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). 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,

Influence of the apical enlargement size on the endotoxin level reduction of dental root canals

Gram-negative bacteria play an essential role in endodontic infections because they have virulence factors such as endotoxin. Due to its potential cytotoxic activity, special attention has been given to the removal/neutralization of this endotoxin in the root canal system. OBJECTIVE: The aim of this study was to evaluate the influence of the apical enlargement size (AES) by using rotary instruments on the endotoxin level reduction of dental root canals. MATERIAL AND METHODS: Forty root canals of the mandibular premolar teeth were used. Escherichia coli endotoxin (055: B55) was inoculated into thirty root canals. Ten teeth served as the negative control group. After the incubation period, the first endotoxin samples were collected from the root canals with a sterile/apyrogenic paper point for the analysis of the endotoxin units (EU/mL) present before instrumentation (S1). Specimen instrumentation was performed with the Mtwo® rotary system in the sequence 10/.04, 15/.05, 20/.06, 25/.06, 30/.05, 35/.04 and 40/.04. To monitor the effectiveness of increasing apical enlargement on endotoxin removal, the second endotoxin samples were collected from all the root canals after instrumentation with the following instruments: #25/.06- (S2); #30/.05- (S3); # 35/.04- (S4); and #40/.04- (S5). Limulus amebocyte lysate (LAL) was used to quantify the levels of endotoxin. The results were statistically compared by using repeated measures of ANOVA with post hoc Tukey testing. RESULTS: Increasing levels of endotoxin removal was achieved by large sized apical enlargement: S2 (AES #25/.06)- 89.2%, S3 (AES #30/.05)- 95.9%, S4 (AES #35/.04)- 97.8% and S5 (AES #40/.04)- 98.2%. Substantial reduction of endotoxin content was obtained in S4 and S5 compared to S2 (

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 p0.05). 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 reduction226490495CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP302575/2009-0sem informação13/02402- 9; 10/13743-3; 10/19136-1; 10/17877-4; 11/09047-

In vitro evaluation of the antimicrobial activity of five root canal sealers

The aim of the present study was to analyze the antimicrobial properties of five endodontic sealers: Endo Fill, Endomethasone, Endomethasone N, Sealer 26 and AH-Plus, against the following microorganisms: Candida albicans, Staphylococcus aureus, Enterococcus faecalis, Streptococcus sanguis and Actinomyces naeslundii. The sealers were tested immediately, 24 h, 48 h and 7 days after manipulation.The direct contact method through the observation of the microbial growth in liquid medium and the agar diffusion test were used to evaluate the antimicrobial properties of the sealers. The results, in both methodologies used, showed that immediately after manipulation, Endo-Fill and Endomethasone demonstrated the highest antimicrobial activity, with no statistically significant difference between them. Sealer 26 demonstrated the lowest antimicrobial activity. At all other times after manipulation, there were no statistically significant differences among all the sealers tested. In conclusion, none of the sealers totally inhibited the growth of the microorganisms. Furthermore, the antimicrobial activity of each sealer decreased with time and was dependent upon the microbial susceptibility to them.O objetivo do presente estudo foi analisar as propriedades antimicrobianas de cinco cimentos endodônticos: Endo Fill, Endomethasone, Endomethasone N, Sealer 26 e AH-Plus, em diferentes períodos pós-manipulação, i.e., imediatamente e após 24 horas, 48 horas e 7 dias, contra os seguintes microrganismos: Candida albicans, Staphylococcus aureus, Enterococcus faecalis, Streptococcus sanguis e Actinomyces naeslundii. Os métodos usados foram o contato direto através da observação do crescimento microbiano em meio líquido e o teste de difusão em agar. Os resultados, nas duas metodologias usadas, mostraram que: 1) imediatamente após a manipulação, Endo-Fill e Endomethasone apresentaram a maior atividade antimicrobiana, sem diferenças estatisticamente significantes entre eles. Sealer 26 teve a menor atividade antimicrobiana; 2) nos outros tempos pós-manipulação, não houveram diferenças estatisticamente significantes entre os cimentos testados. Foi concluído que nenhum dos cimentos inibiu completamente o crescimento dos microrganismos testados. A atividade antimicrobiana de cada cimento diminuiu com o tempo e dependeu da suscetibilidade microbiana a eles.3035Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Antimicrobial and cytotoxic effects of phosphoric acid solution compared to other root canal irrigants

Phosphoric acid has been suggested as an irrigant due to its effectiveness in removing the smear layer. The purpose of this study was to compare the antimicrobial and cytotoxic effects of a 37% phosphoric acid solution to other irrigants commonly used in endodontics. The substances 37% phosphoric acid, 17% EDTA, 10% citric acid, 2% chlorhexidine (solution and gel), and 5.25% NaOCl were evaluated. The antimicrobial activity was tested against Candida albicans, Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Actinomyces meyeri, Parvimonas micra, Porphyromonas gingivalis, and Prevotella nigrescensaccording to the agar diffusion method. The cytotoxicity of the irrigants was determined by using the MTT assay. Phosphoric acid presented higher antimicrobial activity compared to the other tested irrigants. With regard to the cell viability, this solution showed results similar to those with 5.25% NaOCl and 2% chlorhexidine (gel and solution), whereas 17% EDTA and 10% citric acid showed higher cell viability compared to other irrigants. Phosphoric acid demonstrated higher antimicrobial activity and cytotoxicity similar to that of 5.25% NaOCl and 2% chlorhexidine (gel and solution).232158163CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP302575/2009-0Sem informação2009/53976-0; 2010/50817-5; 2011/09047-

Surface Morphology Alterations In Bovine Dentin Exposed To Different Bleaching Agents

Aim: This study evaluated the morphological changes caused by internal bleaching agents on dentin surface. Methods: Twenty crowns of bovine incisors were cut into slabs that were randomly distributed in six experimental groups (n = 5), according to the bleaching agent used: G1 – sodium perborate + water, G2 – sodium perborate + 2% chlorhexidine gel, G3 – sodium perborate + 30% hydrogen peroxide, G4 – 30% hydrogen peroxide, G5 – 37% carbamide peroxide and G6 – gel base without carbamide. Two Control Groups were used: C1 with distilled water and C2 with 2% chlorhexidine gel. The specimens were immersed in the respective test bleaching agent and incubated at 37 °C for seven days. Following, they were prepared for scanning electron microscopy and five images from each tooth segment were recorded and analyzed for surface morphological alterations, by three previously calibrated examiners. Inter-examiner agreement was verified using the Kappa test. The rank averages obtained for the groups were subjected to Kruskal-Wallis analysis of variance at 5% significance level. Results: The analysis of the scores obtained indicated that all tested materials caused some morphological alteration on dentin, except for sodium perborate + water (G1) and Control Groups 1 and 2. Hydrogen peroxide and carbamide peroxide caused significantly more severe alterations (p < 0.05) to dentin structure, than the other bleaching agents evaluated. Conclusions: Sodium perborate-based pastes seemed to be the most harmless agent to dentin structures in non-vital tooth bleaching, while hydrogen peroxide solutions and carbamide peroxide agents caused the greatest alterations.8125-2

Apexification with a New Intra-Canal Medicament: A Multidisciplinary Case Report

Dental trauma generally requires multidisciplinary planning and treatment for good prognosis. When immature teeth are traumatized to a degree where pulp necrosis ensues, the objective of root canal treatment should be apexogenesis and root maturation. Apexification of the root is the conventional choice, which involves cleaning the canal and filling it with a temporary medication that stimulates the formation of a calcific apical barrier. Dental Trauma Service of Piracicaba Dental School, State University of Campinas (UNICAMP), Brazil employs a dressing for apexification treatments with calcium hydroxide, chlorhexidine gel 2% and zinc oxide. This paper reports the case of a dental trauma of the maxillary central incisors and subluxation on teeth 11, 12 and 21 that were treated with multidisciplinary collaboration (Endodontics, Periodontology and Operative Dentistry) to improve prognosis. After five-years there were no pathological conditions and the teeth showed every evidences of success

In vitro evaluation of the susceptibility of endodontic pathogens to calcium hydroxide combined with different vehicles

The aim of this study was to investigate in vitro the antimicrobial activity of calcium hydroxide [Ca(OH)2] in combination with different vehicles against endodontic pathogens. For such purpose, a broth dilution test was performed. Pastes were prepared with Ca(OH)2 powder and the following vehicles: sterile water, glycerin, camphorated monochlorophenol (CMCP), CMCP + glycerin, polyethyleneglycol and CMCP + polyethyleneglycol. The time required for the pastes to produce negative cultures against the tested microorganisms was recorded and analyzed statistically using the Kruskal Wallis test at 5% significance level. Timing for pastes to eliminate the aerobic and facultative anaerobic microorganisms ranged from 6 to 24 h, while strict anaerobic microorganisms were inhibited within 30 s to 5 min. Microbial susceptibility, ranked from weakest to strongest, can be presented as follows: Enterococcus faecalis (the most resistant microorganism), Candida albicans, Staphylococcus aureus, Porphyromonas gingivalis, Porphyromonas endodontalis and Prevotella intermedia (the last two microorganisms required the same time to be eliminated). In conclusion, calcium hydroxide pastes needed more time to eliminate facultative than anaereobic microorganisms. These findings suggest that the antimicrobial property is related both to paste formulation and to microbial susceptibility.O objetivo deste estudo foi avaliar in vitro a atividade antimicrobiana do hidróxido de cálcio [Ca(OH)2] em associação com diferentes veículos frente a patógenos endodônticos. O teste de difusão em caldo foi utilizado. Foram preparadas pastas com pó de Ca(OH)2 e os seguintes veículos: água destilada, glicerina, PMCC (paramonoclorofenol canforado), PMCC + glicerina, e PMCC + polietilenoglicol. O tempo necessário para as pastas produzirem culturas negativas frente aos microorganismos testados foi registrado e analisado estatisticamente por meio do teste de Kruskal Wallis com nível de significância de 5%. Foram necessárias de 6 a 24 h para eliminar os microrganismos aeróbios e facultativos e de 30 s a 5 min para os anaeróbios estritos. A suscetibilidade microbiana em ordem crescente foi: Enterococcus faecalis (patógeno mais resistente), Candida albicans, Staphylococcus aureus, Porphyromonas gingivalis, Porphyromonas endodontalis e Prevotella intermedia (os últimos dois microrganismos necessitaram do mesmo tempo para serem eliminados). Concluiu-se que as pastas de hidróxido de cálcio necessitaram de maior tempo para eliminar os microrganismos facultativos do que os anaeróbios. Esses achados sugerem que a propriedade antimicrobiana está relacionada tanto à formulação da pasta quanto à suscetibilidade microbiana.175180Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Treatment outcomes of pulp revascularization in traumatized immature teeth using calcium hydroxide and 2% chlorhexidine gel as intracanal medication

Objective: Pulp revascularization is an effective treatment for immature necrotic teeth. Calcium hydroxide has been used in pulp revascularization as an intracanal medication due to its antimicrobial action and the non-exhibition of crown discoloration and cytotoxicity for stem cells from the apical papilla. Our study aimed to investigate the clinical success and quantitative radiographic changes of root development in immature traumatized teeth using calcium hydroxide plus 2% chlorhexidine gel as intracanal medication. Methodology: In this retrospective study, 16 patients were treated with a standardized pulp revascularization protocol. Calcium hydroxide and 2% chlorhexidine gel were manipulated in a 1:1 (v/v) ratio and inserted into root canals with Lentulo spirals (Dentsply Maillefer, Baillaigues, Switzerland). Patients were followed up for a period from 9 to 36 months for the evaluation of clinical and radiological data. Radiographic measurements of root length, root width, apical diameter, and MTA placement from the apex were quantified using software ImageJ. Wilcoxon test and t-test were used, according to nonparametric or parametric data, respectively, for changes over time in root length, root width, and apical diameter. Results: Fifteen teeth survived during the follow-up period (93.75%) and met the criteria for clinical success. Although the changes seem to be very small in many cases, significant increases in the average root length (14.28%, p&lt;0.0001), root width (8.12%, p=0.0196), and decrease in apical diameter (48.37%, p=0.0007) were observed. MTA placement from the apex and age at the time of treatment was not significantly associated with the quantitative radiographic outcomes. Conclusions: Pulp revascularization in traumatized immature teeth treated with calcium hydroxide plus 2% chlorhexidine gel as intracanal medication had high success and survival rates, showing periodontal healing and resolution of signs and symptoms. However, concerning the continued root development, the outcomes can still be considered unpredictable