Photobiomodulation for Preventive Therapy of Recurrent Herpes Labialis: A 2-Year In Vivo Randomized Controlled Study.

Objective: The present study aimed to evaluate the effectiveness of the application of photobiomodulation therapy (PBMT) in the prevention of recurrent herpes labialis (RHL) through a randomized controlled clinical trial. Background data: RHL is a lifelong infection that effects patients' quality of life. In the literature PBMT has shown positive results preventing RHL, decreasing recurrences and severity of lesions. Despite the good results reported, there are still few controlled clinical studies published on the subject. Methods: For this study, 158 volunteers were recruited and were randomly divided into three study groups: Laser 1-1 J/point (L1J): n = 61, Laser 2-2 J/point (L2J): n = 50, and placebo-0 J/point: n = 47. The treatment consisted of a protocol of 15 sessions throughout 6 months and 2 years of follow-up posttreatment. Results: The results showed that L1J presented the most satisfactory results concerning the reduction of the number of lesions per year and less severity of recurrences in the long-term evaluation when compared with L2J. Both Laser Groups (L1J and L2J) were statistically more efficient than placebo in all aspects analyzed. All patients who received laser treatment (L1J and L2J) and presented recurrences had significant improvement in frequency and/or severity of lesions. No patient had side effects from treatment. Conclusions: PBMT can be effective in the reduction of the frequency of recurrences of RHL and in the severity of postirradiation lesions that may appear.

Photobiomodulation therapy and 3% potassium nitrate gel as treatment of cervical dentin hypersensitivity: a randomized clinical trial.

OBJECTIVES: This randomized controlled trial aimed to evaluate different protocols for dentin hypersensitivity treatment with low-power lasers and desensitizing agents, and the association between low-power lasers and desensitizing agents. MATERIALS AND METHODS: Fifty-four patients (303 teeth) were randomly allocated to three groups: G1, 3% nitrate potassium gel, UltraEZ (n = 17); G2, photobiomodulation therapy (PBM) with a low-level infrared laser (n = 17), 100 mW, spot size of 0.028 cm2, and dose of 1 J per point; and G3, nitrate potassium + PBM (n = 20). Treatments were applied to the buccal cervical region at intervals of 72 h, and all protocols were performed in three sessions. The patients' response to evaporative stimuli was rated using the visual analog scale (VAS). Re-evaluations were performed immediately after each application and 1 week, 1 month, and 3 months after treatment. A two-way repeated measures test and Tukey's post hoc test were used for multiple comparisons (α = 5%). RESULTS: There was a reduction in pain levels at the end of treatment in all groups. There were no significant differences in VAS score changes between the groups immediately after treatment and after the third month, compared to the baseline (p > 0.05). CONCLUSION: Under the limitations of this in vivo study, the proposed three-session protocol was effective in reducing dentin hypersensitivity after 3 months, regardless of the desensitization mechanism used. Conservative and long-term protocols are interesting for the control of pain caused by dentin hypersensitivity. CLINICAL RELEVANCE: The increase in cervical dentin hypersensitivity prevalence warrants easy-to-apply and long-lasting desensitizing protocols for pain control.

Treatment of oral leukoplakia with CO2 laser (10,600 nm): analysis of 37 cases.

Oral leukoplakia is a potentially malignant disorder, defined as a white plaque that cannot be diagnosed as another known disease or disorder, and has an increased risk of malignancy. The aim of the present study was to evaluate the results of CO2 laser treatment in a well-defined cohort of patients with oral leukoplakia in order to identify the occurrence of clinical outcomes of relapse, resolution, or malignancy after treatment. The study group comprised 37 patients. Before treatment, clinical photographs and incisional biopsies were obtained in all cases. In addition, the post-treatment results were documented using photographs. Evaluation of treatment results was performed by an independent researcher who had not performed the surgery. The minimum, maximum, and mean values of continuous variables were calculated. Statistically significant relationships were tested using the Cox regression analysis. A survival curve was constructed according to the Kaplan-Meier method to analyze the malignant transformation and recurrence of oral leukoplakia. The clinical outcomes analyzed were resolution, recurrence, and malignancy. The mean follow-up period was 36 months (range, 6-239 months). In 13/37 patients, leukoplakia recurred between 6 and 93 months (mean, 38.2 months). In 8/37 patients, a malignant transformation occurred (mean, 50.6 months). In 16/37 patients, lesion resolution occurred. No risk factor was statistically significant for malignancy or recurrence of lesions. The treatment of the lesions by CO2 laser was efficient in the removal of the lesions; however, it did not avoid the clinical outcomes of recurrence or malignancy.

Treatment of oral leukoplakia with CO2 laser (10,600 nm): analysis of 37 cases

Abstract Oral leukoplakia is a potentially malignant disorder, defined as a white plaque that cannot be diagnosed as another known disease or disorder, and has an increased risk of malignancy. The aim of the present study was to evaluate the results of CO2 laser treatment in a well-defined cohort of patients with oral leukoplakia in order to identify the occurrence of clinical outcomes of relapse, resolution, or malignancy after treatment. The study group comprised 37 patients. Before treatment, clinical photographs and incisional biopsies were obtained in all cases. In addition, the post-treatment results were documented using photographs. Evaluation of treatment results was performed by an independent researcher who had not performed the surgery. The minimum, maximum, and mean values of continuous variables were calculated. Statistically significant relationships were tested using the Cox regression analysis. A survival curve was constructed according to the Kaplan-Meier method to analyze the malignant transformation and recurrence of oral leukoplakia. The clinical outcomes analyzed were resolution, recurrence, and malignancy. The mean follow-up period was 36 months (range, 6-239 months). In 13/37 patients, leukoplakia recurred between 6 and 93 months (mean, 38.2 months). In 8/37 patients, a malignant transformation occurred (mean, 50.6 months). In 16/37 patients, lesion resolution occurred. No risk factor was statistically significant for malignancy or recurrence of lesions. The treatment of the lesions by CO2 laser was efficient in the removal of the lesions; however, it did not avoid the clinical outcomes of recurrence or malignancy.

Is prolonged bleaching more harmful to dental enamel than daily dietary and hygienic oral habits?

Abstract The ultrastructural and mechanical properties of enamel surface were evaluated after prolonged bleaching treatments with 10% carbamide peroxide in the presence or absence of orange juice (erosive challenge) and toothbrushing (abrasive challenge). In total, 145 incisor bovine teeth were used in this study. Twenty-five samples were prepared for the ultrastructural evaluations, and 120 samples were prepared for microhardness and roughness tests. These 120 samples were divided into eight experimental groups (n = 15): G1- artificial saliva; G2- abrasion; G3- erosion; G4- dental bleaching; G5- erosion + abrasion; G6- bleaching + abrasion; G7- bleaching + erosion; and G8- bleaching + erosion + abrasion. All groups were tested at T0 (before treatment), T1 (14 days), T2 (21 days), and T3 (28 days). Two-way analysis of variance for repeated measures and the post hoc Sidak tests (p ≤ 0.05) were used. The roughness evaluation demonstrated an increase in damage for all experimental groups with an increase in the time period. For microhardness, the groups exposed to artificial saliva (AS) and abrasive challenge did not show any differences at any time points, while the other groups showed a decrease in microhardness from T0 to T3. Ultrastructural evaluation showed different surface alterations in response to the treatments. Despite prolonged bleaching periods, the procedure caused lesser enamel surface alterations than exposure to orange juice alone or in combination with brushing.

Association of Nd: YAG laser and calcium-phosphate desensitizing pastes on dentin permeability and tubule occlusion

Abstract Objective To evaluate the efficacy of Nd:YAG laser associated with calcium-phosphate desensitizing pastes on dentin permeability and tubule occlusion after erosive/abrasive challenges. Methodology Dentin specimens were exposed to 17% ethylene diamine tetra-acetic acid (EDTA) solution for 5 min and randomly allocated into five groups: G1, control (no treatment); G2, Nd:YAG laser (1 W, 10 Hz, 100 mJ, 85 J/cm2); G3, Laser + TeethmateTM Desensitizer; G4, Laser + Desensibilize Nano P; and G5, Laser+Nupro®. Specimens underwent a 5-day erosion-abrasion cycling. Hydraulic conductance was measured post-EDTA, post-treatment, and post-cycling. Post-treatment and post-cycling permeability (%Lp) was calculated based on post-EDTA measurements, considered 100%. Open dentin tubules (ODT) were calculated at the abovementioned experimental moments using scanning electron microscopy and ImageJ software (n=10). Data were analyzed using two-way repeated measures ANOVA and Tukey's test (α=0.05). Results G1 presented the highest %Lp post-treatment of all groups (p<0.05), without significantly differences among them. At post-cycling, %Lp significantly decreased in G1, showed no significant differences from post-treatment in G3 and G4, and increased in G2 and G5, without significant differences from G1 (p>0.05). We found no significant differences in ODT among groups (p>0.05) post-EDTA. At post-treatment, treated groups did not differ from each other, but presented lower ODT than G1 (p<0.001). As for post-cycling, we verified no differences among groups (p>0.05), although ODT was significantly lower for all groups when compared to post-EDTA values (p<0.001). Conclusion All treatments effectively reduced dentin permeability and promoted tubule occlusion after application. Combining Nd YAG laser with calcium-phosphate pastes did not improve the laser effect. After erosive-abrasive challenges, treatments presented no differences when compared to the control.

The effect of a single irradiation of low-level laser on nipple pain in breastfeeding women: a randomized controlled trial.

Photobiomodulation with low-level laser therapy (PBM-LLLT) has been introduced as a new tool to relieve nipple pain and repair nipple damage in breastfeeding women; however, evidence is needed to assess its effectiveness. The aim was to evaluate the effect of a single application of PBM-LLLT for breastfeeding women with nipple pain and damage; side effects were also collected. We conducted a randomized double-blinded controlled trial with women with nipple damage who were exclusively breastfeeding and rooming-in at Amparo Maternal maternity service, São Paulo, Brazil (May 2016 to May 2017). Women were randomly assigned into laser (n = 40) or control group (n = 40). Intervention was a single irradiation (660 nm, 100 mW, 2 J, 66.66 J/cm2, 3.3 W/cm2, 20 s of irradiation, punctual, and continuous mode) applied directly. Women reported pain levels at recruitment (before and immediately after irradiation), 6 and 24 h after the treatment. Pain level during a breastfeed was assessed using the Visual Analogue Scale (0 to 10). The primary outcome was the level of nipple pain immediately after the laser irradiation. Data were analyzed using hierarchical model and Wald test. At baseline, pain levels were similar (mean of 7.4 in laser group and 7.1 in control group). Women's perception of pain reduced approximately one point in both groups. Thirty-one percent of participants in the laser group (11/36) reported secondary effects, such as tingling (10/36) and pricking (2/36). The laser protocol of a single application was not effective in reducing pain in women with damaged nipples. Tingling sensation may be experienced by women receiving laser treatment for nipple damage.

Mechanical properties and surface roughness of polymer-based materials containing DCPD particles

Abstract The purpose of this study was to synthesize dicalcium phosphate dihydrate (DCPD) particles functionalized with triethylene glycol dimethacrylate (TEGDMA) through different routes by varying the receptor solution: ammonium phosphate (AP groups) or calcium nitrate (CN groups) and the moment in which TEGDMA was incorporated: ab initio (ab) or at the end of dripping the solution (ap). Two syntheses were performed without adding TEGDMA (nf). The particles were characterized by X-ray diffractometry, true density (using a helium pycnometer), surface area, and scanning electron microscopy. A 20 vol% of DCPD particles from the D, E, and F groups was added to the resin matrix to determine the degree of conversion (DC), biaxial flexural strength (BFS), the flexural modulus (FM), and surface roughness after an abrasive challenge (RA). A group with silanized barium glass particles was tested as a control. The data were submitted to ANOVA/Tukey's test (DC, BFS, and RA), and the Kruskal-Wallis test (FM) (alpha = 0.05). BFS values varied between 83 and 142 MPa, and the CN_ab group presented a similar value (123 MPa) to the control group. FM values varied between 3.6 and 8.7 GPa (CN_ab and CN_nf groups, respectively), with a significant difference found only between these groups. RA did not result in significant differences. The use of calcium nitrate solution as a receptor, together with ab initio functionalization formed particles with larger surface areas. Higher BFS values were observed for the material containing DCPD particles with a higher surface area. In general, the DC, FM, and RA values were not affected by the variables studied.

Photobiomodulation with Low-Level Laser in the Treatment of Trismus After Radiotherapy: A Case Report.

Background: Radiotherapy is one of the treatments for cancer, which leads to many oral side effects that affect the quality of life of the patient; among them, trismus is considered. Objective: Considering the various therapies to treat this collateral effect of radiotherapy, photobiomodulation (PBM) with low-level laser is a contemporary alternative. Methods: In this article, an all-clinical case report is presented in which the patient was given trismus after radiotherapy and PBM with low-level laser. The measurement of the buccal opening was evaluated in each treatment session with a digital caliper, and the pain was evaluated through the visual analog scale (VAS). Results: The efficacy of the PBM protocol on the trismus after radiotherapy was evidenced by the decrease of pain and increase of the buccal opening. Conclusions: The use of PBM with low-level laser is an option for the treatment of trimus after radiotherapy.

Effect of Er,Cr:YSGG laser associated with fluoride on the control of enamel erosion progression.

OBJECTIVE: To evaluate the effect of Er,Cr:YSGG laser associated or not with acidulated phosphate fluoride (APF) on the control of enamel erosion progression. DESIGN: Enamel slabs (4 mm × 4 mm × 2 mm) from bovine incisors were flattened, polished, and received a tape on their test surfaces, leaving a 4 mm × 1 mm area exposed. Specimens were eroded (10 min in 1% citric acid solution) and randomly assigned into 8 experimental groups (n = 10): Control (no treatment); F (APF gel, 1.23% F, pH 3.6-3.9); Er,Cr:YSGG laser irradiation (P1: 0.25 W, 20 Hz, 2.8 J/cm2, 56 W/cm2); Er,Cr:YSGG laser irradiation (P2: 0.50 W, 20 Hz, 5.7 J/cm2, 1136 W/cm2); Er,Cr:YSGG laser irradiation (P3: 0.75 W, 20 Hz, 8.5 J/cm2, 1704 W/cm2); F + Laser P1; F + Laser P2; F + Laser P3. Specimens were then subjected to erosive cycling (5 min immersion in 0.3% citric acid solution, followed by immersion in artificial saliva for 60 min; 4×/day for 5 days). At the end of cycling, surface loss (SL, in µm) was determined with optical profilometry. Selected specimens were further evaluated by environmental scanning electron microscopy (n = 3). Data were analyzed using Kruskal-Wallis and Tukey tests (α = 0.05). RESULTS: Group F + Laser P2 had the lowest SL value, differing significantly from the control; however, with no significant difference from the other groups. All groups, except F + Laser P2, showed no significant difference in SL when compared with the control. An irregular and rough surface, suggestive of a melting action of laser, was observed on enamel in Laser P2 and F + Laser P2 groups. CONCLUSIONS: Association of the Er,Cr:YSGG laser in parameter 2 with fluoride was the only treatment capable of controlling the progression of enamel erosion.

Efficacy of Photocoagulation of Vascular Malformations in the Oral Mucosa Using Nd: YAG Laser.

The purpose of this study was to analyze the effectiveness of Nd: YAG laser photocoagulation in the treatment of vascular malformations in the oral and perioral area; 93 patients (104 lesions) were evaluated in an Ambulatory of Oral Medicine (2006-2013). The sample consisted of 57 women (61%) and 36 men (39%), aged 8 to 85 years. The lesion size was smaller than 3 cm in most patients. The lesions were located on the lips, jugal mucosa, tongue, palate, gingiva, and retromolar trigone. All patients were treated on an outpatient basis using local anesthesia and Nd: YAG laser (Power Laser C ) with a wavelength of 1064 nm and a fiber optic diameter of 400 µm. After treatment no patients had complications, however, in patients of deep lesions, 2 or more irradiations were required to treat the lesions. Finally, the authors conclude that the clinical and aesthetic satisfactory results of the 93 patients treated with Nd: YAG laser suggest that this type of laser is effective and safe in the treatment of oral and perioral vascular malformations.

Photobiomodulation in the Postoperative of Bichectomy Surgeries: Case Series.

BACKGROUND: Several photobiomodulation (PBM) protocols with low-power lasers have been reported for pain control and tissue repair in the postoperative period of oral surgeries. However, there are still no reports of a protocol for bichectomy surgeries' postoperative period. OBJECTIVE: This article presents six reports of clinical cases in which bichectomy surgery was performed. METHODS: In the postoperative period, three patients were submitted to PBM with low-power lasers, while three patients did not receive it. Facial edema was evaluated using a millimeter tape. Pain was determined using the visual analog scale. RESULTS: Data of each clinical case were evaluated in a descriptive way and compared. CONCLUSIONS: The efficacy of the PBM protocol on the postoperative period of bichectomy surgeries was evidenced by the decrease of edema and pain.

Is photobiomodulation (PBM) effective for the treatment of dentin hypersensitivity? A systematic review.

The present study aims to evaluate the current scientific data regarding the effectiveness of photobiomodulation (PBM) in the treatment of dentin hypersensitivity (DH) as an alternative method for pain control. A systematic review was conducted to assess the effectiveness of PBM as treatment for DH. A complete literature search was performed up to October 2016. Searches were conducted using Boolean operators and MeSH terms. References of all selected full-text articles and related reviews were scanned. A total of 280 articles were identified (241 articles were excluded by the title and abstract). Of the 39 articles selected for analysis, 36 were excluded because they presented one or more exclusion criteria. Therefore, three articles were qualified for inclusion in this systematic review. PBM may not lead to adverse effects provided that adequately controlled parameters are followed when treating DH. More consistent studies should be conducted in order to adequately observe the advantageous therapeutic effect of PBM.

Antimicrobial photodynamic therapy (aPDT) and photobiomodulation (PBM - 660nm) in a dog with chronic gingivostomatitis.

Chronic gingivostomatitis in dogs is an inflammatory syndrome of the oral cavity, which treatment and control of concomitant periodontitis allow healing in most of the cases. In the presence of recurrent lesions, invasive methods are necessary to treat lesions and pain. As a conservative adjuvant method, photobiomodulation (PBM) with low power laser is able to promote reduction of tissue pain and tissue inflammation besides increasing vascularization and healing, restoring the normal function of the irradiated organ in a shorter time. In veterinary medicine, there is no standardization of technique for its use in oral tissue for treating gingivostomatitis in dogs. In the present case, a dog was submitted to aPDT (7.2J/point, 3min/point, 180J/cm2) and PBM (1.6J/point, 40s/point, 25J/cm2), using a semiconductor diode laser, with wavelength of 660nm, spot size of ​​0.04cm2 and output power of 40mW. The established protocol proved to be effective as coadjutant treatment for chronic gingivostomatitis, restoring the integrity of dog's affected mucosa and gingiva.

Photobiomodulation in the Prevention of Tooth Sensitivity Caused by In-Office Dental Bleaching. A Randomized Placebo Preliminary Study.

OBJECTIVE: Analyze the effect of photobiomodulation in the prevention of tooth sensitivity after in-office dental bleaching. BACKGROUND DATA: Tooth sensitivity is a common clinical consequence of dental bleaching. Therapies for prevention of sensitivity have been investigated in literature. MATERIALS AND METHODS: This study was developed as a randomized, placebo blind clinical trial. Fifty patients were selected (n = 10) and randomly divided into five groups: (1) control, (2) placebo, (3) laser before bleaching, (4) laser after bleaching, and (5) laser before and after bleaching. Irradiation was performed perpendicularly, in contact, on each tooth during 10 sec per point in two points. The first point was positioned in the middle of the tooth crown and the second in the periapical region. Photobiomodulation was applied using the following parameters: 780 nm, 40 mW, 10 J/cm2, 0.4 J per point. Pain was analyzed before, immediately after, and seven subsequent days after bleaching. Patients were instructed to report pain using the scale: 0 = no tooth sensitivity, 1 = gentle sensitivity, 2 = moderate sensitivity, 3 = severe sensitivity. RESULTS: There were no statistical differences between groups at any time (p > 0.05). More studies, with others parameters and different methods of tooth sensitivity analysis, should be performed to complement the results found. CONCLUSIONS: Within the limitation of the present study, the laser parameters of photobiomodulation tested in the present study were not efficient in preventing tooth sensitivity after in-office bleaching.

The potential of low-power laser for reducing dental sensitivity after in-office bleaching: a case report.

Postoperative sensitivity is one of the most common side effects of in-office bleaching with hydrogen peroxide. Laser phototherapy (LPT) has been suggested as an adjunctive treatment to prevent or minimize tooth sensitivity. This case report aimed to verify the efficacy of LPT in the reduction of sensitivity after in-office bleaching. Tooth bleaching was performed with 35% hydrogen peroxide activated with a hybrid LED-laser device. Immediately after the bleaching treatment, the patient reported dental sensitivity, as measured with a visual analog scale (VAS). To reduce sensitivity, LPT was applied with a 780-nm laser using the following parameters: 70 mW, exposure time of 10 seconds per point of irradiation (middle region of the buccal surfaces of each compromised tooth) in contact mode, energy of 1 J per point. Immediately after LPT, the patient reported a substantially lower level of pain on the VAS. Twenty-four hours after bleaching, the score on the VAS indicated that sensitivity levels had rebounded, and the patient received additional LPT. After 48 hours, the patient reported no dental sensitivity. The results in this patient indicated that irradiation with an infrared low-power laser substantially reduced dental pain generated by bleaching, suggesting that LPT should be considered as an auxiliary method to reduce postbleaching tooth sensitivity.

In situ evaluation of fluoride-, stannous- and polyphosphate-containing solutions against enamel erosion.

OBJECTIVE: To evaluate the anti-erosive effect of solutions containing sodium fluoride (F: 225ppm of fluoride), sodium fluoride+stannous chloride (F+Sn: 225ppm of fluoride+800ppm of stannous), sodium fluoride+stannous chloride+sodium linear polyphosphate (F+Sn+LPP: 225ppm of fluoride+800ppm of stannous+2% of sodium linear polyphosphate), and deionized water (C: control), using a four-phase, single-blind, crossover in situ clinical trial. METHODS: In each phase, 12 volunteers wore appliances containing 4 enamel specimens, which were submitted to a 5-day erosion-remineralization phase that consisted of 2h of salivary pellicle formation with the appliance in situ, followed by 2min extra-oral immersion in 1% citric acid (pH 2.4), 6x/day, with 90min of exposure to saliva in situ between the challenges. Treatment with the test solutions was performed extra-orally for 2 min, 2x/day. At the end of the experiment, surface loss (SL, in µm) was evaluated by optical profilometry. Data were analyzed using ANOVA and Tukey tests (α=0.05). The surface of additional specimens was evaluated by x-ray diffraction after treatments (n=3). RESULTS: C (mean SL±standard-deviation: 5.97±1.70) and F (5.36±1.59) showed the highest SL, with no significant difference between them (p>0.05). F+Sn (2.68±1.62) and F+Sn+LPP (2.10±0.95) did not differ from each other (p>0.05), but presented lower SL than the other groups (P<0.05). Apatite and stannous deposits on specimen surfaces were identified in the x-ray analysis for F+Sn and F+Sn+LPP. CONCLUSIONS: Sodium fluoride solution exhibited no significant anti-erosive effect. The combination between sodium fluoride and stannous chloride reduced enamel erosion, irrespective of the presence of linear sodium polyphosphate. CLINICAL SIGNIFICANCE: Under highly erosive conditions, sodium fluoride rinse may not be a suitable alternative to prevent enamel erosion. A rinse containing sodium fluoride and stannous chloride was shown to be a better treatment option, which was not further improved by addition of the sodium linear polyphosphate.

Evaluation of different treatment protocols for dentin hypersensitivity: an 18-month randomized clinical trial.

This randomized and longitudinal in vivo study aimed to assess different protocols for the treatment of dentin hypersensitivity with low-power laser (with different doses), high-power laser, and a desensitizing agent, for a period of 12 and 18 months. The lesions from 32 patients (117 lesions), who were submitted to the inclusion and exclusion criteria, were divided into nine groups (n = 13): G1: Gluma Desensitizer (Heraeus Kulzer), G2: low-power laser with low dose (three points of irradiation in vestibular portion and an apical point 30 mW, 10 J/cm2, 9 s per point with the wavelength of 810 nm, with three sessions with an interval of 72 h), G3: low-power laser with high dose (one point in the cervical area, and one apical point 100 mW, 40 J/cm2, 11 s per point with the wavelength of 810 nm in three sessions with an interval of 72 h), G4: low-power laser with low dose + Gluma Desensitizer, G5: low-power laser with high dose + Gluma Desensitizer, G6: Nd:YAG laser (Power Laser™ ST6, Research® in contact 1.0 W, 10 Hz and 100 mJ, ≈85 J/cm2, with the wavelength of 1064 nm), G7: Nd:YAG laser + Gluma Desensitizer, G8: low-power laser with low dose + Nd:YAG laser, and G9: low-power laser with high dose + Nd:YAG laser. The level of sensitivity of each volunteer was assessed by visual analog scale of pain (VAS) with the aid of air from the triple syringe and exploration probe, 12 and 18 months after treatment. All analyses were performed separately for air and probe stimulus. The level of significance was considered for values of p < 0.05. After statistical analysis, all treatments were shown to be effective in reducing dentinal hypersensitivity, and the results were considered not statistically different from those at 12 months. Therefore, until the 18-month evaluation, it could be said that no statistical differences were observed in the sensitivity levels for all treatments.

Effects of different radiation doses on the microhardness, superficial morphology, and mineral components of human enamel.

OBJECTIVE: To evaluate the effects of three different radiotherapy doses (20, 40, and 70Gy) on the microhardness, superficial morphology, and mineral content (based on Ca and P values) of three different depths of human enamel (cervical, middle, and occlusal). DESIGN: Thirty-four third molars were cut, separated, and prepared. Microhardness samples (n=30) were embedded in acrylic resin and then polished, and depths were delimited. Microhardness tests were performed on cervical, middle, and occlusal enamel pre- and post-radiotherapy with a load of 50g for 30s. For the scanning electron microscopy (SEM) analysis (n=4) and energy dispersive X-ray spectroscopy (EDS) (n=12), samples were fixed in a 3% glutaraldehyde solution, washed in 0.1M cacodylate solution, and dehydrated in crescent concentrations of ethanol. Microhardness data were tested for significant differences using a two-way analysis of variance (ANOVA) and Tukey's test (p<0.05), while SEM and EDS were evaluated qualitatively. RESULTS: The results showed a decrease in microhardness values only in the cervical enamel, regardless of the radiation dose used; no morphological or mineral change was observed. CONCLUSION: Radiotherapy can affect the microhardness values of only cervical enamel without compromising the morphological or mineral (Ca and P) content at any depth.

The association between Nd:YAG laser and desensitizing dentifrices for the treatment of dentin hypersensitivity.

This study aims to evaluate the association between Nd:YAG laser (with and without a photoabsorber) and two desensitizing dentifrices containing 15% NovaMin or 8% arginine, as potential treatments for dentin hypersensitivity (DH). DH was simulated by EDTA application for 2 min. Specimens were then analyzed with an environmental scanning electron microscope (ESEM) to ensure open dentin tubules (ODT), counted by using ImageJ software. Specimens were randomized into eight groups (n = 10): Laser (L), Laser+Photoabsorber (LP), Arginine (A), Arginine+Laser (AL), Arginine+Laser+Photoabsorber (ALP), NovaMin (N), NovaMin+Laser (NL), and NovaMin+Laser+Photoabsorber (NLP). Laser irradiation was performed with 1 W, 100 mJ, 10 Hz, ≅85 J/cm2; 4 irradiations of 10 s each, with 10 s intervals between them. After treatment, specimens were again analyzed by ESEM and submitted to erosive/abrasive cycling for 5 days. A final ESEM analysis was performed. Data were analyzed with two-way repeated measure ANOVA and Tukey tests (α = 0.05). After treatment, groups N, NL, and NLP presented the lower number of ODT, but they did not different from LP, ALP, and AL. Group A presented the highest number of ODT and it did not differ from group L. Groups L, AL, ALP, and LP presented intermediate results, without differing from each other. After cycling, group A presented the highest number of ODT and did not differ significantly from the other groups, except NLP. None of the associations tested presented better tubule occlusion than NovaMin by itself. Arginine was the only treatment that presented improved tubule occlusion when associated with Nd:YAG laser.