Wear analysis promoted in simulated canals apical third after endodontic preparation with K3 Taper .04 System

The authors analyzed the wear in apical third after K3 .04 System preparation. 12 sets of instruments were used and 12 simulated canals in transparent epoxy resin blocks with angles of curvature 20 and 40 degrees. Canals were photographed before preparation and after the utilization of instruments which prepared the apical stop: 30, 35, 40 e 45. The images were overposed in Adobe Photoshop program and the wear was measured in millimeters, in two points, 1 (A) and 5 (B) millimeters from the working length. By Variance Analysis the interaction existence was studied among these three factors: canal curvature, instrument caliber and curve location. In canals of 20 degrees, in both analyzed points, the wear mean promoted by instrument 40 and instrument 35 there was not statistically significant. In canals of 40 degrees, in location A, there was not statistically significant difference in the wear mean promoted by four different instruments. There was a deviation from the original trajectory to the outside the curve, in both analyzed points

Wear promoted in the apical third of simulated canals after instrumentation with protaper universal system

OBJECTIVE: This study evaluated the wear in the apical third of simulate canals after preparation with ProTaper Universal Rotary System. MATERIAL AND METHODS: 24 sets of instruments were used in 24 simulated canals in transparent epoxy resin blocks with degree of curvature of either 20°or 40°. The canals were photographed preoperatively and after preparation of the apical stop with ProTaper F3, F4 and F5 instruments. The initial and final images were exported to Adobe Photoshop® software and superimposed to detect the root canal wall differences (in mm) between them, in two points located 1 (A) and 5 (B) mm from the point where the working length was established. Data were subjected to analysis of variance to verify the existence of interaction among the factors: canal curvature, instrument size and curve location. Significant level was set at 5%. RESULTS: Regardless of the location and the canal curvature, F4 and F5 instruments produced the greatest wear (

Effect of blood contamination on the push-out bond strength of calcium silicate cements

ARTICLE Effect of Blood Contamination on The Push-Out Bond Strength of Calcium Silicate Cements Flavia Kolling Marquezan1 Patricia Maria Poli Kopper1 Angela Isabel dos Santos Dullius2 Diego Machado Ardenghi3 Renata Grazziotin-Soares3 1Department of Conservative Dentistry, UFRGS - Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil 2Department of Statistics, UFSM - Universidade Federal de Santa Maria, Santa Maria, RS, Brazil 3College of Dentistry, University of Saskatchewan, SK, Canada ABSTRACT This study investigated the effect of blood-contamination on the push-out bond strength of BiodentineTM (BD) and MTA Angelus® (MTA-A) to root dentin over time. Twenty-five teeth were sectioned horizontally to obtain 120 root slices. The lumens were filled with MTA-A or BD: 60 for each cement (30 uncontaminated and 30 blood contaminated). Push out bond strength to dentin was assessed at 24 h (n=10), 7 days (n=10) and 28 days (n=10). Failure modes were classified as: cohesive, adhesive or mixed failure. Two-way ANOVA was used to investigate the interaction between blood contamination vs. hydration period. Mann Whitney test compared different materials in each period, and it also compared the contaminated versus uncontaminated material for each period. Friedman, followed by Dunn`s test, compared periods of hydration for each material, regardless of blood contamination. Failure modes were reported descriptively. The interaction hydration period vs. blood contamination was highly significant for MTA-A (P=0.001) and it was not significant for BD (P=0.474). There were no differences between bond strength of uncontaminated and contaminated BD in any of the periods. Bond strength of uncontaminated MTA-A increased at each time of hydration; but it remained stable over time for blood-contaminated samples. BD had higher bond strength than MTA-A in all periods of hydration. Cohesive failure predom

XP Endo Finisher-R and PUI as supplementary methods to remove root filling materials from curved canals

This study assessed the ability of XP-endo Finisher R (FKG, La Chaux-de-Fonds, Switzerland) to remove filling remnants from curved mesiobuccal canals of maxillary molars, using the passive ultrasonic irrigation (PUI) technique as a comparison. Twenty-four curved main mesiobuccal canals (MB1) of maxillary molars were instrumented with Wave One (#25/07) and filled with gutta-percha points and AH Plus Sealer. Samples were then re-treated with a standardized protocol with Wave One (#35/06) as the master apical file. Micro-CT scans measured baseline volume of remaining filling material (in mm3 ). Samples were divided into two groups (n = 12) according to the supplementary cleaning approach: (PUI) or XP-endo Finisher R. Statistics compared baseline and final volume of filling material (within-group); and the percentage of filling material reduction (between-group). Mean baseline volumes, final volumes, and percentages of reduction (%) of filling material for XP-endo Finisher R and PUI were respectively: 0.060 mm3 , 0.042 mm3 , and 31.28%; and 0.064 mm3 , 0.054 mm3 , and 16.57%. Both tested protocols reduced the amount of filling material (p < 0.05). XP-endo Finisher R had higher percentage of reduction as compared to PUI (p < 0.05). XP-endo Finisher R and PUI used as supplementary cleaning protocols during re-treatment improved the removal of root filling material in curved canals; but XP-endo Finisher R was approximately twice more efficient. The complete filling material removal during re-treatment procedures is still a challenge. Supplementary cleaning protocols may help to remove the remaining material after the complete mechanical preparation of curved canals. XP-endo Finisher R was approximately twice more efficient than PUI

Micro Push-out Bond Strength and Bioactivity Analysis of a Bioceramic Root Canal Sealer

Introduction: Bioactive endodontic sealers have been developed to improve the quality of root canal obturation. EndoSequence Bioceramic (BC) Sealer is amongst calcium silicate-based materials recently developed for permanent root canal filling. The objective of this study was to evaluate the bioactivity of BC Sealer and its micro push-out bond strength to dentin compared to AH-Plus (AH) sealer. Methods and Materials: To perform the micro push-out test, 24 root canals of mandibular premolars were instrumented and divided into two groups (n=12). Each root was cut into 4 slices and lumens of the canals were filled with the sealers and submitted to micro push-out test. Failure mode was assessed using scanning electron microscopy (SEM). Bioactivity of BC sealer was investigated with scanning electron microscopy/energy-dispersive X-ray (SEM/EDS) and X-ray diffraction (XRD). Bioactivity assessments were reported descriptively. Bond strength data were analyzed by parametric t-test (α=5%). Results: In micro push-out test AH had higher bond strength mean values (16.29 MPa) than BC sealer (9.48 MPa) (P&lt;0.05). Both groups had low amount of adhesive failure. SEM showed the presence of a mineral precipitate after 30 days and EDS analysis showed that those precipitates have high proportion of Ca. XRD showed peaks of crystalline phases of calcium carbonate compatible with the bioactivity. Conclusion: BC sealer showed indications of bioactivity and lower bond strength to dentine compared to AH.Keywords: Bioactivity; Bioceramic; Dentine; Micro Push-Out Bond Strength; Root Canal Seale

Avaliação, In Vitro, da Microinfiltração Coronária na Interface Amálgama de Prata e Três Materiais Restauradores Provisórios de Uso em Endodontia

The purpose of this study was to evaluate in vitro the microinfiltration at the interface temporary sealing material (Bioplic ® , Coltosol ® and Tempore ® ) and silver amalgam. Fifty seven third molars were used, which were restored with silver amalgam and endodontic cavities were made. The canals were emptied, allowing the paper cone placement; the pulpar chamber filled with cotton and the referred materials were inserted. Imperme-abilization and thermocycling (5oC/55oC) procedures were performed as well as immersion in 2% metylene blue for 24 hours. The specimens were sectioned longitudinally in mesiodistal direction and the results thus obtained were evaluated by the KruskalWallis test which showed that Tempore ® has greater infiltration degrees. Bioplic ® and Coltosol ® obtained better results and there was no difference between them.O objetivo deste estudo foi avaliar in vitro, em dentes extraídos, a microinfiltração de corante na interface material restaurador provisório (Bioplic®, Coltosol® e Tempore®) e amálgama de prata. Utilizou-se 57 terceiros molares hígidos, onde foram confeccionadas amplas restaurações de amálgama de prata. O acesso endodôntico foi realizado sobre essas restaurações, permanecendo o amálgama nas bordas. Os condutos foram esvaziados, permitindo a colocação de cones de papel. A câmara pulpar foi preenchida com algodão e sobre esta se inseriu os três diferentes materiais provisórios. Os espécimes foram impermeabilizados, submetidos à termociclagem (5ºC/55ºC) e imersos em azul de metileno 2% por 24 horas. Após, os dentes foram seccionados longitudinalmente no sentido mésio-distal. Os resultados obtidos avaliados pelo teste Kruskal-Wallis, o qual constatou que o Tempore® possuiu maiores graus de infiltração. O Bioplic® e o Coltosol® tiveram melhores resultados e não diferiram entre si. Torna-se válida a realização deste estudo, pois ocorre, freqüentemente, a necessidade da realização de acessos endodônticos em dentes restaurados com amálgama de prata

Profile of articles addressed to dental pulp revascularization in PubMed database

Introduction: The study aimed to explore the profile of articles published on pulp revascularization by a bibliometric analysis. Material and methods: A search was conducted on the PubMed database and studies were independently categorized according to: (i) year of publication; (ii) country where the study was conducted; (iii) study design; (iv) main topic addressed; (v) main conclusion of the article; and (vi) clinical application/other results. Findings were reported descriptively. There was not restriction regarding to initial date and the established final date was December 2014. Results: 133 studies were found; but only 86 articles were included. The most of them was published recently (23.2% in 2014) and were conducted in 24 different countries. The most frequent study design was case report (37.2%), followed by narrative reviews (16.2%). The main topic addressed was the radiographic outcomes (38.3%) and tissue engineering (19.7%). Some of the articles point the clinical application of their results. Conclusion: Most of the publications highlight that the disinfection of the root canal (and the stimulation of residual stem cells) would induce formation of new hard tissue on the dentin wall and continue root development in length, improving the tooth survival. The number of publications on pulp revascularization has increased recently, but the majority of articles published are studies with low levels of evidence