Effects of a lectin-like protein isolated from Acacia farnesiana seeds on phytopathogenic bacterial strains and root-knot nematode

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The induction of cytotoxicity, oxidative stress, and genotoxicity by root canal sealers in mammalian cells

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Microbial leakage of MTA, Portland cement, Sealapex and zinc oxide-eugenol as root-end filling materials

Objective: The aim of this study was to compare the microbial leakage of mineral trioxide aggregate (MTA), Portland cement (PC), Sealapex and zinc oxide-eugenol (ZOE) as root-end filling materials.Study design: An in vitro microbial leakage test (MLT) with a split chamber was used in this study. A mixture of facultative bacteria and one yeast (S. aureus + E. faecalis + P. aeruginosa + B. subtilis + C. albicans) was placed in the upper chamber and it could only reach the lower chamber containing Brain Heart Infusion broth by way of leakage through the root-end filling. Microbial leakage was observed daily for 60 days. Sixty maxillary anterior human teeth were randomly assigned to different groups - MTA and PC (gray and white), Sealapex + zinc oxide and ZOE, control groups and subgroups to evaluate the influence of EDTA for smear layer removal. These materials were further evaluated by an agar diffusion test (ADT) to verify their antimicrobial efficacy. Data were analyzed statistically by Kruskal-Wallis and Mann-Whitney test.Results: In the MLT, Sealapex + zinc oxide and ZOE did not show evidence of microbial leakage over the 60-day experimental period. The other materials showed leakage from the 15th day. The presence of smear layer influenced microbial leakage. Microbial inhibition zones were not observed in all samples tested by ADT.Conclusion: Sealapex + zinc oxide and ZOE did not show microbial leakage over the experimental period, whereas it was verified within 15 to 45 days in MTA and Portland cement.

Fifteen-year Follow-up of a Conservatively Managed, Root-fractured Permanent Incisor

The purpose of this case report was to describe the successful long-term conservative management of a root-fractured permanent maxillary right central incisor in an 8-year-old patient. After the initial approach of splinting the traumatized tooth, the patient was followed on a regular basis for 15 years. Clinically, the crown of the root-fractured incisor showed no displacement or discoloration, and thermal tests suggested pulp vitality over the follow-up period. Radiographically, an increase in the diastasis was observed between the apical and coronal fragments due to both the growth of the alveolar process and the healing with interposition of hard and soft tissue between the fragments and confirmed with computed tomography scan in the 15-year follow-up appointment. (Pediatr Dent 2012;34:156-8) Received June 21, 2010 vertical bar Lost Revision August 18, 2010 vertical bar Accepted August 27, 2010

Measurement of the differential cross section d sigma/dt in elastic p(p)over-bar scattering at root s=1.96 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Radiographic and microbiologic evaluation of posttreatment apical and periapical repair of root canals of dogs' teeth with experimentally induced chronic lesion

The objective of the present study was to evaluate radiographically and bacteriologically apical and periapical repair in dogs' teeth with induced chronic periapical lesions with the use of two different operative techniques (techniques 1 and 2). The study was conducted on 40 root canals of upper and lower premolars from two dogs aged approximately 12 months. Periapical lesions were induced by leaving the root canals exposed to the oral environment for 5 days and then sealing them with zinc oxide-eugenol for 45 days. After this period, radiographic examination revealed the occurrence of a radiolucent lesion and endodontic treatment was started. The two techniques did not differ in terms of chemomechanical preparation, final filling, or type of cement, but differed in terms of irrigating solution and the presence of an antibacterial dressing. Thus 4% to 6% hypochlorite and hydrogen peroxide (10 volumes) were used in technique 1 during chemomechanical preparation and an antibacterial dressing based on calcium hydroxide was applied between sessions, whereas Dakin's fluid (0.5% sodium hypochlorite solution) and a final filling with no antibacterial dressing were used in technique 2. After chemomechanical preparation, the root canals were filled with gutta-percha cones and Sealapex (Sealapex-Sybron, Kerr, Sao Paulo, Brazil), and the animals were killed 270 days after the final filling. Blocks were cut into 6-μm sections and stained by the Brown and Brenn method. Radiographic, histomicrobiologic and statistical analysis permitted us to conclude the following: radiographically there was a marked reduction or even the disappearance of the radiolucent area present before treatment with greater success in the group treated with technique 1 (group I) than in the group treated with technique 2 (group II); the extent of bacterial invasion of dentinal tubules was greater and more intense in group II than in group I; and the amount of microorganisms detected in the ramifications of the apical delta and in the lumen of the root canal was intense in group II and mild or absent in group I. © 1994.

Effect of dentine surface treatment on leakage of root fillings with a glass ionomer sealer.

The purpose of this study was to observe the quality of seal of the glass ionomer cement, Ketac-Endo, after treatment of the root canal wall. The root canals of 140 extracted human teeth were prepared biomechanically. The root canals were treated with either EDTA or received an intracanal dressing of calcium hydroxide or camphorated paramonochlorphenol. The root canals were filled by the lateral condensation technique with gutta-percha points and the sealer Ketac-Endo, or zinc oxide-eugenol cement or Sealapex. The teeth were placed into a 2% methylene blue dye solution inside a flask, which was attached to a vacuum pump. Leakage was measured linearly. Sealapex exhibited significantly less leakage than Ketac-Endo or zinc oxide-eugenol cement (P<0.01). The use of EDTA and intermediary dressings reduced significantly (P<0.01) the leakage observed with the zinc oxide-eugenol sealer and Ketac-Endo.

Apical leakage following root canal dressing with calcium hydroxide.

The purpose of this study was to analyse the apical leakage in teeth filled by the lateral condensation technique following medication with calcium hydroxide. One hundred and twenty extracted human teeth were biomechanically prepared by using exclusively reaming motion with files up to #40. Half of the teeth received a calcium hydroxide dressing for 3 days. The medication was removed by irrigation and reaming motion with files #40 up to #70. The teeth were divided in 6 experimental groups, according to the dimension of the utilized instrument. The root canals were filled and posteriorly the teeth were placed into a 2% methylene blue dye solution inside a flask, which was attached to a vacuum pump. Leakage was measured linearly, and the results showed significantly (p<0.01) less leakage in the experimental groups that received calcium hydroxide dressings than in the control groups. The results persisted even after the removal of 300 micrometers of dentin from the root canal dentinal walls.

Anaerobic microorganisms in root canals of human teeth with chronic apical periodontitis detected by indirect immunofluorescence

Aiming to assess the presence of selected anaerobic microorganisms in root canals of human teeth with chronic apical periodontitis, 25 central and lateral upper incisors presenting with radiographic evidence of chronic apical periodontitis were studied. The pulp chamber was opened under aseptic conditions and samples of the root canal content were collected with sterile absorbent paper points, which were placed and dispersed in test tubes containing reduced transport medium (RTF). Aliquots were dried on glass slides and stained by indirect immunofluorcscencc for detection of Actinomyces viscosus, Fusobacterium nucleatum, Porphyromonas gingivalis and Prevotella intermedia. The results showed a positive indirect immunofluorescence reaction in 24 of the 25 samples. Fourteen were positive for the specie Actinomyces viscosus, 12 for Prevotella intermedia, 10 for Fusobacterium nucleatum and 4 for Porphyromonas gingivalis. A semiquantitative assay was easily implemented for assessment of degree of infection by the organisms in individual cases. © Munksgaard, 1996.

pH changes at the surface of root dentin when using root canal sealers containing calcium hydroxide

The purpose of this study was to investigate long-term pH changes in cavities prepared in root surface dentin of extracted teeth after obturation of the root canal with gutta-percha and a variety of sealers containing calcium hydroxide. After cleaning and shaping, root canals in 50 recently extracted, human single-rooted teeth were divided into five groups. Each of four groups was obturated with gutta-percha and either Sealapex, Sealer 26, Apexit, or CRCS, all of which contain calcium hydroxide. The remaining group served as the control and was not obturated with gutta-percha or sealer. Cavities were prepared in the facial surface of the roots in the cervical and middle regions. The pH was measured in these dentinal cavities at the initiation of the experiment, and 3, 7, 14, 21, 28, 45, 60, 90, and 120 days after obturation. Results indicate that the pH at the surface of the root does not become alkaline when calcium hydroxide cements are used as root canal sealers. Regardless of the sealer used, the observed pattern of pH change was not different from that seen in the control group of roots that were not treated with sealer. It is concluded that calcium hydroxide-containing cements, although suitable for use as root canal sealants, do not produce an alkaline pH at the root surface. If such a pH change is related to treatment of root resorption, these sealants do not contribute to this treatment. Copyright © 1996 by The American Association of Endodontists.

Apical leakage after root canal filling with an experimental calcium hydroxide gutta-percha point

This study was an in vitro analysis of the apical seal of root canals filled with an experimental calcium hydroxide gutta-percha point. One hundred and ten recently extracted human permanent teeth with a single root were used. The root canals were biomechanically prepared, and some received a dressing of calcium hydroxide for 7 days. Root canals not dressed were filled by the lateral condensation technique with either regular gutta-percha or calcium hydroxide gutta-percha points. The dressed root canals were filled with the same sealers and regular gutta-percha points. The specimens were placed into a 2% methylene blue dye solution under vacuum, and the apical leakage was linearly evaluated. The experimental groups with calcium hydroxide dressing and the one with calcium hydroxide gutta-percha points exhibited significantly (p < 0.05) less leakage than the groups filled with regular gutta-percha points. The results obtained indicated that calcium hydroxide guttapercha points produced an improvement in the apical sealing quality of the root canal filling. Copyright © 1996 by The American Association of Endodontists.

Calcium hydroxide root canal sealers: Evaluation of pH, calcium ion concentration and conductivity

The calcium hydroxide ionization of four root canal sealers (Sealapex, CRCS, Sealer 26, and Apexit) was studied by measuring conductivity and pH and by conducting atomic absorption spectrophotometry. Samples 6 mm in diameter and 15 mm long were prepared from these sealers. After setting and 48 h storage in a desiccator, five samples of each material were placed in 50 mL distilled water and analysed after 0,1,2,4, 6 and 24 h and 5, 15 and 30 days. The results showed that Sealapex was the root canal sealer showing the highest pH, ionic calcium and total calcium values (P<0.05) throughout the experimental period, followed by CRCS, Apexit and Sealer 26.