Plant extract incorporated into glass ionomer cement as a photosensitizing agent for antimicrobial photodynamic therapy on Streptococcus mutans.

BACKGROUND: A plant extract (EB) incorporated into glass ionomer cement (GIG) could be a potential photosensitizer for Antimicrobial PDT (aPDT) against caries-microorganisms, replacing methylene blue (MB), due to the presence of chlorophyll. GIC + EB + aPDT could be an therapeutic alternative to dentin decontamination and sealing, allowing reduction of operative time. OBJECTIVE: Evaluate Dioscorea altissima (EB) incorporated into GIC as a photosensitizer for aPDT against Streptococcus mutans. METHODS: Groups (n = 24; ntotal = 192): G1-GIC; G2-GIC + LASER; G3-GIC/EB; G4-GIC/EB + LASER; G5-GIC+MB; G6-GIC + aPDT; G7-GIC/EB + MB; and G8 - GIC/EB+aPDT. In aPDT groups, MB was the photosensitizer. In LASER groups, MB was not used. The irradiation protocol was 660 nm/100 mW/5 J/150 J/cm²/50 s, with a 5-min pre-irradiation time for the MB groups. Antibacterial assays were carried out in 24-well microplates. The wells were completed with one milliliter of a S. mutans in BHI at 1.3 × 108 CFU/mL suspension. After incubation, PDT or laser was performed. After MTT bacteria viability test, the data were submitted to the Kolgomorov-Smirnoff normality test, followed by one-way ANOVA and Tukey's posterior test, α < 0.05. RESULTS: Group G6 showed significant inhibition (p < 0.001), followed by groups G4, G5, G7, and G8, which did not show significant differences among them (p > 0.05). Groups G2 and G3 also showed similar results (p > 0.05) and were the least active compared to the others. CONCLUSIONS: EB potentiated the antimicrobial action of GIC against S. mutans and laser irradiation over GIC/EB presented better antimicrobials results. The results indicate that EB could be a potential photosensitizer for aPDT.

Bis(4-methyl phenyl)iodonium as an alternative component to diphenyliodonium in camphorquinone-based ternary initiating systems.

OBJECTIVE: To evaluate the influence of different co-initiators (diphenyliodonium hexafluorophosphate - DPI - and bis(4-methyl phenyl)iodonium hexafluorophosphate - BPI) on chemical and mechanical properties of resins. METHODS: Nine experimental resins (50% Bis-GMA and 50% TEGDMA, w/w) with 60 wt% filler particles were formulated. The initiating system used was camphorquinone (CQ-1 mol%) and ethyl dimethylaminobenzoate (EDAB-2 mol%). Experimental groups were established according to DPI and BPI quantities (0.25, 0.5, 0.75, and 1 mol%). The control group was a resin containing only CQ-EDAB. Light transmission through the resin during polymerisation was analysed with a UV-vis spectrophotometer. Real-time polymerisation of the systems was evaluated using an FTIR spectrometer. Real-time polymerisation shrinkage strain was evaluated, and the flexural strength and modulus of materials were obtained by 3-point bending. Experimental groups were statistically analysed by Analysis of Variance and Tukey's test (α = 0.05). Dunnett's test was applied to compare experimental groups with control. RESULTS: Light transmission rapidly increased initially for resins containing DPI or BPI. After 30 s cure, the irradiance on the lower surface of resin specimens was similar for all groups. After 10 s of light irradiation, groups containing DPI and BPI had higher conversion than the control. However, conversion after 120 s post-irradiation was similar for all groups. The rate of polymerisation, shrinkage strain, and the maximum strain rate were higher for groups containing DPI/BPI. The use of iodonium salts increased the flexural strength and flexural moduli of resins. SIGNIFICANCE: DPI and BPI increased resin reactivity similarly. Increased rate of polymerization influenced light transmission through the resin in the first seconds of polymerisation and increased resin shrinkage and rate of shrinkage, as well as flexural strength and moduli.

The influence of nanofillers on the properties of ethanol-solvated and non-solvated dental adhesives.

OBJECTIVES: The aim of this study was to evaluate the influence of different concentrations of nanofillers on the chemical and physical properties of ethanol-solvated and non-solvated dental adhesives. MATERIALS AND METHODS: Eight experimental adhesives were prepared with different nanofiller concentrations (0, 1, 2, and 4 wt%) and 2 solvent concentrations (0% and 10% ethanol). Several properties of the experimental adhesives were evaluated, such as water sorption and solubility (n = 5, 20 seconds light activation), real-time degree of conversion (DC; n = 3, 20 and 40 seconds light activation), and stability of cohesive strength at 6 months (CS; n = 20, 20 seconds light activation) using the microtensile test. A light-emitting diode (Bluephase 20i, Ivoclar Vivadent) with an average light emittance of 1,200 mW/cm2 was used. RESULTS: The presence of solvent reduced the DC after 20 seconds of curing, but increased the final DC, water sorption, and solubility of the adhesives. Storage in water reduced the strength of the adhesives. The addition of 1 wt% and 2 wt% nanofillers increased the polymerization rate of the adhesives. CONCLUSIONS: The presence of nanofillers and ethanol improved the final DC, although the DC of the solvated adhesives at 20 seconds was lower than that of the non-solvated adhesives. The presence of ethanol reduced the strength of the adhesives and increased their water sorption and solubility. However, nanofillers did not affect the water sorption and strength of the tested adhesives.

Increased rates of photopolymerisation by ternary type II photoinitiator systems in dental resins.

To evaluate the effects of Type I and Type II photoinitiator systems on curing efficiency, degree of conversion (DC) and chemico-physical properties of resin based materials. A comonomer base containing 50%wt 2.2-bis[4-(2-hydroxy-3-methacryloxypropoxy)phenyl]propane (bis-GMA) and 50%wt triethyleneglycol dimethacrylate (TEGDMA) was formulated with either 0.5 or 1mol% of Type II camphoroquinone (CQ), Type I monoacylphosphine oxide (MAPO) or bis-acylphosphine oxide (BAPO) photoinitiators. The Type II system was either a binary (1: 2 CQ:amine) or ternary system (1: 2 CQ:amine + 0.5 mol% DPI). Degree and rate of polymerization was measured by Fourier Transform Infrared Spectroscopy (FTIR). Knoop micro-hardness prior to and following ethanol immersion was assessed. Flexural strength and modulus was measured under three-point bend test. Water sorption and solubility was also evaluated. The photoinitiator absorption spectra and the total absorbed energy per unit volume (Eabs) for 0.5mol% photoinitiator in each material was calculated. Despite the reduced total absorbed energy per unit volume for CQ based systems, ternary Type II system significantly improved curing efficiency (P < 0.05) compared to both Type I photoinitiators and degree of conversion compared to MAPO only, whilst exhibiting comparable mechanical and physical properties compared to both Type I based materials at equivalent molar concentrations of photoinitiator (P > 0.05). Ternary Type II systems is an efficient alternative to improve the polymerization of resin materials, promoting similar or even better properties than Type I initiators. DPI can increase the reactivity of CQ systems and promote polymerization rates superior than Type I photoinitiators.

Mechanical properties of a glass ionomer cement incorporated with Amazon plant extract.

To evaluate the mechanical properties (MP) and antimicrobial activity of a glass ionomer cement (GIC) incorporated with an antimicrobial agent from the aerial parts of Dioscorea altissima. MP were: syneresis & imbibition; solubility; elasticity module; surface microhardness and fluoride release, and the anti-Streptococcus mutans (Smut) activity was accessed by microdilution broth assay and 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) analysis. Syneresis & imbibition did not change over time for both groups, but EG showed lower values at days 7th and 30th. The control group (CG)'s and the experimental group (EG)'s weights were similar before the solubility assay, but after seven days, CG exhibited weight gain in comparison to EG. The elasticity module had no significant differences between groups. The CG showed lower surface microhardness compared to the EG. CG and EG had similar behaviors regarding fluoride release. EG showed diminished Streptococcus mutans count in comparison to CG. EG showed similar or better mechanical properties and an improvement in the antibacterial activity than the original cement.

Evaluation of the Accuracy of Conventional and Digital Impression Techniques for Implant Restorations.

PURPOSE: The increased use of CAD systems can generate doubt about the accuracy of digital impressions for angulated implants. The aim of this study was to evaluate the accuracy of different impression techniques, two conventional and one digital, for implants with and without angulation. MATERIALS AND METHODS: We used a polyurethane cast that simulates the human maxilla according to ASTM F1839, and 6 tapered implants were installed with external hexagonal connections to simulate tooth positions 17, 15, 12, 23, 25, and 27. Implants 17 and 23 were placed with 15° of mesial angulation and distal angulation, respectively. Mini cone abutments were installed on these implants with a metal strap 1 mm in height. Conventional and digital impression procedures were performed on the maxillary master cast, and the implants were separated into 6 groups based on the technique used and measurement type: G1 - control, G2 - digital impression, G3 - conventional impression with an open tray, G4 - conventional impression with a closed tray, G5 - conventional impression with an open tray and a digital impression, and G6 - conventional impression with a closed tray and a digital impression. A statistical analysis was performed using two-way repeated measures ANOVA to compare the groups, and a Kruskal-Wallis test was conducted to analyze the accuracy of the techniques. RESULTS: No significant difference in the accuracy of the techniques was observed between the groups. Therefore, no differences were found among the conventional impression and the combination of conventional and digital impressions, and the angulation of the implants did not affect the accuracy of the techniques. CONCLUSIONS: All of the techniques exhibited trueness and had acceptable precision. The variation of the angle of the implants did not affect the accuracy of the techniques.

Terapia interdisciplinar na otimização da estética vermelha e branca / Interdisciplinary therapy in the optimization of pink and white aesthetics ­ case report

Este relato descreveu um caso clínico no qual foi realizado um planejamento multidisciplinar priorizando, além do restabelecimento funcional, uma adequada estética ao paciente. Para que tais metas fossem alcançadas, foi importante a implementação de uma visão multidisciplinar do caso, garantindo um planejamento integrado capaz de reunir todos os requisitos para a otimização de resultados satisfatórios, considerando os padrões de estética periodontal e dental. O presente caso clínico descreveu uma abordagem clínica multidisciplinar para reabilitação anterior envolvendo cirurgia plástica periodontal, para aumento de coroa e confecção de facetas em resina composta pela técnica direta para devolução de estética dental, resultando em sucesso clínico e satisfação da paciente.

This report describes a clinical case in which a multidisciplinary planning was performed, prioritizing, in addition to functional restoration, adequate aesthetics to the patient. In order to achieve these goals, it was important to implement an interdisciplinary view of the case, guaranteeing an integrated planning capable of meeting all the requirements for the optimization of satisfactory results, considering the patterns of periodontal and dental aesthetics. The present case report describes a multidisciplinary clinical approach for previous rehabilitation involving periodontal plastic surgery for crown lengthening and direct composite resin veneers to retrieve dental esthetics achieving clinical success and patient satisfaction.

Depressive behavior induced by unpredictable chronic mild stress increases dentin hypersensitivity in rats.

OBJECTIVE: The present study evaluated the nociceptive response induced by dentin hypersensitivity after dental erosion in rats that were exhibited to unpredictable chronic mild stress (UCMS)-induced depressive-like behavior. DESIGN: Adult male rats were subjected to UCMS (depression [D] group) or not (no depression [ND] group) for 30days and received either acidic solution to induce dental erosion (E) or water (W), thus forming the WND, END, WD, and ED groups. After the end of treatment, depressive-like parameters (i.e., sucrose preference and immobility in the forced swim test) and dentin hypersensitivity were evaluated. Plasma tumor necrosis factor α (TNF-α) and corticosterone levels were measured, and astrocytic glial fibrillary acidic protein (GFAP) expression was evaluated in the prefrontal cortex, hippocampus, amygdala, and hypothalamus. RESULTS: Administration of the acidic solution potentiated dentin hypersensitivity and increased corticosterone levels in the ED group compared with the WD group. TNF-α levels only increased in the WD group. The ED group exhibited an increase in astrocytic GFAP expression in the hypothalamus and prefrontal cortex but decreases in the hippocampus. CONCLUSIONS: These results suggest that UCMS exacerbated the nociceptive response associated with dentin hypersensitivity, concomitant with an increase in plasma corticosterone levels. Hypothalamic and prefrontal cortex astrogliosis in the ED group may be attributable to the increase in corticosterone associated to UCMS procedure. The reduction of astrocytic GFAP expression in the hippocampus in the ED group supports the association between dentin hypersensitivity and depression.

Stress and its role in the dentin hypersensitivity in rats.

INTRODUCTION: The perception of pain varies individually. Chronic stress leads to analgesia. The use of animal chronic mild stress model to mimic human condition was previously developed and now applied in the evaluation of pain perception in rats with dentin hypersensitivity (DH). AIMS: Using DH model induced by dentin erosion (DE) mediated by acidic solution, the present study aimed the evaluation of the interaction of chronic stress and pain induced by DH in rats with DE. METHODS: DH was induced by ad libitum 30-day intake of acidic solution. Stress was induced by the New York subway model. Body weight was weekly taken, during treatment. Groups WO (water, no stress), WS (water and stress), EO (acidic solution, no stress) and ES (acidic solution, stress) were submitted to treatments. RESULTS: After 30 days, all groups were submitted to DH test assessed by cold water stimuli in the labial surface of molars, for 5s, and the rats responses were scored as grades 0, 0.5, 1, 2, or 3. After euthanasia, blood was taken to obtain the levels of corticosterone, stomachs were observed in fresh preparations, kidneys and livers were submitted to histological evaluation. Open field model supported stress evaluation, as did corticosterone analysis. Stressed animals showed significant increase in pain perception and a decrease in locomotion frequency, tending to be more frequent in the periphery of the arena, corroborating stressed behavior and the need of protection as a pain relief. Corticosterone levels were increased in the stressed rats with dentin erosion and also corroborate present findings. Finally, reduction in weight gain was impaired in stressed group with dentin erosion. CONCLUSION: The animal model enabled the evaluation of how chronic mild stress interfered in DH pain perception.

Effects of radiant exposure and wavelength spectrum of light-curing units on chemical and physical properties of resin cements.

OBJECTIVES: In this study, we evaluated the influence of different radiant exposures provided by single-peak and polywave light-curing units (LCUs) on the degree of conversion (DC) and the mechanical properties of resin cements. MATERIALS AND METHODS: Six experimental groups were established for each cement (RelyX ARC, 3M ESPE; LuxaCore Dual, Ivoclar Vivadent; Variolink, DMG), according to the different radiant exposures (5, 10, and 20 J/cm2) and two LCUs (single-peak and polywave). The specimens were made (7 mm in length × 2 mm in width × 1 mm in height) using silicone molds. After 24 hours of preparation, DC measurement was performed using Fourier transform infrared spectrometry. The same specimens were used for the evaluation of mechanical properties (flexural strength, FS; elastic modulus, E) by a three-point bending test. Data were assessed for normality, after which two-way analysis of variance (ANOVA) and post hoc Tukey's test were performed. RESULTS: No properties of the Variolink cement were influenced by any of the considered experimental conditions. In the case of the RelyX ARC cement, DC was higher when polywave LCU was used; FS and E were not influenced by the conditions evaluated. The LuxaCore cement showed greater sensitivity to the different protocols. CONCLUSIONS: On the basis of these results, both the spectrum of light emitted and the radiant exposure used could affect the properties of resin cements. However, the influence was material-dependent.

Zirconia Rehabilitation Focused on the Emergence Profile: A Case Report.

The first choice for anterior rehabilitation has been metal-free materials due to their successful aesthetic results. However, the definitive clinical work accuracy may be affected by the lack of clinicians' expertise and familiarization with the latest techniques, as well as recurrent laboratory procedures. This manuscript presents a clinical experience with zirconia ceramic for anterior crowns and zirconia CAD/CAM abutments, including both clinical and laboratory steps after the implant installation. The 'emergence profile' and the 'double scanning' techniques obtained by the waxing technique appear to be a very promising procedure for aesthetic improvement of the single-implant zirconia restoration in anterior teeth.

Efficacy of a bioactive material and nanostructured desensitizing on dentin hypersensitivity treatment / Eficácia de um material bioativo e dessensibilizante nanoestruturado no tratamento da hipersensibilidade dentinária

Introduction: Dentin hypersensitivity is a frequent occurrence in dental practice. It is clinically characterized by acute, short, and temporary pain in response to mechanical, chemical, thermal, or osmotic stimuli resulting from dentin exposure. Objective: To compare in vivo the effect of an experimental crystalline bioactive material and nanostructured desensitizing on the pain assessment among patients with cervical dentin hypersensitivity. Material and method: Thirty patients were selected for this study, who were randomly assigned to two groups (n=15) in a split-mouth design. Each patient received two treatments: group 1 (fluoride gel and bioactive material) and group 2 (fluoride gel and nanostructured desensitizing). Pain analyses were performed using a visual analogue scale, ranging 0-10. Baseline pain measurement was performed prior to initial treatment (T0) and new measurements were carried out weekly for 3 weeks (T1, T2, and T3) before materials were reapplied. Final pain analysis was performed 3 months after initial treatment (T4). Degree of pain reduction was calculated using the formula T0 - Tperiod after treatment. The data of the pain measurements were analyzed using 2-way repeated measure ANOVA and Tukey’s test (α=0.05). Result: Regardless of evaluation period, there was no statistical difference on pain reduction between the treatments (p>0.05). The degree of pain was reduced significantly in each evaluated period for all tested treatments (p<0.05), by approximately three degrees after 3 months. Conclusion: The tested desensitizing materials were effective on dentin hypersensitivity reduction.

Introdução: A hipersensibilidade dentinária é uma ocorrência frequente na prática clínica; clinicamente caracterizada por dor aguda, curta e temporária, em resposta ao estímulo mecânico, químico, térmico ou osmótico causada pela exposição dentinária. Objetivo: Comparar in vivo o efeito de um material bioativo cristalino experimental e um dessensibilizante nanoestruturado na avaliação da dor de pacientes com hipersensibilidade dentinária cervical. Material e método: Trinta pacientes foram selecionados para este estudo, que foram randomicamente divididos em dois grupos (n=15) em um desenho experimental de boca dividida. Cada paciente recebeu dois tratamentos: grupo 1 (flúor gel e material bioativo) e grupo 2 (flúor gel e dessensibilizante nanoestruturado). As análises de dor foram realizadas usando uma escala visual analógica, variando de 0-10. A mensuração da dor inicial foi realizada previamente ao tratamento inicial (T0) e novas análises foram realizadas semanalmente durante 3 semanas (T1, T2 e T3) antes da reaplicação dos materiais. A análise final da dor foi realizada 3 meses após o início do tratamento (T4). O grau de redução de dor foi mensurado pela fórmula: T0 - Tperíodo após tratamento. Os dados das mensurações de dor foram analisados pela ANOVA para medidas repetidas 2 critérios e teste de Tukey (α=0,05). Resultado: Independente do período de avaliação, não houve diferença estatística entre todos os tratamentos na redução da dor (p>0,05). O grau de dor reduziu significativamente em cada período avaliado para todos os tratamentos testados (p<0,05), aproximadamente três graus após 3 meses. Conclusão: Os materiais dessensibilizantes testados foram efetivos na redução da hipersensibilidade dentinária.

Short-term microbiological effects of photodynamic therapy in non-surgical periodontal treatment of residual pockets: A split-mouth RCT.

BACKGROUND AND OBJECTIVE: Photodynamic therapy (PDT) has been used as a therapeutic alternative to treat periodontitis, especially in challenging sites that require additional periodontal therapy such as residual pockets. The aim of this split-mouth randomized trial was to evaluate the microbiological and clinical effects of PDT on non-surgical treatment of unresponsive pockets. STUDY DESIGN/MATERIALS AND METHODS: A split-mouth, randomized controlled clinical trial was conducted in 15 patients presenting at least two residual pockets (probing pocket depth [PPD] ≥5 mm with bleeding on probing [BoP]) in single-rooted teeth in supportive periodontal therapy. The selected sites randomly received: (1) SRP + PDT: scaling and root planing combined with photodynamic therapy (methylene blue as a photosensitizer), or (2) SRP: scaling and root planing alone. The concentrations of Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans were evaluated using a Real-time PCR technique at baseline and 3, 7, 14, and 90 days. Clinical parameters were assessed at baseline and 3 months post-therapies. RESULTS: Both treatments promoted clinical improvements, with additional benefits to the SRP + PDT group in PPD reduction and clinical attachment level gain (P < 0.05) after 3 months. Only the SRP + PDT group exhibited a statistically significant reduction in the levels of A. actinomycetemcomitans on the 3rd and 7th days after therapy (P < 0.05), and a lower concentration of this pathogen was detected at 7 days in the SRP + PDT group when compared to the other therapy (P < 0.05). CONCLUSION: The combined therapeutic approach SRP + PDT may reduce A. actinomycetemcomitans levels for a short-term period, associated with additional improvement in clinical parameters in treating residual pockets. Lasers Surg. Med. 48:944-950, 2016. © 2015 Wiley Periodicals, Inc.

Can mouth washes containing chlorhexidine 0.12% be used as synonym of a water solution of chlorhexidine 0.12%? / Pode lavagens da boca contendo 0.12 % de clorexidina ser utilizado como sinónimo de uma solução aquosa de cloro-hexidina 0.12 % ?

Chlorhexidine digluconate (CHX) is a gold standard drug in dentistry and is widely used as a reference in both in vitro and in vivoexperiments. Due to ease of access, mouth washes containing CHX 0.12% are used as a substitute for aqueous CHX 0.12% solution in laboratory experiments. Additionally, it is well known that for product flavor purposes, volatile compounds are added to mouth washes formulations. Volatiles added to CHX 0.12% may improve wash's antibacterial ability. Volatiles add potency to the mouth wash formulation. Compared with an aqueous CHX 0.12% solution, it is proposed that CHX solutions and Periogard^® would have antimicrobial activity. Antimicrobial activity was assessed in the present study via disk diffusion assays against Streptococcus mutans, Streptococcus sanguinisand Escherichia coli. Periogard^® showed a significantly higher antibacterial activity in relation to CHX 0.12% (p<0.05) and a similar activity in relation to CHX 1% (p>0.05). Periogard^(r) volatiles were analyzed by gas-chromatography/mass spectrometry (GCMS) and the presence of antibacterial menthol, menthone, isomenthol, menthyl acetate, trans-anethol and eugenol was verified. Finally, the use of Periogard^® as a synonym of CHX 0.12% must be avoided, because its antibacterial activity is closely related to CHX 1%...

Gluconato de clorexidina (CHX) é um fármaco considerado padrão ouro, em Odontologia, amplamente usado como referência em estudos in vitro e in vivo. Em razão da facilidade de acesso, enxaguatórios bucais que contêm CHX 0,12% são usados em substituição à solução aquosa de clorexidina (CHX 0,12%), em experimentos laboratoriais. É sabido que devido à palatabilidade do produto, os mesmos enxaguatórios bucais contêm compostos voláteis em sua formulação, além da CHX 0.12%. Visto que voláteis adicionados podem acrescentar poder antibacteriano à formulação, a comparação da resposta antibacteriana da solução aquosa de CHX em diferentes concentrações e de Periogard^® é proposta no presente artigo. Para tanto, utilizou-se o ensaio do disco de difusão em ágar com inóculos de Streptococcus mutans, Streptococcus sanguinis e Escherichia coli. Periogard^® mostrou atividade antibacteriana significativa contra as três cepas analisadas, quando comparada à atividade de CHX 0.12% (p<0,05) e atividade similar à CHX diluída a 1% (p>0,05). A presença de compostos voláteis no Periogard^® foi analisada por GC-MS e observou-se que mentol, mentona, isomentol, acetato de mentila, trans-anetol e eugenol estão presentes na formulação. Deste modo, o uso de Periogard^(r) como sinônimo de CHX 0,12% deve ser evitado, uma vez que sua atividade se assemelha àquela da CHX diluída a 1%...

In vitro activity of Amazon plant extracts against Enterococcus faecalis.

Previous studies analyzing 2,200 plant extracts indicated anti-enterococcal activity in 25 extracts obtained from Brazilian forests' plants. In the present study, these extracts were subjected to microdilution broth assay (MDBA) and disk diffusion assay (DDA) using planktonic Enterococcus faecalis ATCC(®) 29212™ and were submitted to phytochemical analysis in TLC and HPLC. Three extracts obtained from Ipomoea alba (MIC < 40 µg/mL), Diclinanona calycina (MIC ≤ 40 µg/mL) and Moronobea coccinea (40 < MIC < 80 µg/mL; MBC = 80 µg/mL) showed significant bactericidal activity in the MDBA and four extracts obtained from I. alba (14.04 ± 0.55 mm diameter) S. globulifera (14.43 ± 0.33 mm and 12.18 ± 0.28 mm diameter) and Connarus ruber var. ruber (13.13 ± 0.18 mm diameter) were active in DDA. Residues H2O obtained from Psidium densicomum (mean of 16.78 mm diameter) and from Stryphnodendron pulcherrimum (mean of 15.97 mm diameter) have shown an improved antibacterial activity after fractionation if compared to that obtained from the respective crude extracts. Antioxidant activity was observed in some residues of the active extracts. TLC analysis showed that phenolic compounds are likely to be found in active extracts. Three molecules were isolated from S. globulifera and were identified by (13)C NMR lupeol, α-amyrin and 3ß-hydroxyglutin-5-ene. The present chemical and biological findings suggest that these extracts are a potential source of new anti-Enterococcus compounds to be introduced in endodontic therapy.

The influence of Brazilian plant extracts on Streptococcus mutans biofilm.

UNLABELLED: Nineteen plant extracts obtained from plants from the Brazilian Amazon showed activity against planktonic Streptococcus mutans, an important bacterium involved in the first steps of biofilm formation and the subsequent initiation of several oral diseases. OBJECTIVE: Our goal was to verify whether plant extracts that showed activity against planktonic S. mutans could prevent the organization of or even disrupt a single-species biofilm made by the same bacteria. MATERIAL AND METHODS: Plant extracts were tested on a single-bacteria biofilm prepared using the Zürich method. Each plant extract was tested at a concentration 5 times higher than its minimum inhibitory concentration (MIC). Discs of hydroxyapatite were submersed overnight in brain-heart infusion broth enriched with saccharose 5%, which provided sufficient time for biofilm formation. The discs were then submersed in extract solutions for one minute, three times per day, for two subsequent days. The discs were then washed with saline three times, at ten seconds each, after each treatment. Supports were allowed to remain in the enriched medium for one additional night. At the end of the process, the bacteria were removed from the discs by vortexing and were counted. RESULTS: Only two of 19 plant extracts showed activity in the present assay: EB1779, obtained from Dioscorea altissima, and EB1673, obtained from Annona hypoglauca. Although the antibacterial activity of the plant extracts was first observed against planktonic S. mutans, influence over biofilm formation was not necessarily observed in the biofilm model. The present results motivate us to find new natural products to be used in dentistry.

The influence of Brazilian plant extracts on Streptococcus mutans biofilm

Nineteen plant extracts obtained from plants from the Brazilian Amazon showed activity against planktonic Streptococcus mutans, an important bacterium involved in the first steps of biofilm formation and the subsequent initiation of several oral diseases. Objective: Our goal was to verify whether plant extracts that showed activity against planktonic S. mutans could prevent the organization of or even disrupt a single-species biofilm made by the same bacteria. Material and Methods: Plant extracts were tested on a single-bacteria biofilm prepared using the Zürich method. Each plant extract was tested at a concentration 5 times higher than its minimum inhibitory concentration (MIC). Discs of hydroxyapatite were submersed overnight in brain-heart infusion broth enriched with saccharose 5%, which provided sufficient time for biofilm formation. The discs were then submersed in extract solutions for one minute, three times per day, for two subsequent days. The discs were then washed with saline three times, at ten seconds each, after each treatment. Supports were allowed to remain in the enriched medium for one additional night. At the end of the process, the bacteria were removed from the discs by vortexing and were counted. Results: Only two of 19 plant extracts showed activity in the present assay: EB1779, obtained from Dioscorea altissima, and EB1673, obtained from Annona hypoglauca. Although the antibacterial activity of the plant extracts was first observed against planktonic S. mutans, influence over biofilm formation was not necessarily observed in the biofilm model. The present results motivate us to find new natural products to be used in dentistry. .

In vitro activity of Amazon plant extracts against Enterococcus faecalis

Previous studies analyzing 2,200 plant extracts indicated anti-enterococcal activity in 25 extracts obtained from Brazilian forests' plants. In the present study, these extracts were subjected to microdilution broth assay (MDBA) and disk diffusion assay (DDA) using planktonic Enterococcus faecalis ATCC® 29212TM and were submitted to phytochemical analysis in TLC and HPLC. Three extracts obtained from Ipomoea alba (MIC < 40 µg/mL), Diclinanona calycina (MIC < 40 µg/mL) and Moronobea coccinea (40 < MIC < 80 µg/mL; MBC = 80 µg/mL) showed significant bactericidal activity in the MDBA and four extracts obtained from I. alba (14.04 ± 0.55 mm diameter) S. globulifera (14.43 ± 0.33 mm and 12.18 ± 0.28 mm diameter) and Connarus ruber var. ruber (13.13 ± 0.18 mm diameter) were active in DDA. Residues H2O obtained from Psidium densicomum (mean of 16.78 mm diameter) and from Stryphnodendron pulcherrimum (mean of 15.97 mm diameter) have shown an improved antibacterial activity after fractionation if compared to that obtained from the respective crude extracts. Antioxidant activity was observed in some residues of the active extracts. TLC analysis showed that phenolic compounds are likely to be found in active extracts. Three molecules were isolated from S. globulifera and were identified by 13C NMR lupeol, α-amyrin and 3β-hydroxyglutin-5-ene. The present chemical and biological findings suggest that these extracts are a potential source of new anti-Enterococcus compounds to be introduced in endodontic therapy.

Avaliação por extensometria da deformação superficial do osso, gerada por próteses sobre implantes com diferentes pilares protéticos em função do cantilever: estudo in vitro / Strain gauge analysis of coronal bone deformation according different prosthetic implant abutment and cantilever length types: an in vitro study

O objetivo deste estudo foi avaliar a transmissão da carga mastigatória ao osso de suporte em próteses implantossuportadas em função do cantiléver, variando o tipo de pilar (Micro-Unite Ucla). A partir de dois modelos de poliuretano (norma ASTM F –1839), foram inseridos três implantes em cada, a uma distância de 8 mm, que conformaram os grupos: 1) implantes de hexágono externo e pilares Micro-Unit; 2) implantes de hexágono externo e pilares Ucla. Foram confeccionadas estruturas protéticas em resina acrílica ativada quimicamente sob cilindros com base de Co-Cr, que foram fundidas pela técnica convencional à brasagem. Foram fixados extensômetros no poliuretano entre os implantes e um na distal do implante mais próximo ao cantiléver. Em uma máquina de ensaio universal (2000RK – Kratos, São Paulo, Brasil), foi realizada a aplicação da carga de 150 N. A carga foi aplicada entre os implantes e no cantiléver nos intervalos de 5, 10, 15, 20 e 25 mm. Os dados obtidos foram analisados estatisticamente para cada extensômetro e levando em consideração a extensão do cantiléver. Quanto maior a extensão do cantiléver, maior a deformação superficial do osso ao redor do implante mais distal. A utilização do componente tipo Micro-Unit apresentou valores de deformação inferiores em relação ao Ucla.

Objectives: to evaluate transmission of masticatory loads according to different prosthetic implant abutment and cantilever lengths. Material and methods: two polyurethane models (ASTM F-1839) received 3 external hex dental implants 8 mm each apart divided into two groups: 1) Micro-Unit and, 2) Ucla. Metallic frameworks were prepared using acrylic resin and cast over CoCr prosthetic cylinders. Strain gauges were attached at the polyurethane-abutment interface and at the distal part of the implant near the cantilever. After, a 150 N load (2000 RK, Kratos, São Paulo, Brazil) was applied at 15, 20, and 25 mm from the most distal implant. Statistical analysis considered abutment type and cantilever lengths. Results: longer cantilevers generate more deformation in the distal implant. Deformation values at Micro-Unit were lower than at Ucla abutment type.

New trends in dentistry: plant extracts against Enterococcus faecalis. The efficacy compared to chlorhexidine

Enterococcus faecalis is an important pathogen associated with endodontic diseases, and its elimination and control are of paramount importance, as it represents one of the major causes of failure in the treatment of endodontic disease. Twenty-five plant extracts obtained from Brazilian forests were found to be effective against planktonic E. faecalis and were subjected to two traditional antibacterial assays, the microdilution broth assay (MDBA) and the disk diffusion assay (DDA), using chlorhexidine (CHX) as a control. Seven out of 25 extracts showed significant antibacterial activity and were tested in a biofilm assay, and three of these extracts were subjected to chemical fractionation. Residues were tested for their antibacterial activity, and the first chemical findings were described based on thin layer chromatography (TLC). Extracts obtained from Ipomoea alba, Symphonia globulifera and Moronobea coccinea showed significant bactericidal activity in the MDBA. The same I. alba and S. globulifera extracts, as well as the extract obtained from Connarus ruber var. ruber, showed significant activity in the DDA. RH2O obtained from Psidium densicomum and Stryphnodendron pulcherrimum showed better antibacterial activity compared to the respective crude extracts and CHX. TLC analysis showed that phenolic compounds and triterpenes represent the first findings of chemical groups that may occur in all species. The results of the present study include the discovery of six active extracts against planktonic E. faecalis and support further testing via assays involving biofilm formation, as well as the determination of the compounds' chemical profiles, as their activity was significantly better than that observed for CHX.