Effects of Glide Path on the Centering Ability and Preparation Time of Two Reciprocating Instruments

Introduction: The aim of this in vitro study was to evaluate the effects of establishing glide path on the centering ability and preparation time of two single-file reciprocating systems in mesial root canals of mandibular molars. Methods and Materials: Sixty extracted mandibular molars with curvatures of 25-39 degrees and separate foramina for the mesiobuccal and mesiolingual canals, were divided into four groups (n=15); WaveOne+glide path; WaveOne; Reciproc+glide path and Reciproc. Non-patent canals were excluded and only one canal in each tooth was instrumented. A manual glide path was established in first and third groups with #10, 15 and 20 hand K-files. Preparation was performed with reciprocating in-and-out motion, with a 3-4 mm amplitude and slight apical pressure. Initial and final radiographs were taken to analyze the amount of dentin removed in the instrumented canals. The radiographs were superimposed with an image editing software and examined to assess discrepancies at 3-, 6- and 9-mm distances from the apex. The Kruskal-Wallis test was used for statistical analysis. The level of significance was set at 0.05. Results: Preparation in groups without glide paths was swifter than the other groups (P=0.001). However, no difference was observed regarding centering ability. Conclusion: Establishing a glide path increased the total instrumentation time for preparing curved canals with WaveOne and Reciproc instruments. Glide path had no influence on the centering ability of these systems.Keywords: Centering Ability; Glide Path; Reciproc; Root Canal Preparation; Single-File Instrumentation; WaveOn

Irrigant Agitation Techniques versus Passive Ultrasonic Irrigation for Removing Debris from Curved Root Canals: An Environmental Scanning Electron Microscopic Study

Introduction: The aim of this study was to compare the efficacy of passive ultrasonic irrigation (PUI) versus mechanical agitation of the irrigant promoted by the EasyClean (EC) and XP-Endo Finisher (XP-F) systems in removing debris from root canal walls, using environmental scanning electron microscopy (ESEM). Methods and Materials: Twelve curved mesiobuccal canals of mandibular molars were prepared with the ProTaper Next system up to file X2 (25/0.06). The specimens were embedded in flasks containing silicone putty, sectioned lengthwise, and a 4-mm long groove was made on the canal wall of the buccal half of the specimen, extending from 2 mm up to 6 mm short of the apex. Five cross-sectional markings were made along this groove to establish standardized locations for imaging. The same specimens were used to prepare a negative control group (without debris), a positive control group (completely covered by debris), and 3 experimental groups according to the final irrigation protocol employed: PUI, EC or XP-F. ESEM images were obtained and evaluated by 3 examiners. The amount of debris observed on the images was classified according to a 4-category scoring system. The kappa test was used to assess inter-examiner agreement, and the Kruskal-Wallis and Dunn tests were used to compare the scores (P<0.05). Results: The scores attributed to the PUI, EC, and XP-F groups were statistically similar to those attributed to the negative control group (P>0.05). Conclusion: Based on this in-vitro study, the mechanical agitation of the irrigant promoted by EC and XP-F was as effective as using PUI to remove debris from the root canal walls

Effectiveness of Sodium Hypochlorite plus EDTA Compared with Peracetic Acid in Removing Smear Layer and Killing Enterococcus faecalis

Introduction: The aim of this study was to evaluate the effectiveness of 2.5% sodium hypochlorite associated with 17% Ethylenediaminetetraacetic acid (NaOCl-EDTA), versus that of 1% peracetic acid (PA), in removing the smear layer, as assessed by scanning electron microscopy (SEM), and in exerting bactericidal action against Enterococcus faecalis (E. faecalis), as assessed by the real-time polymerase chain reaction (real-time PCR). Methods and Materials: Fifty-five extracted mandibular single-rooted premolars were selected, and divided into two experimental groups (NaOCl-EDTA and PA; n=25) and one control group (0.9% saline; n=5). Pre- and post-instrumentation samples were collected and assessed for the presence of E. faecalis using real-time PCR. The teeth were instrumented using hand files and the ProTaper Universal system (hybrid technique) for a standardized time of 7 min. A total of 20 mL of NaOCl followed by 5 mL of EDTA were applied during instrumentation in the NaOCl-EDTA group, whereas 20 mL of PA and 20 mL of saline were applied in the PA and control groups, respectively. An additional 5 mL of saline was applied in all the groups to neutralize the environment. A scoring system was used to conduct the SEM assessment. The results were submitted to the Kruskal-Wallis test, complemented by Dunn's test (SEM analysis) (P<0.05). Results: A significant microbial reduction was observed in both the PA and the NaOCl-EDTA groups (P<0.05). In the PA group, the presence of a smear layer in the apical third was significantly greater than in the cervical third (P<0.05); no significant differences were observed between the middle and cervical thirds, or between the middle and apical thirds (P>0.05). In the NaOCl-EDTA group, the smear layer scores were significantly higher in the apical third than in the cervical and middle thirds (P<0.05). Conclusion: This in vitro study showed that there was no significant difference between PA and NaOCl-EDTA irrigation regimens regarding either antimicrobial action against E. faecalis or removal of the smear layer, except for greater removal in the middle third by the NaOCl-EDTA group.Keywords: Endodontic Irrigation; Enterococcus faecalis; Peracetic Acid; Real-Time Polymerase Chain Reaction; Sodium Hypochlorite

Root Fracture Resistance of Maxillary Premolars Obturated with Three Root Canal Sealers after Passive Ultrasonic Irrigation: An in Vitro study

Introduction: Maxillary premolars, may be more susceptible to fracture due to their anatomy; especially when there is loss of tooth structure. Therefore, it is necessary to evaluate materials and techniques that may increase fracture resistance during and post root canal treatment. This in vitro study aimed to evaluate root fracture resistance of maxillary premolars when filled with three root canal sealers as well as whether this resistance would be increased by passive ultrasonic irrigation (PUI). Methods and Materials: Sixty-four maxillary premolars with two roots were randomly divided into one negative control group (intact canals; n=8), one positive control group (instrumented, unsealed canals; n=8), and six experimental groups (n=8), which were instrumented with ProTaper Next rotary system up to X2 file and subdivided according to final irrigation (with or without PUI) and type of sealer used (AH-Plus [AH], MTA Fillapex [MTA], or EndoSequence BC Sealer [ES]). The specimens were subjected to fracture strength test in a universal testing machine at a speed of 1 mm/min until fracture. The maximum force required to induce fracture was recorded (N).  Results: The lowest force required to cause root fracture was observed in the positive control group (310.48±54.08 N); this was significantly different from the other groups (P<0.05). There was no significant difference between experimental groups obturated with the same sealer, whether with or without PUI (AH with PUI: 558.80±87.12 N; AH without PUI: 508.75±97.55 N; MTA with PUI: 507.27±174.55 N; MTA without PUI: 516.69±96.56 N; ES with PUI: 526.76±143.97 N; ES without PUI: 628.40 ± 94.74 N) (P>0.05). There was also no significant difference between the experimental groups and the negative control group (P>0.05). Conclusions: In this in vitro study PUI did not increase the fracture resistance of maxillary premolars, while AH Plus, MTA Fillapex, EndoSequence sealers increased fracture resistance of instrumented root canals

Comparison of the effectiveness of the protaper system versus hand instrumentation in endodontic retreatment: a scanning electron microscopy study

Abstract Introduction: Several rotary systems have been evaluated for removal of endodontic filling materials from the canal. Moreover, studies focusing on the comparison of the effectiveness of rotary systems versus hand instrumentation have yielded mixed results in terms of the efficacy and amount of time required by each technique. Objective: To compare the effectiveness of a nickel-titanium rotary system and of hand instrumentation using stainless steel files and Gates-Glidden burs in the removal of gutta-percha from root canals, as well as the time required to complete the procedure by each method. Material and methods: Forty single-rooted teeth were prepared and obturated then divided in two groups, according to the method employed for removal of the gutta-percha: ProTaper Universal rotary retreatment system (rotary instrumentation) and stainless steel hand files with Gates-Glidden burs (hand instrumentation). The time required to remove gutta-percha by each method was recorded. Roots were then sectioned lengthwise and the apical, middle, and coronal thirds were analyzed by SEM under two magnifications: x400 an

Correlation between Histopathological Findings and Results of Direct Immunofluorescence in the Diagnosis of Canine Localized Cutaneous Chronic Lupus Erythematosus

Background: Localized chronic cutaneous lupus erythematosus (CCLE), also known as discoid lupus erythematosus, is one of the most prevalent canine autoimmune skin diseases. Histopathology is considered the gold standard for the diagnosis of CCLE and the accuracy of which can be increased by use of direct immunofluorescence (DIF). This study aimed to investigate the fluorescence pattern revealed by DIF in cases of canine localized CCLE and to establish and compare its effectiveness with that obtained from histopathology.Materials, Methods & Results: Eleven dogs suspicious to localized CCLE, i.e., those animals that presented mucocutaneous lesions as erythema, leucoderma, erosive-ulcerative lesions, and loss of nasal planum architecture and its transition to the haired skin underwent medical physical and laboratory examinations (blood count, platelet count, determination of alanine transaminase, alkaline phosphatase, total protein, serum albumin, urea, creatinine). Only those animals that proved to be normal across both the physical and laboratorial evaluation were included in Group I. Animals belonging to this group were submitted to general anesthesia to biopsy two samples of lesioned skin from nasal planum to histopathologic examination and DIF test. Five dogs with no skin lesions were included in Group II as negative control to the DIF assay. Two samples of no lesioned skin from nasal planum were biopsied to histopathologic and DIF evaluation. The kappa (k) coefficient was used to determine the degree of agreement and reliability of the results of both tests. A P-value < 5% was considered to be statistically significant. In Group I, all animals were normal across both the physical and laboratorial evaluation. A diagnosis of canine CCLE was established in 81.8% (9/11) of the animals based on histopathology analysis. Two dogs, numbers 10 and 11, respectively, had histopathologic findings suggestive of cutaneous leishmaniasis and compatible with canine demodicosis. The DIF assay confirmed the diagnostic of canine CCLE in 100% (11/11) of the cases, including dogs numbers 10 and 11. Direct immunofluorescence positivity for canine localized CCLE was determined by the presence of homogeneous green fluorescence in the basement membrane zone, with IgM and C3 immunoreagents being found at a significantly higher frequency (P = 0.007) than IgA and IgG (P = 0.017 and P = 0.037, respectively). In Group II, no alterations from histopathologic examination and unspecific fluorescence from DIF reaction were shown in all animals belonging to this group. A substantial and significant degree of agreement or reliability (k = 0.738 and P = 0.002, respectively) was established between the results of both tests.Discussion: In veterinary medicine, there is a lack of studies about DIF around autoimmune dermatoses. This is the first manuscript comparing histopathological and direct immunofluorescence findings in the diagnostic of dogs with localized CCLE. In the present study, the positivity to the DIF assay for canine localized CCLE was established by the presence of green fluorescence of a homogeneous morphologic pattern, especially for IgM and C3, located in the BMZ and cutaneous annexes. Direct immunofluorescence excluded the suspicion of cutaneous leishmaniasis determined by the histopathological findings and confirmed the diagnostic of canine localized CCLE in the dog number 10. Statistically, a substantial degree of agreement and reliability was shown between DIF and histopathology. Therefore, we concluded that the DIF assay is a highly effective and useful complementary examination that improves our ability to diagnose canine CCLE

Leptin’s and antigen-presenting cells’ functions in periodontitis – an overview / Leptin e as funções das células que apresentam antigénios na periodontite - uma visão geral

Leptin is a hormone synthesized predominantly by white adipose tissue. Its production levels are directly proportional to the total mass of this tissue in an individual’s body. Apart from its classic role in the regulation of hunger and satiety, it also plays an important part in scenarios involving innate and adaptive immune responses. It has been discovered that leptin levels are altered in a variety of inflammatory responses, such as periodontitis, a condition which derives from a persistent inflammatory immune response from a host facing bacterial infection. The initial trigger for this reaction is the recognition of the pathogens by antigen presenting cells, such as macrophages and dendritic cells, whose actions can be influenced by leptin. This review aims to present the relationship between leptin, dendritic cells and macrophages in the context of periodontal disease. Thus, we have assembled the most important findings related to leptin’s role in the modulation of the immune response carried out by these cells in periodontitis

Bothrops jararaca Peptide with Anti-Hypertensive Action Normalizes Endothelium Dysfunction Involved in Physiopathology of Preeclampsia

Preeclampsia, a pregnancy-specific syndrome characterized by hypertension, proteinuria and edema, is a major cause of fetal and maternal morbidity and mortality especially in developing countries. Bj-PRO-10c, a proline-rich peptide isolated from Bothrops jararaca venom, has been attributed with potent anti-hypertensive effects. Recently, we have shown that Bj-PRO-10c-induced anti-hypertensive actions involved NO production in spontaneous hypertensive rats. Using in vitro studies we now show that Bj-PRO-10c was able to increase NO production in human umbilical vein endothelial cells from hypertensive pregnant women (HUVEC-PE) to levels observed in HUVEC of normotensive women. Moreover, in the presence of the peptide, eNOS expression as well as argininosuccinate synthase activity, the key rate-limiting enzyme of the citrulline-NO cycle, were enhanced. In addition, excessive superoxide production due to NO deficiency, one of the major deleterious effects of the disease, was inhibited by Bj-PRO-10c. Bj-PRO-10c induced intracellular calcium fluxes in both, HUVEC-PE and HUVEC, which, however, led to activation of eNOS expression only in HUVEC-PE. Since Bj-PRO-10c promoted biological effects in HUVEC from patients suffering from the disorder and not in normotensive pregnant women, we hypothesize that Bj-PRO-10c induces its anti-hypertensive effect in mothers with preeclampsia. Such properties may initiate the development of novel therapeutics for treating preeclampsia

Bothrops jararaca Peptide with Anti-Hypertensive Action Normalizes Endothelium Dysfunction Involved in Physiopathology of Preeclampsia

Preeclampsia, a pregnancy-specific syndrome characterized by hypertension, proteinuria and edema, is a major cause of fetal and maternal morbidity and mortality especially in developing countries. Bj-PRO-10c, a proline-rich peptide isolated from Bothrops jararaca venom, has been attributed with potent anti-hypertensive effects. Recently, we have shown that Bj-PRO-10c-induced anti-hypertensive actions involved NO production in spontaneous hypertensive rats. Using in vitro studies we now show that Bj-PRO-10c was able to increase NO production in human umbilical vein endothelial cells from hypertensive pregnant women (HUVEC-PE) to levels observed in HUVEC of normotensive women. Moreover, in the presence of the peptide, eNOS expression as well as argininosuccinate synthase activity, the key rate-limiting enzyme of the citrulline-NO cycle, were enhanced. In addition, excessive superoxide production due to NO deficiency, one of the major deleterious effects of the disease, was inhibited by Bj-PRO-10c. Bj-PRO-10c induced intracellular calcium fluxes in both, HUVEC-PE and HUVEC, which, however, led to activation of eNOS expression only in HUVEC-PE. Since Bj-PRO-10c promoted biological effects in HUVEC from patients suffering from the disorder and not in normotensive pregnant women, we hypothesize that Bj-PRO-10c induces its anti-hypertensive effect in mothers with preeclampsia. Such properties may initiate the development of novel therapeutics for treating preeclampsia

Potential Polyunsaturated Aldehydes in the Strait of Gibraltar under Two Tidal Regimes

Diatoms, a major component of the large-sized phytoplankton, are able to produce and release polyunsaturated aldehydes after cell disruption (potential PUAs or pPUA). These organisms are dominant in the large phytoplankton fraction (>10 μm) in the Strait of Gibraltar, the only connection between the Mediterranean Sea and the Atlantic Ocean. In this area, the hydrodynamics exerts a strong control on the composition and physiological state of the phytoplankton. This environment offers a great opportunity to analyze and compare the little known distribution of larger sized PUA producers in nature and, moreover, to study how environmental variables could affect the ranges and potential distribution of these compounds. Our results showed that, at both tidal regimes studied (Spring and Neap tides), diatoms in the Strait of Gibraltar are able to produce three aldehydes: Heptadienal, Octadienal and Decadienal, with a significant dominance of Decadienal production. The PUA released by mechanical cell disruption of large-sized collected cells (pPUA) ranged from 0.01 to 12.3 pmol from cells in 1 L, and from 0.1 to 9.8 fmol cell−1. Tidal regime affected the abundance, distribution and the level of physiological stress of diatoms in the Strait. During Spring tides, diatoms were more abundant, usually grouped nearer the coastal basin and showed less physiological stress than during Neap tides. Our results suggest a significant general increase in the pPUA productivity with increasing physiological stress for the cell also significantly associated to low nitrate availability