Apical Sealing Ability of Mineral Trioxide Aggregate, Intermediate Restorative Material and Calcium Enriched Mixture Cement: A Bacterial Leakage Study.

INTRODUCTION: This in vitro study compared the apical sealing ability of three common root end filling materials namely mineral trioxide aggregate (MTA), intermediate restorative material (IRM) and calcium-enriched mixture (CEM) cement using a bacterial leakage model. METHODS AND MATERIALS: The study was conducted on 83 single-rooted human teeth. Tooth crowns were cut and root canals were prepared using the step-back technique. Apical 3 mm of the roots were cut and a three-mm-deep cavity was prepared using an ultrasonic instrument. The samples were divided into three groups (n=25) according to the root-end filling material including MTA, IRM and CEM cement. The roots were inserted into cut-end microtubes. After sterilization with ethylene oxide, microtubes were placed in sterile vials containing 10 mL of Brain Heart Infusion (BHI) broth and incubated at 37°C and 0.1 mL of Enterococcus faecalis suspension compatible with 0.5 McFarland standard (1.5×108 cell/ ml), which was refreshed daily. This procedure was continued for 70 days. The data were analyzed using the chi-square, Kruskal-Wallis and log rank tests. The level of significance was set at 0.05. RESULTS: No significant difference was found in bacterial microleakage among three groups; MTA showed slightly (but not significantly) less microleakage than IRM and CEM. However, the difference in the mean time of microleakage was significant among the groups (P<0.04) and in MTA samples leakage occurred in a longer time than CEM (P<0.012). CONCLUSION: The three tested root end filling materials had equal sealing efficacy for preventing bacterial leakage.

Efficacy of a Novel Rotary System in Reduction of Intracanal Bacteria: An in Vitro Study.

INTRODUCTION: This in vitro study aimed to assess the effectiveness of a single-file rotary system (OneShape) in reduction of intracanal bacteria. METHODS AND MATERIALS: Eighty one single-rooted mandibular first premolars with single canals were used. Six samples were selected as aseptic control group. Seventy five remaining specimens were infected by Enterococcus faecalis and incubated for 72 h at 37(°)C. Then they were randomly divided into three groups (n=25). In each group, cleaning and shaping procedures were done using either two conventional rotary systems (ProTaper and iRace), or the single-file system (OneShape). Microbial samples from the intracanal environment were taken by paper points in two steps, before and after instrumentation. Then, they were diluted and plated in blood agar. In order to compare bacterial reduction and turbidity, the Kruskal-Wallis test was used followed by the Chi-Square and Mann-Whitney tests for pairwise comparison. The level of significance was set at 0.05. RESULTS: The control group didn't show any bacterial growth. The pre- and post-instrumentation samples were significantly different between three groups (P=0.02). Hence, there was no significant differences between turbidity of samples (P>0.05). CONCLUSION: OneShape system is efficient in bacterial reduction. In this regard ProTaper is the most effective system in intracanal bacterial reduction followed by iRaCe and OneShape, respectively.

Prevalence of dental anomalies among 7- to 35-year-old people in Hamadan, Iran in 2012-2013 as observed using panoramic radiographs.

PURPOSE: This study was performed to evaluate the prevalence of all types and subtypes of dental anomalies among 7- to 35-year-old patients by using panoramic radiographs. MATERIALS AND METHODS: This cross-sectional study was conducted on 1649 people in Hamadan City, in 2012-2013. The prevalence of four types and 12 subtypes of dental anomalies was evaluated by two observers separately by using panoramic radiography. Dental anomalies were divided into four types: (a) shape (including fusion, taurodontism, and dens invagination); (b) number (including hypodontia, oligodontia, and hyperdontia); (c) structure (including amelogenesis imperfecta, dentinogenesis imperfecta, and dentin dysplasia); and (d) position (including displacement, impaction, and dilacerations). RESULTS: The reliability between the two observers was 79.56% according to the Kappa statistics. The prevalence of dental anomalies diagnosed by panoramic radiographs was 29%. Anomalies of position and number were the most common types of abnormalities, and anomalies of shape and structure were the least in both genders. Anomalies of impaction (44.76%), dilacerations (21.11%), hypodontia (15.88%), taurodontism (9.29%), and hyperdontia (6.76%) were the most common subtypes of dental anomalies. The anomalies of shape and number were more common in the age groups of 7-12 years and 13-15 years, respectively, while the anomalies of structure and position were more common among the other age groups. CONCLUSION: Anomalies of tooth position were the most common type of dental anomalies, and structure anomalies were the least in this Iranian population. The frequency and type of dental anomalies vary within and between populations, confirming the role of racial factors in the prevalence of dental anomalies.

Comparison of the accuracy of cone-beam computed tomography, photostimulable phosphor imaging plate, charge coupled device, and conventional intraoral radiography in the diagnosis of internal root resorption: an in vitro study / Comparação da precisão da tomografia computadorizada de feixe cônico, placa de imagem de fósforo fotoestimulável, chargecoupleddevice(CCD), e radiografia intra-oral convencional no diagnóstico de reabsorção radicular interna: um estudo in vitro

Objective: Various radiographic methods are used to identify the internal root resorption. The aim of this study was to assess and compare the diagnostic accuracy of cone-beam computed tomography (CBCT), photostimulable phosphor (PSP) imaging plate, charge coupled device (CCD), and conventional intraoral radiography (CIR), for internal root resorption. Material & Methods: This experimental study was conducted in Hamadan in 2012. Fifty seven carries-free single-rooted teeth were divided into three intervention groups of 15 teeth and one control group of 12 teeth. Teeth were split into two parts using a disk. Cavities of 0.5, 1 and 1.5 mm in depth were created in root canal of teeth to simulate internal root resorption artificially. Finally, the teeth fragments were fused. All teeth were examined with four different procedures and the results were compared with known simulated internal root resorption as the gold standard to determine the sensitivity and specificity of the procedures. Results: The sensitivity of CBCT, PSP, CCD, and CIR for diagnosis internal root resorption of 0.5 mm in depth was 93%, 73%, 60%, and 53% respectively. The sensitivity of all four procedures for diagnosis of internal root resorption with 1 and 1.5 mm in depth was the same and equal to 100%. Specificity of the four radiology procedures for diagnosis of internal root resorption of any depth was 100%, 100%, 83% and 75% respectively. Conclusion: CBCT provides the most accurate information on the depth and location of root resorption followed by the PSP and CCD respectively. Accordingly, conventional intraoral radiography was the least accurate procedure

Objetivos: Vários métodos radiográficos são utilizados para identificar a reabsorção radicular interna. O objetivo deste estudo foi avaliar e comparar a precisão do diagnóstico de reabsorção radicular interna por tomografia computadorizada de feixe cônico (TCFC), placa de imagem de fósforo fotoestimulável(FFE), Charge CoupledDevice( CCD) e radiografia intra-oral convencional (RIC). Material e Métodos: Este estudo experimental foi realizado em Hamadan em 2012. Cinqüenta e sete dentes anteriores livres de cárie foram divididos em três grupos de 15 dentes e um grupo de 12 dentes foi utilizado como controle. Os dentes foram divididos em duas partes usando um disco. Cavidades de 0,5, 1 e 1,5 mm de profundidade foram criados nos canais radiculares dos dentes para simular a reabsorção radicular interna artificialmente. A seguir , os fragmentos de dentes foram unidos . Todos os dentes foram examinados com quatro diferentes procedimentos e os resultados foram comparados com um padrão ouro conhecido de diagnóstico de reabsorção radicular interna simulada para determinar a sensibilidade e especificidade dos procedimentos. Resultados: A sensibilidade da TCFC, FFE, CCD e RIC para diagnóstico reabsorção radicular interna de 0,5 mm de espessura foi de 93 %, 73 %, 60 % e 53 %, respectivamente. A sensibilidade dos quatro processos para o diagnóstico da reabsorção radicular interna com 1 e 1,5 mm de profundidade foi a mesma e igual a 100 %. A especificidade dos quatro procedimentos de radiologia de diagnóstico de reabsorção radicular interna de qualquer profundidade foi de 100 %, 100 %, 83 % e 75 %, respectivamente. Conclusão: A TCFC fornece as informações mais precisas sobre a profundidade e localização da reabsorção radicular, seguido pelo FFE e CCD, respectivamente. Assim, a radiografia intra-oral convencional foi o procedimento menos preciso.

Sealing Ability of Resilon and MTA as Root-end Filling Materials: A Bacterial and Dye Leakage Study.

INTRODUCTION: Endodontic surgery is a valuable option for maintaining patient's natural dentition when previous orthograde endodontic treatments fail to succeed. Proper root-end preparation and placement of a retro-filling material are recommended for successful endodontic surgery. The objective of this experimental study was to compare sealing ability of Resilon/Epiphany system, as a potential root-end filling material, with ProRoot MTA using both dye and bacterial leakage models. MATERIALS AND METHODS: Ninety two single-rooted extracted human teeth were decoronated and prepared endodontically. Specimens were randomly divided into four experimental groups (n = 20) and four control groups (n = 3). After removal of apical 3 mm and root-end cavity preparation, MTA, or Resilon were used to fill root end cavities. For bacterial leakage, specimens (20 for each experimental group, 3 negative, and 3 positive controls) were subjected to E. faecalis over a 70-day period. Methylene blue was used for dye leakage (the same in number as before). Using stereomicroscope (40× mag.) complete dye leakage was assessed after 72 h. Kaplan-Meier survival analysis was performed for bacterial leakage. The data was analyzed using t-test and Chi-square analysis (α = 0.05). RESULTS: All of the positive controls and none of negative controls revealed leakage. Result of log rank test showed no significant difference between MTA and Resilon in time of bacterial leakage at the end of the 70 days (P > 0.05) There was also no statistical difference in complete dye leakage for both groups (P > 0.05). CONCLUSION: Leakage occurred in both MTA and Resilon as root-end filling material but the difference was not statistically significant. Resilon might be noticed as a potential root-end filling material if good isolation is attainable.

Endodontic treatment of a mandibular first molar with three mesial canals and broken instrument removal.

To succeed in any dental procedure, the clinician's awareness of the patient's dental anatomy and its variations is crucial. In endodontic therapy, obtaining full information about the root canals' variations can affect the outcome substantially. This case report presents the endodontic treatment of a mandibular first molar exhibiting three mesial root canals with 4 mm of a separated K-file in the coronal third of the mesiolingual canal on an 18-year-old female patient. This case demonstrates the importance of locating additional canals in any roots undergoing endodontic treatment and how the clinician's awareness of aberrant internal anatomy may change the treatment results.

The knowledge and attitude of general dentists toward denture adhesives in Tehran.

BACKGROUND: The purpose of this study was to generate discussion and communication among a group of general dentists in Tehran on their viewpoints regarding denture adhesives. Have they accepted denture adhesive as a material to enhance denture retention, stability and function? MATERIALS AND METHODS: In the summer of 2007, a questionnaire was mailed to 300 general dentists who were assigned with a random systematic sampling method from general dentists in Tehran. The questions were arranged in two parts of evaluating knowledge and attitude. In evaluation of knowledge, dentists were classified into groups of good, moderate, weak and lack of knowledge. In evaluation of attitude, dentists were classified into positive, moderate and negative groups. (Evaluating attitude was carried out in good and moderate groups of knowledge.) RESULTS: The study showed that 14%, 32% and 37% of the general dentists had respectively good, moderate and weak knowledge toward denture adhesive while 16.3% had no knowledge about this material. In evaluation of attitude through dentists with positive and moderate knowledge toward denture adhesive, 9.3%, 71.3% and 19.4% had respectively positive, moderate and negative attitude toward denture adhesive. The chi2 test showed a significant statistical relation between situation of knowledge and experiences of dentists. DISCUSSION: This study demonstrated that the rate of knowledge of these 300 general dentists in Tehran towards denture adhesives has not been in a good situation. It is believed that denture adhesive be able to enhance the fitness of a denture and provide psychological relief to the patient. Dentists agreed that education, not only for practitioners but also for patients, would raise the advantageous features and reduce the misuse of denture adhesive. Education of the topic "Denture adhesive" should be more concerned in dental universities.