Impact of root canal preparation using two single-file systems on the intra-radicular microbiome of teeth with primary apical periodontitis.

OBJECTIVES: This study aimed to describe the effects of two single-file systems on the diversity of the endodontic microbiome of teeth with primary asymptomatic apical periodontitis. MATERIALS AND METHODS: The root canals from single-rooted teeth with apical periodontitis were prepared using either the Reciproc Blue (RB) or the XP-endo Shaper (XPS) instrument system. The latter was followed by a supplementary step with the XP-endo Finisher (XPF) instrument. For irrigation, 5.25% sodium hypochlorite was used. Root canal samples were taken at the baseline (S1), after preparation (S2), and after the supplementary step (S3). DNA was extracted and subjected to high-throughput sequencing using the MiSeq Illumina platform. RESULTS: Samples from 10 teeth from the RB and 7 from the XPS group were subjected to DNA sequencing. Initial samples differed significantly from post-preparation samples in bacterial diversity, with no significant difference when comparing the two instrument systems. The most dominant phyla in S2 were Bacteroidetes, Proteobacteria, Firmicutes, Fusobacteria, and Actinobacteria. The same phyla were found to dominate baseline samples and samples taken after using XPF, but with differences in the ranking of the most dominant ones. At the genus level, the most dominant genera identified after RB instrumentation were Bacteroidaceae [G-1], Fusobacterium, and Staphylococcus, while the most dominant genera after XPS instrumentation were Fusobacterium and Porphyromonas. These genera were also dominant in the initial samples. CONCLUSIONS: Both treatment protocols had measurable effects on the root canal microbial diversity, with no significant differences between them. Most of the dominant taxa involved in the primary infection and probably in the aetiology of apical periodontitis were eliminated or substantially reduced. CLINICAL RELEVANCE: The most dominant taxa that persisted after instrumentation were Fusobacterium, Porphyromonas, Staphylococcus, and Bacteroidaceae [G-1].

Catalytic dehydration of glycerol over Cu-Fe-Al-based oxides: understanding changes in active sites throughout the reaction.

The glycerol conversion into acetol using Fe, Al and Cu-based oxides was investigated. XRD results indicate the formation of nanosized particles with high phase dispersion, however, Raman, Mössbauer, 27Al NMR and XPS spectroscopies suggest the presence of iron(iii) oxide, Al2O3 and CuO phases. The FTIR with pyridine adsorption revealed high Lewis acidity. The TPR profile showed the reduction temperature range for the Fe3+ and Cu2+ sites, indicating the suitable condition for pretreatment. The N2 adsorption-desorption isotherms indicated the presence of micro-mesopores with interesting textural properties and specific area varying between 71 and 220 m2 g-1, while the porous morphology was observed by SEM and TEM images. The optimized catalytic tests showed glycerol conversion of 60% and acetol selectivity of 92% with 17% of coke according to TG profile. The recycling tests confirmed the efficiency of the solid, reaching 28% conversion and 91% acetol selectivity after four reuses and, after reactivation in an oxidizing atmosphere, the catalytic performance obtained results close to the second reuse. The interaction between the different Lewis acid sites involved in the mechanisms for the acetol and coke formation on the catalyst surface is discussed. The charge distribution represented by colors which indicates the acid-base surface was evaluated by a simple theoretical-computational study based on the DFT approach. The synergy between the active sites indicates that the presence of Cu0/Cu+ drastically increases the acetol selectivity which is a more important characteristic than the high Lewis acidity of Fen+ and Al3+.

How I do it: brainwashing for purulent ventriculitis.

BACKGROUND: The management of ventriculitis remains controversial, with no single management strategy that can provide a good outcome. There are few articles describing the brainwashing technique, and most for neonatal intraventricular hemorrhage. This technical note is important because it describes a practical way to perform brainwashing in case of ventriculitis, and it is more feasible compared to endoscopic lavage in developing countries. METHOD: We describe in a stepwise fashion the surgical technique of ventricular lavage. CONCLUSION: Ventricular lavage is a neglected technique that can help to improve ventricular infection and hemorrhage prognosis.

Synthesis, Characterization and Photocatalytic Activity of CoFe2O4/Fe2O3 Dispersed in Mesoporous KIT-6.

The present work aimed to synthesize and characterize a solid based on CoFe2O4/Fe2O3-KIT-6 and evaluate its performance in the photocatalytic degradation of the remazol red ultra RGB dye. By analyzing XRD, N2 physisorption, and Mössbauer results, it was possible to identify that the desired CoFe2O4/Fe2O3 phase was achieved, which maintained its structural properties. The FTIR-pyridine indicated the presence of Lewis acid sites, while TPD-CO2 showed a large amount of weak basic sites. The band-gap energy indicated that the compound can be applied in photocatalytic degradation under UV/visible light, with the possibility of magnetic separation at the end of the reaction. The photocatalysis results indicated that there was complete degradation of the remazol red ultra RGB dye within 1 h of reaction. Despite the absence of H2O2, the combination of the proposed photocatalyst with the anatase phase (TiO2) showed significant improvements in the degradation process. The proposed mechanism for complete dye degradation indicated that a sequence of radical reactions is necessary, generating oxidant species such as •OH and the final products were CO2 and H2O.

Root Canal Microbiome Associated With Asymptomatic Apical Periodontitis as Determined by High-Throughput Sequencing.

INTRODUCTION: Advanced DNA sequencing technology allows more detailed analysis and description of the endodontic microbiome. This study used the MiSeq high-throughput sequencing platform (Illumina, San Diego, CA) to describe the endodontic microbiome of teeth with primary asymptomatic apical periodontitis with no sinus tract. METHODS: Root canal samples from 25 patients were prepared for DNA sequencing analysis. Bacterial diversity of the microbiome was identified and compared between cases and according to the size of the related apical periodontitis lesions. Statistical analyses of the operational taxonomic unit distribution was performed using principal component analysis with the Bray-Curtis distance and a principal coordinate analysis, 2-way permutational multivariate analysis of variance. The chi-square or Fisher exact test was used to evaluate the prevalence of different operational taxonomic units related to small and large apical periodontitis lesions. RESULTS: Although there was a very high bacterial diversity in the microbiome of teeth with asymptomatic apical periodontitis, 4 phyla dominated the microbiome: Firmicutes (27%), Bacteroidetes (21%), Proteobacteria (21%), and Actinobacteria (12%). There was high variability in species composition between root canal samples with no common species pattern for the cases. Large lesions showed a higher number of species but did not significantly differ from small lesions in bacterial diversity indexes. Bacteroidaceae [G-1] bacterium HMT 272, a previously uncultivated but still unnamed and uncharacterized taxon, was the most prevalent and abundant phylotype. CONCLUSIONS: High-throughput sequencing technology confirmed the complexity of the endodontic microbiome and revealed that microbial heterogeneity is a feature between cases. This indicates that various microbial combinations of the endodontic microbiome are able to illicit periapical inflammatory diseases.

Limitations and Management of Static-guided Endodontics Failure.

Endodontic treatment in severely calcified canals is always a challenging task because it can result in accidents such as deviations or perforations. Recently, guided endodontics has become an alternative approach for pulp canal calcification, facilitating the location of root canals more predictably through the combined use of cone-beam computed tomographic imaging, oral scanning, and endodontic access guides. Although several reports have shown that guided endodontics is safer, faster and can be performed without an operating microscope and by less experienced operators, the technique has limitations, and iatrogenesis may occur. This article describes the limitations of static-guided endodontics and possible causes of failures. In the present case, not fixing the guide to the bone and inaccuracies generated by manually performing mesh merger software led to root perforation. Endodontic microsurgery was effective in resolving this case and should be considered the treatment of choice when guided endodontics cannot be used safely or when it fails.

Tracing the toxic ions of an endodontic tricalcium silicate-based sealer in local tissues and body organs.

BACKGROUND: This study aimed to track the toxic ions released by MTA Fillapex, BioRoot RCS, and an experimental tricalcium silicate-based sealer (CEO) into local and distant tissues as well as to investigate their potential adverse effects. In addition, the chemical constituents of the sealers were also evaluated. The main components of the dry powders, pastes, and mixed sealers were characterized. MATERIAL AND METHODS: Dry powder and sealer discs were each set for 72 h and their main components were characterized by energy dispersive X-ray spectroscopy. Polyethylene tubes filled with sealers were used to measure silicon and calcium ions. Polyethylene tubes filled with sealers or empty tubes were implanted into the dorsal connective tissue of Wistar rats. On days 7, 15, 30, and 45, the animals were euthanized and their brains, livers, kidneys, and subcutaneous tissues were removed and processed to determine the concentrations of chromium, cobalt, copper, lead, iron, magnesium and nickel using an inductively coupled plasma optical emission spectrometer. RESULTS: The main compounds in all sealers were carbon, oxygen, silicon, and calcium. MTA Fillapex release more Si while highest levels of Si were found in presence of BioRoot. The release of Si and Ca ions promoted by MTA Fillapex raise by time. No traces of cobalt, chromium, or magnesium were detected in any tissue. Irrespective of the sealer, no traces of copper and lead were found in the subcutaneous tissue; however, they were observed in the organs. The highest concentration of iron was identified in the liver. All sealers exhibited similar nickel traces in the brain, kidney, and liver except for MTA Fillapex, which demonstrated levels higher than CEO in the subcutaneous tissue on day 7. Tracing nickel ions over time revealed that lowest concentrations were found in subcutaneous tissue. CONCLUSION: Taken together, our data demonstrate that CEOs have chemical compositions similar to those of other commercial sealers. Furthermore, none of them exhibited a threat to systemic health. Moreover, the minimal amounts of iron and nickel detected were not related to the sealers.

The use of antimicrobial photodynamic therapy in the successful management of a nonsurgical complex type II Dens Invaginatus.

Because of its complex root canal morphology, dens invaginatus (DI) is a developmental anomaly that represents an endodontic challenge to complete cleaning, shaping, and disinfecting the root canal system. The present case report describes the use of antimicrobial photodynamic therapy as an adjunctive treatment in the successful management of nonsurgical complex type II DI in a left maxillary lateral incisor with thin and fragile dentin walls associated with periradicular lesion.

The use of antimicrobial photodynamic therapy in the successful management of an invasive cervical resorption class 4: A case report with five years follow-up.

A 41-year-old male with a dental history of invasive cervical resorption (ICR) was initially treated with a surgical endodontics approach and secondly with antimicrobial photodynamic therapy (aPDT) along with endodontic retreatment. The use of aPDT was essential to promote bacterial reduction in the resorption defect. Combining these techniques allowed for clinical, radiographic, and tomographic success after five years of follow-up.

Photocatalytic degradation of ibuprofen using titanium oxide: insights into the mechanism and preferential attack of radicals.

The present work studied ibuprofen degradation using titanium dioxide as a photocatalyst. Mechanistic aspects were presented and the preferred attack sites by the OH˙ radical on the ibuprofen molecule were detailed, based on experimental and simple theoretical-computational results. Although some previous studies show mechanistic proposals, some aspects still need to be investigated, such as the participation of 4-isobutylacetophenone in the ibuprofen degradation and the preferred regions of attack by OH˙ radicals. The photodegradation was satisfactory using 0.03 g of TiO2 and pH = 5.0, reaching 100% decontamination in 5 min. The zeta potential curve showed the regions of attraction and repulsion between TiO2 and ibuprofen, depending on the pH range and charge of the species, influencing the amount of by-products formed. Different by-products have been identified by GC-MS, such as 4-isobutylacetophenone. Ibuprofen conversion to 4-isobutylacetophenone takes place through decarboxylation reaction followed by oxidation. The proposed mechanism indicates that the degradation of ibuprofen undergoes a series of elementary reactions in solution and on the surface. Three different radicals (OH˙, O2 -˙ and OOH˙) are produced in the reaction sequence and contribute strongly to the oxidation and mineralization of ibuprofen and by-products, but the hydroxyl radical has a greater oxidation capacity. The simple study using the DFT approach demonstrated that the OH˙ radical attacks preferentially in the region of the ibuprofen molecule with high electronic density, which is located close to the aromatic ring (C[double bond, length as m-dash]C bond). The presence of the OH˙ radical was confirmed through a model reaction using salicylic acid as a probe molecule.

Evaluation of the Cyclic and Torsional Fatigue Resistance of Thermally Treated Hyflex CM versus Aurum Blue Nickel-titanium Rotary Instruments.

Introduction: We aim to evaluate the cyclic and torsional fatigue resistance of two rotary instruments, Hyflex CM 25/0.06 (HCM) (Coletene-Whaledent, Allstetten, Switzerland) and Aurum Blue (AB) 25/0.06 (Meta-Biomed, Republic of Korea). Methods and Materials: Forty rotary instruments, HCM 25/0.06 and AB 25/0.06 (n=20 each) were used. The instruments were rotated in an artificial stainless steel canal with a 60° angle and a 5-mm radius of curvature (n=10) at body temperature (35°±1°C). The torsional test evaluated the torque and angle of rotation at failure of new instruments (n=10) in the portion 3 mm from the tip according to ISO 3630-1. The fractured surface of each fragment was observed by scanning electron microscopy. The data were analyzed using unpaired student's t- test, and the level of significance was set at 5%. Results: AB 25/0.06 had significantly greater number of cycles to failure than HCM 25/0.06 (P<0.05). The torsional test showed there were no significant differences in the torsional strength and angular rotation to fracture between the groups (P>0.05). Conclusion: Based on this in vitro study, AB 25/0.06 instrument was more resistant to cyclic fatigue than the HCM 25/0.06 instrument, suggested that these instruments are safer than HCM 25/0.06 for the preparation of severely curved canals. However; there was no significant difference in the torsional properties of the two instruments then appear to have similar performance during constricted canal preparation.

The impact of the use of magnifying dental loupes on the performance of undergraduate dental students undertaking simulated dental procedures.

OBJECTIVES: This study aimed to evaluate the impact of the use of magnification (2.5x dental loupes) for third-year dental students in simulated endodontics and fixed prosthodontics assessments compared to those using no magnification. METHODS: Upon institutional review board exemption, third-year dental students were assessed during endodontics and fixed prosthodontics exams in the simulation laboratory. The endodontic group (n = 93) consisted of students who made an endodontic access preparation on a plastic lower left first molar (Nissan). The prosthodontic group (n = 86) consisted of students who made porcelain fused to metal preparation (PFM) on a plastic lower right first molar mounted on an acrylic lower jaw model (Columbia Dentoform). The impact of the use of dental loupes was evaluated. Assessment of the tasks was undertaken by experts-calibrated, blinded examiners-using a standardized marking rubric for each task. The statistical analysis included Chi-square test, one-way ANOVA, and Logistic regression. The level of significance adopted was 5%. RESULTS: Students' preparations using magnification were better compared with those without magnification. Students using magnification had a significantly higher pass rate than those not using magnification in both endodontic and prosthodontic groups (P < 0.05). CONCLUSIONS: In conclusion, third-year dental students who used loupes in the endodontics and prosthodontics simulation laboratory had significantly higher scores at the assessments.

Use of technology in endodontics by undergraduate dental students in a south-eastern state of Brazil.

INTRODUCTION: This study aimed to determine the level of incorporation of current technologies for endodontic treatment in undergraduate dentistry courses in a south-eastern state of Brazil. METHODS: For data collection, a self-assessment-based online questionnaire was created using the "Google Forms" platform, consisting of 12 multiple-choice and a few open-ended questions. The questions were related to the use of current technologies for diagnosis, imaging, use of ultrasonics in endodontics, instrumentation, use of apex locator, microscopy, photodynamic therapy and thermoplastic techniques during endodontic treatment. The questionnaire was sent to 54 dental schools in Minas Gerais. RESULTS: The results show low technological incorporation during the various stages of endodontic treatment by undergraduate students in dentistry courses in Minas Gerais. CONCLUSION: Despite the availability of several technologies to help perform different stages of endodontic treatment, it was observed that most universities do not teach the use of these technologies. Additional studies are needed to correlate how the lack of incorporation of these technologies could impact on the quality of the endodontic learning for undergraduate students.

Perfil de susceptibilidade aos carbapenêmicos de bacilos Gram-negativos fermentadores da glicose isolados de hemoculturas / Carbapenem susceptibility profile of Gram-negative glucose fermenting bacilli isolated from hemocultures

As Enterobacteriaceae são bactérias Gram-negativas e frequentes causadoras de infecções hospitalares. Os carbapenêmicos (CROs) são considerados as mais recentes linhas de defesa contra infecções por microrganismos multirresistentes, no entanto o desenvolvimento de bactérias multirresistentes a esta classe medicamentosa tem prejudicado o tratamento farmacológico. Nesse sentido, o presente estudo trata-se de uma análise retrospectiva, tendo como objetivo avaliar o perfil de resistência e susceptibilidade de bacilos Gram-negativos fermentadores da glicose aos carbapenêmicos em isolados de hemoculturas positivas no período de janeiro de 2018 a janeiro 2019. Das 5.733 hemoculturas realizadas nesse período, cerca de 5,4% (311 amostras) foram positivas. Dentre essas, 34,4% (107 amostras) positivas para enterobactérias e 65,6% (204 amostras) positivas para outras espécies. Foi observada uma maior incidência de Klebsiella pneumoniae (34,6% dos casos), seguido pela Klebsiella sp. (28,9%) e a Escherichia coli (26,2%). Contudo, três (03) isolados de hemocultura da espécie Klebsiella pneumoniae se mostraram resistentes aos três antibióticos (ertapenem, meropenem e imipenem). Dois isolados de Enterobacter cloaceae também obtiveram resistência aos antibióticos utilizados e uma espécie de Enterobacter aerogenes mostrou-se resistente apenas ao ertapenem e meropenem e sensibilidade ao imipenem.Enterobacteriaceae are Gram-negative bacteria and frequent causes hospital infections. Carbapenemic (CRO) are considered the latest lines of defense against infections by multidrug-resistant microorganisms, however the development of multidrug-resistant bacteria in this drug class has impaired treatment pharmacological. The present study is a retrospective analysis, with the objective of evaluating the resistance and susceptibility profile from isolates in blood cultures from January 2018 to January 2019, from positive blood cultures with enterobacteria growth and analysis of antibiograms performed from fermenter Gram-negative glucose bacilli to carbapenem antimicrobials. Of the 5,733 blood cultures performed from January 2018 to January 2019, about 5.4% (311 samples) were positive. Among these, 34.4% (107 samples) positive for enterobacteria and 65.6% (204 samples) for other species. A higher incidence of Klebsiella pneumoniae (34.6% of cases) was observed, followed by Klebsiella sp. (28.9%) and Escherichia coli (26.2%), however, three hemoculture isolates of the species Klebsiella pneumoniae, which were resistant to the three antibiotics (ertapenem, meropenem and imipenem). Two (2) isolates of Enterobacter cloaceae also obtained resistance to the antibiotics used and one (1) species of Enterobacter aerogenes proved resistant only to ertapenem and meropenem and sensitivity to imipenem.

As Enterobacteriaceae são bactérias Gram-negativas e frequentes causadoras de infecções hospitalares. Os carbapenêmicos (CROs) são considerados as mais recentes linhas de defesa contra infecções por microrganismos multirresistentes, no entanto o desenvolvimento de bactérias multirresistentes a esta classe medicamentosa tem prejudicado o tratamento farmacológico. Nesse sentido, o presente estudo trata-se de uma análise retrospectiva, tendo como objetivo avaliar o perfil de resistência e susceptibilidade de bacilos Gram-negativos fermentadores da glicose aos carbapenêmicos em isolados de hemoculturas positivas no período de janeiro de 2018 a janeiro 2019. Das 5.733 hemoculturas realizadas nesse período, cerca de 5,4% (311 amostras) foram positivas. Dentre essas, 34,4% (107 amostras) positivas para enterobactérias e 65,6% (204 amostras) positivas para outras espécies. Foi observada uma maior incidência de Klebsiella pneumoniae (34,6% dos casos), seguido pela Klebsiella sp. (28,9%) e a Escherichia coli (26,2%). Contudo, três (03) isolados de hemocultura da espécie Klebsiella pneumoniae se mostraram resistentes aos três antibióticos (ertapenem, meropenem e imipenem). Dois isolados de Enterobacter cloaceae também obtiveram resistência aos antibióticos utilizados e uma espécie de Enterobacter aerogenes mostrou-se resistente apenas ao ertapenem e meropenem e sensibilidade ao imipenem.

Antimicrobial photodynamic therapy and guided endodontics: A case report.

A 35-year-old woman with a history of pulp canal obliteration (PCO) and apical periodontitis was treated with guided endodontics combined with antimicrobial photodynamic therapy (aPDT). The use of aPDT was paramount to the approach performed, and its application should be encouraged in cases of severely calcified canals when apical patency is unachievable. The combination of these techniques ensured successful clinical, radiographic, and tomographic outcomes at the 1-year follow-up. Key Words: Antimicrobial PDT, guided endodonics, periodontitis, pulp canal obliteration.

Quantitative Assessment of the Efficacy of Two Different Single-file Systems in Reducing the Bacterial load in Oval-Shaped Canals: A Clinical Study.

INTRODUCTION: This randomized clinical study compared the in vivo antibacterial efficacy of Reciproc Blue (RB), XP-endo Shaper (XP-S), and XP-endo Shaper associated with XP-endo Finisher (XP-F) systems in infected oval-shaped root canals with primary apical periodontitis. METHODS: In this study, 28 human teeth with a single root and a single canal were randomly assigned to 2 groups according to the instrumentation technique: group 1, RB (n = 14) and group 2, XP-endo (XP-S and XP-F, n = 14). The single-rooted teeth were prepared by reciprocating and rotary nickel-titanium instruments with 5.25% sodium hypochlorite irrigation. Samples were collected from the canal at the baseline (S1), after chemomechanical preparation (S2), and after XP-F instrumentation (S3). The DNA extracts were subjected to quantitative analysis for total bacterial counts by quantitative real-time polymerase chain reaction. The data were analyzed using the analysis of variance test, and the level of significance was set at 5%. RESULTS: All samples tested positive for the presence of bacteria at baseline, and the bacterial counts substantially reduced after treatment procedures (P < .01). The results showed no statistical difference between RB and XP-S instrumentation with respect to the bacterial reduction (P > .05). A marked bacterial reduction was observed after the use of the XP-F instrument (P < .01). CONCLUSIONS: The XP-S and RB systems sharply reduced the bacterial load in oval-shaped root canals with primary apical periodontitis. XP-F used as a supplementary instrument to chemomechanical preparation promoted a significantly higher bacterial reduction.

Synthesis of Fe2SiO4-Fe7Co3 Nanocomposite Dispersed in the Mesoporous SBA-15: Application as Magnetically Separable Adsorbent.

The mixture containing alloy and oxide with iron-based phases has shown interesting properties compared to the isolated species and the synergy between the phases has shown positive effect on dye adsorption. This paper describes the synthesis of Fe2SiO4-Fe7Co3-based nanocomposite dispersed in Santa Barbara Amorphous (SBA)-15 and its application in dye adsorption followed by magnetic separation. Thus, it was studied the variation of reduction temperature and amount of hydrogen used in synthesis and the effect of these parameters on the physicochemical properties of the iron and cobalt based oxide/alloy mixture, as well as the methylene blue adsorption capacity. The XRD and Mössbauer results, along with the temperature-programmed reduction (TPR) profiles, confirmed the formation of Fe2SiO4-Fe7Co3-based nanocomposites. Low-angle XRD, N2 isotherms, and TEM images show the formation of the SBA-15 based mesoporous support with a high surface area (640 m2/g). Adsorption tests confirmed that the material reduced at 700 °C using 2% of H2 presented the highest adsorption capacity (49 mg/g). The nanocomposites can be easily separated from the dispersion by applying an external magnetic field. The interaction between the dye and the nanocomposite occurs mainly by π-π interactions and the mixture of the Fe2SiO4 and Fe7Co3 leads to a synergistic effect, which favor the adsorption.

O uso do microscópio operatório associado aos novos recursos na microcirurgia parendodôntica moderna / The use of the operating microscope associated with the new resources in modern endodontic microsurgery

Introdução: mesmo quando um tratamento endodôntico ou retratamento mais rigoroso é realizado, a periodontite apical pode persistir, levando à destruição do ligamento periodontal, cemento, osso alveolar e dentina. Nesses casos, o tratamento endodôntico cirúrgico, se realizado com o microscópio operatório (MO), ressecção mínima da raiz, retropreparo com pontas ultrassônicas e materiais para retrobturação biocompatíveis, pode alcançar mais de 90% de sucesso. Os procedimentos endodônticos cirúrgicos foram completamente transformados pela incorporação do MO, associado a novos recursos como aparelhos de ultrassom piezocirúrgico com pontas específicas para microcirurgia, microespelhos flexíveis, microexploradores, microcuretas endodônticas, microcondensadores e microinstrumentos para sutura. O MO pode otimizar todas as etapas de uma microcirurgia parendodôntica, incluindo o descolamento do retalho, a osteotomia, identificação do ápice radicular, apicectomia, remoção de tecido inflamatório, observação da superfície remanescente da raiz, retropreparo, obturação retrógrada e sutura. Objetivo: o objetivo do presente artigo é apresentar todos os passos da microcirurgia parendodôntica moderna e descrever os novos recursos disponíveis no mercado para melhorar a taxa de sucesso dessa modalidade. Conclusão: o uso de técnicas modernas de microcirurgia parendodôntica melhora significativamente as taxas de sucesso da terapia, quando comparada às técnicas tradicionais.

Targeting autophagy by small molecule inhibitors of vacuolar protein sorting 34 (Vps34) improves the sensitivity of breast cancer cells to Sunitinib.

Resistance to chemotherapy is a challenging problem for treatment of cancer patients and autophagy has been shown to mediate development of resistance. In this study we systematically screened a library of 306 known anti-cancer drugs for their ability to induce autophagy using a cell-based assay. 114 of the drugs were classified as autophagy inducers; for 16 drugs, the cytotoxicity was potentiated by siRNA-mediated knock-down of Atg7 and Vps34. These drugs were further evaluated in breast cancer cell lines for autophagy induction, and two tyrosine kinase inhibitors, Sunitinib and Erlotinib, were selected for further studies. For the pharmacological inhibition of autophagy, we have characterized here a novel highly potent selective inhibitor of Vps34, SB02024. SB02024 blocked autophagy in vitro and reduced xenograft growth of two breast cancer cell lines, MDA-MB-231 and MCF-7, in vivo. Vps34 inhibitor significantly potentiated cytotoxicity of Sunitinib and Erlotinib in MCF-7 and MDA-MB-231 in vitro in monolayer cultures and when grown as multicellular spheroids. Our data suggests that inhibition of autophagy significantly improves sensitivity to Sunitinib and Erlotinib and that Vps34 is a promising therapeutic target for combination strategies in breast cancer.