Effectiveness of Single Session of Low-Level Laser Therapy with a 940 nm Wavelength Diode Laser on Pain,Swelling,and Trismus After Impacted Third Molar Surgery

Abstract

Introduction: In low-level laser therapy (LLLT), applications are generally performed in repetitive sessions using wavelengths of around 800 nm, at which the depth of penetration of laser is greater. The present study aimed to investigate the effects of LLLT with a 940 nm diode laser, which was performed extraorally on all the primarily and secondarily affected areas immediately after surgery in a single session, on pain, swelling, and trismus that occurred after impacted tooth extraction. Materials and methods: Thirty-five outpatients with similarly impacted lower third molars on both sides were selected. The teeth of patients were removed in two separate operations. Postoperatively, the patients received laser therapy with energy of 4 J/cm² on one side and no laser energy was applied to the other side (placebo side). Swelling, trismus, and subjective assessment of pain on a visual analog scale were evaluated and compared between the laser-treated and placebo sides. Results: There was no statistically significant difference in pain, swelling, or trismus between the sides (Mann–Whitney U test p > 0.05). However, according to the clinical outcomes, swelling and trismus were less in the laser-treated side than in the placebo side. Conclusions: A single-session LLLT that would be applied with a diode laser immediately after impacted tooth extraction might help patients to be less affected by postoperative trismus and swelling.

Introduction

Surgical trauma during impacted third molar removal causes postoperative pain, swelling, and trismus.¹ To reduce or prevent these postoperative complications, many techniques such as the use of local or systemic corticosteroids, enzymes, nonsteroidal anti-inflammatory drugs, tube drains, different incisions, ice packs, and cryotherapy have been proposed.^2

–6 In the last two decades, the use of low-level laser therapy (LLLT) has been added to these alternatives.

The LLLT induces cellular biostimulation, accelerates tissue regeneration, improves wound healing, and reduces pain and swelling through anti-inflammatory mechanisms by inhibition of interleukin-6, monocyte chemotactic protein-1, interleukin-10, and tumor necrosis factor-α.^7,8 Nevertheless, clinical outcomes of LLLT can vary depending on each laser parameter (such as repetitive sessions, application technique, application area, wavelength, irradiation time, amount of energy) since standardization of the LLLT applications has not been established yet.⁹

It is remarkable that LLLT has been applied mostly at wavelengths around 800 nm in recent studies.¹⁰ Although these wavelengths are preferred due to greater transmission of light at these wavelengths, in the recent studies on LLLT, it has been demonstrated that diode lasers with wavelengths of 940–980 nm are also effective in reducing postoperative inflammation, improving wound healing, and accelerating regeneration.^11

–15 However, the number of published studies is limited and some of these researches are experimental animal studies, cell culture studies, or single case reports.

Repetitive sessions attract attention in many of the recent studies, in which the efficacy of LLLT has been demonstrated on pain, swelling, and trismus after impacted tooth extraction.^11,16
–18 Repetitive sessions lead to the need for clinical visits of patients at each time and to loss of time and labor for both patients and physicians. The studies investigating the effects of LLLT on postoperative complications using new generation lasers in a single session are also available; however, these studies are limited in number.^19,20 In low-level laser applications, point irradiation is performed generally at the insertion of the masseter muscle, where edema is observed.^16,19,21 However, postoperative swelling due to tissue response is observed not only in the angulus region to which the masseter muscle is attached but also in the adjacent tissues in varying amounts and in the anterior aspect of the angulus region depending on the incision as well as the dissection margins of flap. For this reason, the area from the tragus to the corner of the mouth is mostly taken into consideration for postoperative edema measurements.^11,16,19,20 In this respect, we planned to stimulate the surrounding tissue regionally using a 940 nm diode laser in addition to the areas primarily affected by the surgery, including also the masseter muscle. The aim of the present study was to investigate the effects of LLLT with a 940 nm diode laser, which was performed with a large irradiation field in a single session, on pain, swelling, and trismus that occurred after impacted tooth extraction to reduce the number of patient visits.

Materials and Methods

Thirty-five outpatients, older than 18 years of age (range, 18–40 years), with similarly impacted mandibular third molars on both sides were selected for the present single-blind, randomized, split-mouth clinical study. Patients with American Society of Anesthesiologists (ASA) Class I, those not using any drugs 1 week before the surgery, those who were not allergic to anesthesia or drugs that would be used in the present study, and those who were the residents of Van province to provide regular patient visits were included. All teeth were Class II, Class B according to the Pell–Gregory classification and mesioangular according to Winter's classifications. Bone removal and tooth sectioning were necessary in all operations. Patients were excluded from the study if the medical history or physical examination finding was not suitable (presence of systemic disease, usage of corticosteroids, presence of pericoronitis, presence of smoking habit, pregnancy, and breastfeeding). The present study was approved by the Ethics Committee of Yüzüncü Yıl University (Reference No. YYU-11-30012014) and conducted in accordance with the Declaration of Helsinki. Informed consents were obtained from all patients included in the study.

All teeth were surgically removed under local anesthesia with articaine HCl (articaine HCl 80 mg + epinephrine 0.020 mg; Maxicaine^®; Vem, Ankara, Turkey) in two separate operations with a minimum 3-week interval. A total of 2 mL local anesthetic solution was used in all procedures and all surgeries were performed by the same surgeon. The bone was removed after an envelope incision; the tooth was sectioned and removed. After achieving hemostasis, the socket was irrigated and the wound was primarily closed. Since a split-mouth technique was used in the present study, the side of the tooth to which laser or placebo would be applied was determined randomly by tossing a coin. The patients received laser therapy on one side and no laser energy was applied to the other side (the probe was contacted with the skin, but no energy was applied) immediately after the surgery (day 0). Accordingly, two treatment groups were established as the laser group and the placebo group.

A diode laser device (Ezlase 940; Biolase Technology, Inc., Irvine, CA) with a continuous wavelength of 940 nm and power density of 0.5 watt/cm² (a peak power output of 2.75 watt, a spot size of 35 × 8 mm = 2.8 cm²) and a bleaching handpiece were used. The laser probe was contacted with the skin and energy was transmitted to a triangular region bordered by the masseter muscle insertion in the angulus mandible, auricular tragus lobe, and mesial margin of the mandibular second molar. After resetting the cumulative energy measurement to zero on the device, laser application was continued until the total energy reached the level of 50 J (50 J/12 cm² = 4 J/cm²) on the device screen. In the placebo side, the laser probe was applied in the same way, but no energy was given. The patients were blinded to the side that received laser energy. The postoperative treatment included flurbiprofen (Majezik^® 100 mg tablets; Sanovel Ilac San. Tic., Istanbul, Turkey) orally every 12 h for 3 days and benzydamine HCl+chlorhexidine gluconate mouthwash for 7 days in all patients. The same suggestions and dietary advice were given to all patients.

The patients were instructed to rate and record pain intensity on a continuous 10-cm visual analog scale (VAS), in which 0 indicates no pain and 10 indicates the worst pain imaginable. The patients recorded two pain scores, one being on the postoperative 2nd day and one being on the postoperative 7th day.

Facial swelling was determined preoperatively and immediately after the surgery. The outer contour of the cheek (the distance between the tip of the chin and the lower part of the auricular lobe) was measured using the method of Markovic and Todorovic.²² The maximum mouth opening was measured between the right upper and right lower central incisors using a vernier-calibrated sliding caliper before each operation. The measurements of trismus and swelling were repeated on the postoperative 2nd and 7th days. All measurements of trismus and swelling were performed by a blinded clinician.

For coefficient evaluation of swelling and trismus, the measurements performed on the postoperative 2nd and 7th days were calculated with modified Carrillo's formula.^23,24 Data analysis was performed using the IBM SPSS Statistics for Windows (version 20.0; IBM Corp., Armonk, NY). Descriptive statistics are expressed as mean, standard deviation, minimum and maximum for continuous variables, and as number and percentage for categorical variables. Mann–Whitney U test was performed to compare the means of the groups for continuous variables. The sample size was calculated with a power of at least 0.80 and at a type-1 error of 0.05 for every variable. The statistical significance level was set at p < 0.05.

Results

The present study included asymptomatic mesioangularly positioned 70 teeth from 35 patients (average age, 25 years), of whom 20 were males (average age 26 years) and 15 were females (average age 24 years).

The mean operation time from the initial incision to the final suture was 15.17 min. There was no abnormal hemorrhage during the operations and all patients had primary healing. No change in skin color (due to hematoma or ecchymosis) was observed.

No significant differences were noted between the placebo and control groups in terms of pain VAS scores (p = 0.670 and p = 0.836 for the postoperative 2nd and 7th days, respectively), swelling (p = 0.407 and p = 0.970 for the postoperative 2nd and 7th days, respectively), and trismus (p = 0.247 and p = 0.713 for the postoperative 2nd and 7th days, respectively) (Table 1). None of the patients experienced any adverse reactions to the applied laser therapy and medications. In the laser group, the rates of swelling and trismus (32% and 20%, respectively) were less than those in the placebo group.

Table 1.

Comparison of Postoperative Pain, Swelling, and Trismus Measurements in the Study Groups

		Mean	SD	P
xVAS 2nd day	Placebo	1.37	1.75	0.670
	Laser	1.40	1.439
VAS 7th day	Placebo	0.34	0.639	0.836
	Laser	0.57	1.22
Swelling 2nd day coefficient	Placebo	0.41	0.609	0.407
	Laser	0.31	0.592
Swelling 7th day coefficient	Placebo	0.09	0.288	0.970
	Laser	0.09	0.292
Trismus 2nd day coefficient	Placebo	16.03	0.539	0.247
	Laser	13.37	1.235
Trismus 7th day coefficient	Placebo	6.86	2.542	0.713
	Laser	5.74	2.361

SD, standard deviation; VAS, visual analog scale.

It was considered that the order of receiving laser or placebo in the first and second (3 weeks after the first operation) operations could have an effect on pain scores of the patients; comparison of the patients in whom placebo side was first operated with the patients in whom laser side was first operated revealed no significant difference in terms of pain VAS scores (p = 0.78). Additionally, comparison of the patients in whom placebo side was operated 3 weeks after the first operation with the patients in whom laser side was operated 3 weeks after the first operation also revealed no significant difference in terms of pain VAS scores (p = 0.37) (Table 2). However, the pain VAS score of the patients in whom placebo side was first operated and had slightly higher pain VAS scores was determined to be reduced by 50% after the second operation (3 weeks after the first operation). Although the mean pain VAS scores of the male patients was slightly higher compared with the female patients, there was no significant difference between the male and female patients in terms of pain VAS scores (p = 0.46).

Table 2.

Comparison of the Mean Pain Visual Analog Scale Scores According to the Order of Operations and Gender

	Pain VAS score Mean ± SD	p
Placebo first operation	1.7 ± 1.7	0.78
Laser first operation	1.4 ± 1.2
Placebo second operation	1.1 ± 1.4	0.37
Laser second operation	1.4 ± 1.2

Discussion

In the present study, it was aimed to observe whether stimulation of all areas, which were primarily and secondarily affected by the surgery, using a 940 nm diode laser in a single session would have favorable effect on the postoperative pain, swelling, and trismus. The results of the present study revealed that this strategy contributed to a lower postoperative swelling and trismus. In the literature, the studies in which LLLT was performed in a single session have revealed different outcomes concerning the effects of LLLT on postoperative pain and swelling. While some authors have concluded that LLLT is effective on pain and swelling, some have determined no favorable effect either on pain or swelling.^19,20,25 Although we did not obtain a positive effect of LLLT on pain, we observed an acceptable clinical effect on swelling. The studies that performed LLLT in repetitive sessions have not generally reported a significant difference for pain between LLLT and placebo.^11,16,17 Although the result of the present study concerning pain appeared to be consistent with the results in the literature, relatively higher pain in the laser group than in the placebo group might be a result of a limitation of the split-mouth technique. If the release of inflammatory mediators is lower in the presence of an anti-inflammatory condition, the release of pain mediators and thereby pain are expected to be lower. Since the method for the first application side in the split-mouth technique was decided on the toss of a coin, it was not possible to control the severity of pain after the second operation—pain threshold of the patient may change depending on the first operation.¹⁰ The analyses performed taking this factor into account resulted in no significant difference in VAS scores according to the order of the operations. Based on the clinical outcomes, however, it was observed that the patients, in whom placebo side was first operated and reported higher VAS scores, felt lesser pain after the second operation. It was determined that the positive effect of LLLT on the pain was apparent. Some of the patients, in whom pain threshold was considered to be changed due to the first operation, had also increased pain VAS scores after the second operation. In these patients, most of the first operations were also performed in the placebo side. The mean pain VAS score did not differ between the patients in whom laser side was operated first or 3 weeks after the first operation. We are of the opinion that the pain scores could be affected by the randomization technique by which the first and second operation sides were determined. However, it might not be correct to mention about a clear positive effect of LLLT on pain.

In the present study, the effects of demographic factors on the pain scores could also be discussed. The patients included in this study comprised patients having similar socioeconomic class and similar oral hygiene habits. Accordingly, control patient visits could be regularly performed and possible occurrence of alveolitis related to oral hygiene could be eliminated. In the literature, data on age and gender have not yet been clear.²⁶ There are researchers suggesting that elderly patients and males have greater pain scores.^27,28 In the present study, the male patients had slightly higher pain VAS scores than the female patients. There was no remarkable difference among our patients in terms of age. No remarkable difference was noted between the patients at the oldest age and the patients at the youngest age in terms of pain scores. With regard to surgical difficulty, the symmetrical teeth with the same impacted level were preferred in the present study.

Comparing with single-session procedures, the results of the present study were favorable in terms of trismus and were in line with the literature. We are of the opinion that minimal thermal effect, which occurs during laser applications, might play a role in the clinical outcomes that were obtained for trismus. Since the main body of the masseter muscle was within the irradiation field, relaxation might occur due to thermal effect. In the present study, the power density and the irradiation time were low; however, an increase in heat, even at a minimal level, is expected, despite the thermal change not being measured.²⁹ Such a minimal thermal effect might also influence the clinical outcomes. Moreover, since trismus is a parameter that could be affected by pain,³⁰ better results can be obtained for trismus with successful pain control.

In the studies on LLLT, it has been observed that many researchers apply 4 J/cm².^16,17,19 This is due to the fact that the postoperative swelling would not be reduced when the amount of energy is below 4 J/cm².^18,31 Therefore, 4 J/cm² is accepted as the threshold value in such studies. In the anti-inflammatory mechanism of LLLT, it has been reported that LLLT provides protein absorption through activation of macrophages and regulation of intracapillary pressure by decreasing vascular permeability.^32,33 In addition, it has been highlighted that the time of LLLT application, that is, the phase of inflammatory process and whether swelling is initiated or not, is also important.²⁹ As is known, inflammatory response is a process that starts with surgical procedures. Performing LLLT as the first session immediately after surgery, that is, at the beginning of the inflammatory process at which swelling has not developed yet, is a standard application in all studies. We also observed that swelling was lower even with this standard and single step without repetitive sessions. However, depending on the method by which we evaluated the postoperative swelling, clinical success might not be reflected by statistical results.

In the present study, laser application was performed extraorally since the extraoral route has been demonstrated to have significant clinical efficacy compared with the placebo and intraoral route.²¹ There are also studies using extraoral and intraoral applications of laser therapy in combination. However, we believe that extraoral application is the predominant effective method in these studies.

In their study, Amarillas-Escobar et al.¹⁷ applied laser therapy to multiple points (six extraoral points and intraoral application) in a total of four sessions. The results of that particular study, despite not statistically significant, were in favor of LLLT. It would be more appropriate for the studies to focus rather on maximum clinical success in a single session than on the success achieved in repetitive LLLT sessions. This is due to fact that repetitive sessions cause loss of time and labor for both patients and physicians. This appears as a non-negligible disadvantage of repetitive sessions of LLLT rather than their advantages. For this reason, researchers should focus on single-session applications, the clinical success of which could be verified statistically by studying with different laser parameters and different medical combinations.

Conclusion and Summary

In conclusion, the LLLT performed with a 940 nm diode laser is a therapeutic option with clinically favorable effects on swelling and trismus, which are likely to develop following impacted tooth extraction. A single-session LLLT with a diode laser that would be performed by clinicians immediately after impacted tooth extraction might positively contribute to the healing and anti-inflammatory processes.

Footnotes

Acknowledgments

The authors thank Sadi Elasan from Yuzuncu Yil University, Faculty of Medicine, Department of Biostatistics, for his valuable contribution to the statistical analysis of the present study.

Author Disclosure Statement

No competing financial interests exist.

References

Grossi

, Maiorana

, Garramone

, Borgonova

, Creminelli

, Santoro

. Assessing postoperative discomfort after third molar surgery: a prospective study. J Oral Maxillofac Surg, 2007; 65:901–917.

Mehrabi

, Allen

, Roser

. Therapeutic agents in perioperative third molar surgical procedures. Oral Maxillofac Surg Clin North Am, 2007; 19:69–84.

Chopra

, Rehan

, Mehra

, Kakkar

. A randomized, double-blind, placebo-controlled study comparing the efficacy and safety of paracetamol, serratiopeptidase, ibuprofen and betamethasone using the dental impaction pain model. Int J Oral Maxillofac Surg, 2009; 38:350–355.

Mocan

, Kişnişci

, Uçok

. Stereophotogrammetric and clinical evaluation of morbidity after removal of lower third molars by two different surgical techniques. J Oral Maxillofac Surg, 1996; 54:171–175.

van der Westhuijzen

, Becker

, Morkel

, Roelse

. A randomized observer blind comparison of bilateral facial ice pack therapy with no ice therapy following third molar surgery. Int J Oral Maxillofac Surg, 2005; 34:281–286.

Gelesko

, Long

, Faulk

, Phillps

, Dicus

, White

Jr.

Cryotherapy and topical minocycline as adjunctive measures to control pain after third molar surgery: an exploratory study. J Oral Maxillofac Surg, 2011; 69:e324–e332.

Coluzzi

, Convissar

. Lasers in clinical dentistry. Dent Clin North Am, 2004; 48:xi–xii.

Boschi

, Leite

, Saciura

, et al. Anti-inflammatory effects of low-level laser therapy (660 nm) in the early phase in carrageenan-induced pleurisy in rat. Lasers Surg Med, 2008; 40:500–508.

Brignardello-Petersen

, Carrasco-Labra

, Araya

, Yanine

, Beyene

, Shah

. Is adjuvant laser therapy effective for preventing pain, swelling, and trismus after surgical removal of impacted mandibular third molars? A systematic review and meta-analysis. J Oral Maxillofac Surg, 2012; 70:1789–1801.

10.

, Yu

, Li

, Pan

, Zhuang

, Duan

. A systematic review and meta-analysis on the efficacy of low-level laser therapy in the management of complication after mandibular third molar surgery. Lasers Med Sci, 2015; 30:1779–1788.

11.

Ferrante

, Petrini

, Trentini

, Perfetti

, Spoto

. Effect of low-level laser therapy after extraction of impacted lower third molars. Lasers Med Sci, 2013; 28:845–849.

12.

Lobo

, Pol

. Evaluation of the use of a 940 nm diode laser as an adjunct in flap surgery for treatment of chronic periodontitis. J Indian Soc Periodontol, 2015; 19:43–48.

13.

Kuboyama

, Ohta

, Sato

, Abiko

. Anti-inflammatory activities of light emitting diode irradiation on collagen-induced arthritis in mice (a secondary publication). Laser Ther, 2014; 23:191–199.

14.

Medina-Huertas

, Manzano-Moreno

, De Luna-Bertos

, Ramos-Torrecillas

, García-Martínez

, Ruiz

. The effects of low-level diode laser irradiation on differentiation, antigenic profile, and phagocytic capacity of osteoblast-like cells (MG-63). Lasers Med Sci, 2014; 29:1479–1484.

15.

Anand

, Gulati

, Govila

, Anand

. Low level laser therapy in the treatment of aphthous ulcer. Indian J Dent Res, 2013; 24:267–270.

16.

Kazancioglu

, Ezirganli

, Demirtas

. Comparison of the influence of ozone and laser therapies on pain, swelling, and trismus following impacted third-molar surgery. Lasers Med Sci, 2014; 29:1313–1319.

17.

Amarillas-Escobar

, Toranzo-Fernández

, Martínez-Rider

, et al. Use of therapeutic laser after surgical removal of impacted lower third molars. J Oral Maxillofac Surg, 2010; 68:319–324.

18.

Røynesdal

, Björnland

, Barkvoll

, Haanaes

. The effect of soft-laser application on postoperative pain and swelling. A double-blind, crossover study. Int J Oral Maxillofac Surg, 1993; 22:242–245.

19.

Aras

, Güngörmüş

. The effect of low-level laser therapy on trismus and facial swelling following surgical extraction of a lower third molar. Photomed Laser Surg, 2009; 27:21–24.

20.

López-Ramírez

, Vílchez-Pérez

, Gargallo-Albiol

, Arnabat-Domínguez

, Gay-Escoda

. Efficacy of low-level laser therapy in the management of pain, facial swelling, and postoperative trismus after a lower third molar extraction. A preliminary study. Lasers Med Sci, 2012; 27:559–566.

21.

Aras

, Güngörmüş

. Placebo-controlled randomized clinical trial of the effect two different low-level laser therapies (LLLT)—Intraoral and extraoral—On trismus and facial swelling following surgical extraction of the lower third molar. Lasers Med Sci, 2010; 25:641–645.

22.

Markovic

, Todorovic

. Effectiveness of dexamethasone and low-power laser in minimizing oedema after third molar surgery: a clinical trial. Int J Oral Maxillofac Surg, 2007; 36:226–229.

23.

Carrillo

, Calatayud

, Manso

, Barberia

, Martinez

, Donado

. A randomized double-blind clinical trial on effectiveness of helium-neon laser in the prevention of pain, swelling and trismus after removal of impacted third molars. Int Dent J, 1990; 40:31–36.

24.

Goldman

, Chiapella

, Bass

, et al. Laser therapy of rheumatoid arthritis. Lasers Surg Med, 1980; 1:93–101.

25.

Fernando

, Hill

, Walker

. A randomised double blind comparative study of low level laser therapy following surgical extraction of lower third molar teeth. Br J Oral Maxillofac Surg, 1993; 31:170–172.

26.

Osunde

, Saheeb

. Effect of age, sex and level of surgical difficulty on inflammatory complications after third molar surgery. J Maxillofac Oral Surg, 2015; 14:7–12.

27.

Yuasa

, Sugiura

. Clinical postoperative findings after removal of impacted mandibular third molars: prediction of postoperative facial swelling and pain based on preoperative variables. Br J Oral Maxillofac Surg, 2004; 42:209–214.

28.

Bello

, Adeyemo

, Bamgbose

, Obi

, Adeyinka

. Effect of age, impaction types and operative time on inflammatory tissue reactions following lower third molar surgery. Head Face Med, 2011; 28:7–8.

29.

Meneguzzo

, Lopes

, Pallota

, Soares-Ferreira

, Lopes-Martins

RÁ

, Ribeiro

. Prevention and treatment of mice paw edema by near-infrared low-level laser therapy on lymph nodes. Lasers Med Sci, 2013; 28:973–980.

30.

Pedersen

. Interrelation of complaints after removal of impacted mandibular third molars. Int J Oral Surg, 1985; 14:241–244.

31.

Carrillo

, Calatayud

, Manso

, Barberia

, Martinez

, Donado

. A randomized double-blind clinical trial on the effectiveness of helium-neon laser in the prevention of pain, swelling and trismus after removal of impacted third molars. Int Dent J, 1990; 40:31–36.

32.

Lievens

. The effect of the combined HeNe and I.R. Laser treatment on the regeneration of the lymphatic system during the process of wound healing. Lasers Med Sci, 1991; 6:193–199.

33.

AlGhamdi

, Kumar

, Moussa

. Low-level laser therapy: a useful technique for enhancing the proliferation of various cultured cells. Lasers Med Sci, 2012; 27:237–249.