This investigation assessed the susceptibility of Streptococcus mutans and Lactobacillus acidophilus to Photodynamic Therapy (PDT) when grown simultaneously in dentine carious lesions. PDT is a technique that utilizes light to activate photosensitizers in the presence of oxygen to produce reactive radicals. A culture medium of 1% glucose, 2% sucrose, 1% young primary culture of L. acidophilus 108 CFU/mL, and S. mutans 108 CFU/mL was utilized to inoculate the bacterial induced caries on human dentine slabs. Different concentrations of the photosensitizer (0.75, 1.5, 3.0, 4.0, and 5.0 g/L) were activated through exposure to the light-emitting diode source with a central wavelength of 450 nm and a fluency of 5.7 J/cm2. Two light intensities (19 and 47.5 mW/cm2) were tested. Four different groups were analyzed: L-D- (control group), L-D+ (drug group), L+D+1 (PDT group 1, light intensity of 19 mW/cm2), and L+D+2 (PDT group 2, light intensity of 47.5 mW/cm2). ANOVA/Tukey tests were utilized to compare groups (α = 5%). Both light intensities required 5.0 g/L of curcumin for significant bacterial reduction (p < 0.05). No significant effect was found for L-D+, thus proving the absence of a potential inherent toxicity. Curcumin has a toxic effect on microorganisms at appreciable concentrations upon photoactivation. However, it was required to use the maximum concentration of the drug for a successful procedure.

Aim of this study was to investigate the influence of gutta-percha and metallic posts on the efficiency of Cone Beam Computed Tomography (CBCT) in diagnosing Vertical Root Fracture (VRF). Forty-eight teeth were divided into 3 experimental and 3 control groups. The teeth of the first experimental group and the first control group received neither gutta-percha nor metal posts. The teeth of the second experimental group and the second control group were filled with gutta-percha, and the teeth of the third experimental group and the third control group were filled with the metal posts. The teeth of the experimental groups were artificially fractured. The teeth were evaluated through images taken by a Prexion scanner with a 0.1 mm resolution. Fisher’s exact test was used to measure the following values: sensitivity, false negative, specificity, false positive and accuracy for the VRF detection through the scanner. Three observers calibrated and blinded to the protocol evaluated the images. The inter-observer Kappa coefficient was 0.83. The presence of posts and gutta-percha reduced the sensitivity and the accuracy in detecting the VRF. Regarding to the sensitivity (p = 0.837, p = 0.304, p = 0.837 for evaluator 1, 2 and 3, respectively) and specificity (p = 0.162, p = 0.056, p = 0.062 for evaluator 1, 2 and 3, respectively), Fisher’s exact test showed no statistically significant difference among the evaluated groups. However, a significant difference was observed in relation to the accuracy in the results of evaluator 2 (p = 0.03), which showed a much lower accuracy for the post group (50 %) than for the Nonfilled group (93.8 %). The Prexion tomograph was precise in detecting vertical root fractures and the CBCT diagnostic ability was not influenced by the presence of posts or gutta-percha.

There is already a societal awareness of the growing impact of nanoscience and nanotechnology, with nanomaterials (with at least one dimension less than 100 nm) now incorporated in items as diverse as mobile phones, clothes or dentifrices. In the healthcare area, nanoparticles of biocompatible materials have already been used for cancer treatment or bioimaging enhancement. Nanotechnology in dentistry, or nanodentistry, has already found some developments in dental nanomaterials for caries management, restorative dentistry and orthodontic adhesives. In this review, we present state-of-the-art scientific development in nanodentistry with an emphasis on two imaging techniques exploiting nanomaterials: optical coherence tomography (OCT) and photoacoustic imaging (PAI). Examples will be given using OCT with nanomaterials to enhance the acquired imaging, acting as optical clearing agents for OCT. A novel application of gold nanoparticles and nanorods for imaging enhancement of incipient occlusal caries using OCT will be described. Additionally, we will highlight how the OCT technique can be properly managed to provide imaging with spatial resolution down to 10′s–100′s nm resolution. For PAI, we will describe how new nanoparticles, namely TiN, prepared by femtosecond laser ablation, can be used in nanodentistry and will show photoacoustic microscopy and tomography images for such exogenous agents.

Objective: To evaluate the efficacy of photobiomodulation for bone repair of critical surgical wounds with implants of bone morphogenetic proteins (BMPs) and bovine biological membranes, using histological and histomorphometric analysis. Background: Tissue engineering has been developing rapidly through the use of various biomaterials for the treatment of bone defects, such as mechanical barriers consisting of biological membranes and implants of biomaterials for bone supply. Materials and methods: Thirty-two male rats were divided into four groups ( n = 8): group I-C: control; group II-PT: photobiomodulation therapy; group III-PM: Gen-Pro ^® BMPs+Gen-Derm ^® membrane; and group IV-PMPT: Gen-Pro ^® BMPs+Gen-Derm ^® membrane+photobiomodulation therapy. A 3 mm bone cavity was performed in the upper third of the lateral surface of the right rat femur to obtain a bone defect considered to be critical. The irradiated groups received seven applications of AlGaAs diode laser 830 nm, P = 40 mW, continuous wave (CW) emission mode, f ∼ 0.6 mm, 4 J/cm ² per point (north, south, east, and west) at 48 h intervals, for a total of 16 J/cm ² per session (final dose: 112 J/cm ² ). Bone repair was evaluated at sacrifice 15 and 30 days after the procedure. The specimens were embedded in paraffin and stained with hematoxylin and eosin and Picrosirius for analysis by light microscopy and by the Leica interactive measurement module software. Statistical analysis was performed ( p < 0.05%). Results: Histological analysis confirmed the histomorphometric results, with the experimental groups showing bone neoformation of significantly higher quality and quantity at the end of 30 days compared with the control group. Conclusions: Photobiomodulation therapy was effective for bone repair mainly when associated with BMPs and a biological membrane. The results of this study are promising and stimulate further scientific and clinical research.

OBEJTIVO: avaliar a eficácia do laser de baixa intensidade no tratamento da dor em pacientes com desordens temporomandibulares. MÉTODO:consistiu de um ensaio clínico randomizado divididos em dois grupos: Grupo 1: laser AsGaAl, Grupo 2: laser InGaAlP, do qual participaram 20 pacientes entre 19 e 35 anos de idade, com diagnóstico de sinais e sintomas de DTM. Os pacientes tinham a amplitude de movimento para abertura máxima da boca e lateralidade registados no início e no final do tratamento a laser. O Laser foi aplicado em quatro pontos pré-auriculares, totalizando 12 sessões três vezes por semana, durante um mês. Dor dos pacientes foi registrado com base na utilização da escala analógica visual (EAV) e também por exame físico dos pontos álgicos. RESULTADOS: observou-se redução significante (p<0,028) do nível de dor em ambos os grupos, porém no G1 a significância foi maior. A evolução do limiar de sensibilidade muscular evidenciou diferença estatisticamente significante (p<0,05) para G1 e G2. A laserterapia no Grupo 1 melhorou a abertura bucal em média de 4,643 mm, enquanto no Grupo 2, a média foi de 3,71 mm por paciente. CONCLUSÃO: houve eficácia em ambos os lasers no controle da dor e abertura bucal dos pacientes.

Objective: The aim of this study was to evaluate the photodynamic potential of extracts of Schinopsis brasiliensis Engl. on bacteria involved in several human infections. Background data: Photodynamic therapy (PDT) involves the interaction of light with an appropriate and photosensitizer wavelength, and the prospect of existing photosensitive compounds in herbal extracts enhanced by the application of laser diode has been promising. Methods: The antibacterial activity against Escherichia coli , Staphylococcus aureus , Pseudomonas aeruginosa and Enterococcus faecalis was obtained by the disk diffusion method on agar. The laser diode InGaAIP was used with 660 nm wavelength, 100 mW, and 4 J/cm ² , and the application was performed in a timely manner for 34 sec on each disk tested. The groups tested were: Laser and bark extract (B+L+); bark extract only (B+L-); Laser and leaf extract (F+L+); leaf extract only (F+L-); Laser and malachite green (M+L+); malachite green only (M+L-); and laser only (L+). Results: There were significant differences between the B+L- and B+L+ groups ( p =0.029) and between the L+F- and L+F+ groups ( p =0.029) at various concentrations of the nebulized extracts of bark and leaf. Among the tested pathogens , S. aureus showed the highest zone of inhibition, 24.55±0.36 mm in group B+L+, 500 mg.mL ⁻¹ . Conclusions: PDT with malachite green was effective, and groups B+L+ and F+L+ showed excellent activity on the bacteria tested, suggesting the presence of photosensitizers in extracts of S. brasiliensis Engl.