Xanthogranulomatous cholecystitis with histologic features suggestive of IgG4 related cholecystitis - A morphologic overlap with IgG4 related disease.

AIMS: Both xanthogranulomatous cholecystitis (XGC) and IgG4-related cholecystitis (IgG4-CC) are rare chronic fibroinflammatory tumefactive diseases of the gallbladder, which cause a strong confusion with resectable malignancy in view of their mass forming tendency with extension into the liver. We aim to study the histopathologic features of xanthogranulomatous cholecystitis with regard to IgG4-related cholecystitis in extended cholecystectomy specimens. METHODS AND RESULTS: Sixty cases of extended cholecystectomy with liver wedge resection, diagnosed as XGC on histopathology from January 2018 to December 2021 were retrieved from the archives. Representative sections were reviewed by two pathologists independently. Immunohistochemistry was performed for IgG4 and IgG4/IgG was derived. The cases were dichotomized in two groups on the basis of IgG4 positive plasma cells. Six cases with >50 IgG4 positive plasma cells had storiform fibrosis, IgG4/IgG ratio >0.40 and extra-cholecystic extension. Of these, 50 % had obliterative phlebitis and 66.7 % had perineural plasma cell wrapping. CONCLUSIONS: A small subset of XGC cases (~10 %) had morphologic overlap with IgG4-CC, but should not be overcalled as the diagnosis of IgG4-RD requires an integrative approach based on clinical, serologic and imaging criteria and not solely on histopathology.

When Clinico-Morphological and Molecular Studies Tell Different Stories: A Case of Myelodysplastic Syndrome.

Myelodysplastic syndromes (MDSs) are clonal hematopoietic stem cell disorders characterized by cytopenias, dysplasia in one or more of the major myeloid cell lines, ineffective hematopoiesis, with cellular marrow, and risk for leukemic transformation. We present a case of a 66-year-old male with a history of multiple packed red blood cell (PRBC) transfusions. Routine investigations, bone marrow aspiration, and biopsy were done. The clinical and morphological findings raised suspicion of MDS with isolated del (5q), so cytogenetics was done. When cytogenetics was done, there was a big mismatch in finding between clinical, morphological, and molecular findings which brought a major change in prognosis as well as treatment. It is, therefore, very essential to not rely only on the clinical and morphological findings to reach a diagnosis. Molecular findings play a pivotal role to come to a final conclusion.

Epstein-Barr Virus-associated Mixed Lymphoepithelioma-like Carcinoma and Adenocarcinoma of the Gall Bladder: An Unusual Entity.

Schmincke described lymphoepithelioma as an undifferentiated carcinoma with abundant lymphoid stroma in the nasopharynx. Tumors with a similar histomorphology in extrapharyngeal areas have been referred to as lymphoepithelioma-like carcinoma (LELC). The association of an Ebstein-Barr virus (EBV) infection with lymphoepithelioma is well established in the nasopharynx but not so well at the extrapharyngeal sites. Only four cases of LELC have been reported in the gall bladder, of which all were negative for the EBV. This paper reports the first case of an EBV-associated mixed gall bladder carcinoma exhibiting a distinct phenotype of LELC and adenocarcinoma with mucinous differentiation. The EBV was confirmed by the strong granular membranous and cytoplasmic expression of LMP-1 (latent membrane protein-1) on immunohistochemistry and nuclear EBER RNA on chromogen in-situ hybridization in the tumor. This is the first case of LELC positive for EBV in the gall bladder. LELC has a more favorable prognosis than conventional adenocarcinoma or squamous cell carcinoma, irrespective of the site. Although a higher T stage and nodal metastasis were exceptional in the present case in contrast to the previous cases, the EBV-associated lymphocytic response might limit the disease spread and confer better overall survival and prognosis in these patients. Nevertheless, more prospective studies with a larger cohort will be needed to understand the pathogenesis, biological behavior, and prognosis of this rare entity.

On comprehensive analysis of root canal shaping ability of three endodontic files of different kinematics.

Infection of the tooth's root canal requires what is called root canal treatment (RTC). The most important part of endodontic treatment is to shape the root canal and remove its infected portion using endodontic files of various protocols, kinematics and designs that suit the particular geometry. Cleaning and Shaping the canal efficiently remove the root canal bacterial biofilms or tissue remnants while keeping its natural geometry. The result is determined by shaping the ability of the relevant endodontic file. In the available literature, no norm has been established for the measurement of various endodontic files' ability to do effective shaping. We present in this study a method to analyse and measure the shaping ability of endodontic files of three different kinematics.

Effect of volumetric shrinkage of restorative materials on tooth structure: A finite element analysis.

Post-treatment coronal hermetic seal of the root canal opening prevents the food or saliva which assist to achieve successful endodontic treatment. Gutta-percha is filled in the inner canal, that is, from cervical third to apical third. Gutta-percha does not provide the hermetic seal because it does not bound with dentine walls. Various new restorative materials have been developed in the last 6-7 decade but drawback related to the polymerization shrinkage of the composite resin remains a clinical problem. In general, dental composites having volumetric shrinkage of the material depends on its formulation and curing conditions. In this article, the effect of this polymerization shrinkage on the tooth structure has been studied.

Force and vibration generated in apical direction by three endodontic files of different kinematics during simulated canal preparation: An in vitro analytical study.

During root canal shaping, pain could result from the high level of force or vibration generated. This could be related to file kinematics or geometry. In the present study, a comparison is made between forces and vibrations generated by endodontic files having three different kinematics. Square pillar resin blocks were used as simulated root canals to study forces and vibrations generated by the file having reciprocating motion (WaveOne Gold), transline motion (Self-Adjusting File), and rotary motion (2Shape). The forces and vibrations were measured using the dynamometer and accelerometer, respectively. Recorded time domain signals were processed in MATLAB to calculate the root mean square value. A one-way analysis of variance and Tukey's test for post hoc comparison at 95% confidence interval were applied over the root mean square data of different files. From a statistical analysis of the file systems, the null hypotheses could not be accepted (P < 0.05) as 95% of the confidence interval. Differences between the means were statistically significant. The root mean square values of force and vibration for WaveOne Gold significantly exceeded those of Self-Adjusting File, 2Shape1, and 2Shape2 while the root mean square values of vibration for 2Shape1 and 2Shape2 were significantly less than the Self-Adjusting File; however, the root mean square value of force for the 2Shape2 was significantly more than for the Self-Adjusting File. Under the present experimental conditions, significant differences in the root mean square values of force and vibration of the three endodontic files of different kinematics have been observed. The WaveOne Gold file system generated higher apical force and vibration than the transline and rotary file system.

Computer-aided design-based guided endodontic: A novel approach for root canal access cavity preparation.

In cases of teeth with unusual morphology like calcified pulp canal, guided endodontic treatment is suggested. An endodontic guide which navigates burs according to a preplanned path is used. Existing approaches of endodontic guide design are based on visual observation and analysis of tomographic scan of teeth. Hence, they are time-consuming and expert-dependent. Computer-aided design-based methodology was employed to design and fabricate a customized endodontic guide. A cone beam computed tomographic scan with MIMICS software was used to create a solid model of the teeth. The solid model generated was sliced through the developed program in MATLAB. The geometric centers of consecutive slices were joined to plot the root canals central axis. To gauge the optimum bur angulation for guide design, a straight line fitted in the data set of the geometric center helped create minimally invasive access. Methodology involved simulated verification of the drill path to judge the accuracy and feasibility of root canal access cavity preparation. Next, endodontic guides for extracted teeth were designed and fabricated using a three-dimensional printer, followed by guided root canal access cavity preparation for extracted teeth. To validate the proposed methodology, using a MATLAB image processing tool box, the deviation between the prepared root canal access cavity axis and root canal axis was analyzed in radiographs of post-treated teeth. The deviation between the tool path axis and root canal axis in simulated root canals was found to be not more than 0.210 ± 0.04 mm. The deviation between the axis of the planned root canal access cavity and the prepared root canal access cavity was 0.07 ± 0.02 mm. The proposed method reveals encouraging results for endodontic guide design.

Force and vibration correlation analysis in the self-adjusting file during root canal shaping: An in-vitro study.

BACKGROUND/PURPOSE: The focus of this study was to find a correlation between the forces and vibrations during root canal shaping. This can be used to predict the fracture of the self-adjusting file (SAF) in root canal shaping. MATERIALS AND METHODS: Forty J-shaped resin blocks were used in this study. Simulated root canals of resin blocks were prepared with the SAF. Force and vibration during root canal shaping were measured by dynamometer and accelerometer respectively. The recorded time domain signal of force and vibration were transformed to frequency domain signals. Frequency domain signals had been used for correlation study between force and vibration amplitude. The root mean square (RMS) value of force and vibration signature for new file and file just before failure were statistically compared using t-test at 95% confidence interval (CI). RESULTS: Vibrations generated during root canal shaping exhibited positive linear correlation (r = 0.9173) with force exerted by the SAF on the root canal. It means vibration has strong correlation with force. The RMS values of force and vibration increase significantly (P < 0.05) just before the fracture. CONCLUSION: From force and vibration analysis of SAF it was concluded that the vibration is well associated with force applied by the SAF on root canal. Therefore, the trend of force variation was reflected in the vibration signature. The sudden increment in vibration was the symptom of bulge formation and the end of useful life of the SAF.

Preservation of root canal anatomy using self-adjusting file instrumentation with glide path prepared by 20/0.02 hand files versus 20/0.04 rotary files.

OBJECTIVES: To compare the relative axis modification and canal concentricity after glide path preparation with 20/0.02 hand K-file (NITIFLEX®) and 20/0.04 rotary file (HyFlex™ CM) with subsequent instrumentation with 1.5 mm self-adjusting file (SAF). MATERIALS AND METHODS: One hundred and twenty ISO 15, 0.02 taper, Endo Training Blocks (Dentsply Maillefer, Ballaigues, Switzerland) were acquired and randomly divided into following two groups (n = 60): group 1, establishing glide path till 20/0.02 hand K-file (NITIFLEX®) followed by instrumentation with 1.5 mm SAF; and Group 2, establishing glide path till 20/0.04 rotary file (HyFlex™ CM) followed by instrumentation with 1.5 mm SAF. Pre- and post-instrumentation digital images were processed with MATLAB R 2013 software to identify the central axis, and then superimposed using digital imaging software (Picasa 3.0 software, Google Inc., California, USA) taking five landmarks as reference points. Student's t-test for pairwise comparisons was applied with the level of significance set at 0.05. RESULTS: Training blocks instrumented with 20/0.04 rotary file and SAF were associated less deviation in canal axis (at all the five marked points), representing better canal concentricity compared to those, in which glide path was established by 20/0.02 hand K-files followed by SAF instrumentation. CONCLUSION: Canal geometry is better maintained after SAF instrumentation with a prior glide path established with 20/0.04 rotary file.

Assessment of the fracture resistance of teeth instrumented using 2 rotary and 2 reciprocating files versus the Self-Adjusting File (SAF): An ex vivo comparative study on mandibular premolars.

AIM: Current ex vivo study compared fracture resistance of teeth instrumented using 5 endodontic files, filled with Gutta-percha and AH Plus. MATERIALS AND METHODS: Sixty freshly extracted, single-rooted mandibular premolars were acquired and decoronated to obtain 15 mm segments. These samples were randomly divided into six groups (n = 10). Group 1 served as the control containing untreated samples (without instrumentation or filling). In Groups 2-6, samples were instrumented using rotary (Universal ProTaper and Revo-S), reciprocating (WaveOne and RECIPROC(®)), and self-adjusting file (SAF), respectively. Following instrumentation, the samples were filled by lateral compaction with Gutta-percha and AH Plus. A week later, after the sealer was completely set, a vertical load was applied to the specimen's canal in each group until fracture. The loads required for fracture were recorded, and statistical analysis was performed. RESULTS: The mean fracture load differed significantly among the groups (P < 0.01; one-way ANOVA). Tukey's post-hoc tests revealed that the fracture resistance was similar in the control and SAF groups (P > 0.05) and was significantly higher than that of the 2 rotary and reciprocating groups (P < 0.01). CONCLUSION: The samples instrumented by the SAF exhibited a better fracture resistance.

Integrating techniques to re-establish dentogingival esthetics.

The aim of this article was to report the clinical case of a male patient of 20 years with hyperpigmented gingiva and moderate fluorosis, whose smile was reestablished by the use of a laser assisted depigmentation procedure, an enamel microabrasion technique, followed by at-home bleaching and subsequent remineralization therapy. The association of these techniques presented excellent results and the patient was satisfied. All techniques are painless, fast and easy to perform, in addition to preserving the hard and soft dental structure. Treatment showed immediate and permanent results; these techniques must be divulged among professionals and their patients.

An insight into neurophysiology of pulpal pain: facts and hypotheses.

Pain and pain control are important to the dental profession because the general perception of the public is that dental treatment and pain go hand in hand. Successful dental treatment requires that the source of pain be detected. If the origin of pain is not found, inappropriate dental care and, ultimately, extraction may result. Pain experienced before, during, or after endodontic therapy is a serious concern to both patients and endodontists, and the variability of discomfort presents a challenge in terms of diagnostic methods, endodontic therapy, and endodontic knowledge. This review will help clinicians understand the basic neurophysiology of pulpal pain and other painful conditions of the dental pulp that are not well understood.

Comparing microleakage and layering methods of silorane-based resin composite in class V cavities using confocal microscopy: An in vitro study.

AIMS: This in vitro study compared the effects of different layering techniques on the microleakage of silorane-based resin composite using confocal laser scanning microscope. MATERIALS AND METHODS: Forty caries free premolars extracted for orthodontic reasons were used. A class V cavity was prepared on the buccal surface in each of the premolars, with the gingival margin of the cavity being 1 mm above cementoenamel junction. The cavities were restored with a silorane-based resin composite (Filtek(™) P90 Silorane Low Shrink Restorative, 3M ESPE) using two different layering techniques - split incremental and oblique layering technique. All samples were subjected to 1000 thermal cycles of 5°C/55°C in water with a 30 second dwell time, and after the procedure, the teeth were immersed in 0.6% aqueous rhodamine dye for 48 hours. Sectioned samples were examined under a Confocal Fluorescence Imaging Microscope (Leica TCS-SP5, DM6000-CFS) at 10× magnification, and microleakage scores were analyzed statistically using paired "t" test and Mann-Whitney test. Width of interface between the tooth surface and resin composite was measured using a digital scale (Snagit digital scale). RESULTS: Microleakage was seen along the entire perimeter of restoration irrespective of the layering technique used. The microleakage score was same in both the groups. Statistical analysis of width of interface showed significant difference between the two layering techniques. The width was significantly less in split incremental technique, indicating less polymerization shrinkage. CONCLUSIONS: This in vitro study showed that the silorane-based resin composite shows microleakage irrespective of the layering technique used for class V cavities. However, this problem can be minimized significantly by using split incremental technique for restoration of class V lesions.