Sealer penetration: effect of separated file's cross-section, taper and motion characteristics.

OBJECTIVES: The separated root canal instruments may affect the quality of root canal filling, hence the success of endodontic treatment. The aim of this study was to evaluate the effects of separated file fragments of nickel-titanium rotary systems with different cross-section, taper and motion characteristics on the apical sealer penetration in oval-shaped root canals via confocal laser scanning microscope (CLSM). MATERIALS AND METHODS: Distal roots of 60 mandibular molars with oval-shaped root canals were randomly divided into 4 groups as follows: group 1, FlexMaster Nickel Titanium Rotary File System (NTRFS) (separated instrument: 30/.06); group 2, ProTaper Next NTRFS (X3); group 3, ProTaper Universal NTRFS (F3); group 4, Revo-S NTRFS (AS30/.06). Root canals were filled with gutta-percha and AH plus labelled with 0.1% rhodamine B using a warm vertical compaction technique. Each specimen was horizontally sectioned at 1st, 3rd and 5th mm from apical foramen. Amount of maximum and average penetration depths, penetration percentage and sealer penetrated area were measured and analysed with one-way repeated measures of ANOVA and the Bonferroni post hoc tests. p < 0.05 was considered significant. RESULTS: The penetration depth, percentage and penetrated area of the sealer increased from apical to coronal in all systems. The maximum and average penetration depths and penetration areas were higher in FlexMaster and Revo-S groups at the 3rd mm (p < 0.05). At the 5th mm, the Revo-S group had a higher penetration percentage, when compared with ProTaper Next and ProTaper Universal groups (p < 0.05). CONCLUSIONS: In the 1st mm, separated fragments of any system did not allow the penetration of the sealer, while it was observed that the files with constant taper showed more positive results in terms of sealer penetration at apical 3rd and 5th mm. CLINICAL RELEVANCE: In the presence of a separated file, the taper of the file might significantly affect the amount of penetrated sealer into the dentinal tubules as compared with the cross-section and motion characteristics of the file.

The effect of radiotherapy delivery time and obturation materials on the fracture resistance of mandibular premolars.

OBJECTIVES: This ex vivo study was performed to investigate the effect of radiotherapy (RT) delivery time on fracture resistance of mandibular premolars filled with Biodentine or gutta-percha/sealer (GPS). MATERIALS AND METHODS: Seventy-two mandibular premolars were used in this study. Randomly selected 24 teeth were kept intact for the control groups (with and without irradiation). Then, the remaining 48 teeth were randomly assigned into 4 groups (n = 12) according to RT delivery time (irradiated before or after root canal treatment) and obturation materials as follows: Group RT + GPS, Group: GPS + RT, Group RT + Biodentine and Group Biodentine + RT. The samples were either initially endodontically treated and then irradiated or initially irradiated and then endodontically treated with one of the abovementioned materials. The samples were irradiated at 2 Gy per fraction, 5 times a week for a total dose of 60 Gy in 30 fractions over 6 weeks. The roots were embedded in self-polymerizing acrylic resin. The fracture resistance was evaluated in a universal testing machine. Data was analyzed by one-way ANOVA and Games-Howell post hoc test at p < 0.05. RESULTS: Radiation therapy significantly reduced fracture resistance of intact teeth (p < 0.05). The highest fracture resistance was observed in intact/non-irradiated teeth and the lowest fracture resistance in Biodentine + RT group (p < 0.05). The effect of RT delivery time was insignificant when GPS was preferred as the root canal filling material (p > 0.05); it was significant when preferring Biodentine (p < 0.05). When RT was applied to the teeth after Biodentine obturation, the fracture resistance decreased significantly compared to the teeth that were obturated with GPS after or before RT application (p < 0.05). CONCLUSION: Both RT time and obturation materials (Biodentine or gutta-percha/sealer) affect the fracture resistance of the endodontically treated teeth. CLINICAL RELEVANCE: Endodontic treatment could be completed with both materials after RT; however, when the endodontic treatment was initially completed and the teeth were subsequently exposed to RT, it was shown that the reinforcement effect of Biodentine decreased.

Effect of different irrigation methods in the presence of a separated instrument: an in vitro study.

Objective: The aim of this study was to evaluate the effect of different irrigation methods on sodium hypochlorite (NaOCl)/debris extrusion and dentinal tubule penetration of 2.5% NaOCl in the presence of an apically separated instrument.Materials and methods: Sixty root canals of freshly extracted mandibular single-rooted premolars were chemomechanically prepared up to ProTaper F2. Manual needle irrigation (30-gauge/side-vented) with 2.5% NaOCl was performed between files and a smear layer was removed with 17% ethylenediaminetetraacetic acid. Three mm of notched ProTaper F3 files were separated in the apical third of the roots. Samples were then randomly divided according to the final irrigation systems as follows: EndoActivator, EndoVac, manual needle irrigation, passive ultrasonic activation, and RinsEndo. Samples were mounted to Eppendorf tubes and root canals were irrigated with 3-mL Rhodamine B-labelled 2.5% NaOCl, which was applied using one of the above-mentioned methods. The extruded NaOCl/debris weight was calculated by extracting pre-irrigation weights of tubes from post-irrigation ones. Samples embedded in acrylic resin were sectioned transversely in 1-mm thicknesses at apical 1- and 3-mm levels. NaOCl's penetration depth and percentage into the dentinal tubules were evaluated with the aid of a confocal laser scanning microscope. Data were analysed statistically with Kruskal-Wallis and post hoc Siegel-Castellan tests (p < .05).Results: EndoVac significantly decreased the extruded NaOCl/debris compared to RinsEndo, passive ultrasonic activation, and EndoActivator in the presence of a separated instrument (p < .05). The penetrability of NaOCl significantly increased with the use of RinsEndo and EndoVac compared to the remaining groups (p < .05).Conclusion: In the presence of an irretrievable separated instrument, it could be suggested that devices with apical negative pressure such as EndoVac may improve the penetrability of irrigation solutions to the apical part of the root while preserving periapical tissues from NaOCl/debris extrusion.

Influence of different irrigation protocols on microhardness and flexural strength values of young and aged crown dentin.

OBJECTIVE: To investigate the effect of different irrigation protocols on microhardness (MH) and flexural strength (FS) values of young and aged crown dentin. BACKGROUND: In addition to ageing, root canal irrigation might also affect the mechanical properties of coronal dentin walls. MATERIALS AND METHODS: One hundred and twenty dentin bars (2 mm × 2 mm × 8 mm) were obtained from the crowns of extracted, non-caries, human molars of young and older patients (n = 60 bars; average patient ages: 16.7 and 65.4, respectively). Subgroups were formed as follows: 2.5%NaOCl(sodium hypochlorite)+5%EDTA(ethylenediaminetetraacetic acid), 2.5%NaOCl + 15%EDTA, 2.5%NaOCl, 5%EDTA, 15%EDTA and Saline. NaOCl and saline were used for 20 minutes and EDTA solutions for 1 minute. MH values of each sample were measured before and after the irrigation protocols. The same samples were also submitted for FS analysis. The data were statistically analysed. RESULTS: Young samples had lower MH values at pre- and post-treatment compared to aged samples (P < .05). A significant decrease was observed in MH values of aged samples exposed to 2.5%NaOCl and both NaOCl + EDTA combinations (P < .05). FS values of the young saline-treated group were statistically higher than aged ones (P < .05). Both NaOCl + EDTA combinations caused a significant decrease in FS values of young samples compared to saline (P < .05). CONCLUSION: Ageing has a significant effect on the MH and FS values of crown dentin samples. 5% EDTA solutions revealed similar results to 15%EDTA regarding MH and FS values of crown dentin in both age groups. The NaOCl + EDTA combination had a prominent effect than EDTA alone, on MH values of young-, and FS values of aged dentin samples.

Risks and outcomes of invasive fungal infections in pediatric allogeneic hematopoietic stem cell transplant recipients receiving fluconazole prophylaxis: a multicenter cohort study by the Turkish Pediatric Bone Marrow Transplantation Study Group.

Invasive fungal infections (IFIs) are a major cause of infection-related morbidity and mortality in patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT). Data from pediatric settings are scarce. To determine the incidence, risk factors and outcomes of IFIs in a 180-day period post-transplantation, 408 pediatric patients who underwent allogeneic HSCT were retrospectively analyzed. The study included only proven and probable IFIs. The cumulative incidences of IFI were 2.7%, 5.0%, and 6.5% at 30, 100, and 180 days post-transplantation, respectively. According to the multivariate analysis, the factors associated with increased IFI risk in the 180-day period post-HSCT were previous HSCT history (hazard ratio [HR], 4.57; 95% confidence interval [CI] 1.42-14.71; P = .011), use of anti-thymocyte globulin (ATG) (HR, 2.94; 95% CI 1.27-6.80; P = .012), grade III-IV acute graft-versus-host-disease (GVHD) (HR, 2.91; 95% CI 1.24-6.80; P = .014) and late or no lymphocyte engraftment (HR, 2.71; 95% CI 1.30-5.62; P = .007). CMV reactivation was marginally associated with an increased risk of IFI development (HR, 1.91; 95% CI 0.97-3.74; P = .063). IFI-related mortality was 1.5%, and case fatality rate was 27.0%.The close monitoring of IFIs in pediatric patients with severe acute GVHD who receive ATG during conditioning is critical to reduce morbidity and mortality after allogeneic HSCT, particularly among those with prior HSCT and no or late lymphocyte engraftment.

Effect of root canal sealers on the fracture resistance of endodontically treated teeth: a systematic review of in vitro studies.

OBJECTIVE: The purpose of this study was to systematically review and critically analyze the published data of in vitro studies testing the effect of root canal sealers on the fracture resistance of endodontically treated teeth. METHODS: A comprehensive literature search was performed by using the Medline, Scopus, Web of Science, Cochrane, and Open Grey databases. A hand search of the reference lists of identified articles was also performed. Two reviewers critically assessed the studies for eligibility against inclusion and exclusion criteria and performed data extraction. Evaluation of the risk of bias of the studies was performed. RESULTS: A total of 48 studies were assessed for eligibility. Of these, 20 met the inclusion criteria and were included in the systematic review. All studies had a medium or high risk of bias. Although the majority of the studies reported that the use of root canal sealers increased the fracture resistance of endodontically treated teeth, conflicting evidence was found for the reinforcing effect of resin, glass ionomer, and calcium silicate-based sealers while there was moderate evidence for zinc oxide eugenol-based sealers in favor of no reinforcing effect. CONCLUSION: On the basis of available evidence, the use of root canal sealer increases the fracture resistance of endodontically treated teeth. However, included studies presented considerable risk of bias. Regarding the comparisons among the sealers, no conclusions could be drawn for the superiority of one sealer type to another. CLINICAL RELEVANCE: A considerable heterogeneity was found in the methodologies of included studies. Therefore, this review strongly suggests the development of standardized methods to test the reinforcement effect of root canal filling materials in in vitro studies.

Invasive fungal infections in children with hematologic and malignant diseases.

BACKGROUND: To evaluate the clinical feature and outcome of invasive fungal infections (IFI) in children with hematologic and malign diseases. PATIENTS AND METHODS: The medical records of children with hematologic and malignant diseases, who were hospitalized at our hospital between January 2010 and December 2011, were reviewed. Proven, probable, and possible IFIs were diagnosed according to the revised definitions of the European Organization for Research and Treatment of Cancer/Mycosis Study Group. The demographic, clinical, and laboratory characteristics of the patients who met the study criteria were evaluated. RESULTS: IFI was diagnosed in 67 (7.2%) febrile episodes of 56 patients, of which 10 (1.2%) were proven, 20 (2%) probable, and 37 (4%) possible IFI. Blood culture of 10 cases with proven IFI yielded yeast and the most common isolated agent was Candida parapsilosis. Seventy percent of cases with fungemia had central venous catheter (CVC). Twenty cases with probable IFI had invasive mold infection. The cases with mold infection had higher median C-reactive protein values, lower neutrophil counts, and longer duration of neutropenia compared with the cases with yeast infection. A total of 14 patients (20.9%) died. Presence of CVC, bone marrow transplantation, total parenteral nutrition, prolonged fever, and proven/probable IFI were detected more often in patients who died, compared with patients who survived. CONCLUSIONS: IFIs are important causes of death in children with hematologic and malignant diseases. Mold infections are seen more frequently in cases with prolonged and profound neutropenia, and invasive yeast infections, especially with non-albicans Candida species, in cases with CVC. Early and effective treatment considering these findings will help to decrease the mortality.

A color and shape based algorithm for segmentation of white blood cells in peripheral blood and bone marrow images.

Computer-based imaging systems are becoming important tools for quantitative assessment of peripheral blood and bone marrow samples to help experts diagnose blood disorders such as acute leukemia. These systems generally initiate a segmentation stage where white blood cells are separated from the background and other nonsalient objects. As the success of such imaging systems mainly depends on the accuracy of this stage, studies attach great importance for developing accurate segmentation algorithms. Although previous studies give promising results for segmentation of sparsely distributed normal white blood cells, only a few of them focus on segmenting touching and overlapping cell clusters, which is usually the case when leukemic cells are present. In this article, we present a new algorithm for segmentation of both normal and leukemic cells in peripheral blood and bone marrow images. In this algorithm, we propose to model color and shape characteristics of white blood cells by defining two transformations and introduce an efficient use of these transformations in a marker-controlled watershed algorithm. Particularly, these domain specific characteristics are used to identify markers and define the marking function of the watershed algorithm as well as to eliminate false white blood cells in a postprocessing step. Working on 650 white blood cells in peripheral blood and bone marrow images, our experiments reveal that the proposed algorithm improves the segmentation performance compared with its counterparts, leading to high accuracies for both sparsely distributed normal white blood cells and dense leukemic cell clusters.

Effect of treatment variables on apical extrusion of debris during root canal retreatment: A systematic review and meta-analysis of laboratory studies.

Background: This study aimed to systematically and comprehensively review the effect of various treatment variables on apically extruded debris (AED) during non-surgical root canal retreatment (NSRCRT). Methods: The study protocol is shared in the Open Science Framework database (https://osf.io/kjtdg/?view_only=17060180705745ec9dae9a01614f3880). An electronic search was conducted up to July 2022 to reveal related studies. Two reviewers critically assessed the studies for eligibility against inclusion and exclusion criteria and data extraction. Quantitative data synthesis was performed, and the risk of bias in the studies was also evaluated. Results: Forty-six studies were included in the systematic review and 14 in the meta-analysis. Conflicting or limited evidence was found for the effect of sealer type, obturation technique, and solvent use. The manual instrumentation increased the amount of AED compared to rotary instrumentation during the removal of filling materials (P<0.001). There was no significant difference in the amount of AED between the use of rotary and reciprocating files during the removal of filling materials (P=0.181). Conclusion: Rotary instruments can be recommended instead of manual instruments during the removal of filling materials to control the amount of AED. Further studies with a low risk of bias are needed to clarify the effect of other treatment variables on AED during NSRCRT.

Hemophagocytic bone marrow aplasia with plasma cells in a RAG2-deficient SCID case after a nonconditioned transplantation from a fully matched sibling.

We report a RAG2-deficient patient with severe combined immunodeficiency and hemophagocytic bone marrow aplasia with plasma cells after a nonconditioned transplantation from a fully matched sibling. After engraftment, disseminated BCGosis appeared because of graft versus host disease prophylaxis. On the 55th day, eosinophilia, neutropenia, and thrombocytopenia developed. Aplasia, hemophagocytic histiocytes, and plasma cells were found on his bone marrow with very high level of serum immunoglobulin E. We could not discriminate exactly whether BCGosis or alloimmune response is the cause of hemophagocytic aplasia with plasma cells. Despite the second hematopoietic stem cell transplantation with a reduced intensity conditioning regime, his marrow aplasia did not recover and he died. This case suggests that BCGosis might be associated with hemophagocytic marrow aplasia with plasma cells in an alloimmune reaction.

In vitro assessment of the roles of initial preparation size and solvent application on apically extruded debris in endodontically treated teeth.

Background: This study investigated the effects of solvent use and initial canal enlargement size on apically extruded debris (AED). Methods: The palatal roots of 60 upper molars were assigned to two groups based on the initial preparation size: F3 or F4 ProTaper Universal files. The roots were obturated using the single-cone technique. Each group was subdivided based on the retreatment procedures: with or without solvent. After evaporation, the Eppendorf tubes were weighed using an electronic balance. The data were statistically analyzed (P=0.05). Results: Using a solvent enhanced the amount of AED in samples initially prepared up to F3 or F4 files (P<0.05). When the solvent was used, the AED was greater in samples initially prepared up to the F4 file (P<0.05); however, when the solvent was omitted, the results were reversed (P<0.05). Conclusion: Both parameters had a role in AED. Solvents should be used cautiously during root canal retreatment because of the potential for apical extrusion of filling materials. Using files with smaller tapers during initial preparation might be beneficial when considering the amount of AED compared to those with larger tapers.

Investigating the Therapeutics Effects of Oral Cavity Derived Stem Cells on Neurodegenerative Diseases: A Systematic Review.

Introduction: Published data obtained from in vitro and in vivo studies was reviewed systematically and analyzed critically to evaluate the effect of oral cavity-derived stem cells (OCDSCs) on the recovery or therapy of neurodegenerative diseases (NDs), such as Alzheimer disease (AD), amyotrophic lateral sclerosis (ALS), Huntington (HD) diseases, and Parkinson disease (PD). Methods: An electronic search was accomplished. References of included articles were also manually searched. Studies were critically evaluated for suitability against the inclusion/exclusion criteria and the data was extracted. Bias risk evaluation of the studies and evidence synthesis were conducted. Results: A total of 14 in vivo and 10 in vitro studies met the inclusion criteria. PD was induced in 10 in vivo and 7 in vitro studies, while AD was induced in 2 in vivo and 4 in vitro studies. Two studies (1 in vitro and 1 in vivo) evaluated ALS disease and 1 in vivo study evaluated HD. Moderate evidence was found for in vitro studies reporting the positive effect of OCDSCs on PD or AD recovery. Strong evidence was found for in vivo studies in which PD animal models were used; meanwhile, moderate evidence was found for the impact of OCDSCs on AD recovery. Limited evidence was found for in vivo studies evaluating HD and ALS. Conclusion: Although studies reported favorable data regarding the OCDSCs on NDs, they presented a considerable risk of bias. Because of heterogeneous study characteristics, the current study recommends improving standardized methods to evaluate the therapeutic effects of OCDSCs on the NDs.

t(6;9)(p23;q34) presenting acute myeloid leukemia in a child with an unsuspected 45,X/46,X,derY [?t(Yp;Yq)] chromosomal constitution: yet another Y chromosome overdosage and malignancy association.

Development of leukemia in patients with sexual chromosome abnormalities is relatively rare and mostly involves cases of monosomy X, Turner syndrome. Here, we report on a child having a 45,X/46,X,derY [?t(Yp;Yq)] chromosomal constitution (variant Turner syndrome) presenting with concordant acute myeloid leukemia and a rarely seen clonal neoplasic cell lineage-related karyotype, t(6;9)(p23;q34).

Do resin-based root canal sealers cause more postoperative pain than other sealers? A systematic review of clinical studies and meta-analysis.

OBJECTIVE: To evaluate whether root canal obturation with resin-based sealers increases the incidence and intensity of postoperative pain compared to other sealer types. DATA SOURCES: Medline, Scopus, Web of Science, Google Scholar, Cochrane Library, and gray literature were searched through December 2020. Clinical studies evaluating postoperative pain after obturation with resin-based sealers and other sealer types were included. Risk of bias was assessed through the Cochrane RoB 2.0 tool for randomized clinical trials (RCTs) and ROBINS-I tool for non-randomized clinical trials (nRCTs). Pooled relative risks (RR), standardized mean differences (SMD), and 95% confidence intervals were calculated for quantitative analyses. Of 524 studies, 11 clinical studies (eight RCTs and three nRCTs) involving 1,123 teeth were included. Four studies were assigned low risk of overall bias while seven studies presented high risk of overall bias. Quantitative analyses were performed with six studies for pain incidence, five studies for pain intensity, and four studies for analgesic intake. There was no significant difference between resin- based sealers and other sealer types in postoperative pain incidence at 24 hours (RR 1.102, P = .53), 48 hours (RR 0.943, P = .93), 72 hours (RR 1.019, P = .93), and 1 week (RR 0.559, P = .31), in pain intensity at 12 hours (SMD 0.100, P = .35), 24 hours (SMD 0.090, P = .25), and 48 hours (SMD 0.217, P = .26), and in analgesic intake at 24 hours (RR 2.253, P = .15) and 72 hours (RR 0.650, P = .59). CONCLUSION: Based on the available evidence, resin-based sealers do not increase the postoperative pain incidence, intensity, and analgesic intake compared to other sealer types.

Odonto/Osteogenic Differentiation of Dental Pulp Stem Cells of Type 1 Diabetic Patients with Mineral Trioxide Aggregate/1α,25-Dihydroxyvitamin D3 Combination.

INTRODUCTION: Vitamin D3 plays an important role in the mineralization mechanism and is often deficient in diabetic patients. The objective of this study was to investigate the odonto/osteogenic differentiation potential of the combination of mineral trioxide aggregate (MTA)/1α,25-dihydroxyvitamin D3 (VD3) on dental pulp stem cells (DPSCs) of patients with type 1 diabetes mellitus (T1DM). METHODS: DPSCs isolated from donors (control and T1DM) were cultured and characterized. Cell proliferation and wound healing assays were performed. DPSCs were exposed to 4 different media: growth medium (Dulbecco's modified Eagle's medium, 10% fetal bovine serum, antibiotic, and antimycotic), differentiation medium (DM) (growth medium plus ß-glycerophosphate and ascorbic acid), DM + MTA (DM plus 0.02 mg/mL MTA), and DM + MTA + VD3 (DM + MTA and 10 nmol/L vitamin D3). Odonto/osteogenic differentiation of DPSCs was evaluated by the alizarin red test, relative real-time polymerase chain reaction (dentin sialophosphoprotein, dentin matrix protein 1, collagen type 1 alpha 1, and osteocalcin), immunocytochemistry (antibone sialoprotein II, anti-dentin matrix protein 1, and anti-collagen type 1 alpha 1), and Western blot (dentin matrix protein 1 and osteocalcin) methods. RESULTS: The proliferation rates of DPSCs isolated from controls were significantly higher than DPSCs isolated from T1DM in a time-dependent manner (P < .05). Alizarin red staining and the expression of odonto/osteogenic markers showed that odonto/osteogenic differentiation was more pronounced in controls (P < .05) compared with T1DM patients. Although DM + MTA caused the odonto/osteogenic differentiation in DPSCs derived from controls, DM + MTA + VD3 resulted in the odonto/osteogenic differentiation in DPSCs of T1DM patients (P < .05). CONCLUSIONS: Odonto/osteogenic differentiation was affected by both supplements used for differentiation and the systemic disease, diabetes mellitus. The differentiation potential of T1DM-derived DPSCs was clearly increased with the VD3 supplement, although it was not as efficient as in the controls. The VD3 supplement showed a positive effect on the differentiation of T1DM DPSCs compared with MTA alone.

A living material platform for the biomineralization of biosilica.

Nature has a vast array of biomineralization mechanisms. The commonly shared mechanism by many living organisms to form hardened tissues is the nucleation of mineral structures via proteins. Living materials, thanks to synthetic biology, are providing many opportunities to program cells for many functionalities. Here we have demonstrated a living material system for biosilicification. Silaffins are utilized to synthesize silicified cell walls by one of the most abundant organism groups called diatoms. The R5 peptide motif of the silaffins is known for its ability to precipitate silica in ambient conditions. Therefore, various studies have been conducted to implement the silicification activity of R5 in different application areas, such as regenerative medicine and tissue engineering. However, laborious protein purification steps are required prior to silica nanoparticle production in recombinant approaches. In this study, we aimed to engineer an alternative bacterial platform to achieve silicification using released and bacteria-intact forms of R5-attached fluorescent proteins (FP). Hence, we displayed R5-FP hybrids on the cell surface of E. coli via antigen 43 (Ag43) autotransporter system and managed to demonstrate heat-controllable release from the surface. We also showed that the bacteria cells displaying R5-FP can be used in silicification reactions. Lastly, considering the stimulating effect of silica on osteogenic differentiation, we treated human dental pulp stem cells (hDPSCs) with the silica aggregates formed via R5-FP hybrids. Earlier calcium crystal deposition around the hDPSCs was observed. We envision that our platform can serve as a faster and more economical alternative for biosilicification applications, including endodontics.

Ulcerating molluscum contagiosum in a boy with relapsed acute lymphoblastic leukemia.

Molluscum contagiosum is an infectious disease presenting with flesh-colored, dome-shaped, umblicated papules. A few atypical presentations have been reported in immunodeficient patients. A 5-year-old boy with acute lymphoblastic leukemia, presented with bright white-colored papular lesions with no umblications on the chin during his continuation chemotherapy. Increased number of the lesions covered almost his entire chin in months. Topical therapies did not improve the lesions. After his bone marrow relapse, induction chemotherapy was withheld because of bronchopneumonia after febrile neutropenia. After initiation of a combination of systemic parenteral antibiotic and antifungal therapies, his parents squeezed one of his papular lesions. Meanwhile, systemic acyclovir was added to his therapy, because of herpes labialis. Despite the large spectrum of his therapies, in 1.5 months, this small lesion progressed to a large lesion with erythematous ground and a central ulceration. Etiology of the lesion could not be enlightened until a skin biopsy that was compatible with the molluscum contagiosum. A partial resolution was achieved by cryotherapy. In conclusion, molluscum contagiosum may present as an ulcerating lesion during childhood leukemia treatment. A skin biopsy should be performed for the accurate diagnosis of atypical cutaneous lesions in immunocompromised patients.

The effect of intracanal medication variations on microhardness of simulated immature root dentin.

The effect of different medicaments and irrigation solutions on root dentin microhardness (MH) was evaluated depending on time. After initial measurements, MH of 60 maxillary incisors (n = 15 per group) was measured after 3 steps: irrigation with 2.5% sodium hypochlorite, exposure to medicaments [triple antibiotic (TAP) or calcium hydroxide (CH) pastes, 1 week or 1 month)] and final irrigation [20 mL of 17% EDTA or 20 mL 1% phytic acid (PA)]. The percentage of MH reduction was calculated. Data were analysed statistically at P < 0.05. Treatments caused a significant decrease in MH values compared to baseline and pre-measurements (P < 0.05). TAP significantly reduced the MH values of the samples over time (P < 0.05). Removal of TAP after 1 month with PA resulted in a significant reduction in MH compared to removing TAP after 1 week and CH removing after 1 month (P < 0.05). Considering the chemical preparation steps, the most hazardous effect on MH was observed after the first irrigation.

Influence of reciprocating and rotary instrumentation on microbial reduction: a systematic review and meta-analysis of in vitro studies.

OBJECTIVES: The purpose of this study was to conduct a systematic review and meta-analysis of in vitro studies regarding the effectiveness of reciprocating and rotary instrumentation on microbial reduction in root canals. MATERIALS AND METHODS: PubMed, Scopus, Web of Science, the Cochrane Library, and the gray literature were searched through December 2019. Studies comparing the influence of reciprocating and rotary instrumentation on the removal of microorganisms from root canals that quantified the antimicrobial effect were included. Data extraction was completed using a systematic form for data collection. The risk of bias of the studies was evaluated. Standardized mean differences (SMDs) and confidence intervals (CIs) were calculated using a random effects meta-analysis. RESULTS: Seventeen in vitro studies were included in this systematic review, of which 7 provided adequate data for inclusion in the meta-analysis. Both reciprocating and rotary systems were similarly effective in reducing the microbial load in infected root canals (SMD [95% CI], 0.0481 [-0.271, 0.367]). Three studies showed a low risk of bias, whereas most of the studies (82%) presented a medium risk. CONCLUSIONS: Although both techniques decrease the microbial content (with reductions of 23.32%-88.47% and 23.33%-89.86% for reciprocating and rotary instrumentation, respectively), they are not able to provide complete disinfection of root canals.

Contribution of XP-Endo files to the root canal filling removal: A systematic review and meta-analysis of in vitro studies.

This review was designed to analyse whether the supplementary use of XP-Endo Finisher and XP-Endo Finisher R contributes to the removal of root canal filling materials. Databases were searched up to November 2020. Studies were critically assessed according to inclusion and exclusion criteria. Risk of bias evaluation was performed. Pooled standardised mean differences (SMD) and 95% confidence intervals (95% CI) were calculated. Ten studies involving 192 teeth were eligible for systematic review and meta-analysis could be performed with eight of these studies. Strong evidence showed that XP-Endo Finisher R file contributed significantly to filling material removal from root canals (SMD (95% CI): 0.41 (0.06-0.76)). Although the evidence was conflicting, XP-Endo Finisher R file was superior than other irrigant activation techniques (SMD (95% CI): 0.47 (0.02-0.93)). The supplementary use of XP-Endo Finisher and XP-Endo Finisher R is beneficial in further removal of root canal filling materials from root canal system.