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

Monitoramento do perfil microbiológico de dentes com infecção endodôntica primária durante terapia com diferentes medicações intracanal

Pós-graduação em Odontologia Restauradora - ICT

Incomplete vertical root fracture associated with lateral compaction technique: a microscopic analysis

Objective: This study evaluated the effects of root canal obturation employing lateral compaction technique and spreader load of 1.5 kg on the incidence of complete (CVRF) or incomplete vertical root fractures (IVRF). Material and Methods: Twenty-seven distal roots of extracted human mandibular molars were used. All root canals were prepared by biomechanical step-back technique and obturated by lateral compaction technique. The prepared roots were distributed into two groups: G1- experimental (n = 17) and G2- control (n = 10). During obturation, load of 1.5 kg was applied to a size # 30 finger spreader. Pre- and post-obturation images of the coronal portion of the roots were captured by inverted digital microscopy and analyzed by one trained examiner. Data were evaluated by Fisher’s test (p < 0.05) using GrapH Pad Prism 5.0. Results: No roots exhibited CVRF. All fractures observed before and after obturation were IVRF or “other defects”. In G2 (control group), there was no increase of IVRF number. Interestingly, G1 presented an increase in the IVRF number to 70.59% in the 12 teeth out of 17 teeth studied. The statistical analysis showed that the mean of IVRF increased significantly in G1 when compared to G2 (p < 0.05). Conclusion: The application of a 1.5 kg spreader load during lateral compaction technique does not produce complete vertical root fractures, but may produce incomplete fractures or “other defects”.

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.

A new calcium silicate-based material (Biodentine) for filling radicular perforation in an endodontic-periodontal lesion: a case report

This case report presents an apical radicular perforation management using new calcium silicate-based cement (Biodentine) in a combined endodontic-periodontal lesion. The presence of apical radicular perforation may interfere in the endodontic treatment prognosis. Radicular perforation filling with bioactive cement through endodontic surgery is a possible treatment. This study presents an apical radicular perforation with periodontal involvement, due to alveolar bone loss on the buccal radicular surface from an incorrect intracanal preparation for the fiber post placing. The chosen alternative was a periapical surgery, the perforation was filled with a silicate and calcium chloride bioactive cement (Biodentine; Septodont, Saint-Maur-des-Fosses Cedex, France), and the radicular surface was etched with citric acid, because the access from root canal was impossible. The follow-up was for 8 months, through clinical and radiographic analysis. At the end of the follow-up, radiographic analyses showed the bone healing, and no clinical changes in periodontal probing depth, gingival recession, and the height of the interproximal mesial and distal papillae were observed. The root perforation treatment has a difficult management, especially when the dental root has a simultaneous periodontal commitment. The Biodentine proves to be a promising material for use in these situations.

Portland cement use in dental root perforations: a long term followup

Root canal and furcal perforations are causes of endodontic therapy failure and different materials that stimulate tissue mineralization have been proposed for perforation treatment. In the first case, a patient presented tooth 46 with unsatisfactory endodontic treatment and a periapical radiographic lesion. A radiolucent area compatible with a perforating internal resorption cavity was found in the mesial root. The granulation tissue was removed, and root canals were prepared. The intracanal medication was composed of calcium hydroxide and the perforation cavity was filled with Portland cement. The 11-year followup showed radiographic repair of the tissue adjacent to the perforation and absence of clinical signs and symptoms or periapical lesion. In the second case, a patient presented with edema on the buccal surface of tooth 46. The examination showed a radiolucent area in the furcation region compatible with an iatrogenic perforation cavity. The mesial root canals were calcified, and only the distal root canal was prepared. The cavity was filled with a calcium hydroxide-based paste and the distal root canal was obturated. In sequence, the perforation cavity was filled with Portland cement. The 9-year followup showed the tooth in masticatory function with radiographic and clinical aspects compatible with normality.

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)

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

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Influence of Insertion Techniques for Resin Cement and Mechanical Cycling on the Bond Strength Between Fiber Posts and Root Dentin

Purpose: To evaluate the effect of the insertion technique for resin cement and mechanical cycling on the bond strength between fiber posts and root dentin.Materials and Methods: Sixty-four single-rooted bovine teeth were endodontically prepared to receive glass-fiber posts. The insertion of cement into the root canal was performed using one of the following techniques: POS, insertion with the post; LEN, the use of a lentulo-type drill; EXP, insertion with a straight-tip explorer; or CEN, the use of a Centrix syringe. Half of the specimens were mechanically cycled. All specimens were sectioned into slices of 1.8 mm for the push-out test and 0.5 mm for analysis of the cement layer quality.Results: The insertion technique affected the interaction between factors (bond strength and mechanical cycling; p < 0.0001). Insertion of the Centrix syringe after mechanical cycling showed the highest bond values (13.6 +/- 3.2 MPa). Group-to-group comparisons for baseline and cycled conditions indicated that mechanical cycling significantly influenced the bond strength (p < 0.0001) of the POS and CEN groups. The quality of the cement layer did not differ between the techniques when evaluated in the middle (p = 0.0612) and cervical (p = 0.1119) regions, but did differ in the apical region (p = 0.0097), where the CEN group had better layer quality for the two conditions tested (baseline and cycled).Conclusion: The use of the Centrix syringe improved the homogeneity of the cement layer, reducing the defects in the layer and increasing adhesive strength values to dentin, even after mechanical cycling.

Effect of intracanal dressings on repair and apical bridging of teeth with incomplete root formation

Periapical repair and apical bridging were studied in dog's teeth with incomplete root formation and induced chronic periapical lesions treated with different dressings. A total of 75 root canals from the upper and lower premolars of 4 dogs approximately 6 months of age were chemo-mechanically prepared and filled with the following dressings: antibacterial dressing consisting of a calcium hydroxide+camphorated p-monochlorophenol paste applied for 7 days and followed by monthly renewed calcium hydroxide paste as temporary dressing at 30, 60 and 90 days (Group A); antibacterial dressing consisting of camphorated p-monochlorophenol alone for 7 days, followed by temporary dressing with calcium hydroxide paste renewed at 30, 60 and 90 days (Group B). A control group (Group C) received no dressings. Ninety days after the last calcium hydroxide paste (Groups A, B) and after the last irrigation/aspiration (Group C), the animals were killed, the maxillae and mandibles were removed, and the material submitted to routine histological processing and examination. Both root canal dressings, were of fundamental importance for apical repair and bridging. The apical bridging was predominantly complete in Group A, incomplete in Group B, and absent in Group C. The calcium hydroxide+camphorated p-monochlorophenol combination gave better results than camphorated p-monochlorophenol alone.

Porosity and sealing ability of root fillings with gutta-percha and BioRoot RCS or AH Plus sealers. Evaluation by three ex vivo methods

To investigate the ability of BioRoot RCS, a tricalcium silicate-based root canal sealer and AH Plus to effectively fill the root canals of contralateral teeth using three evaluation methods, and to investigate also the correlation between the methods. The prepared root canals of ten pairs of contralateral mandibular premolar teeth were filled with gutta-percha and sealer using lateral compaction. The percentage of voids within the root canal was assessed by micro-computed tomography, whilst sealing ability was investigated by fluid transport and leakage of fluorescent microspheres. The interaction of sealer with dentine, and sealer penetration were assessed by confocal microscopy. The void volume, fluid flow, microsphere leakage and sealer interaction with dentine for both materials were compared. Nonparametric (Mann-Whitney) tests were used to compare the % void and fluid transport of the two sealers. Spearman correlation was used to assess the pairwise relationships between the techniques. The level of significance was set to 0.05. BioRoot RCS exhibited significantly more percentage of voids than AH Plus. There was no difference in fluid flow and microsphere penetration. BioRoot RCS exhibited a different pattern of sealer penetration and interaction with the dentine walls compared to AH Plus. For both materials, the pairwise correlations between the three techniques were close to zero, indicating weak relationships. MicroCT analysis revealed a higher void volume for BioRoot RCS. The other techniques did not show a difference between the sealing ability of the sealers. The correlation between the three ex vivo methods of assessment was weak demonstrating their complementarity rather than their concordance.

Comparison of different irrigants in the removal of endotoxins and cultivable microorganisms from infected root canals

This study was conducted to compare the effectiveness of different irrigants used to remove endotoxins and cultivable microorganisms during endodontic therapy. Forty root canals were contaminated and divided into groups according to the irrigant: 2% NaOCl + surfactant, 2% CHX, 2.5% NaOCl, and pyrogen-free saline solution (control). Samples were collected after root canal contamination (S1), after instrumentation (S2), and 7 days after instrumentation (S3). Microorganisms and endotoxins were recovered from 100% of the contaminated root canals (S1). At S2, 2% NaOCl + surfactant, 2% CHX, and 2.5% NaOCl were able to completely eliminate cultivable microorganisms. At S3, both 2% CHX and 2.5% NaOCl were effective in preventing C. albicans and E. coli regrowth, but E. faecalis was still detected. No microorganism species was recovered from root canals instrumented with 2% NaOCl + surfactant. At S2, a higher percentage value of endotoxin reduction was found for 2% NaOCl + surfactant (99.3%) compared to 2% CHX (98.9%) and 2.5% NaOCl (97.18%) (p < 0.05). Moreover, at S3, 2% NaOCl + surfactant (100%) was the most effective irrigant against endotoxins. All irrigants tested were effective in reducing microorganisms and endotoxins from root canals. Moreover, 2% NaOCl + surfactant was the most effective irrigant against endotoxins and regrowth of microorganisms.

Estudo in vivo e in vitro da incidência de bifurcação do canal radicular de incisivos inferiores pelo método radiográfico digital direto

Pós-graduação em Biopatologia Bucal - ICT

Avaliação e correlação da presença de endotoxinas e MMP-3, -8 e -9 em canais radiculares com necrose pulpar submetidos ao tratamento endodôntico - estudo in vivo

It is know that endotoxin and various matrix metalloproteinases (MMPs) are involved in the development of periapical lesions. The purpose of this study was to evaluate and correlate the presence of endotoxins and MMP- 3, MMP-8 and MMP-9 in root canals of teeth with necrotic pulp and periapical lesion before, during and after the biomechanical preparation (PBM) using a combination of different irrigations solutions and intracanal dressing. Thirty-three single-root teeth with a diagnosis of pulp necrosis and periapical lesion radiographically visible were selected. Immediately after the coronal opening was collected the first sample from the root canal content. Then, all canals were prepared (cervical and middle thirds) by oscillatory instruments (EndoEze) and irrigated by 2.5% NaOCl. After, a manual preparation was made for the apical third and the teeth were divided into three groups according to the irrigation protocol: G1) 2.5% NaOCl (4 manual files); G2) 2.5% NaOCl (2 manual files) + [Ca (OH)2 0.14%] (2 manual files) and G3) 2.5% NaOCl (2 manual files) + polymyxin B (2 manual files). After the PBM, the second sample was collected; then the third collect was performed after using EDTA final flush. The fourth sample was collected 14 days after placing the dressing [2% chlorhexidine gel + Ca(OH)2]. Quantification of endotoxins was performed by a kinetic chromogenic lysate from amoebocytes of Limulus (LAL) and quantification of MMPs by ELISA assay. The results were analyzed statistically by Kruskal-Wallis and Dunn's test (5%) and ordinal Spearman correlation. Presence of endotoxin was observed in 100% of cases and G3 showed the greatest reduction of endotoxins from the 1st to the 2nd samples (97%), being statistically similar to G2 (84.2%) and different from G1 (49.4%) (p<0.05). The intracanal dressing promoted a significant reduction of endotoxin, no difference among the groups. For...

Atividade antimicrobiana de cimentos endodônticos

The antimicrobial activity is a fundamental property of root-canal sealers due to persistence of residual microorganisms in the root canal system, even after the chemo-mechanical preparation and using of intracanal dressing. The aim of this study is to review the literature about the antimicrobial properties of some of the main root-canal sealers. Although there is controversy regarding this property, probably due to differences in the methodologies used in the studies, it was concluded that the sealers with the best antimicrobial activity were (in ascending order): Endofill, Ketac Endo, Sealapex, AH Plus, Endo CPM Sealer, Sealer 26 and Epiphany. Activ GP still needs scientific research to evaluate this property.