Efficacy of low‐level laser therapy in the treatment of TMDs: a meta‐analysis of 14 randomised controlled trials

This study was designed to evaluate the efficacy of low‐level laser therapy (LLLT) in the treatment of temporomandibular disorders (TMDs). We searched electronic databases and references lists of relevant articles, retrieved all of the published randomised controlled trials in regard to these issues and then performed a meta‐analysis. Fourteen highly qualified RCTs reporting on a total of 454 patients, which evaluated the effectiveness of LLLT for patients suffering from TMDs were retrieved. The results indicated that LLLT was not better than placebo in reducing chronic TMD pain (weighted mean difference = ?19·39; 95% confidence interval = ?40·80–2·03; P < 0·00001; I² = 99%). However, the LLLT provided significant better functional outcomes in terms of maximum active vertical opening (MAVO) (weighted mean difference = 4·18; 95% confidence interval = 0·73–7·63; P = 0·006; I² = 73%), maximum passive vertical opening (MPVO) (weighted mean difference = 6·73; 95% confidence interval = 01·34–12·13; P = 0·06; I² = 73%), protrusion excursion (PE) (weighted mean difference = 1·81; 95% confidence interval = 0·79–2·83; P = 0·59; I² = 0%) and right lateral excursion (RLE) (weighted mean difference = 2·86; 95% confidence interval = 1·27–4·45; P = 0·01; I² = 73%). The results of our meta‐analysis have provided the best evidence on the efficacy of LLLT in the treatment of TMDs. This study indicates that using LLLT has limited efficacy in reducing pain in patients with TMDs. However, LLLT can significantly improve the functional outcomes of patients with TMDs.     

Effects of low‐level laser therapy on burning mouth syndrome

To investigate low‐level laser therapy (LLLT) applied to treat burning mouth syndrome (BMS). This prospective, comparative, partially blinded, single‐centre, clinical trial of GaAlAs Laser, with 815 nm wavelength, included 44 BMS patients divided randomly into three groups: Group I (n = 16): GaAlAs laser 815 nm wavelength, 1 W output power, continuous emissions, 4 s, 4 J and fluence rate 133·3 J cm^?2; Group II (n = 16): GaAlAs infrared laser, 815 nm wavelength, 1 W output power, continuous emissions, 6 s, 6 J and fluence rate 200 J cm^?2; Group III (n = 12) placebo group, sham laser. All groups received a weekly dose for 4 weeks. Pain intensity was recorded using a 10‐cm visual analogue scale; patients responded to the oral health impact profile (OHIP‐14), xerostomia severity test and the hospital anxiety–depression scale (HAD). These assessments were performed at baseline, 2 and 4 weeks. LLLT decreased pain intensity and improved OHIP‐14 scores significantly from baseline to 2 weeks in groups I and II compared with the placebo group. No statistically significant differences were found from 2 to 4 weeks. Overall improvements in visual analogue scale (VAS) scores from baseline to the end of treatment were as follows: Group I 15·7%; Group II 15·6%; Group III placebo 7·3%. LLLT application reduces symptoms slightly in BMS patients.     

Treatment of dentin hypersensitivity with a low‐level laser‐emitting toothbrush: double‐blind randomised clinical trial of efficacy and safety

Dentin hypersensitivity (DH) is defined as pain derived from exposed dentin in response to chemical, thermal, tactile, or osmotic stimuli that cannot be explained as having arisen from any other dental defect or disease. The aim of this trial was to test the efficacy and the safety of a low‐level laser‐emitting toothbrush on management of DH. A prospective, double blind, randomised clinical trial was designed; 96 individuals with hypersensitive teeth without caries or fracture were selected as subjects. The subjects were randomly allocated to either the test group with the 635 nm per 6 mW laser‐emitting toothbrush, or the control group with the 635 nm per 12·9 μW light‐emitting diode (LED) toothbrush. An air blast was applied with a dental air syringe held 3 mm away from the selected tooth and a visual analogue scale (VAS: 0–10) was used to quantify subjective pain. Assessments were completed at a screening visit and after 2‐week and 4‐week of using a test/control toothbrush. Results demonstrated that the use of both control and test toothbrushes resulted in decreased discomfort after 4 weeks. In the test group, pain intensity scores decreased from 5·8 ± 1·2 to 2·3 ± 1·6, and in the control group, the scores decreased from 6·4 ± 1·3 to 5·5 ± 2·0 (P < 0·05). This decrease was significantly greater in the test group. There were no significant adverse events or side effects. It was concluded that the use of the low‐level laser emitting toothbrush is a safe and effective treatment option for the management of DH.     

Effects of low-level laser therapy on the rate of orthodontic tooth movement

OBJECTIVES: To test the hypothesis that mechanical forces combined with low-level laser therapy stimulate the rate of orthodontic tooth movement. STUDY DESIGN: This study was a double blind, randomized placebo/control matched pairs clinical trial to test the efficacy of GaAlAs low-level laser therapy (LLLT) on 12 young adult patients who required retraction of maxillary canines into first premolar extraction spaces using tension coil springs with fixed edgewise appliance. LLLT was applied on the mucosa buccally, distally and palatally to the canine on the test side and using a pseudo-application on the placebo side. Dental impressions and casts were made at the commencement of the trial and at the end of the first, second and third months after starting the trial. Measurement of tooth movements was made on each stage model using a stereo microscope. RESULTS: There was no significant difference of means of the canine distal movement between the LLLT side and the placebo side for any time periods (p-value = 0.77). CONCLUSION: The energy density of LLLT (GaAlAs) at the surface level in this study (25 J/cm(2)) was probably too low to express either stimulatory effect or inhibitory effect on the rate of orthodontic tooth movement.     

Low‐level laser therapy improves bone repair in rats treated with anti‐inflammatory drugs

Summary Nowadays, selective cyclooxygenase‐2 non‐steroidal anti‐inflammatory drugs have been largely used in surgical practice for reducing oedema and pain. However, the association between these drugs and laser therapy is not known up to now. Herein, the aim of this study was to evaluate the action of anti‐COX‐2 selective drug (celecoxib) on bone repair associated with laser therapy. A total of 64 rats underwent surgical bone defects in their tibias, being randomly distributed into four groups: Group 1) negative control; Group 2) animals treated with celecoxib; Group 3) animals treated with low‐level power laser and Group 4) animals treated with celecoxib and low‐level power laser. The animals were killed after 48 h, 7, 14 and 21 days. The tibias were removed for morphological, morphometric and immunohistochemistry analysis for COX‐2. Statistical significant differences (P < 0·05) were observed in the quality of bone repair and quantity of formed bone between groups at 14 days after surgery for Groups 3 and 4. COX‐2 immunoreactivity was more intense in bone cells for intermediate periods evaluated in the laser‐exposed groups. Taken together, such results suggest that low‐level laser therapy is able to improve bone repair in the tibia of rats as a result of an up‐regulation for cyclooxygenase‐2 expression in bone cells.     

Cyanoacrylate Versus Laser in the Treatment of Dentin Hypersensitivity: A Controlled,Randomized, Double‐Masked and Non‐Inferiority Clinical Trial

Background: Dentin hypersensitivity (DH) is a painful, exaggerated response to normal stimuli, such as cold, sweetness, and brushing. The aim of the present controlled, randomized, double‐masked, non‐inferiority clinical trial is to evaluate the effectiveness of cyanoacrylate in the treatment of DH when compared to the application of low‐intensity laser. Methods: The study includes 434 sensitive teeth from 62 patients. A total of 216 teeth were treated with laser and 218 with cyanoacrylate. A numeric rating scale was used to record the parameters of pain related to the stimuli at baseline and after the treatment at intervals of 24 hours and 30, 90, and 180 days. Results: Both groups had significant reductions in DH. However, there was no significant difference between the two groups ≤6 months. Intragroup analysis showed that the effect of cyanoacrylate obtained at 24 hours remained for 90 days in response to air‐jet test and 30 days for cold‐spray test. There was a statistically significant difference between all other intragroup comparisons at the time intervals (P <0.001). Conclusions: It was concluded that cyanoacrylate is as effective as low‐intensity laser in reducing DH. In addition, it is a more accessible and low‐cost procedure and can be safely used in the treatment of DH.     

Clinical and scanning electron microscopy evaluation of the Er,Cr:YSGG laser therapy for treating dentine hypersensitivity: short‐term,randomised, controlled study

Er,Cr:YSGG laser is a rising treatment option for dentine hypersensitivity (DH). However, there is no data available concerning the scanning electron microscope (SEM) evaluation of the clinical application of Er,Cr:YSGG laser in the treatment of DH. The aim of this study was to evaluate and compare the desensitising and tubule occlusion effects of Er,Cr:YSGG laser with different power settings. Twenty patients (60 teeth) participated in this study. For each patient, teeth were randomised to 3 groups. In groups 1 and 2, patients were treated with Er,Cr:YSGG laser at 0·25 and 0·5 W, respectively. In control group, same laser was applied without laser emission. DH was assessed for all groups with a visual analogue scale (VAS). When compared with the baseline data and control group, in both active treatment groups laser irradiation provided a desensitising effect immediately after treatment (P < 0·001). In group 2, VAS scores were significantly lower than group 1. The tubule diameters in the both laser groups were significantly smaller than the control group (P < 0·01). When group 1 compared with group 2, group 2 showed significantly smaller tubule diameters (P < 0·001). Both 0·25 and 0·5 W laser irradiation were effective for the treatment of DH; however, 0·5 W laser irradiation showed best results for the decrease in VAS scores. The SEM findings of the reduction in number/patency of dentine tubules seem to be related to the clinical findings, which were associated with improvement in treatment efficacy.