- Email: [email protected]
Effect of Low-level Laser Therapy on Postoperative Pain in Molars with Symptomatic Apical Periodontitis: A Randomized Placebo-controlled Clinical Trial
CONSORT Randomized Clinical Trial
Effect of Low-level Laser Therapy on Postoperative Pain in Molars with Symptomatic Apical Periodontitis: A Randomized Placebo-controlled Clinical Trial Ezgi Do ganay Yıldız, DDS, PhD,* and Hakan Arslan, DDS, PhD† Abstract Introduction: In this clinical trial, we evaluated the effect of low-level laser therapy (LLLT) on postoperative pain in mandibular molar teeth with symptomatic apical periodontitis. Methods: Forty-two patients were included in the study according to the inclusion and exclusion criteria. Root canal treatment was conducted using reciprocating instruments. The patients were randomly distributed into 3 groups using a Web program as follows: control (no laser was applied), placebo (mock laser therapy), and LLLT. Postoperative pain levels on the 1st, 3rd, 5th, 7th, and 30th day and postoperative percussion pain levels on the visual analog scale were recorded. The chi-square, 1-way analysis of variance, and least significant difference post hoc tests were performed to analyze the data (P = .05). Results: LLLT resulted in lower pain levels than those noted in the control and placebo groups on days 1 and 3 (P < .05). There were no significant differences among the placebo, LLLT, and control groups in terms of postoperative percussion pain levels (P < .05). Conclusions: LLLT can be beneficial in reducing postoperative pain in endodontics. (J Endod 2018;-:1–6)
Key Words Endodontics, host biomodulation, lasers, low-level laser therapy, pain
O
ne of the most imporSignificance tant aspects of endLLLT resulted in lower pain levels than those odontic treatment is pain observed in the control and placebo groups on management. Postoperadays 1 and 3. Only 1 patient needed analgesics tive pain after endodontic postoperatively in the LLLT group. Thus, LLLT treatment is a frequent can be beneficial in reducing postoperative pain complication. According in endodontics. to a systematic review, the frequency of endodontic postoperative pain is between 3% and 58% of patients (1). Low-level laser therapy (LLLT) was first described by Mester et al (2), who found that LLLT biostimulates the growth of hair. Many studies relating to LLLT have been published in dentistry. Fernando et al (3) evaluated the efficacy of LLLT in the reduction of postoperative pain and swelling in patients undergoing the extraction of impacted mandibular third molar teeth and concluded there was no evidence of a difference in pain and swelling on the third day after the operation between the laser and placebo groups. In another study, Gerschman et al (4) evaluated the effect of LLLT on the management of dentinal tooth hypersensitivity and found that LLLT is an effective method for the treatment of both thermal and tactile dentinal hypersensitivity. In 1990, Kurumada (5) evaluated the effects of laser irradiation on vital pulpotomy. The author concluded that laser irradiation induced enhancement of calcification of the wound surface and stimulated the formation of calcified tissue. Arslan et al (6) and Asnaashari et al (7) evaluated the effect of LLLT on postoperative pain after root canal retreatment, and although Arslan et al reported it reduced postoperative pain, Asnaashari et al reported that no significant differences were observed at any time between the LLLT group and the placebo group regarding pain scores. According to our literature research, there is no study that evaluates its effect on postoperative pain after the initial endodontic treatment. Thus, the purpose of this study was to evaluate the effect of LLLT on postoperative pain in mandibular molar teeth with symptomatic apical periodontitis. The null hypothesis was that there is no difference among the groups in postoperative pain.
Materials and Methods The protocol was approved by the research ethics committee (no. 05-2014). The sample size was calculated considering 80% power and a significance level of .05 (effect size = 0.475) according to the results of the study by Yoo et al (8). As a result, 42 specimens were sufficient for 3 groups (n = 14). The patients referred to the clinic between
From the *Department of Endodontics, Faculty of Dentistry, Kırıkkale University, Kırıkkale, Turkey; and †Department of Endodontics, Faculty of Dentistry, Ataturk University, Erzurum, Turkey. Address requests for reprints to Dr Ezgi Doganay Yıldız, Department of Endodontics, Faculty of Dentistry, Kırıkkale University, Kırıkkale 71450, Turkey. E-mail address: [email protected] 0099-2399/$ - see front matter Copyright ª 2018 American Association of Endodontists. https://doi.org/10.1016/j.joen.2018.07.002
JOE — Volume -, Number -, - 2018
Low-level Laser Therapy
1
CONSORT Randomized Clinical Trial March 2015 and October 2015 were assessed for eligibility. The details are presented in the Consolidated Standards Of Reporting Trials flow diagram (Fig. 1). The inclusion criteria were as follows: 1. Patients older than 18 years 2. Patients having a mandibular molar tooth with symptomatic apical periodontitis needing a primary endodontic procedure Preoperative and percussion pain were recorded on a 10-cm visual analog scale (VAS) by the patients. Percussion was performed by tapping on the occlusal surfaces of the teeth with the back end of a mirror handle. It was assessed just before the root canal treatment by the operator who performed the root canal treatment. Diagnosis of the tooth as symptomatic apical periodontitis was conducted according to the book Cohen’s Pathways of the Pulp. Clinical symptoms were defined as follows: 1. Severe preoperative pain (VAS >60) 2. Severe percussion pain (VAS > 60) Exclusion criteria were as follows: 1. Patients with systematic diseases or allergic reactions
2. 3. 4. 5. 6.
Patients who had taken analgesics within the last 3 days Previous root canal treatment Swelling or sinus tract Severe periodontal disease The presence of periodontal pockets more than 3 mm in the corresponding tooth 7. Periapical radiolucency Also, patients having root canal treatment with the following technical difficulties or problems were excluded: 1. 2. 3. 4.
A tooth with curved roots A tooth with an excessively long or short root length Problems in determining the working length Patients with complications during treatment such as broken files, overinstrumentation, overfilling, or incomplete filling
Patients were randomly distributed into 3 groups using a Web program (available at www.randomizer.org). The patient number and group number were recorded on paper. New patients were included in the study in place of lost patients. The root canal treatments were performed by 1 operator (a specialist in endodontics). After each patient signed the informed
Figure 1. The Consolidated Standards of Reporting Trials flow diagram.
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CONSORT Randomized Clinical Trial consent forms, mandibular block anesthesia was performed using a local anesthetic solution containing 1.8 mL 4% articaine with 1:100,000 epinephrine (Ultracaine DS Forte; Aventis, Istanbul, Turkey). The procedure started after lip numbness was achieved. A straight-line access cavity was prepared, and the procedure was completed via rubber dam isolation. The working length was determined using an electronic apex locator (Propex Pixi; Dentsply Maillefer, Ballaigues, Switzerland), and Reciproc instruments (VDW, Munich, Germany) were used according to the manufacturer’s instructions. New Reciproc instruments were used for each patient. A size 10 K-file was used to maintain apical patency, 2 mL 1% sodium hypochlorite was used between in-and-out pecking motions, and a final rinse was performed using 5 mL 1% NaOCl for 1 minute and 5 mL 5% EDTA for 1 minute to remove the smear layer. After root canal preparation, the root canals were dried with paper points and filled using matched single cones and 2Seal sealer (VDW). The pulp chamber was filled with a flowable composite resin, and a nanohybrid composite resin was inserted into the cavity using an incremental technique and cured for 20 seconds using an LED light-curing unit (Valo Cordless; Ultradent, South Jordan, UT) with an output of 1000 mW/cm2. The patients were divided into 3 groups (n = 14) as follows: 1. Control: no laser was applied. 2. Placebo (mock laser therapy): the diode laser tip was placed at a distance of approximately 10 mm from the tissue around the apex of the root; however, it was not activated. 3. LLLT: subsequent to root canal treatment, LLLT was performed using a 970 15 nm diode laser (SIROLaser Xtend; Sirona Dental Systems GmbH, Bensheim, Germany). A 200-mm optical fiber and a bleaching application tip were placed at a distance of approximately 10 mm from the tissue around the apex of the root and activated at 0.5 W and 10 Hz (power density z 286 W/cm2). The tissue around the apex of the mesial root apex was treated for 30 seconds, and the tissue around the apex of the distal root apex was treated for 30 seconds separately. The patients were instructed to use 400 mg ibuprofen (Brufen; Abbott, Latina, Italy) if the pain was unbearable and asked to record analgesic intake. The patients recorded their pain experience on a customized form, which was also used to record any analgesic intake. The following variables were recorded: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12.
Age Sex Tooth number Number of canals Pulp vitality Preoperative pain on the VAS Preoperative and postoperative percussion pain levels (on the 7th day) on the VAS Pain level on the 1st, 3rd, 5th, 7th, and 30th days Pain during laser application Palpation sensitivity, swelling, and sinus tract pre- and postoperatively Analgesic intake after the procedure An unscheduled appointment
Statistical Analysis Linear regression analysis was used to determine the variable (group, age, sex, tooth number, pulp status, preoperative pain, preoperative percussion, or preoperative palpation) that affected postoperative pain the most. The Pearson correlation, t test, chi-square test, 1-way JOE — Volume -, Number -, - 2018
analysis of variance, and least significant different post hoc test were performed to analyze the data (P = .05).
Results Forty-two patients were enrolled in this study (Fig. 1). The age range of the patients was 18–46 years. The demographic data are available in Table 1. There were no statistically significant differences among the groups in terms of demographic data (P > .05). Pulp vitality, preoperative and postoperative palpation sensitivity, swelling, and sinus tract are shown in Table 1 (P > .05). No patient was referred for an unscheduled appointment. Although only 1 patient needed analgesics postoperatively in the LLLT group, there were no significant differences among the groups in terms of the number of patients who needed analgesics postoperatively (P > .05). On day 30, all patients except 1 reported 100% pain relief. The patient reported 95% relief of preoperative pain on day 30. Statistical analysis revealed that there were no significant differences among the groups in terms of preoperative pain levels (P > .05) and percussion pain levels (P > .05). The postoperative pain levels are presented in Figure 2. LLLT resulted in lower pain levels than those noted in the control group and placebo group on day 1 and 3 (P < .05). There were no significant differences between the placebo, LLLT, and control groups in terms of postoperative percussion pain levels (P > .05) (Fig. 3). Regression analysis showed that the most significant factor on postoperative pain was group variation. Sex, pulpal status, tooth number (first or second molar), the presence of preoperative palpation, and an extra canal had no significant effect on postoperative pain on days 1 and 3 (P > .05). According to the Pearson correlation, there was no significant effect of age on postoperative pain on days 1 and 3 (P > .05).
Discussion The purpose of this study was to evaluate the effect of LLLT on postoperative pain in mandibular molar teeth with symptomatic apical periodontitis. The null hypothesis was that there is no difference among the groups in postoperative pain. According to the results of the present study, LLLT resulted in lower pain levels than those observed in the control and placebo groups on days 1 and 3 (P < .05). Thus, the null hypothesis was rejected. Bjordal et al (9) reported that LLLT can modulate inflammatory processes and reduce acute inflammatory pain by lowering, in a dose-dependent manner, levels of prostaglandin E2, interleukin 1 beta, tumor necrosis factor alpha, oxidative stress, and edema. LLLT can also decrease the firing frequency of nociceptors (10). LLLT selectively inhibits nociceptive signals in peripheral nerves (11). In addition to these effects of LLLT, it was found to reduce edema (12). In a systematic review, LLLT has been effective in the management of breast cancer– related lymphedema (13). Thus, it has been claimed that LLLT also improves lymphatic flow. In another study by Yang et al (14), the amount of intracellular calcium was increased followed by histamine release after LLLT. The decreased postendodontic pain levels obtained from the results of the present study may be explained by the ability of LLLT to reduce inflammatory processes, fire nociceptors, increase lymphatic drainage, and increase histamine release. There is no study about the efficacy of LLLT on postendodontic pain after the initial root canal treatment. Arslan et al (6) reported LLLT reduced postoperative pain after root canal retreatment. This finding agrees with those obtained from the present study, with the same parameters used. In another study, Asnaashari et al (7) reported that there were no significant differences between the LLLT and placebo
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CONSORT Randomized Clinical Trial TABLE 1. Demographic Data and Preoperative and Postoperative Status of Some Variables Demographic data Age Sex Female Male Tooth number Left first molar Left second molar Right first molar Right second molar Number of root canals 3 4 5 Preoperative and postoperative status Number of patients with preoperative palpation sensitivity Number of patients with vital pulp Number of patients who needed analgesics postoperatively Number of patients with postoperative palpation sensitivity Number of patients with postoperative swelling Number of patients with postoperative sinus tract Number of patients referred for an unscheduled appointment
Control
Placebo
LLLT
P value
26.00 5.84
27.43 8.89
28.14 9.56
.786
5 9
7 7
7 7
.681
6 2 4 2
5 1 4 4
8 2 3 1
.768
10 4 0
10 4 0
9 5 0
.895
3 10 4 0 0 0 0
5 9 3 0 0 0 0
5 12 1 0 0 0 0
.640 .422 .339 NA NA NA NA
LLLT, low-level laser therapy; NA, not applicable. One-way analysis of variance and the chi-square test were used to analyze the data.
groups in terms of pain reduction after root canal retreatment. Thus, the results of that study are not consistent with the results of the present study. LLLT has been used after endodontic surgery, and it was reported to have a statistically significant effect on reducing pain after endodontic surgery (15). LLLT has also been used after third molar extraction, leading to the conclusion that LLLT application results in a greater reduction of postoperative pain (16). As in another area (ie, orthodontics), it has been reported that LLLT is an effective and noninvasive method for controlling pain in orthodontic patients (17). LLLT has been used in various areas of dentistry for reducing pain. Although a direct comparison cannot be made, those results are in agreement with this study in terms of pain reduction.
In the present study, there was no significant correlation between the age of the patient and postoperative pain. This observation confirms the findings of the studies performed by Ng et al (18) and Polycarpou et al (19). However, the present study disagrees with Ali et al (20), who claimed that postoperative pain would be greater in older age groups when compared with younger age groups. In the study by Ali et al, patients were divided into 2 groups, and they concluded that postoperative pain was higher in the older age group (41–65 years) than the younger age group (15–40 years). In the present study, the age range was 18–46 years and may explain the differences among study results. Although some studies concluded that postoperative pain in females had a higher prevalence than in males (20–23), some studies
Figure 2. The change in pain levels according to day. There were no significant differences among the groups in terms of preoperative pain (P > .05). On days 1 and 3, LLLT was superior to all of the other groups in terms of postoperative pain (P < .05).
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CONSORT Randomized Clinical Trial
Figure 3. The change in pre- and postoperative (1 week later) percussion pain levels. There were no significant differences among the groups in terms of postoperative percussion pain levels (P > .05).
have concluded sex did not have a significant effect (24, 25). In the present study, sex had no influence on postoperative pain. Ali et al (20) reported that when a root canal treatment was performed in a single visit, the vitality of the pulp had no influence on postoperative pain. In another study, a significant association was shown between postoperative pain and nonvital pulp (21, 26). In the present study, no significant effect of pulpal status on postoperative pain was found. Postoperative pain is the result of a complex multifactorial process that is influenced by factors inherent in patients, the tooth treated, and the operator. Different results among studies in terms of sex and pulpal status may be because of this complex process. Regarding tooth type and location, more postoperative pain was found in molars compared with other teeth (18, 22). When comparing between jaws, postoperative pain in the mandibular molars reached higher levels than maxillary molars (20, 22). According to our literature search, there is no study that evaluates the effect of tooth number among mandibular molars (first vs second mandibular molar) on postoperative pain. According to the results of the present study, tooth number among mandibular molar teeth had no significant effect on postoperative pain.
Conclusion Within the limitations of the present study, LLLT resulted in lower pain levels than those observed in the control and placebo groups on days 1 and 3. Only 1 patient needed analgesics postoperatively in the LLLT group. Thus, LLLT can be beneficial in reducing postoperative pain in endodontics.
Acknowledgments Supported in part by the TUBITAK Research Fund (no. 114S910). The authors deny any conflicts of interest related to this study.
References 1. Sathorn C, Parashos P, Messer H. The prevalence of postoperative pain and flare-up in single- and multiple-visit endodontic treatment: a systematic review. Int Endod J 2008;41:91–9.
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2. Mester E, Szende B, Gartner P. [The effect of laser beams on the growth of hair in mice]. Radiobiol Radiother 1968;9:621–6. 3. Fernando S, Hill CM, Walker R. 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;31:170–2. 4. Gerschman JA, Ruben J, Gebart-Eaglemont J. Low level laser therapy for dentinal tooth hypersensitivity. Aust Dent J 1994;39:353–7. 5. Kurumada F. [A study on the application of Ga-As semiconductor laser to endodontics. The effects of laser irradiation on the activation of inflammatory cells and the vital pulpotomy]. Ou Daigaku Shigakushi 1990;17:233–44. 6. Arslan H, Doganay E, Karatas E, et al. Effect of low-level laser therapy on postoperative pain after root canal retreatment: a preliminary placebo-controlled, tripleblind, randomized clinical trial. J Endod 2017;43:1765–9. 7. Asnaashari M, Ashraf H, Daghayeghi AH, et al. Management of post endodontic retreatment pain with low level laser therapy. J Lasers Med Sci 2017;8:128–31. 8. Yoo YJ, Shon WJ, Baek SH, et al. Effect of 1440-nanometer neodymium:yttriumaluminum-garnet laser irradiation on pain and neuropeptide reduction: a randomized prospective clinical trial. J Endod 2014;40:28–32. 9. Bjordal JM, Johnson MI, Iversen V, et al. Low-level laser therapy in acute pain: a systematic review of possible mechanisms of action and clinical effects in randomized placebo-controlled trials. Photomed Laser Surg 2006;24:158–68. 10. Mezawa S, Iwata K, Naito K, Kamogawa H. The possible analgesic effect of soft-laser irradiation on heat nociceptors in the cat tongue. Arch Oral Biol 1988;33:693–4. 11. Sato T, Kawatani M, Takeshige C, Matsumoto I. Ga-Al-As laser irradiation inhibits neuronal activity associated with inflammation. Acupunct Electrother Res 1994; 19:141–51. 12. Stergioulas AT. Low-level laser treatment can reduce edema in second degree ankle sprains. J Clin Laser Med Surg 2004;22:125–8. 13. E Lima MT, E Lima JG, de Andrade MF, Bergmann A. Low-level laser therapy in secondary lymphedema after breast cancer: systematic review. Lasers Med Sci 2014;29: 1289–95. 14. Yang WZ, Chen JY, Yu JT, Zhou LW. Effects of low power laser irradiation on intracellular calcium and histamine release in RBL-2H3 mast cells. Photochem Photobiol 2007;83:979–84. 15. Kreisler MB, Haj HA, Noroozi N, Willershausen B. Efficacy of low level laser therapy in reducing postoperative pain after endodontic surgery–a randomized double blind clinical study. Int J Oral Maxillofac Surg 2004;33: 38–41. 16. Kahraman SA, Cetiner S, Strauss RA. The effects of transcutaneous and intraoral low-level laser therapy after extraction of lower third molars: a randomized single blind, placebo controlled dual-center study. Photomed Laser Surg 2017; 35:401–7. 17. Nahin J, Arshad F, Srinivas BV, et al. The efficacy of low-level laser therapy on pain caused by placement of the first orthodontic archwire: a clinical study. J Contemp Dent Pract 2018;19:450–5.
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CONSORT Randomized Clinical Trial 18. Ng YL, Glennon JP, Setchell DJ, Gulabivala K. Prevalence of and factors affecting postobturation pain in patients undergoing root canal treatment. Int Endod J 2004;37: 381–91. 19. Polycarpou N, Ng YL, Canavan D, et al. Prevalence of persistent pain after endodontic treatment and factors affecting its occurrence in cases with complete radiographic healing. Int Endod J 2005;38:169–78. 20. Ali SG, Mulay S, Palekar A, et al. Prevalence of and factors affecting postobturation pain following single visit root canal treatment in Indian population: a prospective, randomized clinical trial. Contemp Clin Dent 2012;3: 459–63. 21. Albashaireh ZS, Alnegrish AS. Postobturation pain after single- and multiple-visit endodontic therapy. A prospective study. J Dent 1998;26:227–32.
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22. Nagendrababu V, Gutmann JL. Factors associated with postobturation pain following single-visit nonsurgical root canal treatment: a systematic review. Quintessence Int 2017;48:193–208. 23. Walton R, Fouad A. Endodontic interappointment flare-ups: a prospective study of incidence and related factors. J Endod 1992;18:172–7. 24. Torabinejad M, Kettering JD, McGraw JC, et al. Factors associated with endodontic interappointment emergencies of teeth with necrotic pulps. J Endod 1988;14: 261–6. 25. Imura N, Zuolo ML. Factors associated with endodontic flare-ups: a prospective study. Int Endod J 1995;28:261–5. 26. El Mubarak AH, Abu-bakr NH, Ibrahim YE. Postoperative pain in multiple-visit and single-visit root canal treatment. J Endod 2010;36:36–9.
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Effect of Low-level Laser Therapy on Postoperative Pain in Molars with Symptomatic Apical Periodontitis: A Randomized Placebo-controlled Clinical Trial Ezgi Do ganay Yıldız, DDS, PhD,* and Hakan Arslan, DDS, PhD† Abstract Introduction: In this clinical trial, we evaluated the effect of low-level laser therapy (LLLT) on postoperative pain in mandibular molar teeth with symptomatic apical periodontitis. Methods: Forty-two patients were included in the study according to the inclusion and exclusion criteria. Root canal treatment was conducted using reciprocating instruments. The patients were randomly distributed into 3 groups using a Web program as follows: control (no laser was applied), placebo (mock laser therapy), and LLLT. Postoperative pain levels on the 1st, 3rd, 5th, 7th, and 30th day and postoperative percussion pain levels on the visual analog scale were recorded. The chi-square, 1-way analysis of variance, and least significant difference post hoc tests were performed to analyze the data (P = .05). Results: LLLT resulted in lower pain levels than those noted in the control and placebo groups on days 1 and 3 (P < .05). There were no significant differences among the placebo, LLLT, and control groups in terms of postoperative percussion pain levels (P < .05). Conclusions: LLLT can be beneficial in reducing postoperative pain in endodontics. (J Endod 2018;-:1–6)
Key Words Endodontics, host biomodulation, lasers, low-level laser therapy, pain
O
ne of the most imporSignificance tant aspects of endLLLT resulted in lower pain levels than those odontic treatment is pain observed in the control and placebo groups on management. Postoperadays 1 and 3. Only 1 patient needed analgesics tive pain after endodontic postoperatively in the LLLT group. Thus, LLLT treatment is a frequent can be beneficial in reducing postoperative pain complication. According in endodontics. to a systematic review, the frequency of endodontic postoperative pain is between 3% and 58% of patients (1). Low-level laser therapy (LLLT) was first described by Mester et al (2), who found that LLLT biostimulates the growth of hair. Many studies relating to LLLT have been published in dentistry. Fernando et al (3) evaluated the efficacy of LLLT in the reduction of postoperative pain and swelling in patients undergoing the extraction of impacted mandibular third molar teeth and concluded there was no evidence of a difference in pain and swelling on the third day after the operation between the laser and placebo groups. In another study, Gerschman et al (4) evaluated the effect of LLLT on the management of dentinal tooth hypersensitivity and found that LLLT is an effective method for the treatment of both thermal and tactile dentinal hypersensitivity. In 1990, Kurumada (5) evaluated the effects of laser irradiation on vital pulpotomy. The author concluded that laser irradiation induced enhancement of calcification of the wound surface and stimulated the formation of calcified tissue. Arslan et al (6) and Asnaashari et al (7) evaluated the effect of LLLT on postoperative pain after root canal retreatment, and although Arslan et al reported it reduced postoperative pain, Asnaashari et al reported that no significant differences were observed at any time between the LLLT group and the placebo group regarding pain scores. According to our literature research, there is no study that evaluates its effect on postoperative pain after the initial endodontic treatment. Thus, the purpose of this study was to evaluate the effect of LLLT on postoperative pain in mandibular molar teeth with symptomatic apical periodontitis. The null hypothesis was that there is no difference among the groups in postoperative pain.
Materials and Methods The protocol was approved by the research ethics committee (no. 05-2014). The sample size was calculated considering 80% power and a significance level of .05 (effect size = 0.475) according to the results of the study by Yoo et al (8). As a result, 42 specimens were sufficient for 3 groups (n = 14). The patients referred to the clinic between
From the *Department of Endodontics, Faculty of Dentistry, Kırıkkale University, Kırıkkale, Turkey; and †Department of Endodontics, Faculty of Dentistry, Ataturk University, Erzurum, Turkey. Address requests for reprints to Dr Ezgi Doganay Yıldız, Department of Endodontics, Faculty of Dentistry, Kırıkkale University, Kırıkkale 71450, Turkey. E-mail address: [email protected] 0099-2399/$ - see front matter Copyright ª 2018 American Association of Endodontists. https://doi.org/10.1016/j.joen.2018.07.002
JOE — Volume -, Number -, - 2018
Low-level Laser Therapy
1
CONSORT Randomized Clinical Trial March 2015 and October 2015 were assessed for eligibility. The details are presented in the Consolidated Standards Of Reporting Trials flow diagram (Fig. 1). The inclusion criteria were as follows: 1. Patients older than 18 years 2. Patients having a mandibular molar tooth with symptomatic apical periodontitis needing a primary endodontic procedure Preoperative and percussion pain were recorded on a 10-cm visual analog scale (VAS) by the patients. Percussion was performed by tapping on the occlusal surfaces of the teeth with the back end of a mirror handle. It was assessed just before the root canal treatment by the operator who performed the root canal treatment. Diagnosis of the tooth as symptomatic apical periodontitis was conducted according to the book Cohen’s Pathways of the Pulp. Clinical symptoms were defined as follows: 1. Severe preoperative pain (VAS >60) 2. Severe percussion pain (VAS > 60) Exclusion criteria were as follows: 1. Patients with systematic diseases or allergic reactions
2. 3. 4. 5. 6.
Patients who had taken analgesics within the last 3 days Previous root canal treatment Swelling or sinus tract Severe periodontal disease The presence of periodontal pockets more than 3 mm in the corresponding tooth 7. Periapical radiolucency Also, patients having root canal treatment with the following technical difficulties or problems were excluded: 1. 2. 3. 4.
A tooth with curved roots A tooth with an excessively long or short root length Problems in determining the working length Patients with complications during treatment such as broken files, overinstrumentation, overfilling, or incomplete filling
Patients were randomly distributed into 3 groups using a Web program (available at www.randomizer.org). The patient number and group number were recorded on paper. New patients were included in the study in place of lost patients. The root canal treatments were performed by 1 operator (a specialist in endodontics). After each patient signed the informed
Figure 1. The Consolidated Standards of Reporting Trials flow diagram.
2
Doganay Yıldız and Arslan
JOE — Volume -, Number -, - 2018
CONSORT Randomized Clinical Trial consent forms, mandibular block anesthesia was performed using a local anesthetic solution containing 1.8 mL 4% articaine with 1:100,000 epinephrine (Ultracaine DS Forte; Aventis, Istanbul, Turkey). The procedure started after lip numbness was achieved. A straight-line access cavity was prepared, and the procedure was completed via rubber dam isolation. The working length was determined using an electronic apex locator (Propex Pixi; Dentsply Maillefer, Ballaigues, Switzerland), and Reciproc instruments (VDW, Munich, Germany) were used according to the manufacturer’s instructions. New Reciproc instruments were used for each patient. A size 10 K-file was used to maintain apical patency, 2 mL 1% sodium hypochlorite was used between in-and-out pecking motions, and a final rinse was performed using 5 mL 1% NaOCl for 1 minute and 5 mL 5% EDTA for 1 minute to remove the smear layer. After root canal preparation, the root canals were dried with paper points and filled using matched single cones and 2Seal sealer (VDW). The pulp chamber was filled with a flowable composite resin, and a nanohybrid composite resin was inserted into the cavity using an incremental technique and cured for 20 seconds using an LED light-curing unit (Valo Cordless; Ultradent, South Jordan, UT) with an output of 1000 mW/cm2. The patients were divided into 3 groups (n = 14) as follows: 1. Control: no laser was applied. 2. Placebo (mock laser therapy): the diode laser tip was placed at a distance of approximately 10 mm from the tissue around the apex of the root; however, it was not activated. 3. LLLT: subsequent to root canal treatment, LLLT was performed using a 970 15 nm diode laser (SIROLaser Xtend; Sirona Dental Systems GmbH, Bensheim, Germany). A 200-mm optical fiber and a bleaching application tip were placed at a distance of approximately 10 mm from the tissue around the apex of the root and activated at 0.5 W and 10 Hz (power density z 286 W/cm2). The tissue around the apex of the mesial root apex was treated for 30 seconds, and the tissue around the apex of the distal root apex was treated for 30 seconds separately. The patients were instructed to use 400 mg ibuprofen (Brufen; Abbott, Latina, Italy) if the pain was unbearable and asked to record analgesic intake. The patients recorded their pain experience on a customized form, which was also used to record any analgesic intake. The following variables were recorded: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12.
Age Sex Tooth number Number of canals Pulp vitality Preoperative pain on the VAS Preoperative and postoperative percussion pain levels (on the 7th day) on the VAS Pain level on the 1st, 3rd, 5th, 7th, and 30th days Pain during laser application Palpation sensitivity, swelling, and sinus tract pre- and postoperatively Analgesic intake after the procedure An unscheduled appointment
Statistical Analysis Linear regression analysis was used to determine the variable (group, age, sex, tooth number, pulp status, preoperative pain, preoperative percussion, or preoperative palpation) that affected postoperative pain the most. The Pearson correlation, t test, chi-square test, 1-way JOE — Volume -, Number -, - 2018
analysis of variance, and least significant different post hoc test were performed to analyze the data (P = .05).
Results Forty-two patients were enrolled in this study (Fig. 1). The age range of the patients was 18–46 years. The demographic data are available in Table 1. There were no statistically significant differences among the groups in terms of demographic data (P > .05). Pulp vitality, preoperative and postoperative palpation sensitivity, swelling, and sinus tract are shown in Table 1 (P > .05). No patient was referred for an unscheduled appointment. Although only 1 patient needed analgesics postoperatively in the LLLT group, there were no significant differences among the groups in terms of the number of patients who needed analgesics postoperatively (P > .05). On day 30, all patients except 1 reported 100% pain relief. The patient reported 95% relief of preoperative pain on day 30. Statistical analysis revealed that there were no significant differences among the groups in terms of preoperative pain levels (P > .05) and percussion pain levels (P > .05). The postoperative pain levels are presented in Figure 2. LLLT resulted in lower pain levels than those noted in the control group and placebo group on day 1 and 3 (P < .05). There were no significant differences between the placebo, LLLT, and control groups in terms of postoperative percussion pain levels (P > .05) (Fig. 3). Regression analysis showed that the most significant factor on postoperative pain was group variation. Sex, pulpal status, tooth number (first or second molar), the presence of preoperative palpation, and an extra canal had no significant effect on postoperative pain on days 1 and 3 (P > .05). According to the Pearson correlation, there was no significant effect of age on postoperative pain on days 1 and 3 (P > .05).
Discussion The purpose of this study was to evaluate the effect of LLLT on postoperative pain in mandibular molar teeth with symptomatic apical periodontitis. The null hypothesis was that there is no difference among the groups in postoperative pain. According to the results of the present study, LLLT resulted in lower pain levels than those observed in the control and placebo groups on days 1 and 3 (P < .05). Thus, the null hypothesis was rejected. Bjordal et al (9) reported that LLLT can modulate inflammatory processes and reduce acute inflammatory pain by lowering, in a dose-dependent manner, levels of prostaglandin E2, interleukin 1 beta, tumor necrosis factor alpha, oxidative stress, and edema. LLLT can also decrease the firing frequency of nociceptors (10). LLLT selectively inhibits nociceptive signals in peripheral nerves (11). In addition to these effects of LLLT, it was found to reduce edema (12). In a systematic review, LLLT has been effective in the management of breast cancer– related lymphedema (13). Thus, it has been claimed that LLLT also improves lymphatic flow. In another study by Yang et al (14), the amount of intracellular calcium was increased followed by histamine release after LLLT. The decreased postendodontic pain levels obtained from the results of the present study may be explained by the ability of LLLT to reduce inflammatory processes, fire nociceptors, increase lymphatic drainage, and increase histamine release. There is no study about the efficacy of LLLT on postendodontic pain after the initial root canal treatment. Arslan et al (6) reported LLLT reduced postoperative pain after root canal retreatment. This finding agrees with those obtained from the present study, with the same parameters used. In another study, Asnaashari et al (7) reported that there were no significant differences between the LLLT and placebo
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CONSORT Randomized Clinical Trial TABLE 1. Demographic Data and Preoperative and Postoperative Status of Some Variables Demographic data Age Sex Female Male Tooth number Left first molar Left second molar Right first molar Right second molar Number of root canals 3 4 5 Preoperative and postoperative status Number of patients with preoperative palpation sensitivity Number of patients with vital pulp Number of patients who needed analgesics postoperatively Number of patients with postoperative palpation sensitivity Number of patients with postoperative swelling Number of patients with postoperative sinus tract Number of patients referred for an unscheduled appointment
Control
Placebo
LLLT
P value
26.00 5.84
27.43 8.89
28.14 9.56
.786
5 9
7 7
7 7
.681
6 2 4 2
5 1 4 4
8 2 3 1
.768
10 4 0
10 4 0
9 5 0
.895
3 10 4 0 0 0 0
5 9 3 0 0 0 0
5 12 1 0 0 0 0
.640 .422 .339 NA NA NA NA
LLLT, low-level laser therapy; NA, not applicable. One-way analysis of variance and the chi-square test were used to analyze the data.
groups in terms of pain reduction after root canal retreatment. Thus, the results of that study are not consistent with the results of the present study. LLLT has been used after endodontic surgery, and it was reported to have a statistically significant effect on reducing pain after endodontic surgery (15). LLLT has also been used after third molar extraction, leading to the conclusion that LLLT application results in a greater reduction of postoperative pain (16). As in another area (ie, orthodontics), it has been reported that LLLT is an effective and noninvasive method for controlling pain in orthodontic patients (17). LLLT has been used in various areas of dentistry for reducing pain. Although a direct comparison cannot be made, those results are in agreement with this study in terms of pain reduction.
In the present study, there was no significant correlation between the age of the patient and postoperative pain. This observation confirms the findings of the studies performed by Ng et al (18) and Polycarpou et al (19). However, the present study disagrees with Ali et al (20), who claimed that postoperative pain would be greater in older age groups when compared with younger age groups. In the study by Ali et al, patients were divided into 2 groups, and they concluded that postoperative pain was higher in the older age group (41–65 years) than the younger age group (15–40 years). In the present study, the age range was 18–46 years and may explain the differences among study results. Although some studies concluded that postoperative pain in females had a higher prevalence than in males (20–23), some studies
Figure 2. The change in pain levels according to day. There were no significant differences among the groups in terms of preoperative pain (P > .05). On days 1 and 3, LLLT was superior to all of the other groups in terms of postoperative pain (P < .05).
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Figure 3. The change in pre- and postoperative (1 week later) percussion pain levels. There were no significant differences among the groups in terms of postoperative percussion pain levels (P > .05).
have concluded sex did not have a significant effect (24, 25). In the present study, sex had no influence on postoperative pain. Ali et al (20) reported that when a root canal treatment was performed in a single visit, the vitality of the pulp had no influence on postoperative pain. In another study, a significant association was shown between postoperative pain and nonvital pulp (21, 26). In the present study, no significant effect of pulpal status on postoperative pain was found. Postoperative pain is the result of a complex multifactorial process that is influenced by factors inherent in patients, the tooth treated, and the operator. Different results among studies in terms of sex and pulpal status may be because of this complex process. Regarding tooth type and location, more postoperative pain was found in molars compared with other teeth (18, 22). When comparing between jaws, postoperative pain in the mandibular molars reached higher levels than maxillary molars (20, 22). According to our literature search, there is no study that evaluates the effect of tooth number among mandibular molars (first vs second mandibular molar) on postoperative pain. According to the results of the present study, tooth number among mandibular molar teeth had no significant effect on postoperative pain.
Conclusion Within the limitations of the present study, LLLT resulted in lower pain levels than those observed in the control and placebo groups on days 1 and 3. Only 1 patient needed analgesics postoperatively in the LLLT group. Thus, LLLT can be beneficial in reducing postoperative pain in endodontics.
Acknowledgments Supported in part by the TUBITAK Research Fund (no. 114S910). The authors deny any conflicts of interest related to this study.
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