It has been emphasized that one of the most valuable treatment objectives in dental practice is to afford the patient a pain-free treatment. By the evolution of the laser applications, the dental committee aimed to achieve this goal without analgesic drugs and painful methods. Orthodontic treatment is one of these concerns, that one of the major components of patient to reject this treatment is the pain accompanied during the different treatment phases. Another great concern of the patient is not to get through prolonged periods of treatment. The aim of this study is to evaluate the effect of the low-level (GaAlAs) diode laser (809 nm, 100 mW) on the canine retraction during an orthodontic movement and to assess pain level during this treatment. A group of 15 adult patients with age ranging from 14 to 23 years attended the orthodontic department at Dental School, Damascus University. The treatment plan for these patients included extraction of the upper and lower first premolars because there was not enough space for a complete alignment or presence of biprotrusion. For each patient, this diagnosis was based on a standard orthodontic documentation with photographs, model casts, cephalometric, panorama, and superior premolar periapical radiographies. The orthodontic treatment was initiated 14 days after the premolar extraction with a standard 18 slot edgewise brackets [Rocky Mountain Company (RMO)]. The canine retraction was accomplished by using prefabricated Ricketts springs (RMO), in both upper and lower jaws. The right side of the upper and lower jaw was chosen to be irradiated with the laser, whereas the left side was considered the control without laser irradiation. The laser was applied with 0-, 3-, 7-, and 14-day intervals. The retraction spring was reactivated on day 21 for all sides. The amount of canine retraction was measured at this stage with a digital electronic caliper (Myoto, Japan) and compared each side of the relative jaw (i.e., upper left canine with upper right canine and lower left canine with lower right canine). The pain level was prompted by a patient questionnaire. The velocity of canine movement was significantly greater in the lased group than in the control group. The pain intensity was also at lower level in the lased group than in the control group throughout the retraction period. Our findings suggest that low-level laser therapy can highly accelerate tooth movement during orthodontic treatment and can also effectively reduce pain level.

Recent preclinical and clinical data have suggested the potential benefit of photodynamic therapy (PDT) in the treatment of periodontitis. However, currently, there are very limited data from controlled clinical trials evaluating the effect of PDT in the treatment of periodontitis. The aim of the present study was to evaluate the clinical and microbiological effects of the adjunctive use of PDT in non-surgical periodontal treatment in patients receiving supportive periodontal therapy. Twenty-four patients receiving regularly supportive periodontal therapy were randomly treated with either subgingival scaling and root planing followed by a single episode of PDT (test) or subgingival scaling and root planing alone (control). The following parameters were evaluated at baseline and at 3 months and 6 months after therapy: full mouth plaque score (FMPS), full mouth bleeding score (FMBS), bleeding on probing (BOP) at experimental sites, probing pocket depth (PPD), gingival recession (REC), and clinical attachment level (CAL). Primary outcome variables were changes in PPD and CAL. Microbiological evaluation of Aggregatibacter actinomycetemcomitans (A.a.), Porphyromonas gingivalis (P.g.), Prevotella intermedia (P.i.), Tannerella forsythensis (T.f.), Treponema denticola (T.d.), Peptostreptococcus micros (P.m.), Fusobacterium nucleatum (F.n.), Campylobacter rectus (C.r.), Eubacterium nodatum (E.n.), Eikenella corrodens (E.c.), and Capnocytophaga species (C.s.) was also performed at baseline and at 3 months and 6 months after therapy, using a commercially available polymerase chain reaction test. No differences in any of the investigated parameters were observed at baseline between the two groups. At 3 months and 6 months after treatment, there were no statistically significant differences between the groups in terms of PPD, CAL and FMPS. At 3 months and 6 months, a statistically significantly higher improvement of BOP was found in the test group. At 3 months after therapy, the microbiological analysis showed a statistically significant reduction of F.n. and E.n. in the test group. At 6 months, statistically significantly higher numbers of E.c. and C.s. were detected in the test group. The additional application of a single episode of PDT to scaling and root planing failed to result in an additional improvement in terms of PPD reduction and CAL gain, but it resulted in significantly higher reduction of bleeding scores than following scaling and root planing alone.

Myofacial pain dysfunction syndrome (MPDS) is the most common reason for pain and limited function of the masticatory system. The effects of low-level lasers (LLLs) for controlling the discomfort of patients are investigated frequently. However, the aim of this study was to evaluate the efficacy of a particular source producing 660 nm and 890 nm wavelengths that was recommended to reduce of the pain in the masticatory muscles. This was a double-blind and placebo-controlled trial. Sixteen MPDS patients were randomly divided into two groups. For the laser group, two diode laser probes (660 nm (nanometers), 6.2 J/cm(2), 6 min, continuous wave, and 890 nm, 1 J/cm(2) (joules per square centimetre), 10 min, 1,500 Hz (Hertz)) were used on the painful muscles. For the control group, the treatment was similar, but the patients were not irradiated. Treatment was given twice a week for 3 weeks. The amount of patient pain was recorded at four time periods (before and immediately after treatment, 1 week after, and on the day of complete pain relief). A visual analog scale (VAS) was selected as the method of pain measurement. Repeated-measures analysis of variance (ANOVA), the t-test and the paired t-test were used to analyze the data. In each group the reduction of pain before and after the treatment was meaningful, but, between the two groups, low-level laser therapy (LLLT) was more effective (P = 0.031) According to this study, this type of LLLT was the effective treatment for pain reduction in MPDS patients.

Objective: The aim of this in vitro study was to investigate the antibacterial depth effect of continuous wave laser irradiation with a wavelength of 980 nm in the root canal wall dentin of bovine teeth. Background Data: The long-term success of an endodontic therapy often fails due to remaining bacteria in the root canal or dentin tubules, which cannot be sufficiently eliminated through the classical root canal preparation technique nor through rinsing solutions. Materials and Methods: A total of 102 slices of bovine root dentin of different thicknesses (100, 300 and 500 µm) were prepared. The samples were inoculated from one side with 5 µL of an enterococcus faecalis suspension of defined concentration. Four slices per slice thickness served as a control group; the rest of the 30 slices per thickness were subjected to laser irradiation-10 each of these slices were irradiated with distal outputs of 1.75, 2.3, and 2.8 Watts (W). After drying them for 30 sec, the back of the inoculated dentin slice was irradiated for 32 seconds with a 200-µm fiber optical waveguide under constant movement of the fibers. The remaining bacteria were then detached in NaCl under vibration. The eluate produced by this was-taking account of the degree of dilution-plated out on sheep blood agar plates. After 24 h of incubation, the grown bacterial colonies were able to be counted out and evaluated. By doing so, they were compared with the non-irradiated, but otherwise identically treated control group. Results: With a slice thickness of 100 µm, the 980-nm diode laser achieved a maximum bacterial reduction of 95% at 1.75 W, 96% at 2.3 W, and 97% at 2.8 W. With a slice thickness of 300 µm, a maximum of 77% of the bacteria was destroyed at 1.75 W, 87% at 2.3 W, and 89% at 2.8 W. The maximum bacterial reduction with a slice thickness of 500 µm was 57% at 1.75 W, 66% at 2.3 W, and 86% at 2.8 W. Conclusion: The results of this research show that the 980-nm diode laser can eliminate bacteria that have immigrated deep into the dentin, thus being able to increase the success rate in endodontic therapy. 9