-title":"Am. J. Orthod. Dentofacial Orthop."},{"key":"ref_18","first-page":"31","article-title":"Clinical application of a pressure sensitive occlusal sheet for tooth pain time dependent pain associated with a multi bracket system and the inhibition of pain by laser irradiation","volume":"61","author":"Saito","year":"2002","journal-title":"Orthod. Waves"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"371","DOI":"10.1016\/j.ajodo.2005.04.036","article-title":"Pain relief by single low level laser irradiation in orthodontic patients undergoing fixed appliance therapy","volume":"130","author":"Turhani","year":"2006","journal-title":"Am. J. Orthod. Dentofacial Orthop."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"662","DOI":"10.1016\/j.ajodo.2008.06.028","article-title":"Low level laser therapy for pain caused by placement of the first orthodontic archwire: A randomized clinical trial","volume":"136","author":"Tortamano","year":"2009","journal-title":"Am. J. Orthod. Dentofacial Orthop."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"27","DOI":"10.1007\/s10103-007-0449-7","article-title":"The effect of low level laser therapy during orthodontic movement: A preliminary study","volume":"23","author":"Youssef","year":"2008","journal-title":"Lasers Med. Sci."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"925","DOI":"10.2319\/010410-10.1","article-title":"Interventions for pain during fixed orthodontic appliance therapy. A systematic review","volume":"80","author":"Li","year":"2010","journal-title":"Angle Orthod."},{"key":"ref_23","first-page":"8","article-title":"Review of Literature on Low-Level Laser Therapy Benefits for Nonpharmacological Pain Control in Chronic Pain and Osteoarthritis","volume":"24","author":"Dima","year":"2018","journal-title":"Altern. Ther. Health Med."},{"key":"ref_24","first-page":"603","article-title":"Effect of Low-Level Laser Irradiation on Osteoblast Proloferation and Bone Formation","volume":"25","author":"Grassi","year":"2011","journal-title":"J. Biol. Regul. Homeost. Agents"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"335","DOI":"10.1007\/s10103-012-1135-y","article-title":"Analgesic effect of a low-level laser therapy (830 nm) in early orthodontic treatment","volume":"28","author":"Puigdollers","year":"2013","journal-title":"Lasers Med. Sci."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1089\/pho.2012.3338","article-title":"Low-level laser therapy for treatment of pain associated with orthodontic elastomeric separator placement: A placebo-controlled randomized double-blind clinical trial","volume":"31","year":"2013","journal-title":"Photomed. Laser Surg."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"559","DOI":"10.1007\/s10103-012-1258-1","article-title":"The effect of 810-nm low-level laser therapy on pain caused by orthodontic elastomeric separators","volume":"29","author":"Eslamian","year":"2014","journal-title":"Lasers Med. Sci."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"193","DOI":"10.2319\/122214-933.1","article-title":"Evaluation of the use of low-level laser therapy in pain control in orthodontic patients: A randomized split-mouth clinical trial","volume":"86","author":"Farias","year":"2016","journal-title":"Angle Orthod."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"62","DOI":"10.1016\/j.ajodo.2015.06.024","article-title":"Effect of a single dose of low-level laser therapy on spontaneous and chewing pain caused by elastomeric separators","volume":"149","author":"Qamruddin","year":"2016","journal-title":"Am. J. Orthod. Dentofacial Orthop."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"35","DOI":"10.1007\/s10103-013-1345-y","article-title":"The effect of diode superpulsed low-level laser therapy on experimental orthodontic pain caused by elastomeric separators: A randomized controlled clinical trial","volume":"30","author":"Marini","year":"2015","journal-title":"Lasers Med. Sci."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"52","DOI":"10.4103\/ijpn.ijpn_128_20","article-title":"The effectiveness of low-level laser therapy on controlling pain and discomfort during separator placement before fixation of orthodontic appliances","volume":"35","author":"Muctar","year":"2021","journal-title":"Indian J. Pain"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"431","DOI":"10.1007\/s00056-015-0306-4","article-title":"Pain reduced by low-level laser therapy during use of orthodontic separators in early mixed dentition","volume":"76","author":"Stein","year":"2015","journal-title":"J. Orofac. Orthop."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"221","DOI":"10.1007\/s41547-018-0040-5","article-title":"Evaluating the effect of low-level laser therapy on pain induced by orthodontic separation: A randomized split-mouth clinical trial","volume":"2","author":"Gupta","year":"2018","journal-title":"Lasers Dent. Sci."},{"key":"ref_34","first-page":"ZC23","article-title":"Evaluation of Low Level Laser Therapy on Pain Perception Following Orthodontic Elastomeric Separation: A Randomized Controlled Trial","volume":"10","author":"Almallah","year":"2016","journal-title":"J. Clin. Diagn. Res."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"37","DOI":"10.1590\/2176-9451.20.3.037-042.oar","article-title":"Low-level laser therapy effects on pain perception related to the use of orthodontic elastomeric separators","volume":"20","author":"Furquim","year":"2015","journal-title":"Dental Press J. Orthod."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1093\/ejo\/cjx013","article-title":"Evaluating low-level laser therapy effect on reducing orthodontic pain using two laser energy values: A split-mouth randomized placebo-controlled trial","volume":"40","author":"Sultan","year":"2018","journal-title":"Eur. J. Orthod."},{"key":"ref_37","first-page":"e44","article-title":"Comparison of the analgesic effect of Ibuprofen and pulsed low-level laser in reducing pain after orthodontic separator placement and evaluation of the changes in the sulcular pain especially prostaglandin E2 level","volume":"8","author":"Oshagh","year":"2014","journal-title":"J. Dent. Lasers"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"e200","DOI":"10.1007\/s10103-023-03870-7","article-title":"Effectiveness of photobiomodulation with low-level lasers on the acceleration of orthodontic tooth movement: A systematic review and meta-analysis of split-mouth randomised clinical trials","volume":"38","author":"Grajales","year":"2023","journal-title":"Lasers Dent. Sci."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"1581","DOI":"10.1007\/s10103-012-1196-y","article-title":"Efficacy of low-level laser therapy in the management of orthodontic pain: A systematic review and meta-analysis","volume":"28","author":"He","year":"2013","journal-title":"Lasers Med. Sci."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"1300","DOI":"10.1016\/j.jdent.2014.07.013","article-title":"Effectiveness of non-conventional methods for accelerated orthodontic tooth movement: A systematic review and meta-analysis","volume":"42","author":"Gkantidis","year":"2014","journal-title":"J. Dent."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"e28","DOI":"10.1186\/s13005-015-0085-6","article-title":"Does low level laser therapy relieve the pain caused the placement of the orthodontic separators\u2014A meta-analysis","volume":"11","author":"Shi","year":"2015","journal-title":"Head Face Med."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"1881","DOI":"10.1007\/s10103-015-1743-4","article-title":"The effectiveness of low-level diode laser therapy on orthodontic pain management: A systematic review and meta-analysis","volume":"30","author":"Chong","year":"2015","journal-title":"Lasers Med. Sci."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"1789","DOI":"10.1007\/s10103-014-1661-x","article-title":"Low-level laser therapy for orthodontic pain: A systematic review","volume":"30","author":"Li","year":"2015","journal-title":"Lasers Med. Sci."},{"key":"ref_44","unstructured":"(2025, February 01). ClinCalc.com. Available online: https:\/\/clincalc.com\/stats\/SampleSize.aspx."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"c332","DOI":"10.1136\/bmj.c332","article-title":"CONSORT 2010 Statement: Updated guidelines for reporting parallel group randomised trials","volume":"340","author":"Schulz","year":"2010","journal-title":"BMJ"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"446","DOI":"10.1111\/j.1600-051X.1990.tb02343.x","article-title":"Splitmouth and cross-over designs in dental research","volume":"17","author":"Tulloch","year":"1990","journal-title":"J. Clin. Periodontol."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"S240","DOI":"10.1002\/acr.20543","article-title":"Measures of adult pain. Visual Analog Scale for Pain (VAS Pain), Numeric Rating Scale for Pain (NRS Pain), McGill Pain Questionnaire (MPQ) Short\u2013Form McGill Pain Questionnaire (SF-MPQ), Chronic Pain Grade Scale (CPGS) Short Form-36 Bodily Pain Scale (SF-36 BPS) and Measure of Intermittent and Constant Osteoarthritis Pain (ICOAP)","volume":"63","author":"Hawker","year":"2011","journal-title":"Arthritis Care Res."},{"key":"ref_48","doi-asserted-by":"crossref","unstructured":"Vitale, M.C., Falzinella, C., Sfondrini, M.F., Defabianis, P., and Scribante, A. (2023). The Use of Questionnares in Pain Assassment during Orthodontic Treatments: A Narrative Review. Medicina, 59.","DOI":"10.3390\/medicina59091681"},{"key":"ref_49","first-page":"514","article-title":"Questionnaire designing and validation","volume":"62","author":"Kazi","year":"2012","journal-title":"J. Pak. Med. Assoc."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"1061","DOI":"10.1016\/j.cden.2004.05.004","article-title":"Low-level laser therapy in dentistry","volume":"48","author":"Sun","year":"2004","journal-title":"Dent. Clin. N. Am."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"247","DOI":"10.1111\/j.1834-7819.1997.tb00129.x","article-title":"The current status of low level laser therapy in dentistry, Part 1. Soft tissue applications","volume":"42","author":"Walsh","year":"1997","journal-title":"Aust. Dent. J."},{"key":"ref_52","unstructured":"Kert, J., and Rose, L. (1989). Clinical Laser Therapy\u2014Low Level Laser Therapy, Scandinavian Medical Laser Technology."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"3470","DOI":"10.1002\/sim.3634","article-title":"The design and analysis of split mouth studies: What statisticians and clinicians should know","volume":"28","author":"Lesaffre","year":"2009","journal-title":"Stat. Med."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"e29","DOI":"10.34172\/jlms.2021.29","article-title":"The effectiveness of low-level laser therapy in pain induced by orthodontic separator placement: A systematic review","volume":"12","author":"Farzan","year":"2021","journal-title":"J. Lasers Med. Sci."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"131","DOI":"10.4103\/0253-7184.102130","article-title":"Randomized double blind placebo control studies, the \u201cGold Standard\u201d in intervention based studies","volume":"33","author":"Misra","year":"2012","journal-title":"Indian J. Sex. Transm. Dis."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"281","DOI":"10.1007\/s10103-018-2583-9","article-title":"Low-level laser therapy (830nm) on orthodontic pain: Blinded randomized clinical trial","volume":"34","author":"Martins","year":"2019","journal-title":"Lasers Med. Sci."}],"container-title":["Dentistry Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2304-6767\/13\/5\/181\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T17:19:24Z","timestamp":1760030364000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2304-6767\/13\/5\/181"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,4,22]]},"references-count":56,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2025,5]]}},"alternative-id":["dj13050181"],"URL":"https:\/\/doi.org\/10.3390\/dj13050181","relation":{},"ISSN":["2304-6767"],"issn-type":[{"value":"2304-6767","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,4,22]]}}}