Antimicrobial photodynamic therapy against Lactobacillus casei using curcumin, nano-curcumin, or erythrosine and a dental LED curing device.

This study aimed to investigate the photodynamic effects of curcumin, nanomicelle curcumin, and erythrosine on Lactobacillus casei (L. casei). Various concentrations of curcumin (1.5 g/L, 3 g/L), nano-curcumin (3 g/L), and erythrosine (100 µM/L, 250 µM/L) were tested either alone or combined with light irradiation (PDT effect) against L. casei in planktonic and biofilm cultures. The light was emitted from a light-emitting diode (LED) with a central wavelength of 450 nm. A 0.12% chlorhexidine digluconate (CHX) solution served as the positive control, and a solution containing neither photosensitizer nor light was the negative control group. The number of viable microorganisms was determined using serial dilution. There was a significant difference in the viability of L. casei in both planktonic and biofilm forms (P < 0.05). In the planktonic culture, the antibacterial effects of CHX and PDT groups with curcumin 3 g/L and erythrosine 250 µM/L were significantly greater than the other groups (P < 0.05). For L. casei biofilms, the greatest toxic effects were observed in CHX and PDT groups with curcumin 3 g/L, erythrosine 250 µmol/L, erythrosine 100 µmol/L, and nanomicelle curcumin 3 g/L, with a significant difference to other groups (P < 0.05). The antibacterial effects of all photosensitizers (except erythrosine 250 µmol/L at planktonic culture) enhanced significantly when combined with light irradiation (P < 0.05). PDT with curcumin 3 g/L or erythrosine 250 µmol/L produced comparable results to CHX against L. casei at both planktonic and biofilm cultures. Alternatively, PDT with erythrosine 100 µmol/L or nanomicelle curcumin 3 g/L could be suggested to kill L. casei biofilms.

Introducing and assessing the efficacy of a novel method to reduce enamel damage after orthodontic bracket removal using two herbal-based resin colouring agents: An in vitro study.

PURPOSE: The differentiation of resin remnants from enamel is a critical factor to minimize enamel damage after bracket debonding. This study was conducted to produce, and ascertain the efficacy of two colouring agents in minimizing enamel loss, adhesive and bonding remnants, and surface roughness after debonding. METHODS: Two dyes containing annatto (orange colour) and curcumin (yellow colour) were produced. Seventy-two maxillary premolars were divided into three groups. After bracket bonding and debonding, the adhesive remnant was removed with a fine diamond bur. In groups 1 and 2, the orange and yellow dyes were utilized during the removal process, respectively. In group 3 (control) adhesive was removed with no colouring agent. The buccolingual dimension of the teeth was measured at the occlusal, middle, and apical areas, before bonding and after clean-up. The adhesive remnant index (ARI) and bonding remnant index (BRI) scores were recorded and the surface roughness parameters were measured. Data were analysed by ANOVA, Tukey, and Fisher's exact tests (α=0.05). RESULTS: Enamel loss was significantly lower in the groups cleaned by the use of colouring agents than that of the control group (P<0.05). No bonding agent was observed when the dyes were used, whereas 65% of teeth in the control group showed the remaining bonding material (P<0.001). There was no significant difference in ARI scores or surface roughness alterations among the study groups (P>0.05). CONCLUSION: The two dyes produced in this study were effective in enhancing the visibility of residual resin materials and minimizing enamel loss during the clean-up process.

Low level laser therapy, Er,Cr:YSGG laser and fluoride varnish for treatment of dentin hypersensitivity after periodontal surgery: A randomized clinical trial.

This clinical trial aimed to compare the effects of low-level laser therapy (LLLT), Er,Cr;YSGG laser, and fluoride varnish, as compared to the placebo laser on decreasing dentin hypersensitivity (DH). This randomized, double-blinded clinical trial included 60 jaw quadrants in 24 patients who underwent periodontal surgery. The quadrants were randomly assigned to 4 groups and received treatments as follows. Group 1: LLLT with a combination of red and infrared wavelengths, group 2: Er,Cr:YSGG laser (0.25 W and 0.5 W), group 3: fluoride varnish, and group 4: placebo laser. The sensitivity response to the cold spray was recorded using visual analogue scale (VAS) at baseline, immediately, and 1 week post-treatment. The data were analyzed by repeated measures analysis at the significance level of P<0.05. There was a significant reduction in DH after treatment by low-level lasers, Er,Cr:YSGG laser, or fluoride varnish compared to the baseline data (P<0.05), but the placebo group displayed no significant alteration in DH (P=0.069). At 1 week, the VAS score in the Er,Cr:YSGG laser group was significantly lower than that of the LLLT (P= 0.043) and placebo (P<0.001) groups. Furthermore, the subjects who received fluoride varnish exhibited significantly lower DH compared with the placebo group (P = 0.023). Er,Cr:YSGG laser was the most effective strategy in dealing with DH, as it caused the greatest pain reduction over the study period and showed a significant superiority over LLLT and placebo groups. Alternatively, the application of fluoride varnish could be recommended for attenuating DH following periodontal surgery.

The Efficacy of 4% Articaine Versus 2% Lidocaine in Inducing Palatal Anesthesia for Tooth Extraction in Different Maxillary Regions.

PURPOSE: This study was conducted to ascertain the efficacy of buccal injection of articaine compared to lidocaine in inducing palatal anesthesia in different maxillary regions. MATERIALS AND METHODS: This double-blinded, randomized clinical trial included 300 patients who referred for extraction of 1 maxillary tooth. The patients were categorized into 3 strata according to the extraction area (anterior, premolar, molar), and then randomly assigned to 2 groups based on the administered medication. The first group received buccal infiltration by 0.6 mL of 2% lidocaine, whereas the second group was buccally administered using 0.6 mL of 4% articaine. After a waiting period of 2 minutes, the failure or success in achieving palatal anesthesia was assessed by the instrumentation technique. In cases of failed anesthesia, an additional 0.6 mL of the same anesthetic was given, and the procedure was repeated if palatal anesthesia was not attained after a 2-minute delay. If pain remained 2 minutes after the third injection, a supplemental palatal infiltration was administered and the extraction was attempted. RESULTS: The success rate of buccal infiltration in achieving palatal anesthesia was 82.7% in the articaine group and 1.3% in the lidocaine group. There was a significant difference in the success rate and drug volume required to induce palatal anesthesia between the 2 groups (P < .001), but no significant difference was found between different maxillary regions, using either of the medications (P > .05). CONCLUSIONS: Articaine can be considered as a suitable alternative to lidocaine for eliminating painful palatal infiltration in the extraction of maxillary teeth.

Effectiveness of Low-Level Laser Irradiation in Reducing Pain and Accelerating Socket Healing After Undisturbed Tooth Extraction.

Introduction: This study aimed to determine the effect of low-level laser therapy (LLLT) on reducing complications following tooth extraction. Methods: This randomized clinical trial consisted of 40 subjects who underwent lower molar extraction. The patients were randomly assigned to 4 groups. Group 1 was irradiated with a 660 nm laser (200 mW, 30 seconds radiation to lingual, buccal and occlusal surfaces of the socket, 6 J/area). In group 2, an 810 nm laser was applied similar to group 1. In group 3, a combination of 660 and 810 nm lasers was used. The patients in group 4 served as a placebo group. LLLT was performed after 0.5-1 hour of extraction and 2 days later. The participants were asked to record pain degree using a visual analogue scale (VAS) over 7 days. The amount of wound healing was evaluated on the third and seventh days. Results: There was no significant difference in pain scores among the groups at any of the assessment intervals (P >0.05). The between-group differences in wound healing scores were small and insignificant (P >0.05). Conclusion: LLLT with 660 nm or 810 nm lasers or their combination had no greater effect than the placebo laser for reducing the complications of tooth extraction.

A randomized clinical trial comparing the efficacy of low-level laser therapy (LLLT) and laser acupuncture therapy (LAT) in patients with temporomandibular disorders.

This study compared the efficacy of low-level laser therapy (LLLT) versus laser acupuncture therapy (LAT) in patients with temporomandibular disorders (TMDs). In this randomized, double-blind clinical trial, 45 TMD patients were randomly divided into three groups. In group 1 (LLLT), a GaAlAs laser was applied on painful masticatory muscles and TMJs (810 nm, 200 mW, 30 s per point, Gaussian beam, spot size 0.28 cm2, 21 J/cm2) two times a week for 5 weeks. In group 2 (LAT), the laser was emitted bilaterally on acupuncture points (ST6, ST7, LI4) with the same settings as the LLLT group. Group 3 (placebo) underwent treatment with sham laser. The patients were evaluated before treatment (T1), after 5 (T2) and 10 (T3) laser applications, and 1 month later (T4). The mandibular range of motion as well as pain intensity in masticatory system was recorded at each interval. There was no significant difference in mouth opening between the groups (p > 0.05), but the amount of lateral excursive and protrusive movements was significantly greater in LLLT and LAT groups than the placebo group at some intervals (p < 0.05). The overall pain intensity and pain degree at masticatory muscles (except temporal muscle) and TMJs were significantly lower in both experimental groups than the placebo group at most intervals after therapy (p < 0.05). Both LLLT and LAT were effective in reducing pain and increasing excursive and protrusive mandibular motion in TMD patients. LAT could be suggested as a suitable alternative to LLLT, as it provided effective results while taking less chair time.

Is Low-Level Laser Therapy Effective for Treatment of Neurosensory Deficits Arising From Sagittal Split Ramus Osteotomy?

PURPOSE: This study investigated the effectiveness of low-level laser therapy (LLLT) for treating neurosensory impairment after bilateral sagittal split osteotomy (BSSO). MATERIALS AND METHODS: This randomized, double-blinded, split-mouth trial included patients requiring BSSO. After surgery, 1 side of each patient was randomly assigned to laser therapy and the other side served as the control. At 24, 48, and 72 hours after surgery, LLLT was accomplished by intraoral application of a 660-nm laser around the surgical site (200 mW, 10 seconds, 2 J, 1.5 J/cm2) followed by extraoral irradiation by an 810-nm laser (200 mW, 10 seconds, 2 J, 7 J/cm2) along the distribution of the inferior alveolar nerve. Subsequently, extraoral irradiation was repeated 2 times per week for 3 weeks along the path of the inferior alveolar nerve, lower lip, and chin. On the control side, the treatment was similar to the laser side but with laser simulation. The main outcome was assessing nerve damage by a "2-point discrimination test" before and up to 60 days after surgery. RESULTS: The sample consisted of 16 patients. No significant difference was found between the laser and control sides before and after surgery and on postoperative days 15 and 30 (P > .05). The 2-point discrimination distance was significantly shorter on the laser side than on the control side on postoperative days 45 and 60 (P < .05). CONCLUSION: LLLT was effective in the treatment of neurosensory disturbances arising from BSSO. Therefore, LLLT can be recommended to accelerate the recovery of sensory aberrations in patients undergoing BSSO.

Is Low-Level Laser Therapy Effective in the Management of Pain and Swelling After Mandibular Third Molar Surgery?

PURPOSE: This study evaluated the effect of low-level laser therapy (LLLT) on decreasing pain and swelling after removal of impacted third molars. PATIENTS AND METHODS: This randomized, double-blinded, split-mouth study included patients presenting 2 symmetrically impacted mandibular third molars. In each participant, one side was randomly assigned to laser treatment and the other side received placebo. LLLT was performed by intraoral application of a 660-nm laser (200 mW, 6 J per point at 4 points) followed by extraoral application of an 810-nm laser (200 mW, 6 J per point at 3 points). Irradiation at the 810-nm wavelength was repeated on days 2 and 4 after surgery. On the control side, the treatment protocol was similar to the experimental side, but with laser simulation. The main outcomes were the degree of pain during the next 7 days and the edema coefficients on days 2, 4, and 7 after surgery. Data were analyzed using generalized linear models to determine the effect of group and time on pain level and edema coefficients. RESULTS: The final sample consisted of 40 patients. Pain level was significantly lower in the laser than in the placebo side at all time points during the experiment (P < .05). Swelling was significantly lower in the laser than in the placebo group on days 2, 4, and 7 after surgery (P < .05). CONCLUSION: LLLT proved effective in decreasing the intensity of pain and swelling after removal of impacted third molars and can be recommended to alleviate patients' symptoms after surgery.

Effect of low-level laser therapy on tooth sensitivity induced by in-office bleaching.

This study aimed to investigate the effect of low-level laser therapy (LLLT) on tooth sensitivity induced by in-office bleaching. Sixty-six patients enrolled in this randomized clinical trial. Following the in-office procedure with 40% hydrogen peroxide, the participants were randomly divided into three groups. The patients in group 1 received irradiation from a low-level red laser (LLRL; 660 nm, 200 mW, 15 s, 12 J/cm(2)), whereas participants in group 2 were subjected to a low-level infrared laser (LLIL; 810 nm) under similar conditions as in group 1. In group 3 (placebo), the laser treatment was the same as that in groups 1 and 2, but without energy output. The degree of tooth sensitivity was recorded at 1, 24, and 48 h after bleaching using a visual analog scale (VAS). The change in tooth shade was measured 30 days after tooth whitening. The intensity of tooth sensitivity was not significantly different between groups at 1 h after bleaching (p > 0.05). At 24 h after therapy, pain level was significantly lower in the LLIL group compared to the LLRL and placebo groups (p < 0.05). At 48 h after bleaching, VAS scores in the LLIL and LLRL groups were comparable to each other (p > 0.05) and both were significantly lower than that of the placebo group (p < 0.05). There was no significant difference in the efficacy of tooth whitening among groups (p > 0.05). LLLT with an infrared diode laser could be recommended as a suitable strategy to reduce the intensity of tooth sensitivity after in-office bleaching.

Comparison of the effect of low level laser therapy with alvogyl on the management of alveolar osteitis

BACKGROUND: This study investigated the efficacy of low level laser therapy (LLLT) for managing alveolar osteitis (AO).MATERIAL AND METHODS: Sixty patients with alveolar osteitis of mandibular third molars were randomly divided into three groups. In group 1, socket irrigation was followed by alvogyl placement, and the treatment was repeated 48 hours later. In group 2, socket was irradiated with a low power red laser for 3 consecutive days (200 mW, 30 seconds on each of the buccal and lingual surfaces and 30 seconds at the middle of the socket, 6 J per area). The subjects in group 3 underwent treatment with a low power infrared laser with the same parameters as group 2. A visual analogue scale (VAS) was used to record the degree of pain at the morning (T0, before intervention) and at 6 (T1) and 12 (T2) hours later for 3 days. RESULTS: Pain was significantly lower in the alvogyl group than the other groups at T1 and T2 points on day 1 and at T0 and T1 points on day 2 (p < 0.05). At T2 point on day 2 and on day 3, VAS became significantly lower in the red laser group compared to the other groups (p<0.05). The infrared laser was not more efficacious than the other groups at any of the treatment intervals, but it reduced VAS to an acceptable level. CONCLUSIONS: LLLT displayed good results in this study for treatment of alveolar osteitis and should be further investigated as an alternative to alvogyl for AO management

Comparison of the effect of low level laser therapy with alvogyl on the management of alveolar osteitis.

BACKGROUND: This study investigated the efficacy of low level laser therapy (LLLT) for managing alveolar osteitis (AO). MATERIAL AND METHODS: Sixty patients with alveolar osteitis of mandibular third molars were randomly divided into three groups. In group 1, socket irrigation was followed by alvogyl placement, and the treatment was repeated 48 hours later. In group 2, socket was irradiated with a low power red laser for 3 consecutive days (200 mW, 30 seconds on each of the buccal and lingual surfaces and 30 seconds at the middle of the socket, 6 J per area). The subjects in group 3 underwent treatment with a low power infrared laser with the same parameters as group 2. A visual analogue scale (VAS) was used to record the degree of pain at the morning (T0, before intervention) and at 6 (T1) and 12 (T2) hours later for 3 days. RESULTS: Pain was significantly lower in the alvogyl group than the other groups at T1 and T2 points on day 1 and at T0 and T1 points on day 2 (p<0.05). At T2 point on day 2 and on day 3, VAS became significantly lower in the red laser group compared to the other groups (p<0.05). The infrared laser was not more efficacious than the other groups at any of the treatment intervals, but it reduced VAS to an acceptable level. CONCLUSIONS: LLLT displayed good results in this study for treatment of alveolar osteitis and should be further investigated as an alternative to alvogyl for AO management.

A randomized clinical trial of the effect of low-level laser therapy before composite placement on postoperative sensitivity in class V restorations.

This study aimed to investigate the efficacy of low-level laser irradiation when applied just before placement of resin composite on reducing postoperative sensitivity of class V lesions. In this randomized clinical trial, 31 patients with 62 class V cavities were included (two teeth in each participant). The teeth were randomly assigned into laser and placebo groups. After cavity preparation, the teeth in the experimental group were subjected to irradiation from a low-power red laser (630 nm, 28 mW, continuous wave, 60 s, 1.68 J), which was applied for 1 min on the axial wall of the cavity. In the control group, the same procedure was performed but with laser simulation. Then, a self-etch adhesive was applied and the cavities were restored with a microhybrid resin composite. Before treatment and on days 1, 14, and 30 after treatment, tooth sensitivity to a cold stimulus was recorded using a visual analogue scale. Data were analyzed by Friedman and Wilcoxon signed-rank tests (p < 0.05). Pain scores after restorative procedures were significantly lower in the laser group compared to the placebo application (p < 0.05). Although both groups experienced a significant improvement in pain and discomfort throughout the follow-up periods (p < 0.001), the changes in visual analogue scale (VAS) scores between baseline and each follow-up examination were significantly greater in the laser than the placebo group (p < 0.05). Low-level laser therapy (LLLT) before placement of resin composite could be suggested as a suitable approach to reduce postoperative sensitivity in class V restorations.

Effectiveness of Er:YAG laser-aided fiberotomy and low-level laser therapy in alleviating relapse of rotated incisors.

INTRODUCTION: In this study, we compared the effectiveness of laser-aided circumferential supracrestal fiberotomy (CSF) and low-level laser therapy (LLLT) with conventional CSF in reducing relapse of corrected rotations. METHODS: The study included 24 patients who were at the finishing stage of orthodontic treatment and had at least 1 maxillary incisor with 30° to 70° of rotation before starting therapy. The subjects were divided into 4 groups by treatment: conventional CSF, Er:YAG laser-aided CSF, LLLT, and control. After alginate impressions were taken, the archwire was sectioned from the experimental incisors, and they were allowed to relapse. The second impression was taken 1 month later, and the degree and percentage of relapse were calculated in photographs taken from the dental models. Gingival recession, pocket depth, and pain were also measured in the CSF groups. RESULTS: The mean percentages of relapse were 9.7% in the conventional CSF, 12.7% in the Er:YAG laser-aided CSF, 11.7% in the LLLT, and 27.8% in the control groups. Relapse was significantly greater in the control than the experimental groups (P <0.05), which were not statistically different from each other. The changes in sulcus depth and gingival recession were small and not significantly different among the CSF groups (P >0.05), but pain intensity was greater in subjects who underwent conventional CSF (P = 0.003). CONCLUSIONS: Er:YAG laser-aided CSF proved to be an effective alternative to conventional CSF in reducing rotational relapse. LLLT with excessively high energy density was also as effective as the CSF procedures in alleviating relapse, at least in the short term.

Low-level laser therapy for management of TMJ osteoarthritis.

AIMS: This study investigated the efficacy of low-level laser therapy (LLLT) for the management of temporomandibular joint (TMJ) osteoarthritis. METHODOLOGY: In a double-blind clinical trial, 20 patients with TMJ osteoarthritis were randomly divided into laser and placebo groups. The patients in the laser group received irradiation from an 810 nm low-level laser (Peak power 80 W, average power 50 mW, 1500 Hz, 1 micro s pulse width, 120 seconds, 6 J, 3.4 J/cm(2) per point), which was applied on four points around the TMJs and on painful muscles three times a week for 4 weeks. In the placebo group, the treatment was the same as that in the laser group, but with laser simulation. The patients were evaluated before laser therapy (T1), after 6 (T2) and 12 (T3) laser applications and 1 month after the last application (T4), and the amount of mouth opening and the pain intensity were recorded. RESULTS: No significant differences were found in mouth opening either between the study groups or between the different evaluation times in each group (P>0.05). There was no significant difference in pain symptoms of the masticatory muscles and TMJ between the laser and the placebo groups (P>0.05), but some significant within-group improvements were present for Visual Analogue Scale (VAS) scores of the body of the masseter and TMJ in both groups. CONCLUSIONS: LLLT using the present laser parameters was no more effective than the placebo treatment for reducing pain and improving mouth opening in patients with TMJ osteoarthritis.

The efficacy of low-level laser therapy for the treatment of myogenous temporomandibular joint disorder.

Low-level laser therapy (LLLT) has been commonly used for the treatment of painful musculoskeletal conditions, but the results of previous studies on this subject are controversial. The aim of this study was to evaluate the efficacy of LLLT in the management of patients with myogenic temporomandibular joint disorders (TMDs). In this randomized, double-blind clinical trial, 20 patients with myogenic TMD were randomly divided into laser and placebo groups. In the laser group, a pulsed 810-nm low-level laser (average power 50 mW, peak power 80 W, 1,500 Hz, 120 s, 6 J, and 3.4 J/cm(2) per point) was used on painful muscles three times a week for 4 weeks. In the placebo group, the treatment was the same as that in the laser group, but without energy output. The patients were evaluated before laser therapy (T1), after six sessions of laser application (T2), at the end of treatment (T3), and 1 month after the last application (T4), and the level of pain and the amount of mouth opening were measured. There was a significant increase in mouth opening and a significant reduction of pain symptoms in the laser group (p < 0.05). A similar improvement was not observed in the placebo group (p > 0.05). Between-group comparisons revealed no significant difference in pain intensity and mouth opening measurement at any of the evaluation time points (p > 0.05). LLLT can produce a significant improvement in pain level and mouth opening in patients affected with myogenic TMD.

Does ultra-pulse CO(2) laser reduce the risk of enamel damage during debonding of ceramic brackets?

This study seeks to evaluate the enamel surface characteristics of teeth after debonding of ceramic brackets with or without laser light. Eighty premolars were bonded with either of the chemically retained or the mechanically retained ceramic brackets and later debonded conventionally or through a CO(2) laser (188 W, 400 Hz). The laser was applied for 5 s with scanning movement. After debonding, the adhesive remnant index (ARI), the incidence of bracket and enamel fracture, and the lengths, frequency, and directions of enamel cracks were compared among the groups. The increase in intrapulpal temperature was measured in ten extra specimens. The data were analyzed with SPSS software. There was one case of enamel fracture in the chemical retention/conventional debonding group. When brackets were removed with pliers, incidences of bracket fracture were 45% for the chemical retention, and 15% for the mechanical retention brackets. No case of enamel or bracket fracture was seen in the laser-debonded teeth. A significant difference was observed in ARI scores among the groups. Laser debonding caused a significant decrease in the frequency of enamel cracks, compared to conventional debonding. The increase in intrapulpal temperatures was below the benchmark of 5.5 °C for all the specimens. Laser-assisted debonding of ceramic brackets could reduce the risk of enamel damage and bracket fracture, and produce the more desirable ARI scores without causing thermal damage to the pulp. However, some augmentations in the length and frequency of enamel cracks should be expected with all debonding methods.