Effectiveness of XP-endo finisher in the reduction of bacterial load in oval-shaped root canals

This study investigated the effectiveness of XP-Endo Finisher (XPF) associated with XP-Endo Shaper (XPS) or Reciproc Blue (RB) files in reducing bacterial load in oval-shaped root canals (RC) during chemomechanical preparation (CMP) using 0.9% saline solution (NaCl) or 2.5% sodium hypochlorite (NaOCl). Eighty mandibular incisors with single oval-shaped RC were contaminated with Enterococcus faecalis. The teeth were randomly assigned to eight experimental groups (n = 10) according to the CMP, as follows: G1: XPS, G2: XPS + XPF, G3: RB, and G4: RB + XPF. CMP was performed with NaCl or NaOCl. The reduction of bacterial load was assessed by colony-forming unit count before (S1) and after (S2) CMP. Data normality was verified by using Shapiro-Wilk test. ANOVA, Tukey's test, and Bonferroni post-hoc test were used at a 5% significance level. Culturable bacteria were present in all S1 samples (p>0.05). All instrumentation techniques were effective in reducing bacterial load, irrespective of the irrigating solution (p < 0.05). With the use of NaCl, RB was more effective than XPS (p = 0.035). With the use of NaOCl, XPS and RB presented similar effectiveness (p = 0.779). XPF enhanced the bacterial reduction of both systems tested (p < 0.05). The use of NaOCl improved the CMP, irrespective of the instrumentation technique used (p < 0.05). In conclusion, XPS and RB files are effective in reducing bacterial levels in oval-shaped RC. The use of XPF as a method of agitation of the irrigating solution improved the cleaning efficiency of both file systems tested. Mechanical preparation performed with saline solution decreased culturable bacteria from the root canal, but antimicrobial substances such as NaOCl should be used to achieve a significantly better disinfection33CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP308162/2014-5não tem2015/23479-

Proinflammatory Activity Of Primarily Infected Endodontic Content Against Macrophages After Different Phases Of The Root Canal Therapy

Introduction: This study investigated the presence of target bacterial species and the levels of endotoxins in teeth with apical periodontitis. Levels of inflammatory mediators (interleukin [IL]-1β and tumor necrosis factor [TNF]-α) were determined after macrophage stimulation with endodontic content after different phases of endodontic therapy using different irrigants. Methods: Thirty primarily infected root canals were randomly assigned into 3 groups according to the irrigant used for root canal preparation (n=10 per group): GI: 2.5% sodium hypochlorite, GII: 2% chlorhexidine gel, and GIII (control group): saline solution. Root canal samples were taken by using paper points before (s1) and after root canal instrumentation (s2), subsequently to 17% EDTA (s3), after 30days of intracanal medication (Ca[OH]2 + saline solution) (s4), and before root canal obturation (s5). Polymerase chain reaction (16S recombinant DNA) and limulus amebocyte lysate assay were used for bacterial and endotoxin detection, respectively. Macrophages were stimulated with the root canal contents for IL-1β/TNF-α measurement using enzyme-linked immunosorbent assay. Results: Porphyromonas gingivalis (17/30), Porphyromonas endodontalis (15/30), and Prevotella nigrescens (11/30) were the most prevalent bacterial species. At s1, endotoxins were detected in 100% of the root canals (median = 32.43 EU/mL). In parallel, substantial amounts of IL-1β and TNF-α were produced by endodontic content-stimulated macrophages. At s2, a significant reduction in endotoxin levels was observed in all groups, with GI presenting the greatest reduction (P&lt;.05). After a root canal rinse with EDTA (s3), intracanal medication (s4), and before root canal obturation (s5), endotoxin levels reduced without differences between groups (P&lt;.05). IL-1β and TNF-α release decreased proportionally to the levels of residual endotoxin (P&lt;.05). Conclusions: Regardless of the use of sodium hypochlorite or CHX, the greatest endotoxin reduction occurs after chemomechanical preparation. Increasing steps of root canal therapy associated with intracanal medication enhances endotoxin reduction, leading to a progressively lower activation of proinflammatory cells such as macrophages

Monitoring The Effectiveness Of Root Canal Procedures On Endotoxin Levels Found In Teeth With Chronic Apical Periodontitis

Objective: The aim of this study was to monitor the effectiveness of root canal procedures by using different irrigants and intracanal medication on endotoxin levels found in root canals of teeth with chronic apical periodontitis. Material and methods: Thirty root canals of teeth with pulpal necrosis associated with periapical lesions were selected and randomly divided into groups according to the irrigants used: GI - 2.5% NaOCl, GII - 2% chlorhexidine (CHX) gel, and GIII - saline solution (SS) (all, n=10). Samples were collected with sterile/apyrogenic paper points before (S1) and after root canal instrumentation (S2), after use of 17% ethylenediaminetetraacetic acid (EDTA) (S3), and after 30 days of intracanal medication (Ca(OH)2+SS) (S4). A turbidimetric kinetic Limulus Amebocyte Lysate assay was used for endotoxin measurement. Results: Endotoxins were detected in 100% of the root canals investigated (30/30), with a median value of 18.70 EU/mL. After S2, significant median percentage reduction was observed in all groups, irrespective of the irrigant tested: 2.5% NaOCl (99.65%) (GI), 2% CHX (94.27%) (GII), and SS (96.79%) (GIII) (all p<0.05). Root canal rinse with 17% EDTA (S3) for a 3-minute period failed to decrease endotoxin levels in GI and a slight decrease was observed in GII (59%) and GIII (61.1%) (all p>0.05). Intracanal medication for 30 days was able to significantly reduce residual endotoxins: 2.5% NaOCl (90%) (GI), 2% CHX (88.8%) (GII), and SS (85.7%) (GIII, p<0.05). No differences were found in the endotoxin reduction when comparing S2 and S4 treatment groups. Conclusion: Our findings demonstrated the effectiveness of the mechanical action of the instruments along with the flow and backflow of irrigant enduring root canal instrumentation for the endotoxin removal from root canals of teeth with chronic apical periodontitis. Moreover, the use of intracanal medication for 30 days contributed for an improvement of endotoxin reduction.226490495Berutti, E., Marini, R., Angeretti, A., Penetration ability of different irrigants into dentinal tubules (1997) J Endod, 23, pp. 725-727Buck, R.A., Cai, J., Eleazer, P.D., Staat, R.H., Hurst, H.E., Detoxification of endotoxin by endodontic irrigants and calcium hydroxide (2001) J Endod, 27, pp. 325-327Burton, A.J., Carter, H.E., Purification and characterization of the lipid A component of the lipopolysaccharides from Escherichia coli (1964) Biochemistry, 3, pp. 411-418Csako, G., Elin, R.J., Hochstein, H.D., Tsai, C.M., Physical and biological properties of U.S. Standard endotoxin EC after exposure to ionizing radiation (1983) Infect Immun, 41, pp. 190-196Gomes, B.P., Endo, M.S., Martinho FC Comparison of endotoxin levels found in primary and secondary endodontic infections (2012) J Endod, 38, pp. 1082-1086Gomes, B.P., Martinho, F.C., Vianna, M.E., Comparison of 2.5% sodium hypochlorite and 2% chlorhexidine gel on oral bacterial lipopolysaccharide reduction from primarily infected root canals (2009) J Endod, 35, pp. 1350-1353Hong, C.Y., Lin, S.K., Kok, Cheng, S., Lee, M.S., Wang, T.M., The role of lipopolysaccharide in infectious bone resorption of periapical lesion (2004) J Oral Pathol Med, 33, pp. 162-169Horiba, N., Maekawa, Y., Abe, Y., Ito, M., Matsumoto, T., Nakamura, H., Correlations between endotoxin and clinical symptoms or radiolucent areas in infected root canals (1991) Oral Surg Oral Med Oral Pathol, 71, pp. 492-495Jacinto, R.C., Gomes, B.P., Shah, H.N., Ferraz, C.C., Zaia, A.A., Souza-Filho, F.J., Quantification of endotoxins in necrotic root canals from symptomatic and asymptomatic teeth (2005) J Med Microbiol, 54, pp. 777-783Lüderitz, O., Tanamoto, K., Galanos, C., McKenzie, G.R., Brade, H., Zähringer, U., Lipopolysaccharides: Structural principles and biologic activities (1984) Rev Infect Dis, 4, pp. 428-433Marinho, A.C., Martinho, F.C., Zaia, A.A., Ferraz, C.C., Gomes, B.P., Influence of the apical enlargement size on the endotoxin level reduction of dental root canals (2012) J Appl Oral Sci, 20, pp. 661-666Martinho, F.C., Chiesa, W.M., Leite, F.R., Cirelli, J.A., Gomes, B.P., Antigenic activity of bacterial endodontic contents from primary root canal infection with periapical lesions against macrophage in the release of interleukin-1beta and tumor necrosis factor alpha (2010) J Endod, 36, pp. 1467-1474Martinho, F.C., Chiesa, W.M., Marinho, A., Zaia, A.A., Ferraz, C.C., Almeida, J.F., Clinical investigation of the efficacy of chemomechanical preparation with rotary nickel-titanium files for removal of endotoxin from primarily infected root canals (2010) J Endod, 36, pp. 1766-1769Martinho, F.C., Gomes, B.P., Quantification of endotoxins and cultivable bacteria in root canal infection before and after chemomechanical preparation with 2.5% sodium hypochlorite (2008) J Endod, 34, pp. 268-272Oliveira, L.D., Carvalho, C.A., Carvalho, A.S., Alves, J.S., Valera, M.C., Jorge, A.O., Efficacy of endodontic treatment for endotoxin reduction in primarily infected root canals and evaluation of cytotoxic effects (2012) J Endod, 38, pp. 1053-1057Oliveira, L.D., Jorge, A.O., Carvalho, C.A., Koga-Ito, C.Y., Valera, M.C., In vitro effects of endodontics irrigants on endotoxins in root canals (2007) Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 104, pp. 135-142Ozdemir, H.O., Buzoglu, H.D., Calt, S., Cehreli, Z.C., Varol, E., Temel, A., Chemical and ultramorphologic effects of ethylenediaminetetraacetic acid and sodium hypochlorite in young and old root canal dentin (2012) J Endod, 38, pp. 204-20818- Paredes-Vieyra, J., Enriquez, F.J., Success rate of single- versus two-visit root canal treatment of teeth with apical periodontitis: A randomized controlled trial (2012) J Endod, 38, pp. 1164-1169Pérez-Heredia, M., Ferrer-Luque, C.M., González-Rodríguez, M.P., Martín-Peinado, F.J., González-López, S., Decalcifying effect of 15% EDTA, 15% citric acid, 5% phosphoric acid and 2.5% sodium hypochlorite on root canal dentine (2008) Intendod J, 41, pp. 418-423Petsch, D., Anspach, F.B., Endotoxin removal from protein solutions (2000) J Biotech, 76, pp. 97-119Pitts, D.L., Williams, B.L., Morton, T.H., Jr., Investigation of the role of endotoxin in periapical inflammation (1982) J Endod, 8, pp. 10-18Schein, B., Schilder, H., Endotoxin content in endodontically involved teeth (2006) J Endod, 32, pp. 293-295Silva, L.A., Leonardo, M.R., Assed, S., Tanomaru-Filho, M., Histological study of the effect of some irrigating solutions on bacterial endotoxin in dogs (2004) Braz Dent J, 15, pp. 109-114Silva, L.A., Nelson-Filho, P., Leonardo, M.R., Rossi, M.A., Pansani, C.A., Effect of calcium hydroxide on bacterial endotoxin in vivo (2002) J Endod, 28, pp. 94-9825- Sousa, E.L., Martinho, F.C., Nascimento, G.G., Leite, F.R., Gomes, B.P., Quantification of endotoxins in infected root canals and acute 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Perdas de solo e água em plantio de Acacia mangium wild e savana em Roraima, norte da Amazônia Soil and water losses in Acacia mangium wild plantations and natural savanna in Roraima, northern Amazon

Plantios florestais de Acacia mangium constituem uma alternativa cada vez mais adotada em áreas de savanas do norte da Amazônia (Roraima) e podem causar alterações significativas de características do solo. Neste sentido, o objetivo deste estudo foi determinar perdas de solo e de água por erosão, que ocorrem em escoamento superficial (run off) em savana nativa e plantios de acácia na região Amazônica. Para isso, foram instaladas em duas fazendas, Santa Rita e Araçá, localizadas no município de Bonfim, na região da Serra da Lua, calhas coletoras de sedimentos, acopladas a caixas d'água, em Argissolo Vermelho-Amarelo. Foram determinadas a granulometria, a densidade aparente (Dap), a resistência à penetração (RP) e a velocidade de infiltração (VIB), bem como parâmetros físicos relacionados a perdas de solo. O delineamento experimental utilizado foi o de blocos ao acaso, com três tratamentos: cobertura natural de savana (SV), plantio de Acacia mangium com um ano de idade (P1) e plantio de Acacia mangium com quatro anos de idade (P4), em três repetições. O experimento teve a duração de 12 meses (setembro de 2006 a agosto de 2007). Os resultados indicaram maiores perdas de solo e de água no plantio mais recente de acácia (P1), de savana nativa e do plantio com 4 anos (P4). Os resultados foram atribuídos à exposição do solo no período inicial de desenvolvimento da planta, ao selamento superficial e à coesão do solo. O pico de perdas de solo ocorreu nos meses de abril a agosto, sendo o tipo de cobertura vegetal o fator determinante para redução das perdas de solo e de água por erosão, sendo que as práticas de plantio no sentido do declive provavelmente agravaram as perdas de solo nos plantios de Acácia. Neste trabalho, a densidade do solo e o teor de matéria orgânica não representaram bons indicadores do tipo de manejo adotado na área.<br>As an alternative land use of savanna areas in Roraima, commercial forest stands of Acacia mangium are being increasingly implemented. The purpose of this study was the in situ determination of soil and water losses in commercial stands of Acacia mangium and compare them with those under native savanna. The experiment was conducted on a Red-Yellow Argisol (Ultisol) in the region of Serra da Lua where Gerlach sediment and water collectors were installed. Soil density, texture, penetration resistance and infiltration rate were determined. All climate data were recorded by an automatic weather station placed within the experimental area. The experiment had a randomized block design with three treatments: one-year-old Acacia stand (P1), four-year-old Acacia stand (P4); and native savanna (SV). All experimental data were collected within one year. Results indicated that greater soil and water losses occurred in younger Acacia plantations (P1), followed by savanna (SV) and four-year-old Acacia stands (P4). This was attributed to great soil exposure just after planting, when Acacia trees had not yet developed a good soil cover in these sealing-prone soils. The peak of soil and water loss occurred between April and August, and the practice of downslope planting aggravated soil erosion in Acacia stands. Soil bulk density or organic matter contents were not considered good management indicators for this area