Comparing Diode Laser (660 nm) & 8% Arginine Toothpaste vs. Laser Alone for Dentin Hypersensitivity: A Randomized Clinical Trial

Introduction: Dentin hypersensitivity is a common oral problem that occurs as a short and sharp pain. There are many techniques to treat this condition, the latest of which is laser treatment. The aim of this study was to evaluate the effect of two types of low-power diode lasers (660 nm and 810 nm) on dentin hypersensitivity in order to achieve an acceptable clinical application by adjusting the effective parameters. Methods: In this randomized, double-blind clinical trial, sensitive teeth of 7 patients were divided into three groups with a randomized matching method: group I, treated with 660-nm diode laser irradiation, group II, treated with diode laser 810-nm, and group III, the control group. Irradiation parameters for 660-nm and 810-nm diode lasers were the power of 30 mW and 100 mW respectively, in contact and continuous modes, perpendicular to the tooth surface with a sweeping motion. Treatments were carried out in four sessions at weekly intervals. The data obtained were analyzed with SPSS 22, using one-way repeated measures ANOVA and the LSD (least significant difference) test. The significance level was considered as P≤0.05. Results: There were no significant differences in visual analogue scale (VAS) score changes between the two laser groups after the intervention in the first, second and third weeks compared to the baseline (P>0.05). These changes in the fourth week were significantly higher in the 810-nm laser group compared to the 660-nm laser group (P=0.04), and in the 660-nm laser group, they were more than the control group (P=0.02). The mean VAS scores at 1-week, 1-month and 2-month postoperative intervals were significantly lower in the 810-nm laser group than in the 660-nm laser group, and in the 660-nm laser group, they were less than the control group (P<0.001). Conclusion: The use of 660-nm and 810-nm diode lasers with the power of 30 and 100 mW respectively for 120 seconds was effective in reducing pain in patients with dentin hypersensitivity. However, the effect of the 810-nm laser on reducing the dentin hypersensitivity was more long-lasting than that of the 660-nm laser.

Abstracts from the 7th Congress of the World Federation for Laser in Dentistry European Division June 20–22, 2019 Parma, Italy

Background:Dentin hypersensitivity is a prevalent problem, manifested as a short sharp pain. Researchers have used different lasers to treat this condition. The present study aimed to evaluate the effect of 980 and 810-nm high-level diode lasers on dentin hypersensitivity to determine proper laser parameters for clinical applications.Materials and Methods:In this double-blinded randomized clinical trial, seven patients with 60 teeth affected by dentin hypersensitivity were selected for the present double-blind, randomized clinical trial. The patients’ teeth were randomly matched and assigned to three groups: Group 1: 980-nm diode laser; Group 2: 810-nm diode laser; and Group 3: Control, which received only the guiding beam. The laser parameters were 1-W power, continuous wave mode, a distance of 1 mm, no contact, a 45° irradiation angle, and a 30-s exposure time using to-and-fro movements. The treatment consisted of two sessions with a 1-week interval. Pain severity was determined with the visual analog scale (VAS) at all the study intervals using a dry ice spray. The data were analyzed with SPSS version 20 using one-way ANOVA, repeated measures ANOVA, and least significant difference tests. Significance level was set at α = 0.05.Results:The changes in VAS were significant only in the first stage (P = 0.046). The mean VAS scores decreased over time in the 810-nm and 980 laser groups. A comparison of VAS changes relative to the baseline revealed significant changes in VAS scores at all the time intervals with both lasers. The two 810 and 980-nm laser groups did not exhibit any significant differences for 2 months postoperatively (P = 0.098).Conclusion:The application of 810 and 980-nm diode lasers at 1-W power and an exposure time of 30 s was effective in decreasing pain in patients with dentin hypersensitivity, with no significant difference between these two lasers.

The question of whether photobiomodulation should be used as a drug equivalent arose in my mind after listening to presentations at the recent conference of the World Association for Laser Therapy (WALT)-2012 (Gold Cost City, Australia), and later at home when searching MEDLINE for the years 2009–2012. Photobiomodulation (earlier terms: low level laser therapy, LLLT, laser biostimulation) has been used in clinical practice for >40 years by now, and its action mechanisms on cellular and molecular levels have been studied for > 30 years. Enthusiastic medical specialists successfully used photobiomodulation in treating healing-resistant wounds and ulcers (e.g., chronic diabetic ulcers), in pain management, and in spinal cord and nervous system injuries when other methods had had limited success. However, photobiomodulation is still not a part of mainstream medicine. The goal of the present Editorial is to highlight some important recent developments in clinical applications and in studies of cellular and molecular mechanisms behind the clinical findings. One of the impressive and perspective challenges for photobiomodulation is its use in cases of Parkinson’s disease. Research in recent years evidenced that neuroprotective treatment with red and near infrared radiation (NIR) prevented mitochondrial dysfunction and dopamine loss in Parkinson’s disease patients. In another set of experiments, NIR normalized mitochondrial movement and axon transport, as well as stimulating respiration in cytoplasmic hybrid (‘‘cybrid’’) neurons. It is important to recall that reduced axonal transport contributes substantially to the degeneration of neuronal processes in Parkinson’s disease. Another development in recent years is the successful stimulation of stem cells with red and NIR radiation. One example is the treatment of myocardial infarction. The heart has been considered a post-mitotic organ lacking the capacity for self-renewal after injury. Surprisingly enough, human cardiac stem cells, in combination with bone marrow mesenchymal stem cells, were found to reduce infarct size and restore cardiac functions after myocardial infarction. This positive effect can even be increased by irradiation of stem cells. Mesenchymal stem cells were derived from bone marrow and adipose tissue, and stimulated by irradiation at k = 810 nm. Implantation of irradiated cells into the infarcted rat heart resulted in an *50% decrease in cardiac infarct size. An increase in proliferation rates and membrane potential was established after 532 nm irradiation of adipose tissue-derived stem cells. A recent review summarized data about enhancement of the proliferation of various cultured cell lines, including stem cells, as well as cell lines used for the production of viral vaccines and hybrid cell lines. The review underlined that photobiomodulation improves the proliferation of cells without causing any cytotoxic effects. One has to emphasize that laser therapy shares none of the risks associated with stem cell therapy, requires no anesthesia, and is painless. The optimal light parameters in this review were found to be as follows: doses were 0.5–4.0 J/ cm and wavelengths ranged from 600 to 700 nm. It is important to recall that, in this particular wavelength range, two peaks in absorption and action spectra connected with activation of cytochrome c oxidase (the primary photoacceptor for photobiomodulation effects) are situated. The peak at 620 nm belongs to reduced CuA, and that at 680 nm, to oxidized CuB atoms in cytochrome c oxidase molecule. The treatment of vitiligo (a depigmentary disorder) remains a challenge for clinical dermatologists. He-Ne laser irradiation was found to stimulate melanocyte proliferation. The expression of phosphorylated cyclic-adenosine monophosphate (AMP) response element-binding protein, an important regulator of melanocyte growth, was upregulated by He-Ne laser treatment. He-Ne laser irradiation imparted a growth stimulatory effect on functional melanocytes via mitochondria-related pathways. Irradiation with red light caused gene and noncoding RNA regulation for photoacceptor protection in the retina. This finding may open a new challenge for photobiomodulation. One of the major dose-limiting effects of chemotherapy drugs is oral mucositis of treated patients. Oral mucositis can affect up to 100% of patients undergoing high-dose chemotherapy and hematopoietic stem cell transplantation. Photobiomodulation can improve tissue repair and immune response in these patients. Photobiomodulation has been shown to improve functional outcome after surgical intervention to repair injured nerves. LED irradiation at 810 nm accelerated functional recovery and improved the quality of nerve regeneration after autograft repair of severely injured peripheral nerves. Forehead treatments with NIR reversed major depression and anxiety. Transcranial NIR laser therapy was investigated

Introduction: Gingival depigmentation with the help of lasers is known as an effective technique. The aim of this study was to compare the efficiency of 980nm diode and CO2 lasers in the treatment of gingival hyperpigmentation. Methods: In this clinical trial study, 14 individuals (8 females and 6 males) with the age range of 19 to 47 years were selected. One quadrant was randomly treated with CO2 laser (10600 nm, non-contact, super pulse mode) and the opposite quadrant was treated with a diode laser (980 nm, continuous wave [CW], 1.5 W). The area of the pigmented region, Dummett oral pigmentation index (DOPI), the amount of changes in the RGB parameter (red, green, blue) and ΔE* in clinical photographs before, one and three months after the treatment were calculated by ImageJ and Photoshop software. Pain and discomfort were assessed one hour, one day and one week later by the visual analogue scale (VAS). In addition, after 3 months, the cosmetic results achieved for the different therapeutic approaches were evaluated by patients and professional evaluator. Data were analyzed by the paired samples t test, repeated measures ANOVA and Wilcoxon test. Results: The results of this study showed that the duration of CO2 laser treatment was statistically and significantly shorter than the time of 980-diode laser treatment (P<0.05). There were no statistically significant differences in the pigmented lesion area (P>0.05), RGB parameter (P>0.05), DOPI index (P>0.05) and ΔE parameter (P>0.05) in one month and three months after treatment follow-ups between the two types of lasers. There was no statistically significant difference in patient satisfaction (P>0.05) and professional evaluation (P>0.05) between the two groups of lasers. Post-treatment pain scores were not statistically significant between the two groups. Conclusion: Both 980-nm diode laser and 10600-nm CO2 are effective in the treatment of gingival depigmentation while CO2 laser radiation with super pulse mode is faster in terms of operating time. While working with the diode laser is more controllable. Trial Registration Number: IRCT20200309046728N1; https://irct.behdasht.gov.ir/.

Background: The study aimed to clinically estimate an influence of a 635 nm diode laser on the stability of orthodontic mini-implants, to assess mini-implants loss, and to evaluate a pain level after the treatment. Materials and Methods: The randomized clinical split-mouth trial included 20 subjects (13 women and 7 men; age: 32.5 ± 6.1 years), 40 implants (RMO, West Colfax Ave., Denver, CO, USA) with a diameter 1.4 mm and length of 10 mm. Mini-implants were placed in the area of the attached gingiva between the second premolar and first molar teeth, 2 mm below the mucogingival junction of both sides of the maxilla. Each implant on the right side (G1, n = 20) of the maxilla was irradiated with a diode laser, and the implants on the opposite side (left, G2, n = 20) were a control group (without laser irradiation). The 635-nm laser parameters; dose: 10 J per point (20 J/cm2), time: 100 s per point, two points (irradiation on a buccal, and a palatal side of the alveolus/implant), the total energy per session 20 J. Laser application protocol: immediately and 3, 6, 9, 12, 15, and 30 days after surgery. The total energy after all therapeutic sessions was 140 J. The implants’ stability was measured employing a Periotest device (Periotest Test Value—PTV) immediately and 3, 6, 9, 12, 15, 30, and 60 days after the insertion of the mini-implants. Results: We found significantly higher secondary stability, lower mean PTV (6.18 ± 5.30) and (1.51 ± 2.25), for self-drilling mini-implants (G1, test group) in contrast to the control, G2 group (9.17 ± 8.25) and (5.00 ± 3.24), after 30 (p = 0.0003) and 60 days (p = 0.0000). Moreover, the analysis of the mini-implants stability after 635-nm diode laser application revealed significant higher stability in comparison with none irradiated implants (G2 group) after 3 days. (p = 0.0000) There was no significant difference in pain level measured on the NRS-11 scale on both sides of the maxilla. (p = 0.3665) An important finding was that all inserted mini-implants survived during a two-month observation period. Conclusions: 635-nm diode laser at laser irradiation increases the secondary stability of orthodontic mini-implants.

To investigate the effects of gallium-aluminum-arsenide (GaAlAs) diode laser low-level laser therapy (LLLT) on angiogenesis and dentinogenesis of the dentin-pulp complex in a human tooth slice-based in vitro model. Forty tooth slices were prepared from 31 human third molars. Slices were cultured at 37°C, 5% CO2, and 95% humidity and randomly assigned to one of the following groups: group I: no laser treatment, group II: 660-nm diode laser; energy density = 1J/cm2, group III: 660-nm diode laser; energy density = 3J/cm2, group IV: 810-nm diode laser; energy density = 1J/cm2 and group V: 810-nm diode laser; energy density = 3J/cm2. LLLT was applied on the third and fifth days of culture. After 7days, tissues were retrieved for real-time RT-PCR analysis to investigate the expression of VEGF, VEGFR2, DSPP, DMP-1, and BSP in respect to controls. Lower energy density (1J/cm2) with the 660nm wavelength showed a statistically significant up-regulation of both angiogenic (VEGF: 15.3-folds and VEGFR2: 3.8-folds) and odontogenic genes (DSPP: 6.1-folds, DMP-1: 3-fold, and BSP: 6.7-folds). While the higher energy density (3J/cm2) with the 810nm wavelength resulted in statistically significant up-regulation of odontogenic genes (DSPP: 2.5-folds, DMP-1: 17.7-folds, and BSP: 7.1-folds), however, the angiogenic genes had variable results where VEGF was up-regulated while VEGFR2 was down-regulated. Low-level laser therapy could be a useful tool to promote angiogenesis and dentinogenesis of the dentin-pulp complex when parameters are optimized.

Drs Kim and Paxton respond

Statement of the Problem: Considering the relatively high prevalence of oral mucosal ulcers, their fast healing is of significance.Purpose: This study aimed to histopathologically compare the effects of 810 nm and 940 nm diode laser on the healing of iatrogenic oral ulcers in rabbits. Materials and Method: In this single-blind experimental study, mucosal ulcers measuring 3mm in diameter and 1mm in depth were bilaterally created in the buccal mucosa of 18 rabbits using a biopsy punch. The defects were irradiated with 810 nm diode laser on the right side and 940 nm diode laser on the left side. Biopsy samples of the same depth were obtained from the ulcers on days 3 and 7 followed by histopathological analysis. The intensity of inflammation was determined on hematoxylin-eosin-stained sections using a four-point scale. Data were analyzed employing the Wilcoxon signed rank test.Results: The degree of inflammation was not significantly different between the 810nm and 940nm diode laser groups on day 3; but on day 7, animals receiving 810 nm experienced a significantly lower degree of inflammation compared to those treated with 940 nm laser (p= 0.028).Conclusion: When comparing 810- and 940-nm diode lasers, 810 nm irradiation significantly decreased the severity of inflammation in oral wounds created on the buccal mucosa of rabbits in a time-dependent manner.

The Neodynium: Yttrium Aluminum Garnet (Nd:YAG) laser has been the mainstay of performing upper respiratory laser surgery in the equine since 1984. The 808-nm diode laser has also been applied transendoscopically as well as the 980-nm diode laser over recent years. It has been shown that Indocyanine Green (ICG) enhances the performance of the 808- nm laser because it is absorbed at 810 nm of light. The 808- nm laser's tissue interaction combined with ICG is equivalent to or greater than the Nd:YAG laser's cutting ability. The 980-nm diode laser performance was similar to that of the Nd:YAG as determined by the parameters of this study. This study compared the depths and widths of penetration achieved with the 808-nm diode laser after intravenous injection of ICG on equine respiratory tissue. It also compared depths and widths of penetration achieved by the non-contact application of the 980-nm diode laser delivering the same energy of 200 joules. The depths and widths of penetration of both diode lasers were compared to themselves and to the Nd:YAG laser with all factors remaining constant.

ObjectivesIn this study, we aimed to compare the effectiveness of Gluma and high-power 980-nm diode laser, alone or in combination, in the treatment of cervical dentin hypersensitivity. MethodsA total of 20 patients (5 men and 15 women), aged 25 to 60 years, who met the inclusion criteria, were enrolled in this study. A total of 60 teeth were randomly divided into 4 groups: G1, 980 nm diode laser (in 2 sessions within a 1-week interval); G2, Gluma (in 2 sessions within a 1-week interval); G3, 980 nm diode laser plus Gluma; and G4: control. Thermal (cold spray) and air blast (air syringe of dental unit) stimuli were used to evaluate cervical dentin hypersensitivity in the patients. Their pain response was assessed using a visual analogue scale (VAS) before treatment (baseline), in the first treatment session (15 minutes after treatment), in the second treatment session (after 1 week), and in 2-week, 1-month, and 3-month follow-up sessions. The obtained data were analysed using non-parametric tests, including Kruskal–Wallis test, Friedman test, Mann–Whitney test, and Wilcoxon test, in SPSS Version 22 at a significance level of P < .05. ResultsBased on the results, there was a significant difference in the average VAS scores for cold and air blast stimuli between the 4 groups 1 month after the intervention (P < .05). Meanwhile, the laser group had the lowest VAS score for cold and air stimuli. On the contrary, no significant difference was found between the 4 groups 3 months after the intervention (P ˃ .05). ConclusionThe present results showed that 980-nm diode laser alone was more effective than the other 2 intervention methods for 1 month. Trial registrationThe study was registered in the Iranian Registry of Clinical Trials (IRCT20120901010703N5).

The aim of this study was to evaluate low-level laser therapy in cervical dentin hypersensitivity. A randomized controlled clinical trial was conducted with a total of 64 teeth. Dentin desensitizer and diode laser were applied on the cervical dentin surfaces. Distilled water and placebo laser was used as the placebo groups. The irradiance used was 4 J/cm(2) per treatment site. The baseline measurement of hypersensitivity was made by using visual analog scale (VAS). Twenty-four hours and 7 days after the application of desensitizer, diode laser and placebo groups, a new VAS analysis was conducted for the patients' sensitivity level. The mean pain scores of placebo groups were significantly higher than the desensitizer's and diode laser's mean scores (ANOVA, p < 0.05). The VAS analysis revealed a significant decrease in dentin hypersensitivity in 7 days with the use of the desensitizer and low-level laser therapy and no statistically significant difference was observed between these two treatments (p > 0.05). Although low-level laser and glutaraldehyde containing desensitizer present distinct modes of action, experimental agents caused a significant reduction of dentin hypersensitivity without showing secondary effects, not irritating the pulp or causing pain, not discoloring or staining the teeth, and not irritating the soft tissues at least for a period of 1 week with no drawbacks regarding handling and/or ease of application. Low-level laser therapy and desensitizer application had displayed similar effectiveness in reducing moderate dentin hypersensitivity.

The purpose of this study was to evaluate and compare clinically the efficacy of desensitizer toothpaste alone and in combination with the diode laser in the management of dentin hypersensitivity (DH), as well as both the immediate and late therapeutic effects on teeth with gingival recessions. In total, 52 teeth diagnosed with DH in 13 (seven women, six men, aged 16-48 years) healthy adult patients were included in this study, and teeth were randomly divided equally into two groups: the test group, which received treatment with desensitizer toothpaste and GaAlAs (diode) laser, and the control group, treated with desensitizer toothpaste. DH was assessed by means of an air stimulus, and a visual analogue scale (VAS) was used to measure DH. The selected teeth in the test group received laser therapy for three sessions. Teeth subjected to diode-laser treatment were irradiated at 100 mW for 25 sec at 808 nm, with continuous-emission, noncontact mode, perpendicular to the surface, with scanning movements on the region of exposed root surfaces. Significant reduction of DH occurred at all times measured during the three treatment sessions in the test group. When compared with the means of the responses in the three treatment sessions of the two groups, the test group showed a higher degree of desensitization in teeth with gingival recession than did the control group (p < 0.001). The immediate and late therapeutic effects of the diode laser were more evident compared with those of desensitizer toothpaste. Within the limitations of the present study, a significant effect of combined desensitizer toothpaste and diode laser therapy occurs in the treatment of desensitization of teeth with gingival recession. Desensitizer toothpaste appears to have the therapeutic potential to alleviate DH. Conversely, diode laser can be used to reduce DH.

Minimally invasive endodontics is recommended for young, immature teeth to preserve healthy pulp and dentin tissue. The aim of the study was to examine the cold sensitivity of immature teeth that received photobiomodulation (PBM) after vital pulp therapy (VPT). The study followed the STROBE guidelines and included 123 healthy patients aged 8-13. The immature teeth (incisors, premolars and molars) that qualified for VPT received the bioceramic material - Biodentine. In this experiment, teeth were treated immediately and at 24 h post-VPT with a 635-nm diode laser using a power of 100 mW, a power density of 200 mW/cm2 and a total energy of 4 J (PBM group, n = 43), while those not treated were the control group (n = 43). The tooth sensitivity to cold was measured using a visual analogue scale (VAS) before and at 6 h, 1 day, 7, 30, and 90 days after treatment. The predictor variable was PBM skills regarding the ability to decrease cold sensitivity after VPT. The primary endpoint was the time to reverse hypersensitivity to cold, and the secondary endpoint was the occurrence of possible side effects. The Mann-Whitney U test, Friedman test along with Dunn's post hoc test, and the χ2 test were used to investigate tooth sensitivity. Eighty-six immature permanent teeth of 86 children were included in the study. It was shown that the difference was significant for sensitivity to a cold stimulus between the groups at 6 h, 24 h, 7 days, and 30 days, but no difference was found preoperatively and at 90 days (6 h, 24 h, 7 days, and 30 days, p < 0.001, and 90 days, p = 0.079). However, patients in both groups reported a decrease in discomfort provoked by cold stimuli throughout the follow-up period. Photobiomodulation decreased postoperative sensitivity and was more acceptable for patients. Further randomized clinical studies with placebo-controlled groups are needed.

Introduction: Dentinal Hypersensitivity (DH) is one of the most prevalent dental issues that is treated by both periodontists and endodontists. Hypersensitive dentin is a sensitive or painful response that is one of the most prevalent and poorly treated chronic dental disorders. Due to the difficulty in treating cervical DH, a great range of approaches and therapeutic procedures for pain relief in have developed. Treatments with desensitising drugs have been combined with laser treatment in recent decades. The most often utilised lasers in the treatment of DH are Diode Lasers (DL). DL act on DH provoking a melting effect with crystallisation of dentine inorganic component and the coagulation of fluids contained into the dentinal tubules. Aim: To compare the effectiveness of DL of two different wavelengths in managing DH. Materials and Methods: This split-mouth randomised clinical trial conducted in the Department of Periodontology at Vishnu Dental College, Bhimavaram, Andhra Pradesh, India. The duration of the study was, from October 2021 to December 2021. A total of 12 patients with DH were selected and assigned to two groups. All the patients were subjected to desensitisation using DL of two different wavelengths 475 nm Bluelase system and 810 nm. Denlase system and parameters were evaluated 15 minutes after treatment, 7 days, 15 days and 30 days after treatment. Data were entered in Microsoft Excel and analysed using Statitical Package for Social Sciences (SPSS) version 10.5 software. Results: The mean age of the study participants was 45±3 years. There was a significant difference (p-value &lt;0.001) in tooth sensitivity values measured at baseline, and at different time intervals in both groups. Among the two groups, Denlase group showed the greatest reduction in Visual Analogue Scale (VAS) scores from baseline to one month recall compared to Bluelase laser group. Highly significant difference was found when mean VAS scores were compared between baseline and all the other time points (p-value &lt;0.001). Conclusion: The present study concluded that, based on the results obtained, DL of 810 nm Denlase system was effective than DL of 475 nm Bluelase system in reducing the DH. Desensitisation treatment with laser irradiation has shown to be effective in the present study.