Endodontics

Within the limitations of this study, cusp-replacing direct and indirect composite resin restorations presented similar resistance to fracture under simulated occlusal loads and may be a viable treatment option for endodontically treated molars with a guarded prognosis.

Plotino G, Grande NM, Falanga A, Di Giuseppe IL, Lamorgese V, Somma F. Dentine removal in the coronal portion of root canals following two preparation techniques. Journal, 40, 852-858, 2007. parameters: changes in root canal area after instrumentation (DA) and reduction of the mesial and buccal/lingual wall thickness (DT). The data were subjected to Student's t-tests for statistical analysis at a significance level of P < 0.05. Results No statistically significant differences were found between the two groups with respect to the changes in the areas (DA) at the level considered (P ¼ 0.410). No statistically significant differences were noticed between the two groups for dentine thickness (DT) of both the mesial wall (P ¼ 0.077) and the buccal or lingual wall (P ¼ 0.171). Conclusions There was no difference between the ProTaper and Mtwo groups for the amount of dentine removed.

Plotino G, Grande NM, Sorci E, Malagnino VA, Somma F. Influence of a brushing working motion on the fatigue life of NiTi rotary instruments. International Endodontic Journal, 40, 45-51, 2007. Aim To evaluate the cyclic fatigue resistance of Mtwo NiTi rotary instruments when used with a brushing or no-brushing action in oval root canals. Methodology Cyclic fatigue testing of instruments was performed in tapered artificial canals with a 5 mm radius of curvature and an angle of curvature of 60°. Twenty Mtwo instruments for each size were selected and divided into two groups: group A ¼ 10 instruments used with a no-brushing motion (control group); group B ¼ 10 instruments used with a brushingmilling action. Each Mtwo instrument was used for cleaning and shaping 10 oval root canals. In all 80 instruments were rotated until fracture occurred and the number of cycles to failure (NCF) recorded. Data were analysed by one-way anova, Tukey HSD test and independent sample t-test to determine any statistical difference; the significance was determined at the 95% confidence level. Results No statistically significant reduction of NCF between instruments used with a no-brushing motion (group A) and instruments used with a brushing motion (group B) were apparent except for size 25, 0.06 taper. Mtwo size 10, 0.04 taper, size 15, 0.05 taper, size 20, 0.06 taper, size 25, 0.06 taper instruments had a decrease in life span of 1%, 0.5%, 8% and 19%, respectively. Conclusions Fatigue life of instruments of larger size could be reduced by using them with a lateral brushing or pressing movement. However, each file was successfully operated without intracanal failure, demonstrating that Mtwo rotary instruments can be used safely in a brushing action in simulated clinical conditions up to 10 times in oval canals.

Plotino G, Grande NM, Pameijer CH, Somma F. Influence of surface remodelling using burs on the macro and micro surface morphology of anatomically formed fibre posts. International Journal, 41, 345-355, 2008. Aim To evaluate the effect of modifying preformed fibre-reinforced composite (FRC) endodontic posts on their surface morphology and to determine how this procedure affects the integrity of the posts. Summary Surfaces of 10 preformed glass-fibre posts (group 1) and carbon-fibre posts (group 2) were compared with those of individually formed glass-fibre posts (group 3). Ten FRC posts were modelled in order to give them a shape as close as possible to the anatomy of oval root canals. Starting from a preformed cylindrical fibre post 2.5 mm in diameter, it was modelled in such a way as to passively occupy the entire post-space length, using a cast previously created as a guide. Microscopic analyses (optical stereomicroscope and scanning electron microscope) of the post surfaces revealed similar features in all three groups. All posts had regular surfaces after cutting with a diamond bur. Smear layer mainly attributable to the cutting procedures covered the cut surface of some specimens. In conclusion, modulation of a fibre post using a diamondcoated bur did not show a loss of integrity of the post. Key learning points • Because of the importance of micromechanical retention, the surface integrity of fibre posts may be important for adhesion between post and composite resin.

Recent studies detected erosion of the dentinal walls following the use of EDTA as a final flush. Several authors have studied degradation of EDTA and it appears to be caused by an oxidation reaction. The objective of this paper was to verify through nuclear magnetic resonance (NMR) analysis if the oxidizing property of sodium hypochlorite inactivates EDTA. Solutions of sodium hypochlorite and EDTA were analyzed. EDTA tracing and the appearance of new signals indicative of by-products of the reaction, were studied at different time intervals with a NMR analysis. The tracings of NMR analysis confirmed that the reaction between sodium hypochlorite and EDTA lead to a very slow but progressive degradation of this compound. Mindful of the limitations of an in vitro study, the results of this study nevertheless demonstrated that a final flush with sodium hypochlorite cannot limit the chelating effects of EDTA in a clinically realistic time period. (J Endod 2006;32:460 -464)

Objectives: The aim of this study is to analyze the chronological development of macroscopic, microscopic and magnetic resonance imaging (MRI) findings in a rat model of Superior Mesenteric Venous (SMV) ligation, and to evaluate the role of MRI in the diagnosis of mesenteric venous thrombosis. Methods: Thirty adult Sprague-Dawley rats were used and divided in two different groups that underwent a different surgical model and a different monitoring of ischemic damage. Group I underwent macroscopical and histological observation; Group II underwent 7 T μMRI evaluation and histological analysis. Results: The first alterations occurred 30 min after SMV ligation and progressively worsened until the eighth hour. The morphological and MRI findings showed the same course. Conclusions: This study provides a systematic evaluation of early anatomopathological and MRI findings following the SMV ligation. MRI allows to identify the early pathological findings of venous mesenteric ischemia and allows to correlate those to the histopathological features. Our data suggest a relevant role of MRI in the diagnostic management of mesenteric venous thrombosis, allowing to non-invasively identify and characterize the histopathologic findings. So, thanks to these skills, its future application in early diagnosis of human mesenteric venous ischemia is supposable.

To determine whether the shaping of oval-shaped root canals using 2 different preparation techniques resulted in significant morphologic differences. Study design. Forty lower premolars with oval-shaped root canals were divided into group A, instrumented with the Anatomic Endodontic Technology (AET) system, and group B, treated with ProTaper instruments. A modified Bramante technique was used to analyze changes in root canal diameters (⌬D), changes in surface area (⌬A), and the change in buccolingual and mesiodistal ratio (⌬R). The data were subjected to a Student t test at a significance level of P Ͻ 0.05. Results. Statistically significant differences were found between the 2 groups at coronal and middle levels. There was no statistically significant difference at the apical level. Conclusions. The 2 techniques produced a significant difference in the ultimate shape of the coronal and middle portions of oval-shaped root canals, with the AET system removing more tooth structure at these levels. However, no differences were observed at the apical third.

Objective. The objective of this study was to evaluate the influence of the moment when reduced pressure is applied on dye penetration patterns. Study design. Nine hundred and sixty glass capillary tubes of different inner diameter (0.3 mm and 0.8 mm), divided into 48 groups, were submerged into dye in 3 different positions (horizontally, opening upwards, and opening downwards) under different vacuum conditions (passive, 5 kPa, 35 kPa, 70 kPa reduced pressure). When reduced pressure was applied half of the groups were submerged into dye before and half of the groups after the application of reduced pressure. Linear dye penetration was measured. Univariate analysis was performed with Mann-Whitney U test and Kruskal-Wallis test to select variables to be included in the regression model. A multiple logistic regression analysis with backward elimination was performed to assess the influence of different covariates on linear dye penetration. Results. The multivariate linear regression showed that the moment of vacuuming had the greatest positive effect on linear dye penetration value (␤ ϭ 10.6, P Ͻ .0001). Also the level of pressure reduction had a positive effect on the outcome variable (␤ ϭ 0.2, P Ͻ .0001) while the vertical positioning of the tubes has negatively affected the outcome variable both for the open end upside (␤ ϭ Ϫ1.01, P ϭ .024) and the open end downside (␤ ϭ Ϫ1.05, P ϭ .019). Diameter of the tubes (P ϭ .442) and immersion time (P ϭ .727) had no effect on the outcome of linear dye penetration. Conclusions. Even minimum air pressure reduction applied before immersion of the specimens allowed the dye to extensively penetrate the voids. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007;103:289-94) a Professor,

Radiologists receive little formal training regarding the structure of the radiology report and its importance as a medicolegal document; failure to communicate, in fact, represents one of the main problems facing the modern radiologists' activity. Duty to the patient does not end anymore with the written report; the paradox is that we are so advanced in imaging technology, but not in communicating imaging findings. Communication must be timely, appropriate, and fully documented. There is an increasing trend to communicate results directly to the patients; radiologists have the greatest problem when communicating unexpected findings. To improve patient care and reduce the risk of being sued, radiologists should follow shared report guidelines and be more familiar with their professional responsibilities. Semin Ultrasound A lthough imaging technologies have undergone dramatic evolution over the past century, radiology reporting has remained largely static, in both content and structure. Existing free-text reports have been often criticized for a number of inherent deficiencies, including inconsistencies in content, structure, organization, and nomenclature. 1 A radiology report should be accurate and expressed with appropriate confidence with respect to current best practice and knowledge; it has to measure up the central role of the radiologist in the patient's care and management. By providing high-quality service, in fact, the radiologist will continue to be quoted, by other physicians, as a congenial professional colleague who offers valuable advice. Quality has become a critical issue for radiologists. Measuring and improving quality is essential not only to ensure optimum effectiveness of care and comply with increasing regulatory requirements, but also to combat current trends leading to commoditization of radiology services. Unfortunately, radiologists receive little formal training regarding the structure of the radiology report and its importance as a medicolegal document. 3 Good reporting has to include the description of the images, providing the classic radiologic findings, the diagnostic conclusion, and, eventually, the suggestion of further diagnostic imaging tests. Moreover, to reduce medicolegal consequences, a good radiology reading should be complete and correct, with appropriate construction; provide speedy diagnostic information, particularly in the emergency setting; reveal the ability to carry out and optimize the examination, including the imaging technique and the used contrast agent (justification); disclose all the information regarding the administered radiation dose, confirming that the residual risk has been as low as reasonable (optimization); and be clinically focused and attempt to answer the specific question for which the imaging study was performed.

Synovial sarcoma has been defined by the World Health Organization (WHO) in 2002 as a type of mesenchymal tissue cell tumor that exhibits epithelial differentiation and represents the third most common soft-tissue sarcoma in adults, accounting for approximately 10% of soft-tissue sarcomas. To date, only few reports have focused on mediastinal synovial sarcoma imaging findings. Herein, we report a case of a 13 cm primary mediastinal giant synovial sarcoma, diagnosed in a 56-year-old patient admitted in our Department of Radiology with a six-month history of dyspnea and back pain.