Impact of Calcium-Hydroxide, Sodium Ascorbate, and Sodium Thiosulphate on Bond Strength of Composite Restorations to Bleached Dentin.

This study evaluated the impact of using calcium-hydroxide or the antioxidant agents on the bond strength of adhesive restorations to bleached dentin. Forty teeth were prepared and allocated into 8 groups according to the surface treatment after bleaching (application or not of calcium hydroxide, 10% sodium ascorbate and 5% sodium thiosulphate for 10min), and the time of final restoration (immediate or after 7-days). Sodium perborate with 20% hydrogen peroxide was applied for 3 weeks using a developed artificial pulp chamber, with replacement every week. Composite resin restoration was performed and microtensile test was performed. Then, specimens were analyzed using a stereomicroscope and SEM. Data was submitted to Kruskal-Wallis and Dunn tests (p<0.05). The bond strength of non-bleached teeth was similar to the groups restored after 7 days of bleaching (p<0.05). The lowest values of bond strength were showed by groups restored immediately after bleaching (p<0.05). In all groups, there was a considerable predominance of adhesive fractures. Delaying the final restoration of teeth submitted to nonvital bleaching for 7 days permits an increase in bond strength. The immediate restoration of bleached teeth after the use of 10% sodium ascorbate or 5% sodium thiosulfate for 10 minutes showed unsatisfactory results. Clinical relevance Irrespective of the dentin protocol applied before adhesion, a satisfactory and an unsatisfactory result of bond strength values will be obtained delaying the final restoration or immediately performing the final restoration, respectively. Therefore, after nonvital tooth bleaching, clinicians should always delay the final restoration for a minimum period of 7 days.

Development of nanobiosilicate, tricalcium phosphate and chlorhexidine materials for biomineralization with crystallographic similarity to hydroxyapatite and biomodified collagen.

OBJECTIVES: The aim of this work is to test experimental cements, doped with a silicate based bioactive nanoparticle (NanoBiosilicate). Methods, we synthesized a glass nanoparticle by Sol-Gel Stöber method, used to be incorporated in a dental material for endodontic uses. MATERIALS AND METHODS: We assess the mineralizing properties and biocompatibility. Besides the crystallography characterization of the resultant new crystals. Results, After analysis, and comparison with commercial materials, the material tested was similar in mechanical properties required by ISO, The ion release was effective after 2 hr. of setting and the novel material was cell compatible accepted by ISO. RESULTS: We found new formed Calcium Phosphate peaks in the spectroscopic analysis (FTIR), remarkably the crystals formed were comparable to hydroxyapatite when analyzed with a Selected Area Electron Diffractometer, with rings of 2.84 Å for 002, and the 2.77 Å is also visible for 210. The 6.83 Å and 6.88 Å, for respective 222 and 004. The incorporation of Chlorhexidine was not detrimental for this property, Significance, the features mentioned represented a progress in biomineralization field that was associated to an improved mineral structure formation with increased crystallographic similarity to natural hydroxyapatite. When chlorhexidine was added a favorable biomodification of the remaining collagen in dentinal walls and antimicrobial activity potential were also observed.

Curcumin Modifies the Activity of Plasmatic Antioxidant Enzymes and the Hippocampal Oxidative Profile in Rats upon Acute and Chronic Exposure to Ozone.

Ozone (O3) is an oxidating tropospheric pollutant. When O3 interacts with biological substrates, reactive oxygen and nitrogen species (RONS) are formed. Severe oxidative damage exhausts the endogenous antioxidant system, which leads to the decreased activity of antioxidant enzymes such as catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD). Curcumin (CUR) is a natural polyphenol with well-documented antioxidant and anti-inflammatory properties. The aim of this work is to evaluate the effects of curcumin on CAT, GPx, and SOD activity and the inhibition of oxidative damage after the acute and chronic exposure to O3. Fifty male Wistar rats were divided into five experimental groups: the intact control, CUR-fed control, exposed-to-O3 control, CUR-fed (preventive), and CUR-fed (therapeutic) groups. These two last groups received a CUR-supplemented diet while exposed to O3. These experiments were performed during acute- and chronic-exposure phases. In the preventive and therapeutic groups, the activity of plasma CAT, GPx, and SOD was increased during both exposure phases, with slight differences; concomitantly, lipid peroxidation and protein carbonylation were inhibited. For this reason, we propose that CUR could be used to enhance the activity of the antioxidant system and to diminish the oxidative damage caused by exposure to O3.

Do non-clinical subjective factors influence the treatment decisionmaking of Brazilian dentists?

The literature contains little information on several non-clinical factors such as the association between graduate residency programs and the application of minimally invasive dentistry, or on dentists' clinical decision-making processes for replacing restorations for esthetic reasons. This study evaluated whether non-clinical subjective factors influence the treatment decisions made by Brazilian dentists regarding technical and esthetic matters. Dentists were invited to participate in a cross-sectional survey by answering an electronic questionnaire containing clinical cases, regarding what treatment they would select for: T1 - a molar tooth with significant crown destruction and spontaneous pain, and T2 - premolar teeth with extensive amalgam restorations and no carious lesion or associated complaint. The survey also included questions about subjective variants (sociodemographic and professional). Chi Square test and Fischer's Exact test were used toanalyzetheanswers to T1, and one-factor analysis of variance and post-hoc Tamhane were applied to T2. The significance level was set at 5% for all analyses. A total 302 professionals participated in the study. For T1, it was found that clinical decision-making was influenced by the Brazilian region of clinical practice (p=0.005). For T2, a significant association was found between increased loss of patient tooth tissues and whether the professional had completed a residency program in Operative Dentistry (p=0.035), worked in a private practice (p=0.033), or if most of his/her patients belonged to a high estimated socioeconomic level (household income above $4350) (p=0.002). In conclusion, the clinical decision-making of Brazilian dentists varies according to professional profile, mainly with relation to the replacement of restorations due to esthetic concerns.

Vários fatores não clínicos, como a associação entre programas de especialização e a aplicação da odontologia minimamente invasiva, ainda são escassos na literatura. Outro aspecto relevante é a tomada de decisão clínica do dentista quanto à substituição de restaurações em função da aparência estética. Este estudo avaliou se fatores subjetivos não clínicos influenciam na tomada de decisão clínica de dentistas brasileiros com base em questões técnicas e estéticas. Foi realizado um estudo transversal com um questionário eletrônico contendo casos clínicos que foram apresentados a uma lista de profissionais. No questionário, interrogou-se o tratamento proposto para um dente molar com destruição coronária significativa e dor espontânea (T1). Também foi questionado o tratamento proposto para dentes prémolares com extensas restaurações de amálgama e sem lesão cariosa ou queixas associadas (T2). Em seguida, foram questionadas as variantessubjetivas(sociodemográfica eprofissional). Na análise de T1, foram utilizados os testes Qui Quadrado e Exato de Fischer. Em T2, foi aplicada a análise de variância de um fator e post-hoc Tamhane. Para todas as análises, o nível de significância foi estabelecido em 5%. Um total de 302 profissionais participaram deste estudo. A tomada de decisão clínica para T1 foi influenciada pela região brasileira de prática clínica (p = 0,005). Em T2, realizar especialização em Dentística Operatória (p = 0,035), trabalhar em consultório particular (p = 0,033) e a maioria dos pacientes apresentar nível socioeconômico estimado elevado (renda familiar acima de R$10.000,00) (p = 0,002) aumentou significativamente a perda de tecidos dentários. Em conclusão, a tomada de decisão clínica dos dentistas brasileiros varia de acordo com o perfil dos profissionais, principalmente no que se refere à substituição de restaurações por questões estéticas.

Do non-clinical subjective factors influence the treatment decisionmaking of Brazilian dentists? / Fatores subjetivos não clínicos influenciam na tomada de decisão do tratamento de cirurgiões-dentistas brasileiros?

ABSTRACT The literature contains little information on several non-clinical factors such as the association between graduate residency programs and the application of minimally invasive dentistry, or on dentists' clinical decision-making processes for replacing restorations for esthetic reasons. This study evaluated whether non-clinical subjective factors influence the treatment decisions made by Brazilian dentists regarding technical and esthetic matters. Dentists were invited to participate in a cross-sectional survey by answering an electronic questionnaire containing clinical cases, regarding what treatment they would select for: T1 - a molar tooth with significant crown destruction and spontaneous pain, and T2 - premolar teeth with extensive amalgam restorations and no carious lesion or associated complaint. The survey also included questions about subjective variants (sociodemographic and professional). Chi Square test and Fischer's Exact test were used to analyze the answers to T1, and one-factor analysis of variance and post-hoc Tamhane were applied to T2. The significance level was set at 5% for all analyses. A total 302 professionals participated in the study. For T1, it was found that clinical decision-making was influenced by the Brazilian region of clinical practice (p=0.005). For T2, a significant association was found between increased loss of patient tooth tissues and whether the professional had completed a residency program in Operative Dentistry (p=0.035), worked in a private practice (p=0.033), or if most of his/her patients belonged to a high estimated socioeconomic level (household income above $4350) (p=0.002). In conclusion, the clinical decision-making of Brazilian dentists varies according to professional profile, mainly with relation to the replacement of restorations due to esthetic concerns.

RESUMO Vários fatores não clínicos, como a associação entre programas de especialização e a aplicação da odontologia minimamente invasiva, ainda são escassos na literatura. Outro aspecto relevante é a tomada de decisão clínica do dentista quanto à substituição de restaurações em função da aparência estética. Este estudo avaliou se fatores subjetivos não clínicos influenciam na tomada de decisão clínica de dentistas brasileiros com base em questões técnicas e estéticas. Foi realizado um estudo transversal com um questionário eletrônico contendo casos clínicos que foram apresentados a uma lista de profissionais. No questionário, interrogou-se o tratamento proposto para um dente molar com destruição coronária significativa e dor espontânea (T1). Também foi questionado o tratamento proposto para dentes prémolares com extensas restaurações de amálgama e sem lesão cariosa ou queixas associadas (T2). Em seguida, foram questionadas as variantes subjetivas (sociodemográfica e profissional). Na análise de T1, foram utilizados os testes Qui Quadrado e Exato de Fischer. Em T2, foi aplicada a análise de variância de um fator e post-hoc Tamhane. Para todas as análises, o nível de significância foi estabelecido em 5%. Um total de 302 profissionais participaram deste estudo. A tomada de decisão clínica para T1 foi influenciada pela região brasileira de prática clínica (p = 0,005). Em T2, realizar especialização em Dentística Operatória (p = 0,035), trabalhar em consultório particular (p = 0,033) e a maioria dos pacientes apresentar nível socioeconômico estimado elevado (renda familiar acima de R$10.000,00) (p = 0,002) aumentou significativamente a perda de tecidos dentários. Em conclusão, a tomada de decisão clínica dos dentistas brasileiros varia de acordo com o perfil dos profissionais, principalmente no que se refere à substituição de restaurações por questões estéticas.

Age and experience with dental operating microscope: Do these factors influence on the post space preparation and adhesion of glass fiber posts?

This study evaluated the influence of operator's age and experience with dental operating microscope (DOM) on the cleaning of post space walls and on bond strength of glass fiber posts associated with self-adhesive resin cement. Sixty bovine roots were selected. Root canal preparation was performed and roots were filled using gutta-percha/AH Plus. For post space preparation, specimens were divided into four groups (n = 15), according to operator's age and the use of DOM: (1) ≥40 years; (2) ≥40 years with magnification; (3) <40 years; (4) <40 years with magnification. Next, a high-speed bur of the post system and torque-controlled round burs were used for cleaning of post space. Five roots in each group were evaluated for the degree of cleanliness under a stereo microscope using a scoring system. In the remaining 10 specimens from each group, glass fiber posts were cemented with RelyX U200. Two slices (1 ± 0.1 mm) prepared on each root third of all specimens were evaluated by push-out analysis. The scoring system was analyzed using Kruskal-Wallis and push-out data using ANOVA. Significance level was set at 5%. No significant difference was observed in cleaning scores among groups (p > .05). There was no significant difference when comparing the groups and the root thirds (p > .05). The adhesive failure between dentin, cement, and post predominated in all groups. Operator's age and experience with DOM did not influence the cleanliness of root canal walls or the bond strength of glass fiber posts associated with self-adhesive resin cement for post space preparation. RESEARCH HIGHLIGHTS: Although magnification is considered part of Endodontics, little is known about the variables associated. Operator's age and experience with microscope on cleaning of canals and on push-out of posts with self-adhesive resin cement were evaluated.

The sand fly (Diptera: Psychodidae) fauna of the urban area of Lassance, Northeast Minas Gerais, Brazil.

The present study aimed to check the sand flies' fauna on the municipality of Lassance, Minas Gerais, Brazil and detect the presence of Leishmania DNA on the female captured and determine the risk areas of the municipality. Sand flies were collected monthly from May 2018 to April 2019 using automatic light traps for 3 consecutive nights. Eight houses were selected as sample points due its previous reports of tegumentary leishmaniasis and/or canine leishmaniasis. The sand fly's fauna found on the present study it's represented by several medical importance species and the most abundant species found were Lutzomyia longipalpis (77.09%) and Nyssomyia intermedia (10.06%). Leishmania infantum DNA was detected in a pool of Lu. longipalpis resulting on a 2.81% of infection rate. By the frequency of the two most abundant species on this study, we developed a risk area map and it draws attention to sample point 6 due to disparate abundance of sand flies at this site (81.81%). Statistical overview shows Lu. longipalpis as dominant species and, still, Non-Metric Multidimensional Scaling analysis reveal high similarity on fauna's diversity on the study area. Our findings suggest that the diversity of sand flies from the municipality of Lassance may promote the circulation of Leishmania infantum parasites putting in risk the habitants and other mammal's species. Still, our study reinforces the necessity of specific studies focused on breed sites of phlebotomine and its' ecology to expand the knowledge about the behaviour of this group of insects applying directly to leishmaniases' epidemiology.

Epidermal Growth Factor Is Associated with Loss of Mucosae Sealing and Peri-Implant Mucositis: A Pilot Study.

This study aimed to evaluate the correlation between epidermal growth factor (EGF) and receptor (EGFR) levels in different clinical stages of dental implant rehabilitation and trace mucositis development's biological profile. Thirty-six participants from the Specialization in Implant Dentistry, Universidade Federal Fluminense, Brazil, were included in the study and underwent sample collection: inside the alveolar socket, immediately before implant placement (Group 1, n = 10); at the peri-implant crevicular fluid (PICF) during reopening (Group 2, n = 10); PICF from healthy peri-implant in function (Group 3, n = 8); and PICF from mucositis sites (Group 4, n = 18). Quantitative polymerase chain reaction (PCR) evaluated EGF/EGFR gene expression using the SYBR Green Master Mix detection system. The results showed that EGF expression in the peri-implant crevicular fluid was statistically different. There was a higher EGF expression for group C (peri-implant health) (p = 0.04) than for the other groups. Regarding EGFR, there was no statistical difference among the groups (p = 0.56). It was concluded that low levels of EGF gene expression in the peri-implant crevicular fluid are related to the development of peri-implant mucositis and the absence of mucosae sealing. There was no correlation between EGFR gene expression with health or mucositis.

Cytotoxicity, and antimicrobial and physicochemical properties of sealers incorporated with Uncaria tomentosa.

This study evaluated the cytotoxicity, the antimicrobial and physicochemical properties of root canal sealers incorporated with phytotherapic Uncaria tomentosa (UT). Unmodified AH Plus (Dentsply, DeTrey, Germany) and MTA Fillapex (Angelus, Londrina, Brazil) were used as controls. UT was incorporated into AH Plus and MTA Fillapex, at concentrations of 2% and 5% of the total weight of these sealers (w/w). Flowability, setting time, and solubility were evaluated following ISO requirements. The pH values were measured at periods of 12, 24, 48 hours, and 7 days. The antimicrobial activity of the sealers against Enterococcus faecalis was analyzed by both direct contact tests in freshly prepared sealers, and after 7 days. The cytotoxicity of the samples was evaluated by the MTT assay, to check Balb/c 3T3 cell viability. The statistical analysis was performed by one-way ANOVA and Tukey's test (p < 0.05). The incorporation of UT was associated with a decrease in flow, for both sealers, an increase in AH Plus setting time, increase in MTA Fillapex pH values, and solubility (after 14 days), for both sealers (p < 0.05). Regarding the antibacterial evaluation, bacterial reduction was reported after incorporation of UT into both AH Plus and MTA Fillapex, up to 7 days after handling of the material (P<0.05). UT incorporation decreased the cytotoxic effects of both AH Plus and MTA Fillapex sealers in a way directly proportional to their respective concentrations (p < 0.05). In conclusion, UT can be added to both sealers to reduce their cytotoxicity, and improve their antibacterial effects, without compromising their original physicochemical properties.

Clinical and Radiographic Outcomes of Regenerative Endodontic Procedures in Traumatized Immature Permanent Teeth: Interappointment Dressing or Single-Visit?

INTRODUCTION: More data are needed before affirming that single-visit approaches are effective and safe for regenerative endodontic procedures (REPs). This study compared clinical and radiographic outcomes of REPs between interappointment dressing or single-visit protocols. METHODS: Twenty young patients presenting traumatized immature teeth with pulp necrosis were divided into 2 groups. Teeth were submitted to 6% sodium hypochlorite and 2% chlorhexidine irrigation and to 17% EDTA use before blood clot induction. In the interappointment dressing group (n = 11), calcium hydroxide was used with 2% chlorhexidine gel for 21 days before scaffold induction. In the single-visit group (n = 9), the scaffold was induced during the only appointment. Patients were followed up for 24 months. Primary, secondary, and tertiary outcomes were assessed by 3 independent evaluators. Preoperative and follow-up radiographs were assessed for quantitative measurements of the apical diameter, root width, root length, and cervical barrier placement and compared between groups using the t test or Mann-Whitney U test. Categoric variables were assessed with the G test and the Fisher exact test and continuous variables with the Mann-Whitney U test. Statistical significance was set at 5%. RESULTS: One tooth showed persistence of infection. No difference was observed in cervical barrier placement (P > .05); between groups regarding primary, secondary, and tertiary outcomes (P > .05); and in parameters of quantitative radiographic outcomes (P > .05). CONCLUSIONS: Completing REPs with an interappointment dressing or a single-visit protocol presented similar clinical and radiographic outcomes. A single-visit protocol of REPs using 6% sodium hypochlorite, 2% chlorhexidine, and 17% EDTA permitted satisfactory outcomes in necrotic immature permanent teeth.

Comparison of Postobturation Pain Experience after Apical Extrusion of Calcium Silicate- and Resin-Based Root Canal Sealers.

INTRODUCTION: This study compared the intensity of postobturation pain after unintentional apical extrusion of calcium silicate-based root canal sealers (EndoSequence BC Sealer [Brasseler USA, Savannah, GA] and Bio-C Sealer [Angelus, Londrina, PR, Brazil]) with a resin-based sealer (AH Plus; Dentsply Sirona, York, PA). METHODS: A total of 330 patients referred for root canal treatment on molar teeth with asymptomatic irreversible pulpitis were recruited. Root canals were prepared using WaveOne Gold instruments (Dentsply Sirona) in a crown-down technique and irrigated with 2% chlorhexidine gel and saline solution. Next, patients were randomly distributed into 3 groups according to the root canal sealer used (n = 110): AH Plus, BC Sealer, and Bio-C Sealer. Root canal filling was then accomplished with a vertical compaction technique. Patients presenting with an unintentional extrusion of sealers (n = 13/group) were assessed for postobturation pain experience using a visual descriptor scale ranging from 0-10 at 6-, 12-, 24-, and 48-hour and 1-week intervals after treatment. Mixed analysis of variance repeated measures were used to assess the results (α = 0.05). RESULTS: The extrusion rate was similar for all sealers (~12%). There was no significant difference in the postobturation pain results between the root canal sealers evaluated (P > .05). However, after the time interval of 12 hours, AH Plus (P = .04073) and Bio-C Sealer (P = .04327) demonstrated a significant reduction in pain, whereas BC Sealer did not show differences in pain intensity, even in the maximum period evaluated of 1 week (P > .05). CONCLUSIONS: The occurrence of unintentional apical extrusion of calcium silicate-based root canal sealers presents similar postoperative pain results compared with resin-based sealers with low-intensity pain.

Do intracanal medications used in regenerative endodontics affect the bond strength of powder-to-liquid and ready-to-use cervical sealing materials?

Aim: This study evaluated the effect of four intracanal medications commonly used in regenerative endodontic procedures on the bond strength of four calcium silicate-based materials, in which two are powder-to-liquid products (MTA and MTA-HP) and the other are ready-to-use materials (EndoSequence Root Repair Material Fast Set Putty [ERRM] and Bioceramic Repair [BIO-C Repair]). Methods: Ten bovine central incisors were selected and 4 slices (1.0 ± 0.1 mm) were prepared from each root. Next, four 0.8-mm wide holes were drilled in each slice and specimens were filled with one of the following intracanal medications: triple antibiotic paste, double antibiotic paste, calcium hydroxide with distilled water, and calcium hydroxide with 2% chlorhexidine gel. After 21 days, holes were filled with one of the materials: MTA, MTA-HP, ERRM, or BIO-C Repair. After storage, push-out test and failure analysis were performed. Data were submitted to analysis of variance in a 4 × 4 factorial scheme. Tukey's test was used for multiple comparisons. Results: The use of different interappointment dressings did not influence the results (P > 0.05). ERRM and BIO-C Repair presented significantly higher values than MTA and MTA-HP (P < 0.0001). Specimens showed a 100% occurrence of adhesive failures. Conclusion: The use of different intracanal medications presented similar impact on bond strength of calcium silicate-based materials. Ready-to-use ERRM and BIO-C Repair materials presented the best push-out values to dentine, whereas powder-to-liquid MTA and MTA-HP cements showed the lowest results.

Cytotoxicity, and antimicrobial and physicochemical properties of sealers incorporated with Uncaria tomentosa

Abstract This study evaluated the cytotoxicity, the antimicrobial and physicochemical properties of root canal sealers incorporated with phytotherapic Uncaria tomentosa (UT). Unmodified AH Plus (Dentsply, DeTrey, Germany) and MTA Fillapex (Angelus, Londrina, Brazil) were used as controls. UT was incorporated into AH Plus and MTA Fillapex, at concentrations of 2% and 5% of the total weight of these sealers (w/w). Flowability, setting time, and solubility were evaluated following ISO requirements. The pH values were measured at periods of 12, 24, 48 hours, and 7 days. The antimicrobial activity of the sealers against Enterococcus faecalis was analyzed by both direct contact tests in freshly prepared sealers, and after 7 days. The cytotoxicity of the samples was evaluated by the MTT assay, to check Balb/c 3T3 cell viability. The statistical analysis was performed by one-way ANOVA and Tukey's test (p < 0.05). The incorporation of UT was associated with a decrease in flow, for both sealers, an increase in AH Plus setting time, increase in MTA Fillapex pH values, and solubility (after 14 days), for both sealers (p < 0.05). Regarding the antibacterial evaluation, bacterial reduction was reported after incorporation of UT into both AH Plus and MTA Fillapex, up to 7 days after handling of the material (P<0.05). UT incorporation decreased the cytotoxic effects of both AH Plus and MTA Fillapex sealers in a way directly proportional to their respective concentrations (p < 0.05). In conclusion, UT can be added to both sealers to reduce their cytotoxicity, and improve their antibacterial effects, without compromising their original physicochemical properties.

Clinical and Molecular Microbiological Evaluation of Regenerative Endodontic Procedures in Immature Permanent Teeth.

INTRODUCTION: This study evaluated the bacterial levels after regenerative endodontic procedures and their correlation with the treatment outcome using molecular microbiology methods. METHODS: Root canal samples of 15 necrotic immature teeth were analyzed by quantitative polymerase chain reaction. Bacteria were counted before treatment (S1), after irrigation with 6% sodium hypochlorite (S2), and after intracanal dressing (S3) using either triple antibiotic paste (n = 7) or calcium hydroxide with chlorhexidine (n = 8). The Wilcoxon test for related samples and the Mann-Whitney test were used for statistical analysis (P < .05). After a follow-up period of 12-48 months, clinical and radiographic findings were correlated with microbiological data using a linear regression model (P < .05). RESULTS: All S1 and S2 samples were positive for bacteria, but the number of positive S3 samples decreased to 53.3% (P = .001). Overall, there was a significant reduction of bacterial levels after each treatment step (S1-S2, P = .001; S2-S3, P = .02). In the triple antibiotic paste and chlorhexidine groups, 57.1% and 50% of S3 samples were positive with median numbers of 6.97 × 103 and 3.59 × 104 bacterial cells, respectively. No significant differences were found between the groups. Periapical healing occurred in all cases despite the presence of low levels of residual bacteria. However, the latter had a negative impact on the thickness of dentinal walls (R2 = 0.0043). CONCLUSIONS: Although the bacterial levels were drastically reduced after the regenerative endodontic procedures, the residual bacteria influenced the thickness of the dentinal walls.

Resistência de união à dentina de um material fotopolimerizável à base de silicato de cálcio e modificado por resina / Dentin bond strength of resin-modified light-curable calcium-silicate-based material

Objetivo: este estudo teve como objetivo comparar a resistência de união à dentina de um material à base de silicato de cálcio fotopolimerizável modificado por resina (TheraCal LC®; Bisco, Schaumburg, IL, EUA) com MTA branco (WMTA®; Angelus, Londrina, PR, Brasil). Materiais e Métodos: dezesseis incisivos superiores e caninos humanos foram selecionados e três discos de 1 mm foram obtidos a partir do terço médio de cada raiz. Na superfície coronal de cada disco, dois furos de 1,2 mm de largura foram perfurados na dentina. Em seguida, os buracos artificiais foram preenchidos com um dos materiais testados: WMTA® e TheraCal LC®. As fatias dentárias preenchidas foram armazenadas em uma solução salina tamponada com fosfato (PBS) (pH 7,2) por 7 dias a 37°C. Depois disso, a avaliação do push-out foi realizada com uma ponta do êmbolo de 1,0 mm. A carga foi aplicada a uma velocidade de 0,5 mm / min até o deslocamento do selador. Os resultados foram expressos em MPa. O teste U de Mann-Whitney foi aplicado para classificar os materiais quanto à resistência adesiva à dentina. O nível de significância foi estabelecido em = 5%. Resultados: todas as amostras apresentaram resultados de resistência de união à dentina mensuráveis e não ocorreram falhas prematuras. O TheraCal LC® demonstrou valores superiores de resistência de união à dentina quando comparado ao WMTA® (P<0,0001). Conclusões: existe uma vantagem do TheraCal LC® sobre o WMTA® no que diz respeito à resistência da união ao empurrar e, portanto, pode ser considerado um material reparador promissor e inovador

Objective: this study aimed to compare the dentin bond strength of a resin-modified light-curable calcium-silicate-based material (TheraCal LC®; Bisco, Schaumburg, IL, USA) with White MTA (WMTA®; Angelus, Londrina, PR, Brazil). Materials and Methods: sixteen human maxillary incisors and canines were selected and three 1-mm-discs were obtained from the middle third of each root. On the coronal surface of each disc, two 1.2-mm-wide-holes were drilled through the dentin. Then, artificial holes were filled with one of the tested materials: WMTA® and TheraCal LC®. The filled dental slices were stored in a phosphate-buffered saline (PBS) solution (pH 7.2) for 7 days at 37°C. After that, push-out assessment was performed with a 1.0-mm-plunger-tip. Load was applied at a crosshead speed of 0.5 mm/min until sealer displacement. The results were expressed in MPa. Mann-Whitney U test was applied to rank materials regarding dentin push-out bond strength. Significance level was set at a = 5%. Results: All specimens showed measurable results and no premature failure occurred. TheraCal LC® demonstrated superior push-out bond strength values to dentin when compared to WMTA® (P<0.0001). Conclusions: there is advantage of TheraCal LC® over WMTA® as regards to the push-out bond strength and, therefore it may be taken as a promising and innovative reparative material

Convergent responses of fish belonging to different feeding guilds to sewage pollution

This study aimed to evaluate if the presence of pollutants promotes changes in feeding habits of fish species from different trophic guilds: the detritivorous species, Hypostomus francisci, and the piscivorous, Hoplias intermedius. Both species were sampled at 12 sites (with different degrees of pollution) in the Rio das Velhas basin, which is heavily polluted by domestic and industrial sewage from the Metropolitan Region of Belo Horizonte (MRBH). Stable isotope analyses of carbon (δ13C) and nitrogen (δ15N) of fish tissue and the main food resources were performed. Fishes from both trophic guilds altered their diets in degraded environments, but the detritivorous species showed greater trophic plasticity. The isotopic niche of both trophic guilds was broadest in unpolluted sites and more δ15N enriched in polluted regions. The detritivorous species presented high niche-breadth in unpolluted sites, probably due to the greater variety of resources consumed. In addition, the δ15N of the detritivorous was more enriched than the piscivorous species in polluted sites. In conclusion, fishes from both trophic guilds presented similar isotopic responses to environmental pollution. However, the detritivorous species was more sensitive to these alterations and therefore, is likely a better indicator of environmental condition than the piscivorous.(AU)

Este estudo teve como objetivo avaliar se a presença de poluentes promove mudanças nos hábitos alimentares de espécies de peixes de diferentes guildas tróficas: a espécie detritívora, Hypostomus francisci, e a piscívora, Hoplias intermedius. Ambas espécies foram amostradas em 12 locais (com diferentes níveis de poluição) na bacia do Rio das Velhas, que é altamente poluída por esgoto doméstico e industrial da Região Metropolitana de Belo Horizonte (RMBH). Foram realizadas análises de isótopos estáveis de carbono (δ13C) e nitrogênio (δ15N) dos tecidos dos peixes e dos principais recursos alimentares. Espécies de ambas guildas tróficas alteraram suas dietas em ambientes degradados, mas a espécie detritívora apresentou maior plasticidade trófica. O nicho isotópico de ambas as espécies foi mais amplo em locais menos perturbados e mais enriquecido em δ15N em regiões poluídas. A espécie detritívora apresentou grande amplitude em seu nicho isotópico em locais menos perturbados, provavelmente devido à maior variedade de recursos consumidos. Além disso, o δ15N da espécie detritívora foi mais enriquecido que a espécie piscívora em locais poluídos. Em conclusão, ambas as espécies apresentaram respostas isotópicas semelhantes à poluição ambiental. No entanto, a espécie detritívora foi mais sensível a essas alterações e, portanto, é provavelmente uma melhor indicadora de condição ambiental do que a espécie piscívora.(AU)

Dietary Curcumin Prevented Astrocytosis, Microgliosis, and Apoptosis Caused by Acute and Chronic Exposure to Ozone.

Ozone is the most oxidant tropospheric pollutant gas, causing damage through the formation of reactive oxygen and nitrogen species. Reactive species induce the nuclear factor-kappa B (NF-κB) activation leading to neuroinflammation characterized by astrocytosis, microgliosis, and apoptotic cell death. There is interest in evaluating the pharmacological activity of natural antioxidants to confer neuroprotection against the damage caused by ozone in highly polluted cities. Curcumin has been proven to exert a protective action in the central nervous system (CNS) of diverse experimental models, with no side effects. The aim of this work is to evaluate the effect of curcumin in a preventive and therapeutic manner against the astrocytosis, microgliosis, and apoptosis induced by ozone in rat hippocampus. Fifty Wistar rats were distributed into five experimental groups: The intact control, curcumin fed control, ozone-exposed group, and the preventive and therapeutic groups receiving the curcumin supplementation while exposed to ozone. Ozone caused astrocytosis and microgliosis, as well as apoptosis in the hippocampus. Meanwhile, curcumin was able to decrease the activation of microglia and astrocytes, and apoptotic cell death in both periods of exposure. Therefore, we propose that curcumin could be used as a molecule capable of counteracting the damage caused by ozone in the CNS.

In silico analysis of missense mutations in exons 1-5 of the F9 gene that cause hemophilia B.

BACKGROUND: Missense mutations in the first five exons of F9, which encodes factor FIX, represent 40% of all mutations that cause hemophilia B. To address the ongoing debate regarding in silico identification of disease-causing mutations at these exons, we analyzed 215 missense mutations from www.factorix.org using six in silico prediction tools, which are the most common used programs for analysis prediction of impact of mutations on the protein structure and function, with further advantage of using similar approaches. We developed different algorithms to integrate multiple predictions from such tools. In order to approach a structural analysis on FIX we performed a modeling of five selected pathogenic mutations. RESULTS: SIFT, PolyPhen-2 HumDiv, SNAP2, and MutationAssessor were the most successful in identifying true non-causative and causative mutations. A proposed function integrating these algorithms (wgP4) was the most sensitive (90.1%), specific (22.6%), and accurate (87%) than similar functions, and identified 187 variants as deleterious. Clinical phenotype was significantly associated with predicted causative mutations at all five exons. However, PolyPhen-2 HumDiv was more successful in linking clinical severity to specific exons, while functions that integrate 4-6 predictions were more successful in linking phenotype to genotypes at the light chain (exons 3-5). The most important value of integrating multiple predictions is the inclusion of scores derived from different approaches. Modeling of protein structure showed the effects of pathogenic nsSNPs on structure and function of FIX. CONCLUSIONS: A simple function that integrates information from different in silico programs yields the best prediction of mutated phenotypes. However, the specificity, sensitivity, and accuracy of genotype-phenotype predictions depend on specific characteristics of the protein domain and the disease of interest as we validated by the structural analysis of selected pathogenic F9 mutations. The proposed function integrating algorithm (wgP4) might be useful for the analysis of nsSNPs impact on other genes.

Micro-CT evaluation of different final irrigation protocols on the removal of hard-tissue debris from isthmus-containing mesial root of mandibular molars.

OBJECTIVES: This study aimed to compare four final irrigation protocols (passive ultrasonic irrigation [PUI], EndoVac, Self-Adjusting File [SAF] and EasyClean) on the removal of accumulated hard-tissue debris (AHTD) from mesial canals of mandibular molars through microcomputed tomographic (micro-CT) analysis. MATERIALS AND METHODS: Forty mesial roots of mandibular molars presenting isthmuses type I or III were scanned in a micro-CT device and instrumented up to Reciproc R40 instrument. After the completion of canal preparations, root canals of each group were submitted to a final rinse using 20 mL of solution (16 mL of 5.25% NaOCl and 4 mL of 17% EDTA) in a total time of 5 min according to one of the four final irrigation protocols (n = 10): PUI, EndoVac, SAF and EasyClean operated at reciprocating motion. The sample was scanned again after canal preparation and after the use of the final irrigation protocols, and the registered data sets were examined to evaluate the percentage of AHTD. Data were statistically compared using the Tukey test with a significance level set at 5%. RESULTS: All groups presented a decrease on the accumulation of hard-tissue debris after the use of the final irrigation protocols (P < 0.05). No significant differences in the removal of AHTD were observed among the final irrigation protocols (P > 0.05). CONCLUSIONS: All final irrigation protocols showed the same effectiveness in the removal of AHTD. None of them was able to render mesial canals of mandibular molars completely free from packed debris. CLINICAL RELEVANCE: This study highlighted that all final irrigation protocols (PUI, EndoVac, SAF, and EasyClean) promoted a similar removal of AHTD. However, none of the final irrigation protocols was able to render mesial canals of mandibular molars completely free from packed debris.

Cleaning Ability of Irrigants and Orange Oil Solvent Combination in the Removal of Root Canal Filling Materials.

OBJECTIVE: This study investigated the influence of different irrigants and the use of orange oil solvent in the removal of filling materials during root canal retreatment. METHODS: Forty maxillary premolars were shaped using the ProTaper System up to file F3 (size 30, 0.09 taper) and filled by Tagger's hybrid technique using the AH Plus. Samples were randomly assigned to four groups (n=10) according to the irrigating protocol during endodontic retreatment with the ProTaper Universal Re-treatment System: G1, 2% chlorhexidine (CHX) gel; G2, 2% CHX gel with an orange oil solvent; G3, 5% sodium hypochlorite (NaOCl); and G4, 5% NaOCl with an orange oil solvent. Afterwards, the samples were longitu-dinally split into two halves, and the root wall images were prepared by scanning electron microscopy. Two pre-calibrated evaluators analyzed the images using a filling materials remnants score system. Data were statistically analyzed using the Kruskal-Wallis and Dunn's tests (p<0.05). RESULTS: All samples had residual filling materials in the root canal walls after instrumentation. According to the presence of the filling material remnants in the total area of samples, the groups were ranked in the follow-ing order: G2=G4>G1=G3. No statistical differences were found when the CHX and NaOCl were used (p>0.05). Groups in which a solvent was used showed a less effective cleaning ability (p<0.05). The use of NaOCl with solvent presented the highest amounts of filling materials remnants in the critical apical area (p<0.05). CONCLUSION: The use of orange oil with NaOCl or CHX does not improve the removal of residual root canal filling materials.