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This study aimed to evaluate the cause-effect relationship between canal preparation with ProTaper Universal (PTU) system and dentinal defects formation using micro-computed tomography (micro-CT) analysis. Forty mesial canals of mandibular molars with a type II Vertucci's canal configuration were scanned at an isotropic resolution of 14.16 µm. The sample was assigned to an experimental (n = 30) and a control (n = 10) groups, and the mesial canals were prepared with PTU system up to F2 instrument. The specimens from the experimental group were scanned and the cross-section images of the mesial roots, before and after preparation, were screened to identify the presence of dentinal defects. In the control group, the specimens were sectioned perpendicularly to the long axis of the root into 1-mm-thick slices (n = 80) and examined under optical microscope. Once a dentinal defect was detected, the slice was scanned through micro-CT. In the experimental group, dentinal micro-cracks were observed in 4,828 slices (24.04%). In all cross-section images, dentinal defects identified in the postoperative images were already present in the corresponding preoperative image. In the control group, 13 out of 80 slices (16.25%) had at least one dentinal defect visualized under stereomicroscopy, which was identified after a further micro-CT scanning. Micro-CT showed reliability as similar as optical microscopy in detecting dentinal defects, adding the possibility of tracking the dentinal tissue, before and after canal preparation, and providing a clear visualization of micro-cracks. Root canal preparation with PTU system did not induce the formation of new dentinal defects.

We describe prevalence and risk factors for HIV infection among 1,059 inmates in two prisons in Sorocaba, Brazil. Sociodemographics, prison history, and sexual and drug exposures were assessed by interviewer-administered questionnaire. HIV infection was detected in 115 (12.6%) inmates. Seroprevalence was 35% among those with a history of IDU (OR = 11.4, 95% CI 5.58-23.5). Sex with female visitors was reported by 66%, and homosexual practices with other inmates by 10%. Independent predictors of HIV infection were age <35 years (OR = 1.9, 95% CI 1.1-3.4), birthplace (natives of Sorocaba; OR = 2.1, 95% CI 1.2-3.8), and number of previous incarcerations (>/=1 compared to 0) (OR = 1.7, 95% CI 1.07-2.7). Prevalence of HIV infection among these inmates is comparable to rates in metropolitan Sao Paulo and other prison populations internationally. The use of injecting drugs is the most important risk exposure in this population. These findings indicate an urgent need to institute prevention programs for this population both inside and outside prisons. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the percentage of non-instrumented area of root canals prepared with different enlargements using single-file reciprocating systems (Reciproc and WaveOne) and a conventional multi-file rotary (BioRaCe) system by micro-computed tomographic analysis. Thirty mesial roots of mandibular molars with moderate curvature (10° to 20°) presenting a type II Vertucci canal configuration and similar internal volume were chosen and scanned at an isotropic resolution of 14.16 µm. The sample was assigned to 3 groups (n=10) according to the system used for root canal preparation: Reciproc, WaveOne, and BioRaCe groups. Second and third scans were taken after the canals were prepared with instruments sizes 25 and 40, respectively. The recorded images of the surface area voxels of the canals, before and after preparation were examined from the furcation level to the apex to quantify the non-instrumented surface. Statistical data were compared using GLM for repeated-measures with a significance level set at 5%. Instrumentation systems did not influence the percentage of untouched root canal surfaces (p=0.690) whilst a significant reduction in the percentage of static voxels was observed after the enlargement of the root canal (p=0.010) in all groups (p=0.507). None of the systems was able to prepare the entire surface area of the mesial root canal of mandibular molars. The increased final apical size resulted in a significant positive effect on the shaping ability of the tested systems.

Background: Vital pulp therapy (VPT) has recently been reported as an effective approach for preventing and treating carious pulp injury in permanent teeth. Compared with root canal treatment (RCT), which involves complete removal of the pulp tissue, VPT effectively maintains pulp vitality and retains the physiological functions of the pulp. In the research pool, large-scale randomized controlled trials evaluating the treatment outcome of VPT using calcium silicate cements and RCT in cariously exposed permanent teeth are lacking. Here, we present a monocentric clinical protocol to compare the effects of VPT using iRoot BP Plus (Innovative Bioceramix, Vancouver, BC, Canada) as a pulp-capping material with RCT. Methods: The proposed trial is an open-label, single-centre, randomized, controlled, noninferiority trial. In total, 462 patients will be included in this trial according to the following criteria: adult patients (18–50 years old), pulp exposure during the treatment of deep caries in mature permanent teeth, a diagnosis of reversible or partially irreversible pulpitis without apical translucency on X-ray, without periodontitis or systemic disease. Patients with signed informed consent forms will be enrolled and randomly divided into two groups (VPT and RCT) with a balanced treatment allocation (1:1). Clinical evaluations will be conducted at baseline and at 3, 6, 12, and 24 months after treatment, with the potential for extension. The primary outcome measure will be the duration of success. The secondary outcomes will include the success rate at the 1-year follow-up and any adverse reactions. The Kaplan‒Meier method and log-rank test will be used to compare the duration of success of both treatments. For other outcomes, the χ2 test or Fisher's exact test will be used for categorical variables, and the t test or Mann‒Whitney U test will be used for continuous variables to assess the differences between groups. Discussion: The results of this trial will provide a clinical reference for selecting treatments for carious pulp injuries in permanent teeth. Trial registration: ClinicalTrials.gov ChiCTR2100051369. The study has been registered in the Chinese Clinical Trial Registry (ChiCTR) (www.chictr.org.cn). Registered on 21 September 2021 [ABSTRACT FROM AUTHOR]

Aim: To verify the in vitro cytocompatibility of iRoot BP Plus (iRoot) and to compare it with White ProRoot MTA (MTA)., Methodology: Thirty-six human maxillary incisor root canals were prepared using a step-back flaring technique. The apical 3 mm was resected perpendicular to the long axis at the roots, and root-end cavities were prepared with the aid of an ultrasonic device plus a diamond retrotip with continuous irrigation using water, producing standardized preparations. After that, the root-end cavities were filled with iRoot or MTA, and each root was exposed to cell culture media for 24 or 48 h. Human osteoblast cells were exposed to the extracts thus obtained, and a multiparametric cell viability assay was performed, evaluating mitochondrial activity, membrane integrity and cell density. The results were analysed by one-way analysis of variance, complemented with the Duncan post-test (P < 0.05)., Results: Cells exposed to MTA revealed a cytocompatibility pattern similar to the untreated cells (negative control), at both experimental times (P > 0.05). iRoot, however, promoted a significantly poorer viability than MTA and the control, after 48 h of exposure (P < 0.001). Nevertheless, iRoot did not induce critical cytotoxic effects because cell viability remained higher than 70% of the control group in most tests performed., Conclusion: iRoot and MTA were biocompatible and did not induce critical cytotoxic effects., (© 2012 International Endodontic Journal.)

Aim: To test the effect of a noncaustic concentration of peracetic acid (PAA) in a standardized smear layer model., Methodology: The smear layer dissolution kinetics of 0.5% PAA on human dentine were compared to those of 2.25% PAA and 17% ethylenediaminetetraacetic acid (EDTA) solutions. Coronal dentine discs were prepared from six human maxillary molars. A standardized smear layer was produced on the pulpal side of each disc. The smear layer-covered surface was divided into three similar areas and then exposed to one of the three solutions tested. Co-site image sequences (around 40, 500 ×) of the specific areas were obtained after four cumulative demineralisation times (15, 30, 60 and 180 s). An image processing and analysis sequence measured sets of images, providing data of area fraction (AF, dentine-free area in % of total analysis area). A general linear model for repeated measures was used to verify the influence of time and solution type over the change in AF from baseline (ΔAF)., Results: Overall, EDTA and 2.25% PAA produced higher ΔAF values than the 0.5% PAA solution (P < 0.05). No significant difference was observed in ΔAF between 15 s and 30 s (P > 0.05). After 60 s of etching, all tested solutions produced similar ΔAF (P > 0.05), whereas at 180 s, ΔAF of both EDTA and 2.25% PAA continued to increase (P > 0.05)., Conclusions: After 60 s of contact, the 0.5% PAA solution dissolved smear layer as well as 2.25% PAA and 17% EDTA., (© 2011 International Endodontic Journal.)

Little data exists concerning the efficacy of the antiretroviral therapy in the Federal District in Brazil, therefore in order to improve HIV/AIDS patients' therapy and to pinpoint hot spots in the treatment, this research work was conducted. Of 139 HIV/AIDS patients submitted to the highly active antiretroviral therapy, 12.2% failed virologically. The significant associated factors related to unresponsiveness to the lentiviral treatment were: patients' place of origin (OR = 3.28; IC95% = 1.0-9.73; P = 0.032) and Mycobacterium tuberculosis infection (RR = 2.90; IC95% = 1.19-7.02; P = 0.019). In the logistic regression analysis, the remaining variables in the model were: patients' birthplace (OR = 3.28; IC95% = 1.10-9.73; P = 0.032) and tuberculosis comorbidity (OR = 3.82; IC95% = 1.19-12.22; P = 0.024). The patients enrolled in this survey had an 88.0% therapeutic success rate for the maximum period of one year of treatment, predicting that T CD4(+) low values and elevated viral loads at pretreatment should be particularly considered in tuberculosis coinfection, besides the availability of new antiretroviral drugs displaying optimal activity both in viral suppression and immunological reconstitution.

Beriberi is caused by thiamine deficiency. Early 20th century epidemics in Japan were attributed to rice contaminated by citreoviridin mycotoxin. Our investigation of an outbreak of beriberi in Brazil showed an association of beriberi with the consumption of poor quality subsistence farming rice, although, unlike other investigators of this outbreak, we did not identify citreoviridin producing fungi in the implicated rice.

The development of rotary files and other endodontic instrument techniques have revolutionised treatment by enhancing canal preparation and producing rounder, smoother canals that are constructed of Nickel-Titanium (NiTi) alloy. There are two types of movements in these instruments: rotary continuous and reciprocating. Rotary continuous movements involve torsion and flexion, and can cause instrument fractures. An alternative approach to avoid the issue is proposed, which involves reciprocating movement. The present literature review compares the incidence of dentinal crack formation in root canal walls when using stainless steel and NiTi rotary systems. It highlights the potential complications, such as tooth fracture and increased bacterial susceptibility due to contact between instruments and dentinal walls. [ABSTRACT FROM AUTHOR]

Background: As AIDS patients live longer, the management of co-morbidities becomes increasingly important. Previous studies from developed countries give conflicting results as to whether co-infection with hepatitis C virus (HCV) lowers the life expectancy of individuals with AIDS., Methods: This retrospective cohort study was based on a medical record review of a nationally representative sample of 2821 adult AIDS cases diagnosed in 1995 and 1996 in Brazil. We compared the characteristics and survival of patients known to be positive and negative for HCV., Results: A total of 833 patients received HCV testing, and the prevalence was 33%. HCV-positive patients received less intensive antiretroviral treatment. The crude mortality was greater for HCV-positive patients (hazard ratio 1.26; P = 0.04), but HCV status was not a significant predictor in a multivariate analysis that included other predictors of survival., Conclusion: Brazilian AIDS patients with hepatitis C have a shorter survival than those without, but this seems to be mainly as a result of their receiving less antiretroviral treatment. We cannot say whether this is because of the fear of hepatotoxicity, an inability to tolerate treatment, or for other reasons. To improve survival, these patients need optimal treatment of their HIV disease.

Background: Since the last study of survival time among Brazilian AIDS patients, care has improved steadily, culminating in a controversial policy of universal free access to triple antiretroviral treatment since 1996. This large, national study examined how these changes have impacted survival., Methods: Using national data for cases diagnosed in 1995 and 1996, we randomly selected 3930 adult AIDS cases from 18 cities in seven states representing all regions of Brazil. Trained abstracters reviewed medical records, determining dates of diagnosis and death or last contact, exposure category, treatment, and demographics. After review, 2821 cases met the inclusion criteria and were available for Kaplan-Meier and proportional hazards analysis. Data from the earlier study were re-analyzed for comparison., Results: Median survival was 5 months for cases diagnosed in the 1980s, 18 months for those diagnosed in 1995, and 58 months for those diagnosed in 1996. Predictors of longer survival in univariate analysis included antiretroviral treatment, year of diagnosis, higher education, sexual exposure category, female sex, and Pneumocystis carinii pneumonia prophylaxis. In multivariate analysis, the predictive value of most of these was attenuated or disappeared, leaving antiretroviral treatment as the main predictor of survival., Conclusions: Survival time has increased substantially for adult Brazilian AIDS patients. The timing of these gains and analysis of the predictors of survival both indicate antiretroviral treatment as the cause. These findings demonstrate that universal access to antiretroviral treatment in a developing country can produce benefits on the same scale as in richer countries.

Background: Up to 25% of the tooth extraction after root canal treatment could be attributed to the vertical root fracture (VRF). The treatment choice for teeth with VRF would mostly be the extraction despite some repairing methods were also reported. The repairing treatment result of VRF would mostly depend on the fixation strength and the bioactivity of the repairing materials, especially for the posterior teeth with high masticating stresses. This case report designed a novel surgical treatment approach for the VRF of posterior teeth. Methods: a maxillary premolar with buccal-palatal complete VRF was treated with a new dual-layered repairing approach using adhesive resin + iRoot BP Plus bioceramic cement to fill the modified fracture line with retention forms through the intentional replantation. Results: At the 24-month review, the tooth showed desirable periodontal healing and normal function. Conclusions: This case report indicated that the dual-layered repairing approach might be effective for saving the posterior teeth with VRF. Nevertheless, further clinical trials are needed for its long-term result. [ABSTRACT FROM AUTHOR]

Aim: This study aimed to compare the frequency of dentinal microcracks after root canal shaping with three different nickel-titanium (NiTi) systems, namely, ProTaper Gold (PG), HyFlex CM (HCM), and Silk. Methods: One hundred mandibular premolars with a single canal were chosen for this study. All specimens were decoronated and divided into four groups of 25 each. Teeth were mounted in the acrylic block with simulated periodontal ligaments. Group I served as a negative control Group, in which no treatment was performed. Biomechanical preparation was done in the Group II, using the Protaper gold file system. Group III, using the Hyflex CM file system and Group IV, using the Silk file system. Specimens were horizontally sectioned at 3, 6, and 9 mm from the apex using the low-speed diamond disc under water cooling. The slices were then viewed under a stereomicroscope at ×25 to determine the presence of cracks. The absence or presence of cracks was recorded, and the data were analyzed with a Chi-square test. The significance level was set at P < 0.05. Results: Coronal section showed lesser crack formation in all three groups after biomechanical preparation. More number of dentinal microcracks were seen in the apical sections, followed by the middle and the coronal sections in Group II (PG), followed by Group IV (Silk), and Group III (HCM), respectively. Group II showed more microcracks at all three levels of the root canals when compared with Groups III and IV. Intergroup analysis showed no statistically significant difference in microcrack formation. Conclusion: Within the limitation of this in vitro study, it can be concluded that NiTi instruments may cause cracks on the root surface. HCM and Silk files tend to produce a less number of cracks as compared to PG instruments. [ABSTRACT FROM AUTHOR]

Objective: This study evaluated the effects of antioxidants, 10% sodium ascorbate (SA) or 20% alpha‐tocopherol (AT), after post‐space irrigation with 2.5% sodium hypochlorite +17% EDTA (SH) or 1% peracetic acid (PA) on the adhesive interface after glass fiber post cementation. Materials and Methods: Sixty bovine roots were endodontically treated. After preparation, the post‐space was irrigated with SH or PA followed or not by the use of antioxidants (SA or AT) (n = 10). Push‐out bond strength test, failure mode, and dentin penetrability analysis using confocal laser microscope were performed in the cervical, middle, and apical thirds. Data from bond strength and dentinal penetrability were evaluated by one‐way ANOVA and Tukey post hoc test (p < 0.05). Results: SH showed the lowest bond strength regardless of the third (p < 0.05). In apical third, mixed failure was the most incident in all groups. Only in the cervical third of the post‐space, SH‐AT provided the greatest tag extension of the cementation system into dentin (p < 0.05). However, in the middle and apical thirds, SH‐AT, SH‐SA, and PA‐SA provided the largest tag extensions (p < 0.05), but similar to each other (p > 0.05). Conclusions: The use of antioxidants only favored bond strength when SH was used and dentin penetrability of the adhesive and conventional resin cementation, regardless of the solution used to irrigate the post‐space. Clinical Significance: The use of antioxidants (10% sodium ascorbate and 20% alpha‐tocopherol) after post‐space irrigation with sodium hypochlorite appears to increase the bond strength favoring the glass fiber post‐cementation. [ABSTRACT FROM AUTHOR]

This study assessed canal preparation effects on disinfection and dentin preservation. Thirty mandibular incisors were paired into two experimental groups (n = 10). Following contamination, the initial microbial sample was collected. Instruments 30/0.03 (Group 1) and 30/0.05 (Group 2) were employed and a second sample was obtained. Canals were enlarged using instruments 40/0.03 and 40/0.05, respectively, and a third sample was collected. Final irrigation was performed, and sample S4 obtained. A final scan evaluated volume, surface area, unprepared areas, removed dentin and dentin thickness. Data were analysed using Student t-test, Mann-Whitney, Kruskal-Wallis and Dunn tests. A significant difference was observed between S1 and other time points (p < 0.05). Comparison between groups showed no differences in bacterial loads and in the percentage of microbial reduction (p > 0.05). Group 2 exhibited greater reduction in dentin thickness than group 1 in the mesial aspect of the root (p < 0.05). Instrument 30/0.03 might provide effective disinfection and safety during mandibular incisors canal preparation., (© 2024 Australian Society of Endodontology Inc.)

Objective: The aim of this study was to investigate solubility, pH value, chemical structure, radiopacity, and cytotoxicity of AH Plus BC, TotalFill BC, AH Plus, and AH Plus Jet sealers. Materials and methods: Cytotoxicity analysis with direct and extraction tests at 3 different concentrations (1:1, 1:2, 1:4 v/v%) and time (24 h, 48 h, and 72 h) on Saos-2, PdLF, and THP-1 cell lines, chemical structure with scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) analysis, solubility, pH, and radiopacity values of AH Plus BC, TotalFill BC, AH Plus, and AH Plus Jet were evaluated. For statistical analyses of the groups, repeated measures, factorial, and one-way ANOVA tests were used. The statistical significance level was set at p <.05. Results: Resin-based sealers showed higher cytotoxicity values than the bioceramic-based sealers (p < 0.05). Time and concentrations were effective on the cell viabilities for cell lines. Higher peaks of calcium were detected bioceramic-based sealers and higher amount of zirconium was detected in AH Plus BC (p < 0.05). AH Plus BC showed similar radiopacity value with AH Plus, AH Plus Jet, whereas TotalFill BC showed the lowest radiopacity (p < 0.05). Bioceramic-based sealers had higher pH values in all experiment periods, and the difference between resin- and bioceramic-based sealer groups was significant (p < 0.05). However, the solubility values of the tested root canal sealers revealed no differences (p > 0.05). Conclusions: The newly produced AH Plus BC Sealer showed similar properties with TotalFill BC, and their biological properties were better than AH Plus and AH Plus Jet. Clinical relevance: AH Plus BC could be a possible alternative to other bioceramic- or resin-based sealers. [ABSTRACT FROM AUTHOR]

Background: Optimal biomechanical preparation, thorough irrigation, proper disinfection, and finally, well-sealed obturation is a must to attain definitive success in root canal procedure. Proper preparation of the root canal is all the more imperative to establish a hermetic apical seal with adequately placed filling materials. The present study was conducted for comparing the Cleaning Efficiency of F360 system and the WaveOne Gold (WOG) system of rotary NiTi instrumentation for a root canal. Materials and Methods: One hundred freshly extracted noncarious mandibular canines were obtained. Access cavity of standard size was made followed by the establishment of working length. Afterward, random division of all the specimens was done into two study groups: group A: the group in which F360 system was used for instrumentation and group B: the group in which the WOG system was used for instrumentation. Irrigations of all the specimens of both the study groups were done followed by root canal shaping by the instrument system of their respective study groups. Scanning electron microscope (SEM) was used for assessment after specimens were cut buccolingually. Debris score and residual smear layer score were used for assessment. Results: Among group A specimens, the mean smear layer score at the coronal third, middle third, and apical third was 1.76, 2.39, and 2.65, respectively. Among group B specimens, the mean smear layer score at the coronal third, middle third, and apical third was 1.34, 1.59, and 1.92, respectively. While analyzing statistically, it was seen that the mean smear layer score was significantly higher among specimens of group A in comparison to group B. While analyzing statistically, it was seen that the mean debris score was significantly higher among specimens of group A in comparison to group B. Conclusion: The cleaning effectiveness of WOG instruments was significantly enhanced in comparison to F360 equipment. [ABSTRACT FROM AUTHOR]

Background: Platelet concentrates combined with calcium silicate cements may promote reparative dentin formation. However, few studies have reported their effect on dental pulp inflammation. This study aimed to evaluate the effects of concentrated growth factor (CGF) combined with iRoot BP Plus on inflammatory human dental pulp stem cells (hDPSCs) in vitro and inflamed pulp in rats in vivo. Methods: The proliferation of LPS-stimulated hDPSCs treated with 50% CGF with/without 25% iRoot BP Plus was evaluated using Cell Counting Kit-8 on days 1, 4 and 7. The expression of genes associated with inflammation on day 1 and differentiation on day 14 was analysed by real-time polymerase chain reaction. The exposed pulp of rat maxillary molars was injected with 10 mg/mL LPS and directly capped with CGF membrane with/without iRoot BP Plus extract for 1, 7 and 28 days. The teeth were subjected to histologic analyses and immunohistochemistry. Results: The proliferation rates of the inflammatory hDPSCs after the combination treatment were significantly higher than those after the other treatments on days 4 and 7 (P < 0.05). IL-1β, IL-6, and TNF-α levels were increased in inflammatory hDPSCs but decreased after treatment with CGF combined with iRoot BP Plus extract, whereas IL-4 and IL-10 showed the opposite expression patterns. Expression of the odontogenesis-related genes OCN, Runx2, and ALP was dramatically enhanced by combined treatment with CGF and iRoot BP Plus extract. In rat pulp, the average inflammation scores of the CGF and CGF-iRoot BP Plus groups significantly decreased in comparison with those of the LPS group (P < 0.05), and the CGF-iRoot BP Plus group had more reparative dentin than the CGF and BP groups. Immunohistochemical staining showed fewer M1 macrophages on day 1 and more M2 macrophages on day 7 in the CGF-iRoot BP Plus group than in the other groups. Conclusions: The combination of CGF and iRoot BP Plus showed a synergistic effect on anti-inflammatory potential and promoted greater pulp healing than CGF or iRoot BP Plus alone. [ABSTRACT FROM AUTHOR]

Aim: This micro-computed tomography (micro-CT) study aims to quantitatively analyze the dentinal microcracks formed and propagated after endodontic retreatment using different file systems. Methods: Forty extracted mandibular premolars were selected. Biomechanical preparation was done using ProTaper Next rotary files followed by obturation using lateral compaction technique. All specimens were randomly divided into four groups (n = 10) and scanned under 1172; Micro-CT (Skyscan Bruker, Kontich, Belgium). After scanning, the first group was retreated using Hedstrom (H) files (Dentsply Maillefer, Ballaigues, Switzerland), the second group with Gutta Percha Remover (GPR) files (Mani Inc., Japan), the third group with Endostar RE Re Endo Rotary system (RE Endo files) (Endostar RE, Poland), and fourth group with ProTaper Universal Retreatment (PTUR) files (Dentsply Maillefer, Ballaigues, Switzerland). A micro-CT scan was repeated of each sample to observe the newly formed and propagated microcracks. The micro-CT scans before and post retreatment were then evaluated using CT-analyzer software. Data were compared using the Chi-square test. Results: New microcracks formed post retreatment were maximum in the RE Endo group followed by the PTUR group, GPR group, and least in the H file group. Propagation of existing microcracks after retreatment was maximum in the RE Endo group followed by nearly similar in both the GPR group and PTUR group and least in the H file group. On comparing the frequency distribution of the newly formed and propagated microcracks, the Chi-square test showed similar distribution among all four groups, which was found statistically insignificant (P > 0.05). Conclusion: GPR rotary instrument group created the least new microcracks among tested retreatment rotary files. However, the propagation of microcracks was found comparable with the PTUR files. [ABSTRACT FROM AUTHOR]

This study compared shaping ability between two single‐file systems and before/after using supplementary file in untouched area, volume of removed dentin, maximum cut depth (the highest cut depth by main file) and remaining thinnest dentin (the thinnest root dentin after preparation). Ribbon‐shaped distal canals of mandibular molars were prepared with non‐adaptive core (WaveOne Gold) or adaptive core (XP‐endo Shaper) files (n = 15/group) and additionally prepared with a supplementary file (XP‐endo Finisher), and the shaping ability was investigated using micro‐computed tomography. XP‐endo Shaper group demonstrated significantly less overall untouched area than WaveOne Gold group (38.21 ± 6.98% vs. 47.68 ± 9.16%) (p < 0.05). No significant difference was detected between XP‐endo Shaper and WaveOne Gold groups in volume of removed dentin (1.85 ± 0.53 vs. 1.66 ± 0.33 mm3), maximum cut depth (0.10–0.28 vs. 0.10–0.29 mm) and remaining thinnest dentin (0.66–0.80 vs. 0.78–0.88 mm). Supplementary XP‐endo Finisher treatment significantly decreased untouched area (11%–23% reduction) (p < 0.05) with minimally cut root dentin (0.01–0.02 mm). [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the existence of preoperative dentinal defects among differently preserved dentoalveolar bone-blocks (frozen vs. embalmed) and to investigate the effect of varying apical forces (low: <4 N, high: 4–8 N) during root canal preparation on microcrack formation using micro-computed tomography (micro-CT). Thirteen embalmed and seven frozen bone-blocks containing 1–3 single rooted teeth were collected. The teeth were evenly divided into three groups (n = 10): FLow (frozen, <4 N), ELow (embalmed, <4 N), EHigh (embalmed, 4–8 N). After working length determination all specimens were scanned preoperatively. Root canal preparation was performed using nickel-titanium instruments sizes 25/.06 and 40/.06 (F6 SkyTaper; Komet, Lemgo, Germany). A postoperative scan was performed and image stacks were co-registered. All cross-sectional images were screened to identify the presence of dentinal defects. The results were expressed as the percentage of teeth/slices presenting dentinal defects. The statistical analyses were performed with Kruskal-Wallis-Test and Mann-Whitney-U-Test (α = 5%). Embalmed specimens presented a significantly higher percentage of slices with preoperative microcracks (p<0.05) than frozen specimens. No significant difference between groups was observed regarding the induction of microcracks (p>0.05). Root canal preparation does not induce microcracks in dentoalveolar bone-blocks from donors of old age, irrespective of the preservation method and the apically directed forces. [ABSTRACT FROM AUTHOR]

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Background: The ex vivo study is to compare the root canal preparation outcomes achieved by five nickel–titanium single-file instrumentation systems (M3-L, Reciproc Blue, V-Taper 2H, WaveOne Gold, XP-endo Shaper) in severely curved molar root canals. Methods: A total of 60 root canals were selected from extracted human molar teeth with curvatures ranging from 25° to 50° and divided into five groups based on the instrumentation system employed (n = 12). Before and after root canal preparation, a Micro-CT scan was taken, and pre- and post-operative data were analyzed to evaluate the following parameters: volume increment of root canals (VI), untouched root canal areas (UTA), and canal transportation (CT). Apically extruded debris (AD) was collected during preparation. After that, all samples were separated into two parts and examined respectively by scanning electron microscope (SEM) to assess cleaning ability. Data were statistically analyzed with ANOVA (UTA, AD, VI) or Kruskal–Wallis test (CT, SEM-score), the level of significance was set at α = 0.05. Results: There were no significant differences between the five systems regarding the AD, VI, and UTA parameters (P > 0.05). In terms of CT, no significant difference was noted at the straight section of canal and apical levels, while XP-endo Shaper showed less canal transportation than M3-L at the level of curved vertex (P < 0.05), and the centering ability of V-Taper 2H was significantly better than WaveOne Gold at the initial point of bending (P < 0.05). Debris and smear layers were present on the canal walls of all specimens, the apical thirds of the canal presented higher SEM scores than the coronal thirds in all groups (P < 0.05). Reciproc Blue and XP-endo Shaper showed fewer smear scores than WaveOne Gold in the apical thirds (P < 0.01 and P < 0.05, respectively), and no statistical difference was found between other groups in the middle and coronal thirds. Conclusion: The five single-file systems evaluated performed equally in apically debris extrusion, dentin removal, and untouched root canal areas, while XP-endo Shaper and V-Taper 2H resulted in less canal transportation compared to M3-L and WaveOne Gold. Regarding cleaning ability, Reciproc Blue and XP-endo Shaper were associated with less smear layer than WaveOne Gold in the apical thirds. [ABSTRACT FROM AUTHOR]

Background: Studies which examine quality of life (QOL) provide important insights that are needed to understand the impacts of HIV/AIDS anti-retroviral treatment (ART), comorbid conditions and other factors on the daily activities of people living with HIV/AIDS (PLH). This study aimed to determine the inter-relationships between clinical factors, behavioural, socio-demographic variables and QOL among PLH.Methods: The secondary analysis used data collected from 293 people living with HIV/AIDS (PLH) receiving second-line ART in Johannesburg in a clinical trial which evaluated the non-inferiority of ritonavir-boosted darunavir (DRV/r 400/100 mg) compared to ritonavir-boosted lopinavir (LPV/r) over a 48 week-period. Physical functioning, cognitive and mental QOL were measured using the Aids Clinical Trial Group questionnaire. Exploratory factor analyses were used to examine the structure, the relationships between and the construct validity of QOL items. Structural equation models which tested the a priori-hypothesised inter-relationships between QOL and other variables were estimated and goodness of fit of the models to the data was assessed.Results: Patients on darunavir presented with lower pill burden. Older patients and women were more likely to report lower QOL scores. Pill burden mediated the effects of age, sex and treatment regimen on physical functioning QOL and adverse effects; the effects of age, sex, treatment regimen and adverse effects on cognitive QOL; and the effects of sex on mental QOL.Conclusion: QOL among PLH is associated with socio-demographic and clinical factors. Therefore, QOL could be enhanced by considering PLH characteristics, clinical factors such as regimen side-effects profile, management of comorbid conditions and mitigating risks such as potential adverse drug-to-drug interactions among patients on ART. [ABSTRACT FROM AUTHOR]

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Aim The aim of this study was to evaluate the effect of two different concentrations of chitosan irrigation with two rotary systems (Revo-S and One Shape) on smear layer removal during root canal treatment using scanning electron microscope. Materials and methods Forty freshly extracted human premolar with single canal and nearly straight roots were collected. Teeth were decoronated to obtain a standardized root length of nearly 15 ± 1 mm. Samples were randomly divided into four main groups (n = 10) according to rotary preparation system and final chitosan irrigation concentration used. Group I: Revo-S rotary system and 5 ml of 0.2% chitosan solution for 3 min as final irrigation. Group II: One Shape single file and 5 ml of 0.2% chitosan solution for 3 min as final irrigation. Group III: Revo-S rotary system and 5 ml of 0.37% chitosan solution for 3 min as final irrigation. Group IV: One Shape single file and 5 ml 0.37% of chitosan solution for 3 min as final irrigation. During preparation and after change of each succeeding file, root canal irrigated with freshly prepared 5 ml of 2.5% sodium hypochlorite solution. Then, rinsed with 5 ml of distilled water. Finally, root canals were irrigated with final chitosan irrigation concentration as mentioned in groups. Samples were split longitudinally and examined by scanning electron microscope analysis. Root canal cleanliness was qualitatively assessed at the coronal, middle, and apical regions of root halves. Kruskal--Wallis test was used to compare between final irrigation solutions at each section and Mann--Whitney U test was used for pair-wise comparisons between groups whenever indicated. The significance level was set at P value less than or equal to 0.05. Results It showed that there were no statistical significant differences between groups for smear layer covering the dentinal surfaces. When comparing different root levels, there were no statistical significant differences between coronal versus middle levels but between coronal versus apical and middle versus apical statistical significant differences were found. Conclusions Smear layer can be removed effectively in all tested groups from coronal and middle levels compared to apical level. Using multiple file system (Revo-S files) is better than single file system (One Shape file) in removal of the smear layer of root canal. Increasing the concentration of chitosan to 0.37% promoted removal of the smear layer better than 0.2% of chitosan. [ABSTRACT FROM AUTHOR]

This study aimed to systematically review clinical and microbiology-related effects of ultrasonically activated irrigation (UAI) compared to syringe irrigation (SI) during endodontic treatment. Electronic databases searching and manual searching were conducted. Only randomized clinical trials (RCTs) were included comparing UAI to SI. The RoB 2.0 Cochrane tool was used for risk-of-bias (RoB) assessment. The main outcomes were postoperative pain, treatment failure, and microbiology-related outcomes. Qualitative and quantitative analyses, wherever applicable, were performed. Risk ratios (RR) and [standardized] mean differences {[S]MD} were calculated for dichotomous and continuous outcomes, respectively. Certainty of evidence (CoE) was assessed using GRADE tool. Ten RCTs were included. UAI reduced pain incidence within the first 24 h (RR 0.50, 95% CI 0.35–0.71, 308 teeth) and microbial counts (SMDpooled − 0.40, 95% CI [− 0.78, − 0.02], I2 = 0%, 126 teeth) than SI in non-vital teeth with apical periodontitis (AP). Both groups, however, had similar effects regarding pain intensity, lipopolysaccharide amounts, and the incidence of rescue-analgesic intake, treatment failure, and microbial presence (p > 0.05). CoE ranged from low to very low. Very limited evidence suggests that UAI could reduce postoperative-pain risk within the first 24 h and microbial counts for non-vital teeth with AP compared to SI. Most meta-analyses, however, are based on very few studies, mostly low-powered, with an overall very-low-to-low CoE. Further well-designed, larger RCTs are, thus, required. [ABSTRACT FROM AUTHOR]

Objectives: This study was aimed to evaluate the cause-effect relationship between canal preparation with ProTaper Next (PTN) and ProTaper Gold (PTG) using optimum torque reverse (OTR) motion or continuous rotation and dentinal crack formation. Materials and Methods: Fifty distobuccal roots of human maxillary first molars were divided into five groups; Group I: PTG Full rotation, Group II: PTG in OTR, Group III: PTN Full rotation, Group IV: PTN in OTR, Group V: unprepared (control group). After mechanical preparation, the distobuccal roots were sectioned horizontally at 3, 6, and 9 mm from the apex. Images were captured using a stereomicroscope at 25X to determine the presence or absence of dentinal cracks. Friedman test was used to compare between root sections followed by Wilcoxon signed-rank test for pairwise comparison. Kruskal–Wallis test was used to compare between tested rotary systems followed by pairwise comparison with Dunn Bonferroni correction (α = 0.05). Results: Crack development was significantly higher in PTG using OTR motion 36.7% followed by PTN using OTR 33.3%, while the control group showed no cracks. PTG and PTN with full rotation showed crack development with 23.3% and 13.3%, respectively. Conclusions: The type of motion kinematics used during mechanical preparation have an impact on dentinal crack formation. Nickel-titanium instruments with larger taper tend to induce more cracks. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to investigate whether file design and taper significantly influence microcrack initiation during machine preparation. Materials and methods: Sixty extracted teeth with straight single canals were selected. The teeth were randomly assigned to four groups based on their root canal anatomy and the corresponding NiTi rotary file system (I, Mtwo; II, ProTaper Universal; III, F6 SkyTaper; control, no preparation and filling). The root canals of the experimental groups were filled using the single-cone technique. The tested teeth were all subjected to a mechanical chewing simulation with flat lead loading over a period of 3 years (corresponding to 150,000 cycles). The teeth were checked for dentinal defects (accumulative crack growth in length) under the digital microscope (Keyence VHX-5000) at time 0 (baseline prior to chewing simulation) and after 3, 6, 12, 24, and 36 months of loading. The cumulative crack increase was statistically analyzed using the Kruskal–Wallis test, Jonckheere–Terpstra test, and the Wilcoxon rank-sum test. The significance was set at p < 0.05. Results: In contrast to preparation with greater-tapered instruments, ProTaper Universal (group II) and F6 SkyTaper (group III) instrumentation with the smaller tapered Mtwo files (group I) showed less accumulative propagation of craze lines (p < 0.05) at all time points. Conclusion: Instruments with greater taper for root canal instrumentation should be used with care to avoid negative long-term effects in the form of propagation of dentinal defects over time. A positive cutting-edge angle and a smaller taper have a positive effect on a lower craze line development. Clinical relevance: Instruments with a positive cutting-edge angle and a smaller taper are beneficial for the long-term preservation of dentinal tooth structure. [ABSTRACT FROM AUTHOR]

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Aim: To compare microcrack formation in roots of extracted teeth after the shaping of straight and curved root canals with hand, rotary and reciprocating files using micro‐computed tomographic (micro‐CT) analysis. Methodology: Thirty straight mandibular incisors and 30 severely curved mesial roots of mandibular molars were randomly divided into 6 experimental groups (n = 10) according to the systems used for the root canal preparation and the root canal curvature: ProTaper Universal for Hand Use (Dentsply Sirona, Ballaigues, Switzerland), HyFlex EDM (Coltene‐Whaledent, Altstätten, Switzerland) and Reciproc Blue (VDW, Munich, Germany) files used in mandibular incisors (straight canals) and mesial roots of mandibular molars (curved canals). The roots were imaged with micro‐CT scanning at an isotropic resolution of 14 μm before and after root canal preparation, and the cross‐sectional images generated were assessed to detect microcracks. Results: All dentinal defects identified after root canal preparation were already present before instrumentation, and no new microcracks were detected. Dentinal microcracks were present in 19% (ProTaper Universal for Hand Use), 11% (Hyflex EDM) and 23% (Reciproc Blue) of the cross‐sections when the instrumentation was performed in mandibular incisors. Instrumentation of mandibular molars revealed microcracks in 15% (ProTaper Universal for Hand Use), 16% (Hyflex EDM) and 17% (Reciproc Blue) of the cross‐sections. Conclusions: Preparation of straight and curved root canals with ProTaper Universal for Hand Use, HyFlex EDM and Reciproc Blue systems did not produce microcracks in extracted teeth when evaluated with micro‐CT. [ABSTRACT FROM AUTHOR]

This study is aimed at comparing and evaluating the biocompatibility and antibacterial activities of mineral trioxide aggregate (MTA) and iRoot BP Plus as novel retro-filling materials. Discs of both materials were prepared and incubated for 72 h to obtain material extracts in medium. Flow cytometry and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay were used to assess the rate of apoptosis and proliferation of human periodontal ligament stem cells (hPDLSCs) when exposed to eluates of both materials. The expression levels of alkaline phosphatase, collagen type I, osteocalcin, Runt-related transcription factor-2, and Osterix were tested for evaluating the osteogenic differentiation of hPDLSCs. The antibacterial activities of both materials were compared by the direct contact test. The hPDLSCs stimulated by MTA or iRoot BP Plus eluates showed significantly higher cell viability than that of the control group with no eluates. No significant differences were observed among the percentages of necrotic and apoptotic cells stimulated by MTA and iRoot BP Plus eluates and the control group. The expression of all osteogenic differentiation markers of hPDLSCs in both experimental groups were significantly higher than those of the control group, while the increment values in MTA group were significantly higher than those of the iRoot BP Plus group. The antibacterial activity against Enterococcus faecalis showed no significant difference between MTA and iRoot BP Plus. Therefore, both materials may be suitable for retro-filling applications. [ABSTRACT FROM AUTHOR]

Objectives: The purpose of this randomized controlled trial was to compare the 24-month success rates of indirect pulp treatment (IPT) and iRoot BP Plus pulpotomy of primary molars with extremely deep caries. Materials and methods: Generally healthy children aged 3–7 years requiring general anesthesia for treating primary molars with extremely deep caries or reversible pulpitis were recruited. Patients with systemic disease, mental health problems, or manifestations of irreversible pulpitis were excluded. In total, 175 molars were randomized and blinded for either IPT (n = 87) or iRoot BP Plus pulpotomy (n = 88). All teeth were restored with stainless steel crowns and evaluated after 6, 12, 18, and 24 months by two blinded calibrated investigators. Kaplan-Meier survival curves were used to compare the survival rates between the groups. The correlations between success rate and patient characteristics were explored with the Cox proportional hazards model. Results: A total of 168 primary molars in 67 patients (average age: 3.83 years) were evaluated. The cumulative survival probability at 24 months was not significantly different between the IPT (93.8%) and pulpotomy (97.7%) groups (P = 0.238). IPT treatment success was significantly associated with age (odds ratio = 2.347; 95% CI: 1.068–5.156; P = 0.034) and preoperative sensitivity (odds ratio = 9.742; 95% CI: 1.079–87.970; P = 0.043). Conclusions: The 24-month success rates of IPT and iRoot BP Plus pulpotomy performed in primary molars with extremely deep caries were not significantly different. Increasing age and preoperative sensitivity were found to be associated with the cumulative survival probability in IPT-treated primary molars with extremely deep caries. Primary teeth with extremely deep carious lesions without signs of irreversible pulpitis can be treated successfully by either indirect pulp capping or iRoot BP Plus pulpotomy. Trial registration: ChiCTR2000032462 [ABSTRACT FROM AUTHOR]

Background: The capacity of an irrigant to dissolve pulp tissue is of paramount importance as it can clean areas of the root canal that are inaccessible to instrumentation. Aim: To evaluate the tissue dissolving capacity of sodium hypochlorite (NaOCl) and peracetic acid (PAA) in combination. Materials and Methods: Forty maxillary central incisors were split longitudinally and grooved to mimic lateral canals. Pulp retrieved from freshly extracted impacted third molars were placed in grooves and repositioned in a putty index. All samples were irrigated with four different irrigants. 3% NaOCl; 1% PAA; 3% NaOCl and 1% PAA and Normal saline. Samples were irrigated for 5, 10 and 15 min weighed before and after each cycle with precision balance. Statistical analysis with ANOVA and post hoc Bonferroni was performed. Results: All groups showed tissue dissolution, except Group IV (Negative control). Complete dissolution did not occur in any sample. Group III showed statistically significant difference at 10 min. Conclusion: Results suggested that NaOCl and PAA in combination have better tissue dissolving capacity than used individually. [ABSTRACT FROM AUTHOR]

Copyright of Meandros Medical & Dental Journal is the property of Galenos Yayinevi Tic. LTD. STI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

New algorithms for image processing and data analysis techniques have emerged in recent times, microcomputed tomography (µ-CT) is a unique imaging modality which empowers three dimensional structures rapidly and non-invasively at high spatial goal than those that are obtained by using cone beam computed tomography. This review article highlights the working principle, the accuracy of µ-CT over conventional CT and describes in detail the applications of µ-CT in dentistry. This review signifies the importance of µ-CT as essential diagnostic tools in multiple dental applications. Besides providing high resolution images within a short scan time, the instauration of scanned images permits evaluation of tooth without superimposition that congregates a lot of information making the novel technique a fortunate conception. [ABSTRACT FROM AUTHOR]

Copyright of Turkiye Klinikleri Journal of Dental Sciences is the property of Turkiye Klinikleri and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aim: The aim is to assess and compare the microcrack formation in radicular dentin after obturating the root canals with cold lateral condensation (CLC), warm vertical condensation (WVC), and injectable gutta-percha (IGP) techniques using micro-computed tomography (CT). Materials and Methods: Human extracted mandibular premolar teeth (n = 60) were haphazardly assigned based on the obturation technique into three experimental groups (n = 20 each). Root canals are cleaned and shaped with M Two rotary files and 3% sodium hypochlorite irrigant. Cross-sectional images were taken with Micro-CT to record the baseline defects present on root samples. After root canal obturation either with CLC or WVC or injectable obturation techniques, micro-CT images were captured again to analyze the increase in the number and type of dentinal defects. Statistical analysis of data was performed using the Mann–Whitney U test and the Mcnemar test at 5% significance level. Results: An increase in the number of radicular micro-cracks was identified in samples obturated with lateral condensation technique (1.66%). No change in the percentage of micro-cracks was recorded after obturation with warm vertical or injectable guttapercha (IGP) techniques (P > 0.05). The three obturation techniques were not statistically different in the occurrence of micro-cracks after obturation. Conclusion: The three obturating techniques tested showed no significant increase in radicular dentin defects' occurrence or propagation. [ABSTRACT FROM AUTHOR]

The article explores the rise of the new Brazilian cinema during the COVID-19 pandemic in 2020. The pandemic has resulted in the emergence of new trends in the film sector, including the launching of public solicitations for low-budget films and the arrival of lower production costs through the use of digital technology. The pandemic also affected the country's film festivals and resulted in job losses in the sector.

Aim: To evaluate the nanohardness reduction and erosion in root canal dentine after application of 17% ethylenediaminetetraacetic acid (EDTA), 9% etidronic acid (HEBP) and 2% peracetic acid (PAA) either alone or combined with sodium hypochlorite (NaOCl). Methodology: One hundred and sixty single‐rooted teeth were decoronated and their root canals were chemomechanically prepared. For the nanohardness evaluation, 80 roots with instrumented canals were split longitudinally into two halves. Dentine blocks with a length of 7 mm were obtained from the middle third of one half of each tooth and were embedded in epoxy resin blocks exposing the root canal walls. Initial nanohardness values of root canal dentine were measured for each specimen using a nanoindenter with a Berkovich tip. The specimens were divided into seven experimental (n = 10) and one control (n = 10) group according to the final irrigation regimens: Group 1: 2.5% NaOCl, Group 2: 17% EDTA, Group 3: 2.5% NaOCl‐17% EDTA, Group 4: 2% PAA, Group 5: 2.5% NaOCl‐2% PAA, Group 6: 9% HEBP, Group 7: 2.5% NaOCl + 9% HEBP and Group 8: Distilled water (control). The measurement of the nanohardness values was repeated for each specimen after being exposed to the irrigants. The nanaohardness reduction of each sample was calculated and recorded. The other 80 instrumented root canals were used for scanning electron microscope (SEM) evaluation. First, they were irrigated with the same protocols stated above and longitudinally split into two halves. One half of each root canal was viewed using SEM for the amount of erosion. The erosion scores were recorded. Data were analysed statistically using Kruskal–Wallis and Bonferroni‐adjusted Mann–Whitney U‐tests with a significance level of 0.05. Results: Use of etidronic acid and NaOCl + HEBP reduced the nanohardness values significantly more than the other experimental solutions (P < 0.05). There was no significant difference between the values for the nanohardness reduction in the samples irrigated with a single chelator and chelator combined with NaOCl (P > 0.05). Peritubular and intertubular erosion were observed in the samples irrigated with HEBP and NaOCl + HEBP. Conclusion: Final irrigation of root canals using etidronic acid alone or combined with NaOCl was associated with structural alterations in root canal dentine of extracted teeth. [ABSTRACT FROM AUTHOR]

Aim: To investigate a potential cause–effect relationship between dentinal microcracks and fracture resistance of mandibular incisors that had not been endodontically treated. Methodology: Sixty mandibular incisors with circular‐shaped canals were selected based on micro‐computed tomographic scans to create a homogeneous sample. The cross‐sectional images of the specimens were screened to identify and quantify the presence of dentinal microcracks. Then, teeth were embedded in polystyrene resin and subjected to axial compressive loading using a universal testing machine. After fracture, the roots were re‐scanned and fractography analysis was performed by inspection of 3D models to verify crack propagation. Spearman's rank correlation was used to assess the correlation between the number of microcracks and force required to fracture. Results: Dentinal microcracks were detected in 79% of the specimens (n = 44). The incidence of microcracks varied between teeth from 6% to 42% of the total slices per sample (average of 14 ± 17%). The number of microcracks per sample varied from 0 to 1605, with an average of 412 ± 484 (median = 221 and IQR 25% = 15/75% = 658). The load at failure values varied from 227 to 924 N, with an average of 560.3 ± 168.1 N (median = 561 and IQR 25% = 458/75% = 694). The Spearman correlation coefficient (rho) equalled 0.065. Conclusions: There was no cause–effect relationship between the number of dentinal microcracks and the fracture resistance of nonendodontically treated mandibular incisors. The presence and quantity of microcracks did not make these roots more prone to fracture. [ABSTRACT FROM AUTHOR]

Objectives: This systematic review aimed to compare the cytotoxicity of root canal filling materials (RCFMs) assessed using tetrazolium salt‐based tests (TSBT), including the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide (MTT) assay, with those obtained using other cell viability assays. Methods: A search was performed on PubMed, Scopus, Web of Science and OpenGrey up to March 2019, followed by a manual search. According to the Participants, Exposure, Comparator and Outcomes (PECO) criteria, in vitro studies that evaluated the cytotoxic effect of RCFMss on animal and/or human cells through TSBT and at least one other viability assay were compared. The methodological quality of selected papers was assessed using ToxRTool® and SciRAP®. Data were analysed using Wilcoxon's signed‐rank test for paired samples and linear weighting kappa. Results: A total of 230 non‐duplicated records were identified. After applying the eligibility criteria, 55 studies were selected for methodological evaluation, seven were selected by manual searching, 22 were excluded for methodological reasons, and 40 were included. A total of 410 comparisons were performed between TSBT and distinct cell viability tests (DCVT). MTT had moderate concordance with DCVT using human cells (n = 138 samples) (P = 0.507; k = 0.4225) and animal cells (n = 122 samples) (P = 0.124; k = 0.5775). XTT had good concordance using human (n = 110 samples) (P = 0.507; k = 0.6336) and animal cells (n = 12 samples) (P = 0.564; k = 0.6604). MTT, XTT, WST and MTS assays showed moderate concordance with DCVT (n = 410 samples) (P = 0.375; k = 0.5138) and complete agreement in 226 samples. Discussion: The included studies had methodological heterogeneity that was minimized by the systematic review methodology. Conclusions: MTT and XTT do not cause over‐ or underestimation of cell viability during cytotoxicity screening of root canal filling materials, implying that these assays can be considered reliable for this purpose. Nonetheless, the development of protocols for the cytotoxic screening of these materials on 3D tissue‐like cultures aiming to improve their predictability in the clinical scenario is suggested. [ABSTRACT FROM AUTHOR]

Background: Advances in both X-ray sources and X-ray optics have dramatically improved the feasibility of these techniques in various fields. Aims: We aimed to evaluate the frequency of dentinal microcracks observed after root canal preparation with ProTaper Gold (PTG), Hyflex electrodischarge machining (HEDM), Reciproc (RPC), and WaveOne Gold (WOG) using synchrotron radiation-based micro-computed tomographic (SR-μCT) analysis. Subjects and Methods: Forty mandibular molars were assigned to 4 experimental groups (n = 10) according to the file system used for the root canal preparation: Group 1: PTG (25/0.08), Group 2: HEDM (25/0.08), Group 3: RPC (25/0.08), and Group 4: WOG (25/0.07). The specimens were scanned on SR-μCT system before and after root canal preparation. The pre- and postoperative cross-sectional images (N = 183,200) of the mesial roots were screened to identify the presence of dentinal microcracks. The number of microcracks was determined as a percentage for each group. Statistical Analysis: There was no necessity of statistical analysis in the present study. The number of microcracks was determined as a percentage for each group. Results: Among the four file systems tested, HEDM (0.9%) has shown a fewer number of new dentinal microcracks. Conclusions: SR-μCT can be used as a reliable diagnostic tool for further implications. [ABSTRACT FROM AUTHOR]

Aim: To evaluate the incidence of root dentinal microcracks after two extraction techniques through micro‐computed tomographic (micro‐CT) analysis. Methodology: Thirty pairs of premolars, extracted for orthodontic reasons, were assigned to two experimental groups, following a split‐mouth design (n = 30): traumatic technique group (TTG) – teeth extracted following a conventional protocol using forceps, and an atraumatic technique group (ATG) – teeth extracted following an atraumatic technique protocol in which the root was gently detached from the periodontal ligament using a periotome. All teeth were immediately immersed in distilled water and scanned in a micro‐CT device within 72 h following the extraction. The assessment of the images was completed on cross‐section images by two masked evaluators. The Mann–Whitney test was used to assess the significant differences between the groups regarding the number of cross‐sections displaying microcracks whilst the Fischer's exact test was used to assess differences in the frequency of specimens with defects (P < 0.05). Results: A total of 52 750 micro‐CT cross‐sectional images were evaluated. A total of 352 cross‐sections had at least one dentinal defect. Microcracks were observed in five teeth of the TTG group (n = 352 slices) and in two teeth of the ATG group (n = 103 slices). The statistical analysis used was unable to detect a significant difference between the groups in terms of the number of dentinal microcracks (P = 0.233) and in the frequency of teeth displaying microcracks (P = 0.424). Conclusion: A small number of sound teeth without endodontic treatment had dentinal microcracks regardless of the extraction technique applied. No difference was noticed between the traumatic and atraumatic techniques in the incidence of microcracks. [ABSTRACT FROM AUTHOR]