Biochemical changes on the repair of surgical bone defects grafted with biphasic synthetic micro-granular HA + ß-tricalcium phosphate induced by laser and LED phototherapies and assessed by Raman spectroscopy.

This work aimed the assessment of biochemical changes induced by laser or LED irradiation during mineralization of a bone defect in an animal model using a spectral model based on Raman spectroscopy. Six groups were studied: clot, laser (λ = 780 nm; 70 mW), LED (λ = 850 ± 10 nm; 150 mW), biomaterial (biphasic synthetic micro-granular hydroxyapatite (HA) + ß-tricalcium phosphate), biomaterial + laser, and biomaterial + LED. When indicated, defects were further irradiated at a 48-h interval during 2 weeks (20 J/cm2 per session). At the 15th and 30th days, femurs were dissected and spectra of the defects were collected. Raman spectra were submitted to a model to estimate the relative amount of collagen, phosphate HA, and carbonate HA by using the spectra of pure collagen and biomaterials composed of phosphate and carbonate HA, respectively. The use of the biomaterial associated to phototherapy did not change the collagen formation at both 15 and 30 days. The amount of carbonate HA was not different in all groups at the 15th day. However, at the 30th day, there was a significant difference (ANOVA, p = 0.01), with lower carbonate HA for the group biomaterial + LED compared to biomaterial (p < 0.05). The phosphate HA was higher in the groups that received biomaterial grafts at the 15th day compared to clot (significant for the biomaterial; p < 0.01). At the 30th day, the phosphate HA was higher for the group biomaterial + laser, while this was lower for all the other groups. These results indicated that the use of laser phototherapy improved the repair of bone defects grafted with the biomaterial by increasing the deposition of phosphate HA.

Do laser/LED phototherapies influence the outcome of the repair of surgical bone defects grafted with biphasic synthetic microgranular HA + ß-tricalcium phosphate? A Raman spectroscopy study.

The treatment of bone loss is difficult. Many techniques are proposed to improve repair, including biomaterials and, recently, phototherapies. This work studied bone mineralization by Raman spectroscopy assessing intensities of Raman peaks of both inorganic (∼ 960, ∼ 1,070 cm(-1)) and organic (∼ 1,454 cm(-1)) contents in animal model. Six groups were studied: clot, laser, light-emitting diode (LED), biomaterial (HA + ß-tricalcium phosphate), laser + biomaterial, and LED + biomaterial. Defects at right tibia were performed with a drill. When indicated, defects were further irradiated at a 48-h interval during 2 weeks. At the 15th and 30th days, the tibias were withdrawn and analyzed. The ∼ 960-cm(-1) peak was significantly affected by phototherapy on both clot- and biomaterial-filled defects. The ∼ 1,070-cm(-1) peak was affected by both time and the use of the LED light on clot-filled defects. On biomaterial-filled defects, only the use of the laser light significantly influenced the outcome. No significant influence of either the time or the use of the light was detected on clot-filled defects as regards the ∼ 1,454-cm(-1) peak. Raman intensities of both mineral and matrix components indicated that the use of laser and LED phototherapies improved the repair of bone defects grafted or not with biphasic synthetic microgranular HA + ß-tricalcium phosphate.

LED and laser photobiomodulation in the prevention and treatment of oral mucositis: experimental study in hamsters.

PURPOSE: This paper aims to evaluate the effects of laser (660 nm) and light-emitting diode (LED) (670 nm) irradiation in the cheek pouch mucosa of hamsters with oral mucositis (OM) induced by chemotherapy (Che) with 5-fluorouracil (5-FU). MATERIALS AND METHODS: In the preventive groups, the photobiomodulation was started 1 day before the drug administration and was performed every 48 h (Ia, IIa, Ib, and IIb). In the therapeutic groups (IIIa, IIIb, IVa, and IVb), the irradiations were started on the third day after the Che d(0) and was performed every 48 h. In both groups, animals were sacrificed 7 or 14 days after Che. In the positive control groups, the hamsters were subjected to Che but did not receive irradiation, and they were sacrificed in 7 days (Va) or 14 days (Vb). In the negative control groups, no procedures were done and the animals were sacrificed 7 days (Vc) or 14 days (Vd) after the experiment started. RESULTS: The results indicated loss of body mass, xerostomia, and alopecia in the animals subjected to Che and the healing of OM to different degrees after the photobiomodulation treatment. Histologically, the positive control and experimental groups showed inflammation, predominately with lymphocytes and plasma cells, which tended to diminish with time. Epithelial atrophy, hyperemia, fibroblast proliferation, and vascular congestion were also observed at those intervals. CONCLUSIONS: The best results were obtained from the preventive laser and LED photobiomodulation groups; both treatments were effective in diminishing the OM lesions. CLINICAL RELEVANCE: A noninvasive and effective method with sparse side effects of OM would be desirable for use in cancer centers around the world.

Influence of the parameters of the Er:YAG laser on the apical sealing of apicectomized teeth.

Failures in the sealing of the tooth apex have been considered to be responsible for most of the failures of apical surgeries. The Er:YAG laser has been proposed as an alternative for the use of rotator instruments in surgical endodontics due to its precision, lack of vibration, less post-operative discomfort, bacterial reduction, and less stress for patients and professionals. Following approval by the ethics committee, 12 extracted human canines without previous endodontic treatment with anatomically normal roots and free from apical lesions were washed in running tap water and disinfected. The teeth were sectioned axially at the crown-root junction and submitted to routine endodontic treatment. The apical limit was set at 1 mm before the apical foramen. The root canals were routinely filled with Gutta-Percha points and Sealer 26 and were randomly distributed into two groups (n = 6). In group I, apicectomy was performed with the Er:YAG laser (KAVO KEY Laser II®, Germany, λ = 2.940 nm, pulsed mode, 2051 tip, with air spray cooling, 250 mJ/15 Hz). Apical cut was performed of perpendicular mode 3 mm from the apical foramen. In group II, the same procedures and the same sequence as above was used, varying only the parameters of the Er:YAG laser (400 mJ/6 Hz). Sealing of the cervical end the apex was carried out with acrylic resin; the roots were covered by a layer of epoxy glue and two layers of nail polish. The specimens were divided into groups and fixed, by the cervical third, on wax. Impermeabilization of the residual root apical third was performed following the same procedures used in the cervical third but the residual apex was left free from the impermeabilization. After that, the roots were immersed in a 2% methylene blue solution and placed in a bacteriological oven for 48 h and then washed in running tap water for 2 h. The samples were sagittally split into two parts. The segments were visually observed and the one showing the greatest level of dye leakage was selected and kept in an individual container and coded accordingly. Apical staining was measured using a stereoscopic magnifying glass, a compass, and a caliper. The measurement was performed by three endodontists, previously calibrated, and unaware of the sample coding. The results showed that group I showed the greatest level of dye leakage. There was a significantly difference between the groups (p = 0.001). It is concluded that the apicectomies carried out with 400 mJ/6 Hz showed the smallest infiltration value.

Influence of laser therapy on the dynamic formation of extracellular matrix in standard second degree burns treated with bacterial cellulose membrane.

The present study aims to assess the influence of Aluminum-Gallium-Indium-Phosphide laser (AlGaInP laser, λ = 660 nm), whether or not in association with the application of a membrane of bacterial cellulose (Nexfill™), during recovery from induced second-degree burns at the dorsum of Wistar rats. (Rattus norvegicus, Wistar). Forty-eight animals have been distributed into four groups: Control (burns remained untreated), Group I (laser-treated), Group II (treated with Nexfill), and Group III (laser + Nexfill™). In addition to a morphological analysis, immunohistochemical analysis has been performed for type I collagen, type III collagen, fibronectin, and laminin. The Fisher's Test was used to assess differences among groups (p < 0,05). A larger amount of collagen type III was observed in Control, Group II and Group III when compared with Group I (p < 0,05). Group I and Group III have shown a greater collagen deposition when compared with Group II (p < 0,05), but the amount of collagen was similar in Group I, Group III, and Control. Group III has shown larger fibronectin amounts in comparison with Group II (p < 0,05). As regards laminin, Group I has shown a predominant discontinuity pattern on the basal lamina in comparison with Control, Group II, and Group III (p < 0,05). It is concluded that in this current study the laser when used alone (Group I) hasn't influenced collagen deposition neither has it acted on fiber pattern (fibril and/or reticular). Moreover, laser application hasn't accelerated the repair of wounds caused by inflicted second-degree burns.

Avaliação da qualidade de duas técnicas de obturação do canal radicular por meio de radiografia digitalizada / Assessment of two root canal filling techniques through digitalized radiography

A qualidade da obturação endodôntica é normalmente avaliada por meio do exame radiográfico periapical convencional. Entretanto, a interpretação radiográfica visual não pode determinar com precisão se a obturação está satisfatória. Dessa forma, novos métodos de avaliação precisam ser testados, como quantificação da média dos níveis de cinza da imagem do conduto radicular obturado, mensurada por meio dos histogramas dos programas utilizados para avaliação de radiografias digitais. O presente estudo teve como objetivo avaliar a qualidade do preenchimento do canal radicular por meio da mensuração da média dos níveis de cinza dos condutos obturados na imagem radiográfica digitalizada. Para tanto, foram selecionados quarenta dentes incisivos centrais superiores, que foram obturados pelas técnicas da condensação lateral e híbrida de Tagger modificada. Os resultados demonstraram haver diferença significativa na média dos níveis de cinza antes e após aobturação dos condutos radiculares (p < 0,0001), entretanto não houve diferença estatisticamente significativa entre as duas técnicas avaliadas (p > 0,05).

Selamento de cimentos provisórios em endodontia / Sealing of temporary cements in endodontics

Objetivo: Avaliar a microinfiltração coronária de três materiais restauradores temporários utilizados em Endodontia: Bioplic® (Biodinâmica, Londrina, Brasil), IRM® (Dentsply, Petrópolis, Brasil) e Coltosol® (Vigodent, Bonsucesso, Brasil). Métodos: Foram utilizados quarenta pré-molares inferiores íntegros, extraídos, divididos em quatro grupos: Grupo I - material restaurador provisório fotopolimerizável Bioplic® (Biodinâmica, Londrina, Brasil) associado a sistema adesivo; Grupo II - Bioplic® (Biodinâmica, Londrina, Brasil); Grupo III - material restaurador provisório à base de óxido de zinco e eugenol IRM® (Dentsply, Petrópolis, Brasil); Grupo IV - material restaurador provisório pronto para uso Coltosol® (Vigodent, Bonsucesso, Brasil). Os dentes foram imersos em solução de Rodamina B 1% e armazenados em estufa a 37ºC por 24 horas, procedendo-se à ciclagem térmica por sete dias. As temperaturas na câmara variaram em 5, 37 e 50ºC. Após a secção longitudinal dos dentes no sentido vestíbulo-lingual, a infiltração foi medida em milímetros e analisada estatisticamente através da ANOVA e teste de Tukey, com um nível de significância de 5%. Resultados: No grupo em que foi utilizada a técnica do Bioplic® (Biodinâmica, Londrina, Brasil) associado ao ataque ácido foram observados menores índices de infiltração (0,37 ± 0,24), detectando-se diferença estatisticamente significante (p<0,05) entre os grupos I e III, I e IV, II e III. Conclusão: Desta forma, todos os materiais testados apresentaram infiltração coronária, entretanto, com a utilização do Bioplic® (Biodinâmica, Londrina, Brasil) associado ao ataque ácido, foram observados os menores índices, demonstrando assim sua efetividade.

Objective: The aim of this study was to assess the coronal leakage of three temporary cements in endodontics: Bioplic® (Biodinâmica, Londrina, Brazil), IRM® (Dentsply, Petrópolis, Brazil) and Coltosol® (Vigodent, Bonsucesso, Brazil). Methods: Forty human pre-molars were divided into four groups: I (Bioplic® + adhesive system), II (Bioplic®, Biodinâmica, Londrina, Brasil), III (IRM®, Dentsply, Petrópolis, Brasil), and IV (Coltosol®, Vigodent, Bonsucesso, Brasil). The teeth were immersed in 1% Rodamine and kept at 37ºC for 24h. They were then thermal cycled for seven days. Temperatures ranged between 5, 37 and 50ºC. After longitudinal sectioning the leakage was measured in mm and statistical analysis was performed using the ANOVA and Tukey tests with a level of significance of 5%. Results: In the group in which Bioplic® was used with adhesive, a lower level of leakage was detected (0.37 ± 0.24). There was significant difference (p<0.05) between groups I and III, I and IV, II and III. Conclusion: It was concluded that all the tested material showed coronal leakage and that the use of the (Bioplic® Biodinâmica, Londrina, Brasil) plus adhesive system showed the lowest level of leakage.

Effect of low-level laser therapy and mineral trioxide aggregate on alveolar bone repair

Aim: This study aimed to evaluate the effect of low-level laser therapy (LLLT) associated to mineral trioxide aggregate (MTA) on the alveolar bone repair process. Methods: Forty Wistar rats had the upper right incisor extracted and were assigned to 4 groups according to the treatment of the alveolar wound: G1 - no treatment (control group); G2 - sockets were filled with MTA; G2 - sockets were treated with LLLT(l780 nm, 40 mW, 16 J/cm2); and G4 – sockets were treated with LLLT and filled with MTA. The animals were sacrificed 14 days after the surgical procedures. The maxillas were removed, fixed in formalin, decalcified in 0.5% nitric acid and processed histologically. Results: In G1, there was bone formation on the bottom of the socket, but it was not noticeable on the superficial areas, as well as the presence of an intense granulation tissue. In G2, the bone trabeculae were irregular and thin, and were associated with intense vascular hyperemia and chronic inflammation. In G3, there was substantial formation of thick interwoven osteocyte-rich trabecular bone, with an evident osteoblastic rimming. In G4, it was observed an intense deposition of thin irregular bone trabeculae, but vascular hyperemia was quite distinguishable. Conclusion: LLLT was the most successful treatment to improve alveolar bone repair.