A Comparative Evaluation of the Vertical Root Fracture Resistance of Endodontically Treated Teeth using Different Root Canal Sealers: An in vitro Study

Objective: The objective of this study is to evaluate the vertical root fracture resistance of endodontically treated teeth obturated with - Tubli-Seal EWT/Gutta-percha, AH Plus/Gutta-percha, Epiphany SE sealer/Epiphany point. Study design: Sixty-five single rooted premolars were decoronated and root length was 14 mm for each specimen. Fifty five teeth were enlarged up to ISO size 40 master apical file with stainless steel K-files using standardized preparation and remaining ten teeth were served as negative control. Then teeth were randomly assigned into different groups depending on sealer used for obturation as follows: Group 1: Negative control-no instrumentation was performed. Group 2: Positive control-gutta-percha with out the use of any sealer. Group 3: Experimental group-gutta-percha and Tubli-Seal EWT root canal sealer. Group 4: Experimental group-gutta-percha and AH Plus. Group 5: Experimental group-epiphany SE sealer and epiphany points. After 72 hours, the specimens were embedded in autopolymerizing resin leaving 7 mm of each root exposed and were subjected to fracture testing under universal testing machine at a crosshead speed of 1.0 mm per minute until the root fractured. Results were statistically analyzed using one-way ANOVA and independent t-test. Results: Showed that Epiphany SE sealer/Epiphany points showed highest mean fracture resistance and Tubli-Seal EWT group showed the least fracture resistance of all the materials tested. There was no statistically significant difference among experimental groups. Conclusion: Epiphany SE sealer/Epiphany points demonstrated highest fracture resistance values than the other materials tested and intact tooth had highest resistance against vertical root fracture. Clinical significance: Epiphany SE sealer/Epiphany points may be one of the materials of choice in the endodontic treatment of teeth. Keywords: Epiphany sealer/Epiphany points, AH Plus/Guttapercha, Tubli-Seal EWT, Vertical root fracture. How to cite this article: Nagpal A, Annapoorna BM, Prashanth MB, Prashanth NT, Singla M, Deepak BS, Singh A, Tavane PN. A Comparative Evaluation of the Vertical Root Fracture Resistance of Endodontically Treated Teeth using Different Root Canal Sealers: An in vitro Study. J Contemp Dent Pract 2012;13(3):351-355. Source of support: Nil Conflict of interest: None declared.     

Influence of cigarette smoking on blood and salivary super oxide dismutase levels among smokers and non‐smokers

Aim: To determine the influence of smoking on the blood and salivary superoxide dismutase levels among smokers, and to demonstrate the significance in alterations in the levels of superoxide dismutase in association with patient age, periodontal disease status, and duration and smoking frequency. Methods: Sixty healthy male patients (aged 20–60 years) constituted the target population. Blood and saliva samples were collected, and the periodontal index was measured using a Community Periodontal Index probe. Blood and salivary superoxide dismutase levels were calculated with the reagents prepared, and values were measured in a UV spectrophotometer. Results: There was a significant decrease in mean superoxide dismutase levels with an increase in age and smoking duration and frequency (0.23–0.05 U/mL). There was a range of 0.31–0.06 U/mL variation in the mean superoxide dismutase levels as the periodontal disease condition deteriorated. Conclusions: There was a significant reduction in the superoxide dismutase levels in the blood and saliva of smokers with increased duration and frequency of smoking, and as the periodontal disease condition worsened. Thus, this study emphasizes the importance of saliva as an easy, non‐invasive procedure in the diagnosis of patients who are more prone to precancerous lesions and conditions, and its importance in patient education and motivation programs for smoking cessation.     

Spry1 as a novel regulator of erythropoiesis, EPO/EPOR target, and suppressor of JAK2

Sprouty proteins are established modifiers of receptor tyrosine kinase (RTK) signaling and play important roles in vasculogenesis, bone morphogenesis, and renal uteric branching. Little is understood, however, concerning possible roles for these molecular adaptors during hematopoiesis. Within erythroid lineage, Spry1 was observed to be selectively and highly expressed at CFU-e to erythroblast stages. In analyses of possible functional roles, an Mx1-Cre approach was applied to conditionally delete Spry1. At steady state, Spry1 deletion selectively perturbed erythroid development and led to reticulocytosis plus heightened splenic erythropoiesis. When challenged by hemolysis, Spry1-null mice exhibited worsened anemia and delayed recovery. During short-term marrow transplantation, Spry1-null donor marrow also failed to efficiently rescue the erythron. In each anemia model, however, hyperexpansion of erythroid progenitors was observed. Spry function depends on phosphorylation of a conserved N-terminal PY motif. Through an LC-MS/MS approach, Spry1 was discovered to be regulated via the erythropoietin receptor (EPOR), with marked EPO-induced Spry1-PY53 phosphorylation observed. When EPOR signaling pathways were analyzed within Spry1-deficient erythroid progenitors, hyperactivation of not only Erk1,2 but also Jak2 was observed. Studies implicate Spry1 as a novel regulator of erythropoiesis during anemia, transducer of EPOR signals, and candidate suppressor of Jak2 activity.     

The thrombopoietin/MPL/Bcl-xL pathway is essential for survival and self-renewal in human preleukemia induced by AML1-ETO

AML1-ETO (AE) is a fusion product of translocation (8;21) that accounts for 40% of M2 type acute myeloid leukemia (AML). In addition to its role in promoting preleukemic hematopoietic cell self-renewal, AE represses DNA repair genes, which leads to DNA damage and increased mutation frequency. Although this latter function may promote leukemogenesis, concurrent p53 activation also leads to an increased baseline apoptotic rate. It is unclear how AE expression is able to counterbalance this intrinsic apoptotic conditioning by p53 to promote survival and self-renewal. In this report, we show that Bcl-xL is up-regulated in AE cells and plays an essential role in their survival and self-renewal. Further investigation revealed that Bcl-xL expression is regulated by thrombopoietin (THPO)/MPL-signaling induced by AE expression. THPO/MPL-signaling also controls cell cycle reentry and mediates AE-induced self-renewal. Analysis of primary AML patient samples revealed a correlation between MPL and Bcl-xL expression specifically in t(8;21) blasts. Taken together, we propose that survival signaling through Bcl-xL is a critical and intrinsic component of a broader self-renewal signaling pathway downstream of AML1-ETO-induced MPL.     

Replication of RYR3 gene polymorphism association with cIMT among HIV-infected whites

To replicate the association of variants in RYR3 gene with common carotid intima-media thickness (cIMT), a surrogate marker of atherosclerosis, we genotyped single nucleotide polymorphisms (SNPs) rs2229116 and rs7177922 in a sub-population of 244 HIV-positive and HIV-negative men. SNP rs2229116 was associated with common cIMT in HIV infected white men after adjusting for age and use of stavudine (d4T). The association was more evident at younger ages and decreased among older individuals.     

No association between cigarette smoking and incidence of plasma cell myeloma: a meta-analysis of 17 observational studies

Plasma cell myeloma (PCM) is a lymphoproliferative disorder characterized by the malignant growth of monoclonal plasma cells within the bone marrow. Although risk factors for the development of PCM have been identified, the etiology on the majority of patients with PCM remains unclear. Cigarette smoking has been postulated as a potential risk factor for lymphoid malignancies; however, the association with PCM is inconclusive. We have carried out a meta-analysis of observational studies to assess the relationship, if any, between cigarette smoking and PCM. A literature search through December 2011 rendered 4 prospective cohort and 13 case–control studies evaluating such association. Our categorical meta-analysis showed that there is no association between ever, current, and former smokers and PCM.This lack of association was maintained when analyzing by study design, study quality, and geographical area of report. Similarly, meta regression analysis showed no association with the number of cigarettes smoked per day. In conclusion, our meta-analysis shows that there is no relationship between cigarette smoking and an increased incidence of PCM. Future studies should focus on other potential risk factors for PCM.     

Uterine intravenous lipoleiomyomatosis: uncommon manifestation as a huge retroperitoneal mass with intracaval/intracardiac extensions

Lipoleiomyomas are benign mesenchymal tumours of smooth muscle and adipose tissue and uncommonly occur in the uterus. Here we report a case of uterine lipoleiomyoma that manifested purely as intravenous component and clinically presented as a large retroperitoneal mass with extension into inferior vena cava and right atrium. The connection of the mass to the corneal end of the uterus was noted only at surgery.     

Clinical Efficacy of Subgingivally Delivered 1.2% Atorvastatin in Chronic Periodontitis: A Randomized Controlled Clinical Trial

Background: Atorvastatin (ATV) is a specific competitive inhibitor of 3‐hydroxy‐2‐methyl‐glutaryl coenzyme A reductase. Recently, statins have shown pleiotropic effects such as anti‐inflammation and bone stimulation. The aim of the present study is to investigate the effectiveness of 1.2% ATV as an adjunct to scaling and root planing (SRP) in the treatment of intrabony defects (IBDs). Methods: Sixty individuals were randomized into two treatment groups: SRP plus 1.2% ATV and SRP plus placebo gel. At baseline and 3, 6, and 9 months, clinical parameters, which included modified sulcus bleeding index, plaque index, probing depth (PD), and clinical attachment level (CAL), were recorded at baseline. Radiologic assessment of IBD fill was done using computer‐aided software at baseline and 6 and 9 months. Results: Mean PD reduction and mean CAL gain were greater in the ATV group than the placebo group at 3, 6, and 9 months. A significantly greater mean percentage of radiographic bone fill was found in the ATV group (35.49% ± 5.50%) compared to the placebo group (1.82% ± 1.32%) after 9 months. Conclusion: ATV as an adjunct to SRP can provide a new direction in the management of IBDs.     

Efficacy of Subgingivally Delivered Simvastatin in the Treatment of Patients With Type 2 Diabetes and Chronic Periodontitis: A Randomized Double‐Masked Controlled Clinical Trial

Background: Simvastatin (SMV) is a specific competitive inhibitor of 3‐hydroxy‐2‐methyl‐glutaryl coenzyme A reductase. Recently, it has been reported that statins promote bone formation. The present study is designed to investigate the effectiveness of 1.2% SMV in an indigenously prepared, biodegradable, controlled‐release gel as an adjunct to scaling and root planing (SRP) in the treatment of patients with type 2 diabetes and chronic periodontitis (CP). Methods: Thirty‐eight patients were categorized into two treatment groups: SRP plus 1.2% SMV and SRP plus placebo. Clinical parameters were recorded at baseline before SRP and at 3, 6, and 9 months; they included modified sulcus bleeding index (mSBI), probing depth (PD), and clinical attachment level (CAL). At baseline and after 6 and 9 months, radiologic assessment of intrabony defect (IBD) fill was done using computer‐aided software. Results: Mean PD reduction and mean CAL gain were found to be greater in the SMV group than the placebo group at 3, 6, and 9 months. Furthermore, significantly greater mean percentage of bone fill was found in the SMV group (32.64% ± 12.90%) compared to the placebo group (4.22% ± 9.75%) after 9 months. Conclusion: There was a greater decrease in mSBI and PD and more CAL gain with significant IBD fill at sites treated with SRP plus locally delivered SMV in patients with type 2 diabetes and CP.