In-office bleaching protocols using violet LED: A split mouth case report.

A new LED wavelength, violet LED (VL) with a wavelength between 405 - 410 nm was recently introduced to be used for in-office dental bleaching. In comparison to the blue LED system (440 to 485 nm), the shorter wavelength has more energy carried in its photons and also corresponds to the absorption peak of the stained particles, which lead to whitening utilizing a physical process. Considering the need to suggest and develop new protocols with this new technology, this article reports 2 different dental bleaching protocols developed in a split-mouth model using VL. A 25-year-old male patient was submitted to in-office dental bleaching. On the teeth from the left side, the bleaching gel (35% H2O2) was renewed 3 times (every 8 mins), and on the right side, the gel was maintained without renewal during the bleaching session. The irradiation with Violet LED Light (405 nm ± 10 nm) was performed with the following protocol: 1 min of irradiation with 30 s light off until 8 min of total time. A total of 3 cycles were performed (total time of 24 min). Two bleaching sessions were performed with an interval of 7 days between sessions. Based on the results of this split-mouth case report, there was no visible difference in the final color outcome and sensitivity between both bleaching protocols tested.

3D technology to measure dental arches and create a template for lingual brackets technique.

OBJECTIVE: This study aims at identifying anatomical dimensions of dental arches, based on landmarks currently used in the lingual orthodontic technique, and create an archwire form template to be used in orthodontic clinics. METHODS: Maxillary and mandibular dental casts of 140 Caucasian individuals with natural and normal occlusion were digitized (3D), and the images were analyzed with Delcam Power ShapeTM 2010 software. The dental arch shapes and sizes were obtained from 14 landmarks selected on the lingual surface of the teeth. Points and segments defined by the software were used to create an archwire form template. RESULTS: Various dental arch patterns were found for both maxilla and mandible. The smallest sizes were found in females, and the largest were found in male subjects. Six categories were defined for each gender, three for the maxilla and three for the mandible (Small, Medium and Large). A template was created with eighteen anatomic lingual archwire designs, nine for the maxilla and nine for the mandible, for both genders. CONCLUSIONS: Landmarks evaluated in this study showed dental arch differences between genders. This information enables making orthodontic lingual archwires that are more compatible with the anatomical forms and sizes of the maxilla and mandible. The findings also allowed the creation of a template for an anatomic lingual metallic archwire form to be used in the lingual technique.

3D technology to measure dental arches and create a template for lingual brackets technique

ABSTRACT Objective: This study aims at identifying anatomical dimensions of dental arches, based on landmarks currently used in the lingual orthodontic technique, and create an archwire form template to be used in orthodontic clinics. Methods: Maxillary and mandibular dental casts of 140 Caucasian individuals with natural and normal occlusion were digitized (3D), and the images were analyzed with Delcam Power ShapeTM 2010 software. The dental arch shapes and sizes were obtained from 14 landmarks selected on the lingual surface of the teeth. Points and segments defined by the software were used to create an archwire form template. Results: Various dental arch patterns were found for both maxilla and mandible. The smallest sizes were found in females, and the largest were found in male subjects. Six categories were defined for each gender, three for the maxilla and three for the mandible (Small, Medium and Large). A template was created with eighteen anatomic lingual archwire designs, nine for the maxilla and nine for the mandible, for both genders. Conclusions: Landmarks evaluated in this study showed dental arch differences between genders. This information enables making orthodontic lingual archwires that are more compatible with the anatomical forms and sizes of the maxilla and mandible. The findings also allowed the creation of a template for an anatomic lingual metallic archwire form to be used in the lingual technique.

RESUMO Objetivo: O presente estudo tem como objetivo encontrar as formas anatômicas e dimensões das arcadas dentárias com base em pontos de referência utilizados na técnica ortodôntica lingual, e criar um diagrama com um maior número de arcos metálicos para serem utilizados na clínica ortodôntica. Métodos: 140 modelos de indivíduos caucasianos com oclusão normal e natural foram digitalizados (3D) e as imagens, analisadas com o software Delcam Power ShapeTM 2010. A determinação das formas e tamanhos das arcadas dentárias foi obtida a partir de 14 pontos selecionados na superfície lingual dos dentes. Outros pontos e segmentos foram utilizados, com o auxílio do software, para definir um diagrama. Resultados: Foram encontrados diferentes tamanhos de arcadas dentárias linguais, tanto para a maxila quanto para a mandíbula. Os menores tamanhos foram os femininos, e os maiores, os masculinos. Definiram-se seis tamanhos para cada sexo, sendo três para a maxila e três para a mandíbula, nomeados como P, M e G. Foi criado um diagrama com dezoito desenhos de arcos linguais anatômicos, nove para a maxila e nove para a mandíbula, para ambos os sexos. Conclusões: A posição dos pontos de referência nesse estudo evidenciou diferenças entre os sexos, o que permitiu a criação de arcos mais compatíveis com as formas e dimensões anatômicas da maxila e mandíbula. A diferença entre os tamanhos das arcadas dentárias linguais possibilitou a criação de um diagrama com formas de arcos metálicos linguais anatômicos para serem utilizados na técnica lingual, para auxiliar o profissional a criar os seus próprios arcos.

Evaluation of Resin-Based Material Containing Copaiba Oleoresin (Copaifera Reticulata Ducke): Biological Effects on the Human Dental Pulp Stem Cells.

The purpose of this study was to analyze in vitro the biological effects on human dental pulp stem cells triggered in response to substances leached or dissolved from two experimental cements for dental pulp capping. The experimental materials, based on extracts from Copaifera reticulata Ducke (COP), were compared to calcium hydroxide [Ca(OH)2] and mineral trioxide aggregate (MTA), materials commonly used for direct dental pulp capping in restorative dentistry. For this, human dental pulp stem cells were exposed to COP associated or not with Ca(OH)2 or MTA. Cell cytocompatibility, migration, and differentiation (mineralized nodule formation (Alizarin red assay) and gene expression (RT-qPCR) of OCN, DSPP, and HSP-27 (genes regulated in biomineralization events)) were evaluated. The results showed that the association of COP reduced the cytotoxicity of Ca(OH)2. Upregulations of the OCN, DSPP, and HSP-27 genes were observed in response to the association of COP to MTA, and the DSPP and HSP-27 genes were upregulated in the Ca(OH)2 + COP group. In up to 24 h, cell migration was significantly enhanced in the MTA + COP and Ca(OH)2 + COP groups. In conclusion, the combination of COP with the currently used materials for dental pulp capping [Ca(OH)2 and MTA] improved the cell activities related to pulp repair (i.e., cytocompatibility, differentiation, mineralization, and migration) including a protective effect against the cytotoxicity of Ca(OH)2.

Bioactive glass plus laser phototherapy as promise candidates for dentine hypersensitivity treatment.

Treatments for dentine hypersensitivity (DH) may produce positive effects, though do not have lasting results. We investigated the reparative potential of stem cells derived from deciduous teeth (SHEDs) in response to components delivered from substances used in the treatment of the DH, associated or not to laser phototherapy (LPT), to stimulate dentine formation. SHEDs were submitted to substances delivered from a laboratorial P-rich bioactive glass [57SiO2 -26CaO-17P2 O5 (wt %)] or a commercially available desensitizer (Gluma® Desensitizer), associated (or not) to LPT (InGAlP diode laser, 660 nm, 0.028 cm2 , 20 mW, 5 J/cm2 , 7 s, contact mode). Biomaterial characterization was performed by X-ray diffraction, scanning electron microscopy and the particle size was evaluated by dynamic light scattering. SHEDs proliferation and differentiation were analyzed by MTT and Alizarin Red staining, respectively. The conditioned media used in these tests were evaluated regarding their pH and the ionic concentration changes due to ions leached from the bioactive glass (BG). BG majority presented a non-crystalline solid structure and mixed particle sizes characterized by the agglomeration of nanoparticles. Cultures treated with BG alone or in association to LPT showed improved cell growth in relation to Gluma® (p < 0.05). Gluma® was cytotoxic in all tested conditions, regardless irradiated or not. BG associated to LPT induced intense mineral matrix formation. In conclusion, BG releases ionic dissolution products able to promote SHEDs differentiation. BG associated to LPT improves SHEDs proliferation and differentiation in vitro, and may be a promise therapeutic approach for the DH treatment. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 107-116, 2017.

Low-intensity laser phototherapy enhances the proliferation of dental pulp stem cells under nutritional deficiency.

Dental trauma in immature permanent teeth can damage pulp vascularization, which leads to necrosis and cessation of apexogenesis. Studies on tissue engineering using stem cells from human exfoliated deciduous teeth (SHEDs) have yielded promising results. Laser phototherapy (LPT) is able to influence the proliferation and differentiation of these cells, which could improve tissue engineering. SHEDs (eighth passage) were seeded into 96-well culture plates (103 cells/well) and were grown in culture medium supplemented with 15% defined fetal bovine serum (FBS) for 12 h. After determining the appropriate nutrition deficiency status (5% FBS), the cells were assigned into four groups: 1) G1 - 15% FBS (positive control); 2) G2 - 5% FBS (negative control); 3) G3 - 5% FBS+LPT 3 J/cm2; and 4) G4 - 5% FBS+LPT 5 J/cm2. For the LPT groups, two laser irradiations at 6 h intervals were performed using a continuous wave InGaAlP diode laser (660 nm, with a spot size of 0.028 cm2, 10 mW) in punctual and contact mode. Cell viability was assessed via an MTT reduction assay immediately after the second laser irradiation (0 h) and 24, 48, and 72 h later. We found that G3 and G4 presented a significantly higher cell growth rate when compared with G2 (p < 0.01). Moreover, G4 exhibited a similar cell growth rate as G1 throughout the entire experiment (p > 0.05). These findings indicate that LPT with 5 J/cm2 can enhance the growth of SHEDs during situations of nutritional deficiency. Therefore, LPT could be a valuable adjunct treatment in tissue engineering when using stem cells derived from the dental pulp of primary teeth.

Does the hybrid light source (LED/laser) influence temperature variation on the enamel surface during 35% hydrogen peroxide bleaching? A randomized clinical trial.

OBJECTIVE: The present study investigated how a hybrid light source (LED/laser) influences temperature variation on the enamel surfaces during 35% hydrogen peroxide (HP) bleaching. Effects on the whitening effectiveness and tooth sensitivity were analyzed. METHOD AND MATERIALS: Twenty-two volunteers were randomly assigned to two different treatments in a split-mouth experimental model: group 1 (control), 35% HP; group 2 (experimental), 35% HP + LED/laser. Color evaluation was performed before treatment, and 7 and 14 days after completion of bleaching, using a color shade scale. Tooth sensitivity was assessed using a visual analog scale (VAS; before, immediately, and 24 hours after bleaching). During the bleaching treatment, thermocouple channels positioned on the tooth surfaces recorded the temperature. Data on color and temperature changes were subjected to statistical analysis (α = 5%). Tooth sensitivity data were evaluated descriptively. RESULTS: Groups 1 and 2 showed mean temperatures (± standard deviation) of 30.7 ± 1.2 °C and 34.1 ± 1.3 °C, respectively. It was found that there were statistically significant differences between the groups, with group 2 showing higher mean variation (P < .0001). The highest temperature variation occurred for group 2, with an increase of 5.3 °C at the enamel surface. The color change results showed no differences in bleaching between the two treatment groups (P = .177). The variation of the average temperature during the treatments was not statistically associated with color variation (P = .079). Immediately after bleaching, it was found that 36.4% of the subjects in group 2 had mild to moderate sensitivity. In group 1, 45.5% showed moderate sensitivity. In both groups, the sensitivity ceased within 24 hours. CONCLUSION: Hybrid light source (LED/ laser) influences temperature variation on the enamel surface during 35% HP bleaching and is not related to greater tooth sensitivity.

Low-intensity laser phototherapy enhances the proliferation of dental pulp stem cells under nutritional deficiency

Abstract Dental trauma in immature permanent teeth can damage pulp vascularization, which leads to necrosis and cessation of apexogenesis. Studies on tissue engineering using stem cells from human exfoliated deciduous teeth (SHEDs) have yielded promising results. Laser phototherapy (LPT) is able to influence the proliferation and differentiation of these cells, which could improve tissue engineering. SHEDs (eighth passage) were seeded into 96-well culture plates (103 cells/well) and were grown in culture medium supplemented with 15% defined fetal bovine serum (FBS) for 12 h. After determining the appropriate nutrition deficiency status (5% FBS), the cells were assigned into four groups: 1) G1 - 15% FBS (positive control); 2) G2 - 5% FBS (negative control); 3) G3 - 5% FBS+LPT 3 J/cm2; and 4) G4 - 5% FBS+LPT 5 J/cm2. For the LPT groups, two laser irradiations at 6 h intervals were performed using a continuous wave InGaAlP diode laser (660 nm, with a spot size of 0.028 cm2, 10 mW) in punctual and contact mode. Cell viability was assessed via an MTT reduction assay immediately after the second laser irradiation (0 h) and 24, 48, and 72 h later. We found that G3 and G4 presented a significantly higher cell growth rate when compared with G2 (p < 0.01). Moreover, G4 exhibited a similar cell growth rate as G1 throughout the entire experiment (p > 0.05). These findings indicate that LPT with 5 J/cm2 can enhance the growth of SHEDs during situations of nutritional deficiency. Therefore, LPT could be a valuable adjunct treatment in tissue engineering when using stem cells derived from the dental pulp of primary teeth.

Effect of laser phototherapy in the prevention and treatment of chemo-induced mucositis in hamsters

The aim of this study was to investigate the effect of laser phototherapy (LPT) in the prevention and/or treatment of oral mucositis induced by 5-fluorouracil (5-FU; Eurofarma, São Paulo, Brazil) in hamsters. Ninety-six hamsters were divided into four groups (n = 24): Control (no treatment); Preventive [LPT from day (D) D-5 to D+5]; Therapeutic (LPT from D+5 to D+15); and Combined (preventive plus therapeutic LPT from D-5 to D+15). The animals received an intraperitoneal injection of 5-FU on Days 0 and 2. The pouch mucosa was scratched on Days 3 and 4. The irradiation parameters were: indium-gallium-aluminum-phosphide (InGaAlP) diode laser (MM Optics, São Carlos, Brazil) (660 nm), beam area of 0.036 cm2, 40 mW, 1.11 W/cm2, 6.6 J/cm2, power density applied daily of 39.6 J/cm2, in punctual mode (six points and six seconds per point) and contact mode, one application per day. The animals were sacrificed on Days 0, 5, 10 and 15 (n = 6) and weighed, and the pouch mucosa was removed for histopathological analysis. Clinical and corresponding histological scores were compared using ANOVA and Tukey's test (p ≤0.05). Similar weight losses ranging from 5% to 10% occurred in all groups. The therapeutic group had significantly lower clinical and histological scores than the other groups at Day 10. This study showed that positive effects on oral mucositis management were obtained only when LPT was applied in the therapeutic protocol (from D+5 to D+15 after chemotherapy).

Effect of laser phototherapy in the prevention and treatment of chemo-induced mucositis in hamsters.

The aim of this study was to investigate the effect of laser phototherapy (LPT) in the prevention and/or treatment of oral mucositis induced by 5-fluorouracil (5-FU; Eurofarma, São Paulo, Brazil) in hamsters. Ninety-six hamsters were divided into four groups (n=24): Control (no treatment); Preventive [LPT from day (D) D-5 to D+5]; Therapeutic (LPT from D+5 to D+15); and Combined (preventive plus therapeutic LPT from D-5 to D+15). The animals received an intraperitoneal injection of 5-FU on Days 0 and 2. The pouch mucosa was scratched on Days 3 and 4. The irradiation parameters were: indium-gallium-aluminum-phosphide (InGaAlP) diode laser (MM Optics, São Carlos, Brazil) (660 nm), beam area of 0.036 cm2, 40 mW, 1.11 W/cm2, 6.6 J/cm2, power density applied daily of 39.6 J/cm2, in punctual mode (six points and six seconds per point) and contact mode, one application per day. The animals were sacrificed on Days 0, 5, 10 and 15 (n=6) and weighed, and the pouch mucosa was removed for histopathological analysis. Clinical and corresponding histological scores were compared using ANOVA and Tukey's test (p≤0.05). Similar weight losses ranging from 5% to 10% occurred in all groups. The therapeutic group had significantly lower clinical and histological scores than the other groups at Day 10. This study showed that positive effects on oral mucositis management were obtained only when LPT was applied in the therapeutic protocol (from D+5 to D+15 after chemotherapy).

Efeitos da fototerapia com laser em baixa intensidade e dos fatores de crescimento PDGF e BMP-2, isolados ou em associação, na diferenciação ósseo/odontogênica de células-tronco de polpa dentária humana / Effects of low intensity laser therapy and growth factors PDGF and BMP-2 on the odontogenic differentiation of dental pulp stem cells

A fototerapia com laser em baixa intensidade (FTLBI) é capaz de aumentar o metabolismo celular, o que poderia influenciar na diferenciação ósseo/odontogênica das células-tronco da polpa dentária humada (hDPSCs). O PDGF e o BMP-2 são fatores de crescimento envolvidos na dentinogênese e na reparação tecidual. O PDGF tem papel importante durante o desenvolvimento embrionário, na proliferação e migração celular e na angiogênese, enquanto o BMP-2 está fortemente associado à diferenciação celular em tecidos mineralizados, como o osso e a dentina. Sendo assim, o objetivo do estudo foi analisar os efeitos da FTLBI e dos fatores de crescimento (PDGF-BB ou BMP-2), isolados ou em associação, na diferenciação ósseo/odontogênica das hDPSCs. Para o estudo hDPSCs foram cultivadas em meio regular (G1) e irradiadas (G2), meio mineralizante (G3) e irradiadas (G4), meio mineralizante contendo PDGF-BB (G5) e irradiadas (G6), meio mineralizante contendo BMP-2 (G7) e irradiadas (G8). Para os grupos irradiados, a FTLBI foi realizada no modo pontual e em contato, com um laser de diodo semi-condutor, com área de feixe de 0,028cm2 e comprimento de onda 660nm (InGaAlP-vermelho), utilizando-se os seguintes parâmetros: potência de 20mW, densidade de energia de 5J/cm2, tempo de irradiação de 7 segundos por ponto e 0,14J de energia por ponto

A expressão dos genes relacionados à diferenciação ósseo/odontogênica (DSPP, DMP-1 e OCN) através do PCR quantitativo em tempo real (qRT-PCR), a atividade da fosfatase alcalina e os depósitos de cálcio foram analisados em 3, 7 e 14 dias. Os dados obtidos foram comparados pelo teste ANOVA complementado pelo teste de Tukey (p<0,05). As culturas tratadas com meio mineralizante contendo BMP-2 e irradiadas (G8) foram as que mostraram os maiores índices de diferenciação ósseo/odontogênica nos testes realizados. As expressões de DSPP, OCN e DMP-1, ao menos em 14 dias, foram significantemente maiores no G8 que nos demais grupos experimentais, exceto os grupos G3 e G7. Estes grupos apresentaram expressões de DSPP e OCN semelhantes às do G8 em 14 dias. A maior atividade de ALP foi observada no G8 em 3 dias e a menor no mesmo grupo aos 14 dias. A maior quantidade de depósitos de cálcio também foi encontrada no G8 em 14 dias. A associação de FTLBI e BMP-2 se mostrou capaz de induzir a diferenciação ósseo/odontogênica em células-tronco de polpa dentária humana de forma mais marcante que as demais terapias isoladas ou associadas estudadas. Portanto, o uso de uma terapia associando FTLBI e BMP-2 poderia ser de relevância para o restabelecimento da fisiologia pulpar quando aplicada em casos de exposição deste tecido, uma vez que poderia favorecer a diferenciação das células indiferenciadas da polpa dentária.

Laser phototherapy (LPT) is able to increase cellular metabolism, which in turn could influence the odontogenic differentiation of dental pulp stem cells (hDPSCs). PDGF and BMP-2 are growth factors involved in dentinogenesis and tissue repair. PDGF plays a role in embryonic development, cell proliferation, cell migration, and angiogenesis, whereas BMP-2 is strongly associated with cell differentiation in mineralized tissues such as bone and dentin. The aim of this study was to analyze the effects of LPT and the growth factors PDGF-BB and BMP-2 combined or not on the odontogenic differentiation of hDPSCs. These cells were grown in regular medium (G1) and irradiated (G2), mineralizing medium (G3) and irradiated (G4), mineralizing medium containing PDGF-BB (G5) and irradiated (G6), mineralizing medium containing BMP-2 (G7) and irradiated (G8). For irradiated groups, LPT was performed in punctual and contact mode with a semiconductor diode laser, with a beam spot area of 0.028 cm2 and wavelength of 660nm (InGaAlP-visible red), using the following parameters: power of 20mW, energy density of 5J/cm2 and irradiation time of 7 seconds per point (0,14 J per point). Differentiation was assessed by the following analysis: expression of genes related to odontogenic differentiation (DSPP, DMP-1 and OCN) using quantitative real time PCR (qRT-PCR); alkaline phosphatase activity and calcium deposition using alizarin red staining in 3, 7 and 14 days. Data were compared by ANOVA and Tukey´s test (p<0.05).

The cultures treated with mineralizing medium containing BMP-2 and irradiated (G8) showed the highest rate of odontogenic differentiation. The expressions of DSPP, DMP-1 and OCN genes, at least in 14 days, were significantly higher in G8 compared to all other groups, except for the groups G3 and G7. These groups showed similar expressions of DSPP and OCN than G8 in 14 days. G8 showed the highest ALP activity in 3 days and the lowest in 14 days compared to all other groups. The largest amount of calcium deposits was observed in G8 in 14 days. The most striking feature on induction of odontogenic differentiation of hDPSCs was observed when LPT was applied in association with BMP-2. Therefore, the use of a combined LPT and BMP-2 therapy could be of relevance for the re-establishment of pulp physiology when applied in cases of dental pulp exposure by promoting the differentiation of hDPSCs.

In vitro effect of low intensity laser on the cytotoxicity produced by substances released by bleaching gel.

This in vitro study aimed to analyze the effect of different parameters of phototherapy with low intensity laser on the viability of human dental pulp fibroblasts under the effect of substances released by bleaching gel. Cells were seeded into 96 wells plates (1 x 10³ cells/well) and placed in contact with culture medium conditioned by a 35 % hydrogen peroxide bleaching gel for 40 minutes, simulating the clinical condition of the in-office bleaching treatment. Cells cultured in ideal growth conditions served as positive control group (PC), and the cells grown in conditioned medium and non-irradiated served as negative control group (NC). Cells grown in conditioned medium were submitted to a single irradiation with a diode laser (40 mW, 0.04 cm²) emitting at visible red (660 nm; RL) or near infrared (780 nm; NIR) using punctual technique, in contact mode and energy densities of 4, 6 or 10 J/cm². The cell viability was analyzed through the MTT reduction assay immediately and 24 hours after the irradiation. The data was compared by ANOVA followed by the Tukey's test (p ≤ 0.05). The cell viability increased significantly in 24 hours within each group. The PC presented cell viability significantly higher than NC in both experimental times. Only the NIR/10 J/cm² group presented cell viability similar to that of PC in 24 hours. The phototherapy with low intensity laser in defined parameters is able to compensate the cytotoxic effects of substances released by 35 % hydrogen peroxide bleaching gel.

In vitro effect of low intensity laser on the cytotoxicity produced by substances released by bleaching gel

This in vitro study aimed to analyze the effect of different parameters of phototherapy with low intensity laser on the viability of human dental pulp fibroblasts under the effect of substances released by bleaching gel. Cells were seeded into 96 wells plates (1 x 10³ cells/well) and placed in contact with culture medium conditioned by a 35 percent hydrogen peroxide bleaching gel for 40 minutes, simulating the clinical condition of the in-office bleaching treatment. Cells cultured in ideal growth conditions served as positive control group (PC), and the cells grown in conditioned medium and non-irradiated served as negative control group (NC). Cells grown in conditioned medium were submitted to a single irradiation with a diode laser (40 mW, 0.04 cm²) emitting at visible red (660 nm; RL) or near infrared (780 nm; NIR) using punctual technique, in contact mode and energy densities of 4, 6 or 10 J/cm². The cell viability was analyzed through the MTT reduction assay immediately and 24 hours after the irradiation. The data was compared by ANOVA followed by the Tukey's test (p < 0.05). The cell viability increased significantly in 24 hours within each group. The PC presented cell viability significantly higher than NC in both experimental times. Only the NIR/10 J/cm² group presented cell viability similar to that of PC in 24 hours. The phototherapy with low intensity laser in defined parameters is able to compensate the cytotoxic effects of substances released by 35 percent hydrogen peroxide bleaching gel.

Influence of etching time on bond strength in dentin irradiated with erbium lasers.

The purpose of this in vitro study was to evaluate the effect of etching time on the tensile bond strength (TBS) of a conventional adhesive bonded to dentin previously irradiated with erbium:yttrium-aluminum-garnet (Er:YAG) and erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) lasers. Buccal and lingual surfaces of 45 third molars were flattened until the dentin was exposed and randomly assigned to three groups (n = 30) according to the dentin treatment: control (not irradiated), irradiated with Er:YAG (1 W; 250 mJ; 4 Hz; 80.6 J/cm(2)) laser or Er,Cr:YSGG (4 W; 200 mJ; 20 Hz; 71.4 J/cm(2)) laser, and into three subgroups (n = 10) according to acid etching time (15 s, 30 s or 60 s) for each experimental group. After acid etching, the adhesive was applied, followed by the construction of an inverted cone of composite resin. The samples were immersed in distilled water (37 degrees C for 24 h) and subjected to TBS test [50 kilogram-force (kgf), 0.5 mm/min]. Data were analyzed by analysis of variance (ANOVA) and Tukey statistical tests (P < or = 0.05). Control group samples presented significant higher TBS values than those of all lased groups. Both irradiated groups exhibited similar TBS values. Samples subjected to the different etching times in each experimental group presented similar TBS. Based on the conditions of this in vitro study we concluded that Er:YAG and Er,Cr:YSGG laser irradiation of the dentin weakens the bond strength of the adhesive. Moreover, increased etching time is not able to modify the bonding strength of the adhesive to irradiated dentin.

Effect of phototherapy with low intensity laser on local and systemic immunomodulation following focal brain damage in rat.

Brain injury is responsible for significant morbidity and mortality in trauma patients, but controversy still exists over therapeutic management for these patients. The objective of this study was to analyze the effect of phototherapy with low intensity lasers on local and systemic immunomodulation following cryogenic brain injury. Laser phototherapy was applied (or not-controls) immediately after cryogenic brain injury performed in 51 adult male Wistar rats. The animals were irradiated twice (3 h interval), with continuous diode laser (gallium-aluminum-arsenide (GaAlAs), 780 nm, or indium-gallium-aluminum-phosphide (InGaAlP), 660 nm) in two points and contact mode, 40 mW, spot size 0.042 cm(2), 3 J/cm(2) and 5 J/cm(2) (3 s and 5 s, respectively). The experimental groups were: Control (non-irradiated), RL3 (visible red laser/ 3 J/cm(2)), RL5 (visible red laser/5 J/cm(2)), IRL3 (infrared laser/3 J/cm(2)), IRL5 (infrared laser/5 J/cm(2)). The production of interleukin-1IL-1beta (IL-1beta), interleukin6 (IL-6), interleukin-10 (IL-10), and tumor necrosis factor-alpha (TNF-alpha) was analyzed by enzyme immunoassay technique (ELISA) test in brain and blood samples. The IL-1beta concentration in brain of the control group was significantly reduced in 24 h (p<0.01). This reduction was also observed in the RL5 and IRL3 groups. The TNF-alpha and IL-6 concentrations increased significantly (p<0.01 and p<0.05, respectively) in the blood of all groups, except by the IRL3 group. The IL-6 levels in RL3 group were significantly smaller than in control group in both experimental times. IL-10 concentration was maintained stable in all groups in brain and blood. Under the conditions of this study, it is possible to conclude that the laser phototherapy can affect TNF-alpha, IL-1beta and IL-6 levels in the brain and in circulation in the first 24 h following cryogenic brain injury.

Effect of defocused infrared diode laser on salivary flow rate and some salivary parameters of rats.

This study aims to investigate whether infrared diode low-level laser therapy (LLLT) increased salivary flow rate and altered pH value, protein concentration, and peroxidase and amylase activities in saliva of rats. Wistar rats were used and divided into three groups. Experimental groups (A and B) had their parotid, submandibular and sublingual glands submitted to diode laser, 808-nm wavelength, on two consecutive days. The dose results were 4 and 8 J/cm(2), respectively. A red guide light was used to visualize the irradiated area. Group C was irradiated only with red pilot beam and served as control. The saliva samples were collected after each irradiation step (first and second collection days) and 1 week after the first irradiation (seventh day). Statistical analysis was performed, and differences were observed according to different days of salivary collection. The results showed that salivary flow rate for groups A and B was higher on the seventh day if it is compared to data obtained for the first day (p < 0.05). LLLT applications on salivary glands are a therapy procedure that requires further studies.

Tratamento marginal de restaurações cerâmicas com laser de Nd: YAG - avaliação da microinfiltração / Marginal treatment of ceramic restorations using Nd: YAG laser - microleakage evaluation

Introdução - O objetivo deste estudo in vitro foi avaliar a microinfiltração em restaurações de porcelana com tratamento das margens com laser de Nd:YAG (1064 nm). Material e Métodos - Cavidades Classe V para restaurações indiretas, com término em esmalte e cemento/dentina, foram preparadas na face vestibular de 20 dentes bovinos. Após condicionamento ácido e aplicação do sistema adesivo nos preparos cavitários, e tratamento da superfície interna da porcelana com ácido fluorídrico e silano, as restaurações foram cimentadas com cimento resinoso de dupla ativação RelyX ARC (3M ESPE). As amostras foram distribuídas aleatoriamente em 4 grupos (n = 5): G1: controle - sem irradiação; G2, G3 e G4 foram irradiados com laser de Nd:YAG com diferentes parâmetros. Todas as amostras foram imersas em água destilada (37°C, 7 dias) submetidas à ciclagem térmica, impermeabilizadas e imersas em solução de nitrato de prata a 50% (8h). Posteriormente as restauraçõrs foram seccionadas longitudinalmente e imersas em solução fotoreveladora sob luz fluorescente por 16h. O grau de microinfiltração foi avaliado por três examinadores previamente calibrados, através da análise de fotografias, e os valores foram submetidos à análise estatística de Kruskal-Wallis e Mann-Whitney (p < 0,05). Resultados - Os resultados mostraram que em esmalte houve diferença significante entre o grupo controle e os tratados com laser, sem diferença entre os grupos irradiados; em dentina não houve diferença significante entre os grupos. Conclusão - A irradiação com laser de Nd:YAG influenciou negativamente na microinfiltração marginal das restaurações indiretas de cerâmica cimentadas com cimento resinoso