Análise do tempo de ação de medicações intracanais sobre candida albicans, enterococcus faecalis, escherichia cole em canais radiculares

The purpose of this study was to evaluate in vitro the antimicrobial activity of intracanal medications against Candida albicans, Enterococcus faecalis, Escherichia coli present in root canals. It was used 24 single root human teeths, contaminated for 28 days and prepared with physiological saline solution as irrigation solution. The teeth were divided into 2 groups according to the intracanal medication used: 1) 2% gel chlorhexidine, 2) sterile and pyrogen free physiological saline solution. Samples were taken of the root canals immediately after instrumentation, 7 days after intracanal medication and 7 days after removal of intracanal medication. For all samples the antimicrobial activity was performed by plating method. All results were submitted to Mann-Whitney and Dunn's test with significance of 5%. There was significant reduction of microorganisms after instrumentation and the intracanal medication of 2% gel chlorhexidine completely eliminated C. albicans and E. coli, and significantly reduced E. faecalis. It was concluded that 2% gel chlorhexidine as intracanal medication for 7 days was effective on microorganisms

Avaliação in vitro da ação de substâncias químicas auxiliares, clorexidina e medicações intracanais sobre C. albicans, E. faecalis, E. coli e sua endotoxina em canais radiculares: [recurso eletrônico]

The purpose of this study was to evaluate the antimicrobial activity of chlorhexidine gel 2% as auxiliary chemical substance on the biomechanical preparation (BMP) and medication intracanal (ICM) on C. albicans, E. faecalis, E. coli and their endotoxin in root canals. We used 48 single-rooted human teeth divided into four groups according to dressing ICM: 1) Ca(OH)2 + pyrogen-free saline solution; 2) 2% chlorhexidine gel (CLX); 3) Ca(OH)2 + CLX, and; 4) pyrogen-free saline solution (control group). Were collected the contents of root canals to confirm the presence of microorganisms (confirmation), immediately after instrumentation (1st collection), after 7 days of the BMP (2nd collection), after 14 days of the action of ICM (3rd Collection) and 7 days after removal of the ICM (4 th collection). Were performed: the evaluation of antimicrobial activity and the content analysis of endotoxins for all sampling tests. The results were statistically analyzed using Kruskall-Wallis and Dunn tests with a significance of 5%. It was found that the CLX as auxiliary chemical substance has significantly reduced microorganisms confirmation collection when compared. In relation to the neutralization of endotoxin, it was found that the 1st and 2nd collections presented a decrease of 92.03% and 98.10% in mean percentage respectively, when compared to the confirmation collection. In the 3rd and 4th samplings, the Ca (OH)2 + CLX group showed the best results. It was concluded that the BMP and the ICM were able to eliminate the tested microrganisms, however, they were not able to completely eliminate endotoxins root canal

Avaliação histológica de estratégias de engenharia tecidual para a terapia endodôntica

Pós-graduação em Ciência Odontólogica - FOA

Comparação entre soluções irrigadoras na endodontia: clorexidina x hipoclorito de sodio

The objective of this review was reporting an overview about the properties of two irrigating solutions, solution of sodium hypochlorite and chlorhexidine, used in the treatment of root canals. A solution must submit irrigating antimicrobial action, dissolve waste tissue, promote wetting to facilitate the instrumentation, and present biocompatibility with the adjacent tissues. The sodium hypochlorite used in different concentrations has been the solution of choice among professionals by presenting antimicrobial action and act as a solvent tissue. However, today, chlorhexidine has been widely used as an irrigating solution due to specific properties that enable its use, such as substantivity, antimicrobial effectiveness, and low toxicity. Thus the solution of chlorhexidine with different concentrations is presented as an alternative to irrigating solution for the treatment of root canals.

Effects of coronal leakage on concentration of hydrogen ions and calcium hydroxide release of several calcium hydroxide pastes over different periods of time

Purpose: To evaluate the effects of coronal leakage on concentration of hydrogen ions (pH) and calcium release of several calcium hydroxide pastes, over different periods of time. Material and Methods: Fifty extracted human mandibular central incisors (n=10) were instrumented up to the F2 instrument and assigned to the following intracanal dressing: G1- Calen, G2- Calen with 0.4% chlorhexidine (CHX), G3- Calcium hydroxide with camphorated paramonochlorophenol (CPMC) and glycerin, G4- Calen, but temporary filling material maintained during all test (positive control) and G5- Root canal without intracanal dressing (negative control). All groups were immersed in distilled water for 7 days. In sequence, the temporary filling materials were removed, except in controls groups. All specimens were individually mounted on a specific device and only its root again immersed in distilled water. Concentration of hydrogen ions and calcium release by calcium hydroxide pastes in distilled water were evaluated in 24h, 7, 14 and 28 days. The results were submitted to ANOVA test (p = 0.05). After 28 days, root canals from experimental groups were examined in SEM. Results: G1, G2, G3 and G4 presented similar pH values and calcium release and did not differ from each other (p>0.05), up to 7 days. After this time G1, G2 and G3 presented values lower values than G4 (p<0.05). In SEM analysis, calcium hydroxide residues were observed in all experimental groups. Conclusions: After 7 days, coronal leakage decreased the concentration of hydrogen ions and calcium ion release provided by all calcium hydroxide pastes.

Avaliação da eficácia de limpeza de quatro agulhas irrigadoras endodônticas

The irrigation of root canals aims to their cleaning and disinfection, improving endodontic treatment success. OBJECTIVE: To investigate the influence of the diameter and type of irrigation needle and the root canal enlargement on the mechanical efficacy of endodontic irrigation. MATERIAL AND METHODS: Twelve human single-rooted mandibular incisors were used. During some instrumentation stages (enlargement by #20, #30, and #40 K file), root canals were filled with radiographic contrast solution mixed to propyleneglycol and zinc oxide. Needles with different diameters and designs were employed: G1 – 23G and lateral opening; G2 – 22G and apical opening; G3 – 30G and lateral opening; G4 – 30G and apical opening. The needles were inserted up to resistance, with 1 mm step-back to avoid root canal obliteration. The irrigation was performed with 2 mL of distilled water. Before and after irrigation/aspiration, teeth were radiographed at bucco-lingual and mesiodistal direction, using a digital radiographic system. Then, root canal areas, before (filled by contrast solution) and after irrigation (remnant of contrast solution), were submitted to image subtraction with Adobe Photoshop CS4 software. Subsequently, the areas were measured by Image Tool 3.0 software, allowing the obtaining of the cleaning percentage for each modality. Data were analysed by using Anova and Tukey's test. The level of significance was set at P < 0.05. RESULTS: For all root canal enlargements, 30G needles (G3 e G4) presented a better cleaning efficacy. In all groups, higher cleaning efficacy percentage was observed at #30 and #40 K file enlargement. CONCLUSION: Regardless their design, thinner needles were more effective; a better cleaning efficacy occurred in more enlarged root canals.

Influência da agulha irrigadora e da dilatação do canal radicular na eficácia da irrigação endodôntica

Introduction: The irrigation of root canals aims to their cleaning and disinfection, improving endodontic treatment success. Objective: To investigate the influence of the diameter and type of irrigation needle and the root canal enlargement on the mechanical efficacy of endodontic irrigation. Material and methods: Twelve human single-rooted mandibular incisors were used. During some instrumentation stages (enlargement by #20, #30, and #40 K file), root canals were filled with radiographic contrast solution mixed to propyleneglycol and zinc oxide. Needles with different diameters and designs were employed: G1 – 23G and lateral opening; G2 – 22G and apical opening; G3 – 30G and lateral opening; G4 – 30G and apical opening. The needles were inserted up to resistance, with 1 mm step-back to avoid root canal obliteration. The irrigation was performed with 2 mL of distilled water. Before and after irrigation/aspiration, teeth were radiographed at bucco-lingual and mesiodistal direction, using a digital radiographic system. Then, root canal areas, before (filled by contrast solution) and after irrigation (remnant of contrast solution), were submitted to image subtraction with Adobe Photoshop CS4 software. Subsequently, the areas were measured by Image Tool 3.0 software, allowing the obtaining of the cleaning percentage for each modality. Data were analysed by using Anova and Tukey’s test. The level of significance was set at P < 0.05. Results: For all root canal enlargements, 30G needles (G3 e G4) presented a better cleaning efficacy. In all groups, higher cleaning efficacy percentage was observed at #30 and #40 K file enlargement. Conclusion: Regardless their design, thinner needles were more effective; a better cleaning efficacy occurred in more enlarged root canals.

Residues of different gel formulations on dentinal walls: a SEM/EDS analysis

The aim of this study was to evaluate the presence of residues of sodium hypo-chlorite gel, chlorhexidine gel, and EDTA gel on dentina l walls after canal preparat ion throughchemical SEM- elemental chemical microanal ys is (EDS) analysis. Forty-eight single-rootedteeth were selected. They had their crowns sectioned and were instrumented with a reciprocat-ing system. The canals were irrigated with 5 mL of saline solution during root canal preparation.After instrumentation, the root canals were irrigated with 3 mL 17% EDTA followed by 1 min ofultrasonic passive activation (33 20 sec) to remove the smear layer, and then irrigated with3 mL of saline solution. The specimens were randomized into three groups (n 5 12) accord ing tothe chemical substance that filled the root canal for 30 min: GI: 5.5% sodium hypochlorite gel;GII: 2% chlorhexidine gel; GIII: 24% EDTA gel; Negative c ontrol group: no substance was used.Then, the root canals were irrigated with 6 mL of saline solution followed by 1 min of ultrasonicpassive activation (33 20 sec). After ultrasonic activation , the canals were irrigated with 2 mLsaline. The roots were sect ioned, and the perce ntage of each chemical element present in thesamples was analyzed through chemi cal SEM-EDS microanalysis. All expe rimental groupsshowed a significantly higher percentage of chemical elements (Na and/or Cl) than the controlgroup (P < 0.03). This in vitro study has shown that, regardless of chemical solutions used evenafter the final irrigation protocol, chemical residues of d ifferent substances remained attached tothe r oot c anal wa lls. Microsc. Res. Tech. 78:495–49 9, 2015.

Influence of the gutta-percha taper and finger spreader on lateral consensation effectiveness

Introduction: Lateral condensation effectiveness may be influenced by the gutta-percha and finger spreader taper used during root canal obturation. Objective: To evaluate the penetration ability of finger spreader into simulated root canals prepared using MTwo rotary system and filled with different gutta-percha and finger spreader tapers. Material and methods: Resin blocks with curved root canals had the apical diameter enlarged up to #25.06 and distributed into groups (n = 6) according to the gutta-percha taper (#25.02, #25.04, and #25.06) and the finger spreader (#30 and #35 NiTi, and stainless steel B) used to perform cold lateral condensation. After applying a load of 1.5 Kg over the finger spreaders’ head, the distance between the finger spread tip and the apical limit of the root canal preparation were obtained. The data were submitted to Anova and Tukey-Krammer’s test, with 5% of significance. Results: The gutta-percha cones with 0.02 taper enabled higher finger spreader penetration when compared to 0.04 and 0.06 tapers (p < 0.05), which were similar between each other (p > 0.05), regardless of the type and diameter of the finger spreader used. When different finger spreaders were compared among themselves, stainless steel B showed higher penetration ability (p < 0.05). Conclusion: It was concluded that the stainless-steel finger spreaders showed superior penetration ability and gutta-percha with lower tapers enabled a more effective lateral condensation at the apical third.

Ability of different methods to fill retrograde cavities with MTA.

The Mineral Trioxide Aggregate (MTA) has excellent biological property. However, its consistency makes it difficult to be inserted into retrograde cavities. Objective:To evaluate the ability of different methods to fill retrograde cavities with MTA. Material and methods: Root canals of thirty single-rooted resin teeth were prepared and filled. After the cut of 3 mm short of apical third, retrograde cavities with 3 mm deep were prepared using an ultrasound device and retrotips (CVD, São José dos Campos, SP, Brazil). The retrograde preparation was evaluate by using an operative microscope (D.F. Vasconcellos, São Paulo, SP, Brazil). The teeth were randomly divided into three groups (n = 10), according to the method: 1) condenser (Trinity, São Paulo, SP, Brazil); 2) MTA applicator (Angelus, Londrina, Brazil) + condenser; 3) condenser associated with ultrasound (CVD, São José dos Campos, SP, Brazil). After the filling of retrograde cavities with white MTA (Angelus, Londrina, Brazil), teeth were radiographed using a digital system (Kodak RVG 6000, Rochester, NY, USA). The images were analyzed by UTHSCSA Image Tool 3.0 software. The percentage of filling was calculated by the proportion between the total area of retrograde cavity and the filled area. The radiographic density mean of each third of retrograde cavity filled with MTA was measured by using the histogram tool of the software. The results were submitted to ANOVA and Tukey tests, with 5% of significance. Results: There was no difference in percentage of filling among the groups (p > 0.05) (approximately 85%). By comparing the thirds, the condenser and MTA applicator groups showed higher density for apical and middle third than cervical third (p < 0.05). The ultrasound group presented similar density among the thirds. Conclusion: The filling ability was similar for the studied methods. Ultrasound promoted better distribution of MTA in retrograde cavity, but did not increase the density of material.

Effectiveness of several solutions to prevent the formation of precipitate due to the interaction between sodium hypochlorite and chlorhexidine and its effect on bond strength of an epoxy-based sealer

To evaluate the effectiveness of isopropyl alcohol, saline or distilled water to prevent the precipitate formed between sodium hypochlorite (NaOCl) and chlorhexidine (CHX) and its effect on the bond strength of an epoxy-based sealer in radicular dentine. Methodology The root canals of 50 extracted human canines (n = 10) were instrumented. In G1, root canals were irrigated with 17% EDTA and 2.5% NaOCl; G2, as G1, except that 2% CHX was used as the final irrigant. In the other groups, intermediate flushes with isopropyl alcohol (G3), saline (G4) or distilled water (G5) were used between NaOCl and CHX. The specimens were submitted to SEM analysis to evaluate the presence of debris and smear layer, in the apical and cervical segments. In sequence, fifty extracted human canines were distributed into five groups (n = 10), similar to the SEM study. After root filling, the roots were sectioned transversally to obtain dentine slices, in the cervical, middle and apical thirds. The root filling was submitted to a push-out bond strength test using an electromechanical testing machine. Statistical analysis was performed using Kruskal–Wallis and Dunn's tests (α = 5%). Results All groups had similar amounts of residue precipitated on the canal walls (P > 0.05). The push-out bond strength values were similar for all groups, independently of the root third evaluated (P > 0.05). Conclusions Isopropyl alcohol, saline and distilled water failed to prevent the precipitation of residues on canal walls following the use of NaOCl and CHX. The residues did not interfere with the push-out bond strength of the root filling.

Dentinogenesis imperfecta type II: approach for dental treatment

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Influência do diâmetro foraminal do canal radicular, do tipo e da penetração de agulha, e do fluxo da solução irrigadora na limpeza e na extrusão apical

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

In Vitro Alkaline pH Resistance of Enterococcus faecalis

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Surface Characteristics of Reciprocating Instruments Before and After Use - A SEM Analysis

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)