Photobiomodulation, Transmucosal Laser Irradiation of Blood, or B complex as alternatives to treat Covid-19 Related Long-Term Taste Impairment: double-blind randomized clinical trial.

COVID-19 Related Long-Term Taste Impairment (CRLTTI) is a condition that can be expressed after COVID-19 contagion, lasting for months or even years, affecting the routine and quality of life of individuals. Participants expressing CRLTTI, with a minimum of 2 months, attested by PCR-RT test were assessed for taste and smell, and underwent experimental treatments in 6 distinct groups: Photobiomodulation (PBM) in tongue dorsum and lateral (660 nm, 808 nm, association of 660 and 808 nm), Transmucosal Laser Irradiation of Blood (TLIB)-ventral surface of tongue (660 nm), B complex supplementation, and Sham laser. No intergroup statistical differences were observed at the final evaluation, despite the tendencies of better results with PBM and TLIB observed. PBM, TLIB, and B complex might be treatment options in the management of CRLTTI, despite the lack of total remission of taste and smell perception after 8 sessions (PBM and TLIB) or 30 days of B complex supplementation.

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.

Long-term safety of photobiomodulation therapy for oral mucositis in hematopoietic cell transplantation patients: a 15-year retrospective study.

Photobiomodulation therapy (PBMT) has demonstrated efficacy in the prevention and treatment of oral mucositis (OM) in hematopoietic cell transplantation (HCT). However, based on the cell stimulation properties, its long-term safety has been questioned, mainly in relation to risk for secondary malignancies in the oral cavity. The aim of this study was to investigate if different PBMT protocols for OM control have association with immediate and late adverse effects in HCT patients. Data on autologous and allogeneic transplantation, conditioning regimen, PBMT protocols, and OM severity were retrospectively collected from medical and dental records. Presence of secondary malignancies in the oral cavity was surveyed during a 15-year follow-up. Impact of OM on overall survival was also analyzed. Different PBMT protocols for prevention and treatment of OM were recorded over the years. Severe OM (grades 3 and 4) was infrequently observed. When present, we observed a significant decrease of the overall survival. No immediate adverse effect and secondary malignancy was associated to PBMT. In conclusion, the PBMT protocols used in the study were considered safe. The low frequency of severe OM observed encourages the implementation of this technique, with a special emphasis on the dosimetry adjustments focused on the HCT context.

Photodynamic therapy and Acyclovir in the treatment of recurrent herpes labialis: A controlled randomized clinical trial.

BACKGROUND: Herpes Simplex Virus Type 1 (HSV-1) is one of the most widespread infections that can effect the orofacial region. Recurrent infection is considered a life-long oral health problem, leading to pain, discomfort, and social restriction due to esthetic features when active. Effective therapies are needed. This study aimed to compare photodynamic therapy (PDT), Topical Acyclovir (AC), and the association of both in the healing process and self-reported symptomologies of HSV-1 recurrences. METHODS: Patients were randomly assigned into 3 groups (n = 25): PDT (low-power laser, 660 nm, 40 mW, 120 J/cm2, 4.8 J, 120 s per point) and methylene blue (0.005 %) as photosensitizer; AC (5%); PDT + AC.Data concerning lesion size, healing time, and self-reported healing parameters, such as pain, tingling, and edema were taken every day up to complete healing for all studied groups. RESULTS: There was no significant difference in healing time and pain between groups. AC group showed a significant minor reduction of the lesion compared to the AC-PDT group on day 1. Regarding edema and tingling, the comparison of treatments showed a statistical difference only on day 1, where PDT showed better results. CONCLUSION: With all the limitations of this study, it can be concluded that only on day 1 PDT showed positive effects in the treatment of herpes lesions in comparison to AC.

Retreatment of 6 ceramic restorations in a single session - the application of Er:YAG laser and CAD/CAM technology: an 1 year follow up clinical evaluation / Retratamento de 6 restaurações de cerâmica em uma única sessão ­ Utilizando o Laser ER: YAG e a tecnologia CAD/CAM com Acompanhamento de 1 ano

Background: To present the benefits of high power lasers (Er: YAG and Nd: YAG) over the use of the high speed turbine for the extraction of ceramics restorations, without damaging the surfaces of the teeth; being a relatively easier and faster procedure without the use of anesthetic agents, and the preparation of the ceramic restorations and cementing in the single session; with a follow-up of 1 year. Objective: The benefits of lasers over high-speed turbine mechanical instrumentation for crown removal encompass efficient restoration recovery without damage to tooth surfaces; and a relatively easier and faster procedure without the use of anesthetic agents. Methods: The Er: YAG laser (no contact; 3.2-4.0 W, 20 Hz) was used to extract the porcelain prosthesis, followed by a gingivectomy with the Nd: YAG laser on tooth 12 to improve the gingival contour. The dental surfaces where the ceramic prosthesis will be cemented were scanned. Then, CAD / CAM technology was used to make the ceramic veneers that were cemented in the same session. Results: The efficacy the Er:YAG laser energy was observed by the decreased of the time to remove all-ceramic materials through ablation of bonding cements, reducing working time by 75% compared to a high-speed turbine. Conclusions: An Er: YAG laser can safely remove lithium disilicate crowns with the settings used in this study. Laser-assisted removal of all ceramic PDFs is a promising treatment protocol. The use of the Nd: YAG (2.0 W power, short 20Hz, 320 µm optical fiber, in contact) laser allowed gingivoplasty to be performed, automatically cauterizing avoiding post-operative bleeding, and facilitating the preparation of ceramic restorations the same day. The use of high-power lasers and the use of accompanying CAD / CAM technology allowed this clinical case to be completed in a single visit without the use of temporary restorations, achieving absolute patient satisfaction. (AU)

Antecedentes: Apresentar os benefícios dos lasers de alta potência (Er: YAG e Nd:YAG) sobre o uso da turbina de alta velocidade para a remoção de restaurações cerâmicas, sem danificar as superfícies dos dentes; sendo um procedimento relativamente mais fácil e rápido evitando o uso de agentes anestésicos, conseguindo fazer o preparo das restaurações de cerâmica e cimentação em uma única sessão; com seguimento de 1 ano. Objetivo: Os benefícios dos lasers sobre a instrumentação mecânica com turbina de alta velocidade para a remoção da coroa abrangem a recuperação eficiente da restauração sem danos às superfícies dos dentes; e um procedimento relativamente mais fácil e rápido sem o uso de agentes anestésicos. Métodos: O laser Er: YAG (sem contato; 3,2-4,0 W, 20 Hz) foi utilizado para remover a prótese de porcelana, seguido de gengivectomia com o laser Nd: YAG no dente 12 para melhorar o contorno gengival. As superfícies dentais onde a prótese de cerâmica será cimentada foram escaneadas. Em seguida, a tecnologia CAD / CAM foi utilizada para confeccionar as facetas de cerâmicas que foram cimentadas na mesma sessão. Resultados: A eficácia da energia do laser Er: YAG foi observada pela diminuição do tempo na remoção dos materiais cerâmicos por meio da ablação dos cimentos de ligação, reduzindo o tempo de trabalho em 75% em relação a uma turbina de alta velocidade. Conclusão: Um laser Er: YAG pode remover com segurança as coroas de dissilicato de lítio com as configurações usadas neste estudo. A remoção assistida por laser de todos os PDFs de cerâmica é um protocolo de tratamento promissor. O uso do laser Nd: YAG (2,0 W potência, curta 20Hz, 320 µm fibra ótica, em contato) permitiu a realização da gengivoplastia, cauterizando automaticamente evitando sangramento pós-operatório e facilitando o preparo das restaurações cerâmicas no mesmo dia. O uso de lasers de alta potência e o uso da tecnologia CAD / CAM que o acompanha permitiram que este caso clínico fosse concluído em uma única visita, sem o uso de restaurações temporárias, alcançando a satisfação absoluta do paciente (AU)

Associative Protocol for Dentin Hypersensitivity Using Nd:YAG Laser and Desensitizing Agent in Teeth with Molar-Incisor Hypomineralization.

Objective: The aim of this article was to describe and discuss a clinical case in which the Nd:YAG laser and a desensitizing agent were associated in a protocol for dentin hypersensitivity (DH) in teeth with molar-incisor hypomineralization (MIH). Background data: DH is a common condition among the population, being one of the main reasons for patients to seek for a dental treatment. MIH can be considered a condition that induces DH. Methods: The patient was referred for evaluation, complaining of hypersensitivity during eating or drinking cold foods. Clinical evaluation revealed the presence of MIH on the first lower molars. Aiming to treat DH, two strategies for dentin desensitization were associated: the use of a high-power laser (Nd:YAG laser, 1.064 nm; Lares Research), with a 300 µm quartz optical fiber, 1 W of power, 100 mJ of energy, 10 Hz of repetition rate, and 85 J/cm2 of energy density, followed by the application of two layers of a desensitizing agent (Gluma Desensitizer). Results: DH was evaluated immediately, after 1 week and after 1 month of the treatment. Clinical outcomes were satisfactory, confirming the efficacy and considerable durability of the protocol used for the reduction of DH originated from MIH. Conclusions: The association of Nd:YAG laser and a desensitizing agent for controlling DH was effective, showing to be an interesting protocol.

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.

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.

Immediate laser-induced hemostasis in anticoagulated rats subjected to oral soft tissue surgery: a double-blind study.

Given the growing trend towards medical indications for continuous use of anticoagulants, the number of patients on these medications continues to rise. The management of patients on oral anticoagulants requiring oral surgical procedures has aroused much controversy. Changes in an anticoagulation regimen are associated with an increased risk of thromboembolism. However, it seems logical and advantageous for the patients' health if surgery could be performed without any change to the anticoagulation therapy. In dentistry, high-power lasers have been poorly explored in this field. The hemostatic properties of high-power lasers could be helpful during oral soft tissue surgeries in anticoagulated patients. The aim of this study was to compare bleeding time in anticoagulated rats after lingual frenectomy performed with a scalpel or diode laser with bleeding time in healthy animals. Twenty-four male Wistar rats were assigned to four groups (n = 6): (CS) Control-Scalpel Surgery; (AS) Anticoagulated-Scalpel Surgery; (CL) Control-Laser (diode laser 810 nm/1.5 W) Surgery; and (AL) Anticoagulated-Laser Surgery (diode laser 810 nm/1.5 W). Warfarin administration was used to induce anticoagulation. Blood was blotted every 30 seconds with filter paper until bleeding stopped to verify bleeding time. Two blinded researchers performed the surgeries and collected the bleeding time data. Diode laser surgery led to complete hemostasis in rats during and after lingual frenectomy. Zero bleeding was assessed during surgeries and after diode laser surgeries in anticoagulated rats. Laser-induced hemostasis offered an alternative solution to the controversial issue of intraoperative and postoperative bleeding control in patients on anticoagulation therapy.

In-office Treatments for Dentin Hypersensitivity: A Randomized Split-mouth Clinical Trial.

PURPOSE: To assess the effectiveness of four in-office therapies used for the treatment of dentin hypersensitiviy (DH) after one single application. MATERIALS AND METHODS: A randomised, controlled, split-mouth clinical trial was designed to evaluate the following treatments: 5% sodium fluoride varnish (positive control); 3% potassium oxalate; two-step self-etching adhesive; high power diode laser. Nineteen patients were selected and one tooth per quadrant was included in the study. After evaporative stimulation, pain was quantified by the Visual Analog Scale (VAS) at baseline, immediately after treatment, and after 15, 30 and 60 days. RESULTS: Compared to the baseline values, fluoride varnish (p = 0.00) and potassium oxalate (p = 0.00) presented an immediate desensitising effect that remained constant at 15, 30 and 60 days. The high-power diode laser presented significant reduction in VAS scores after 15 days (p = 0.00), while in the self-etching adhesive group, a significant reduction in VAS scores was observed only after 60 days (p = 0.03). The change in VAS ([VAS x days] - VAS baseline) differed among the groups immediately after treatment, being higher in the fluoride varnish and lower in the adhesive groups, but no statistically significant difference was found at time intervals of 15, 30 and 60 days. CONCLUSION: When an immediate desensitising effect is desired after one single application, fluoride varnish and potassium oxalate should be used. High-power diode laser and self-etching adhesive may not be clinically considered an appropriate desensitising therapy after one single application.

Immediate laser-induced hemostasis in anticoagulated rats subjected to oral soft tissue surgery: a double-blind study

Abstract Given the growing trend towards medical indications for continuous use of anticoagulants, the number of patients on these medications continues to rise. The management of patients on oral anticoagulants requiring oral surgical procedures has aroused much controversy. Changes in an anticoagulation regimen are associated with an increased risk of thromboembolism. However, it seems logical and advantageous for the patients' health if surgery could be performed without any change to the anticoagulation therapy. In dentistry, high-power lasers have been poorly explored in this field. The hemostatic properties of high-power lasers could be helpful during oral soft tissue surgeries in anticoagulated patients. The aim of this study was to compare bleeding time in anticoagulated rats after lingual frenectomy performed with a scalpel or diode laser with bleeding time in healthy animals. Twenty-four male Wistar rats were assigned to four groups (n = 6): (CS) Control-Scalpel Surgery; (AS) Anticoagulated-Scalpel Surgery; (CL) Control-Laser (diode laser 810 nm/1.5 W) Surgery; and (AL) Anticoagulated-Laser Surgery (diode laser 810 nm/1.5 W). Warfarin administration was used to induce anticoagulation. Blood was blotted every 30 seconds with filter paper until bleeding stopped to verify bleeding time. Two blinded researchers performed the surgeries and collected the bleeding time data. Diode laser surgery led to complete hemostasis in rats during and after lingual frenectomy. Zero bleeding was assessed during surgeries and after diode laser surgeries in anticoagulated rats. Laser-induced hemostasis offered an alternative solution to the controversial issue of intraoperative and postoperative bleeding control in patients on anticoagulation therapy.

In vitro evaluation of methylene blue removal from root canal after Photodynamic Therapy.

In Endodontics, photosensitizers' such as methylene blue and toluidine blue have been used in Photodynamic Therapy due to their positive results. However, they can stain the dentin from the root canal after Photodynamic Therapy (PDT). The present in vitro study aimed to evaluate different stain removal protocols from root canal after PDT using methylene blue (MB) dye. After mechanical preparation of the root canal of 40 uni-radicular human teeth, PDT was performed using 0,01% MB with parameters of 3min of pre-irradiation and a diode laser irradiation emitting at 660nm, 40mW, 4min, 9.6J. After PDT, different protocols of MB removal were performed: Group 1 - control (0.9% saline solution); Group 2 - sodium hypochlorite (2.5% NaOCl); Group 3-17% ethylenediamine tetraacetic acid (EDTA); Group 4 - passive ultrasonic irrigation (PUI); The color of the dentin of the root canal was measured, before, immediately after the PDT and immediately after the cleaning using a spectrophotometer. The ΔE values found were statistically compared using the ANOVA and Tukey's tests (α=0.05). All the treatments lead to some cleaning of root canal after PDT, however, none of the treatments tested completely removed all staining caused by MB photosensitizer of the root canal. Among the treatments tested, PUI and Hypochlorite 2.5% promoted greater cleaning, with no statistically significant difference between them. In conclusion, within the protocols tested in the present study, no treatments were able to completely remove MB staining of the root canal after PDT.

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.

Surface Characterization and Short-term Adhesion to Zirconia after Ultra-short Pulsed Laser Irradiation.

PURPOSE: To evaluate the suitability of an ultra-short pulsed laser (USPL) to treat zirconia ceramic surfaces and increase their adhesion to dual-curing resin cement. MATERIALS AND METHODS: Twenty 10 × 10 × 5 mm³ blocks were prepared from a zirconia ceramic (Y-TZP). The specimens were polished and randomly assigned to four groups (n = 5) which received the following surface treatments: sandblasting (SB) with Al2O3 particles and silica coating (SC) with SiO2 particles as positive controls; two groups received USPL irradiation, one with 10 scan repetitions (L10) and the other with 20 (L20). Laser irradiation was performed at 1030 nm, 2.3 J/cm², 6 ps pulse duration. The ceramic blocks were duplicated in composite resin and cemented with a dual-curing resin cement. Half of the blocks were then stored in water (37°C) for 24 h and the other half for 1 month. At each time, 40 to 60 sticks per group were subjected to microtensile bond strength testing. Data were analyzed statistically using the Kruskal-Wallis test (α = 0.05). RESULTS: Laser-treated zirconia presented statistically significantly higher roughness than did SB and SC. After 24 h, the highest bond strength means (MPa) were achieved by L10 (42.3 ± 10.8) and L20 (37.9 ± 14.4), and both of them were statistically significantly higher than SB (22.0 ± 5.3) and SC (20.8 ± 7.1) (p < 0.05). After 1 month of storage, L10- and L20-treated zirconia still showed significantly higher bond strengths than did SB- and SC-treated zirconia (p < 0.05). CONCLUSION: USPL irradiation significantly increases bond strength of zirconia ceramic to dual-curing resin cement and might be an alternative for improving adhesion to this material.

Laser Phototherapy (660 nm) Can Be Beneficial for Reducing Gingival Inflammation in Prosthodontics.

Among the new technologies developed, low power lasers have enabled new approaches to provide conservative treatment. Low power lasers act at cellular level, resulting in reduced pain, modulating inflammation, and improved tissue healing. Clinical application of the low power laser requires specific knowledge concerning laser interaction with biological tissue so that the correct irradiation protocol can be established. The present case report describes the clinical steps involved in an indirect composite resin restoration performed in a 31-year-old patient, in whom low power laser was used for soft tissue biomodulation. Laser therapy was applied with a semiconductor laser 660 nm, spot size of 0.028 cm(2), energy density of 35.7 J/cm(2), mean power of 100 mW, and energy per point as 1 J, in contact mode, on a total of 2 points (mesial and distal), totaling 2 J of energy. The therapy with low power laser can contribute positively to the success of an indirect restorative treatment.

Combined Tin-Containing Fluoride Solution and CO2 Laser Treatment Reduces Enamel Erosion in vitro.

The aim of this in vitro study was to evaluate the effect of combined CO2 laser and tin-containing fluoride treatment on the formation and progression of enamel erosive lesions. Ninety-six human enamel samples were obtained, stored in thymol solution and, after surface polishing, randomly divided into 6 different surface treatment groups (n = 16 in each group) as follows: no treatment, control (C); one CO2 laser irradiation (L1); two CO2 laser irradiations (L2); daily application of fluoride solution (F); combined daily fluoride solution + one CO2 laser irradiation (L1F), and combined daily fluoride solution + two CO2 laser irradiations (L2F). Laser irradiation was performed at 0.3 J/cm2 (5 µs/226 Hz/10.6 µm) on day 1 (L1) and day 6 (L2). The fluoride solution contained AmF/NaF (500 ppm F), and SnCl2 (800 ppm Sn) at pH 4.5. After surface treatment the samples were submitted to an erosive cycling over 10 days, including immersion in citric acid (2 min/0.05 M/pH = 2.3) 6 times daily and storage in remineralization solution (≥1 h) between erosive attacks. At the end of each cycling day, the enamel surface loss (micrometers) was measured using a 3D laser profilometer. Data were statistically analyzed by means of a 2-level mixed effects model and linear contrasts (α = 0.05). Group F (-3.3 ± 2.0 µm) showed significantly lower enamel surface loss than groups C (-27.22 ± 4.1 µm), L1 (-18.3 ± 4.4 µm) and L2 (-16.3 ± 5.3 µm) but higher than L1F (-1.0 ± 4.4 µm) and L2F (1.4 ± 3.2 µm, p < 0.05). Under the conditions of this in vitro study, the tin-containing fluoride solution caused 88% reduction of enamel surface loss, while its combination with CO2 laser irradiation at 0.3 J/cm2 hampered erosive loss almost completely.

A terapia fotodinâmica como benefício complementar na clínica odontológica / Photodynamic therapy as a complementary benefit in the dental clinic

Um dos grandes desafios do Cirurgião-Dentista é o controle microbiológico nas patologias dentárias. Independentemente da especialidade, a redução microbiana para o sucesso do tratamento é necessária. A terapia fotodinâmica vem sendo utilizada como coadjuvante ao tratamento tradicional, reduzindo significativamente a quantidade de microrganismos nos sítios-alvo e contribuindo para a solução de casos, principalmente na presença de infecções resistentes. Esta revisão de literatura tem como objetivo apresentar estudos laboratoriais e clínicos relacionados à terapia fotodinâmica em Periodontia, Endodontia e Estomatologia. Apesar da variedade de protocolos utilizados nas recentes pesquisas, a terapia fotodinâmica mostra-se promissora como coadjuvante ao tratamento convencional. Além disso, apresenta grande utilidade, fácil acessibilidade e baixo custo para o Cirurgião-Dentista frente a processos infecciosos em Odontologia.

One of the great challenges of the dentist is the microbiological control in dental pathologies. Regardless of specialty, microbial reduction for successful treatment is necessary. Photodynamic therapy has been used as an adjunct to traditional treatment, significantly reducing the amount of microorganisms in the target sites and contributing to the solution of cases, especially in the presence of resistant infections. This literature review aims to present laboratory and clinical studies related to photodynamic therapy in Periodontics, endodontics and Stomatology. Despite the variety of protocols used in recent research, photodynamic therapy is potentially used as an adjunct to conventional treatment. In addition, it is useful, easy to apply and with low cost to the dentist.

Clinical evaluation of low-power laser and a desensitizing agent on dentin hypersensitivity.

The aim of this randomized, longitudinal clinical study was to evaluate different protocols for dentin hypersensitivity treatment with low-power laser at different dosages, desensitizing agent, and associations, for a period of 6 months. After analysis of the inclusion and exclusion criteria of volunteer participants, those who present pain resulting from non-carious cervical lesions were selected. Twenty-seven patients participated in the study, and 55 lesions were recorded. The lesions were divided into five groups (n = 11), treated, and evaluated: G1: Gluma Desensitizer (Heraeus); G2: low-power laser (Photon Lase, DMC) at low dose (three vestibular points and one apical point of irradiation: 30 mW, 10 J/cm(2), 9 s per point with wavelength of 810 nm), three sessions were performed with an interval of 72 h between them; G3: low-power laser at high dose (application at one cervical and one apical point: 100 mW, 90 J/cm(2), 11 s per point with wavelength of 810 nm), three sessions were performed with an interval of 72 h between irradiations; G4: low-power laser at low dose + Gluma Desensitizer; and G5: low-power laser at high dose + Gluma Desensitizer, the level of sensitivity of each volunteer was evaluated with a visual analog scale of pain (VAS) with the use of air from a triple syringe and exploration with a probe after time intervals of 5 min, 1 week, and 1, 3, and 6 months after treatment. Data were collected and subjected to statistical analysis. Kolmogorov-Smirnov test was used to verify the distribution of the data, and nonparametric Kruskal-Wallis and Friedman tests were performed for comparison among the experimental groups and time intervals studied, respectively. Statistically significant differences between the studied time intervals (p < 0.05) were detected. From the difference in pain, it was observed that for both stimuli, the protocol with the Gluma desensitizing agent presented immediate effects of pain reduction. For low-level lasers, it was observed that there were distinct effects for the different doses; however, both were efficient in reducing pain up to the 6 months of clinical follow-up. Therefore, it could be concluded that all the desensitizing protocols were effective in reducing dentin hypersensitivity, but with different effects. The combination of protocols is an interesting alternative in the treatment of cervical dentin hypersensitivity.

Potential of CO2 lasers (10.6 µm) associated with fluorides in inhibiting human enamel erosion.

This in vitro study aimed to investigate the potential of CO2 lasers associated with different fluoride agents in inhibiting enamel erosion. Human enamel samples were randomly divided into 9 groups (n = 12): G1-eroded enamel; G2-APF gel; G3-AmF/NaF gel; G4-AmF/SnF2 solution; G5-CO2 laser (λ = 10.6 µm)+APF gel; G6-CO2 laser+AmF/NaF gel; G7-CO2laser+AmF/SnF2solution; G8-CO2 laser; and G9-sound enamel. The CO2 laser parameters were: 0.45 J/cm2; 6 µs; and 128 Hz. After surface treatment, the samples (except from G9) were immersed in 1% citric acid (pH 4.0, 3 min). Surface microhardness was measured at baseline and after surface softening. The data were statistically analyzed by one-way ANOVA and Tukey's tests (p < 0.05). G2 (407.6 ± 37.3) presented the highest mean SMH after softening, followed by G3 (407.5 ± 29.8) and G5 (399.7 ± 32.9). Within the fluoride-treated groups, G4 (309.0 ± 24.4) had a significantly lower mean SMH than G3 and G2, which were statistically similar to each other. AmF/NaF and APF application showed potential to protect and control erosion progression in dental enamel, and CO2 laser irradiation at 0.45J/cm2 did not influence its efficacy. CO2 laser irradiation alone under the same conditions could also significantly decrease enamel erosive mineral loss, although at lower levels.