Lenherr P, Allgayer N, Weiger R, Filippi A, Attin T, Krastl G. Tooth discoloration induced by endodontic materials: a laboratory study. International Endodontic Journal, 45, 942–949, 2012.
Aim To ...investigate the discoloration potential of endodontic materials using a bovine tooth model.
Methodology Two hundred and 10 dentine‐enamel cuboid blocks (10 × 10 × 3.5 mm) were prepared out of the middle thirds of bovine tooth crowns. Standardized cavities were prepared in the walls of the pulp chamber leaving 2 mm of enamel and dentine on the labial wall of the crown. The specimens were randomly assigned to 14 groups (n = 15). Endodontic materials were placed into the cavities as follows: group A: empty, group B: blood, group C: calcium hydroxide, group D: ApexCal, group E: Ultracal XS, group F: Ledermix, group G: triple antibiotic paste (3Mix), group H: grey MTA(GMTA), group I: GMTA + blood, group J: white MTA (WMTA), group K: WMTA + blood, group L: Portland cement (PC), group M: PC + blood and group N: AH Plus. The cavities were sealed with composite and stored in water. Standardized colour measurement (VITA Easyshade compact) was performed at the following intervals: prior to (T0) and after placement of the filling (T1), 1 week (T2), 1 month (T3), 3 months (T4), 6 months (T5) and after 1 year (T6). Colour change (ΔE) values were calculated. A two‐way analysis of variance was used to assess significant differences between the endodontic materials. The mean values of all groups were compared using the Tukey multiple comparison test (α = 0.05).
Results Significant differences were detected amongst the experimental groups after 12 months (P < 0.0001). The lowest colour change values were observed in the groups N (AH Plus, 3.2 ± 1.5), A (empty, 3.8 ± 1.4), L (PC, 4.1 ± 1.7), C (calcium hydroxide, 4.7 ± 1.5), E (Ultracal XS, 5.1 ± 1.9) and J (WMTA, 7.9 ± 6.7). The most discoloration was measured in groups G (3Mix, 66.2 ± 9.9) and F (Ledermix, 46.2 ± 11.6). PC showed the best colour stability amongst the Portland cement‐based materials; however, when contaminated with blood (group M), a significantly higher ΔE value (13.6 ± 4.2) was detected (P = 0.032).
Conclusion Materials used in endodontics may stain teeth. Therefore, the choice of material should not rely solely on biological and functional criteria, but also take aesthetic considerations into account.
•Rice plays a significant role in water trade: this is one of the world's largest water consumers.•Entre Rios proved major efficiency in green water use than Santa Fe.•Water Footprint for rice in ...Entre Ríos and Santa Fe underestimated the real water use.•Argentina exports per year approximately 542Mm3 of virtual water through rice crop.
In the context of social responsibility and, of the directives aimed at an integral management of natural resources, the Water Footprint (WF) has been widely spread as an indicator that contributes to a safe and sustainable use of water. The purpose of this study was to determine the WF for rice production (WFR) in two rice-growing areas in Argentina: central-east Entre Ríos and Santa Fe. The calculation was made using the methodology proposed in The Water Footprint Assessment Manual, according to which the WF of a crop, in this case rice, represents the relation between the amount of water satisfying the evapotranspiration demand (CWU) and the field productivity. The WF has three components: green (WFgreen), associated with rain used by the crop (CWUgreen); blue (WFblue), related to underground or surface water that fulfils the evapotranspiration demand (CWUblue); and grey (WFgrey), related to the volume of water required to dilute the residues of pollutants generated from the crop production. To estimate the CWUblue and CWUgreen, a rice water balance model (RWM), specifically developed for continuous flooding irrigation, was applied. Based on daily data of precipitation, crop evapotranspiration and soil variables the model allows calculating gross irrigation depth, surface runoff due to precipitations, variation of water stored in the soil, and deep percolation. Four agricultural seasons were assessed: 2009/2010, 2010/2011, 2011/2012, and 2012/2013. In Entre Ríos, WF was 987m3ton−1 (44% WFgreen and 56% WFblue), whereas in Santa Fe it was 846m3ton−1 (36% WFgreen and 64% WFblue). In accordance with related work in the region, WFgrey was not considered. Although only CWU is part of the WF calculation, the other components of the water balance are necessary for rice production. The RWM model determined the consumptive use of the crop and distinguished blue water from green water, besides calculating the other parameters of the water balance. This made possible to show the inefficiencies in the system since precipitations are not fully used. The WFR, together with these components, is useful to make comparisons between different regions and it is a tool to promote water saving, provided that it is complemented with specific policies, such as the differential application of irrigation taxes or electric power rates.
Objectives
To compare the deviation of different systems for Guided Implant Surgery (GIS) related to the specific tolerance between drills and sleeves.
Material and methods
Four different systems for ...GIS and their appropriate sleeves were used: Camlog Guide (CG), Straumann Guided Surgery (SG), SIC Guide (SIG), and NobelGuide (NG). System‐appropriate metal sleeves were inserted into plexiglass boxes, and guided drilling procedure was performed (i) holding the drills in the most centric position of the sleeves and (ii) applying forces eccentrically. Digital microscope images of the plexiglass boxes were taken and axial deviations were calculated based on the Pythagorean Theorem, whereas coronal and apical deviations were measured with a corresponding software‐device and calculated by subtracting the measured deviations from the original diameter of the drills. Statistically significant differences between centric and eccentric drilling were determined applying the t‐test for independent data.
Results
The axial deviation ranged from 0° (SG) to 5.64° (CG). The apical deviations varied between 0.01 mm (SIG) and 3.2 mm (NG) and the coronal deviations ranged from 0.01 mm (SIG) to 1.60 mm (NG). In terms of angular deviation, there were statistically significant differences between centric and eccentric drilling for all four systems. Coronal and apical deviations, showed no statistical significance between centric and eccentric drilling for SIG and NG, in contrast to CG and SG.
Conclusions
The clinician may have considerable impact on the accuracy of GIS when applying eccentric forces.
The pulp plays a key role in the treatment of traumatic dental injuries (TDIs) and is strongly associated with the outcome, particularly in severe cases. A correct pulp diagnosis is essential as it ...forms the basis for developing the appropriate management strategy. However, many TDIs are complex, and their treatment requires a profound knowledge of the physiological and pathological responses of the affected tissues. This comprehensive review will look at the dentine–pulp complex and its interaction with the surrounding tissues following TDIs. The literature up to 2020 was reviewed based on several searches on PubMed and the Cochrane Library using relevant terms. In addition to the recently revised guidelines of the International Association of Dental Traumatology, this article aims to provide background information with a focus on endodontic aspects and to gather evidence on which a clinician can make decisions on the choice of the appropriate endodontic approach for traumatized permanent teeth.
The effect of fibre orientation on the fatigue strength of a short glass fibre reinforced polyamide-6 has been investigated. Tension–tension axial fatigue tests were conducted with specimens ...extracted from injection moulded plates. Specimens were cut out of plates with different orientations with respect to the longitudinal axis of plates, and therefore displayed different orientations of the reinforcing fibres. Results are presented in the form of
S–
N curves, showing the variation of the fatigue strength as a function of the specimen orientation. The experimental data, both tensile and fatigue tests, have been compared with values predicted by a failure criterion derived from the Tsai–Hill formula. The influence on the fatigue lives of the fibre orientation distribution in the thickness of the specimen is discussed.
This position statement represents a consensus of an expert committee convened by the European Society of Endodontology (ESE) on the endodontic management of traumatized permanent teeth. A recent ...comprehensive review with detailed background information provides the basis for this position statement (Krastl et al. 2021, International Endodontic Journal, https://doi.org/10.1111/iej.13508). The statement is based on current scientific evidence as well as the expertise of the committee. Complementing the recently revised guidelines of the International Association of Dental Traumatology, this position statement aims to provide clinical guidance for the choice of the appropriate endodontic approach for traumatized permanent teeth. Given the dynamic nature of research in this area, this position statement will be updated at appropriate intervals.
The study of morphological and physiological responses of shrubs to climate is crucial for the understanding of future scenarios regarding climate change. In this light, studying shrub growth and ...physiological acclimation along an elevation gradient might be insightful. The phenolic metabolic pathway represents a powerful tool to interpret such processes.
In the South‐Eastern Alps, we investigated the relationships between elevation, plant traits (i.e. age, xylem ring width, annual shoot length), plant–plant interaction (i.e. shrub cover) and flavonoids in Vaccinium myrtillus L. (leaves, berries) in stands above the treeline. The relationships were parsed within causal networks using a confirmatory path analysis.
Elevation was the main driver of V. myrtillus growth, having both direct and indirect effects on the leaf flavonoid content, but this was less evident for berries. In particular, the content of foliar flavonoids showed a peak at mid‐elevation and where the growth of xylem rings was intermediate, while it decreased in stands with higher shoot length. Flavonoid content variability of both leaves and berries was affected by elevation and shoot length. In berries, flavonoid variability was further related to all growth traits and shrub cover.
These findings evidence that flavonoid content is influenced by both elevation and growth traits of V. myrtillus, often showing non‐linear relationships. These results suggest a trait‐mediated response of this plant to climate conditions as a result of trade‐offs between plant growth, plant defence, environmental stress and nutrient/resource availability.
Elevation is a major driver for the stimulation of plant flavonoid production in response to environmental stress, but the interplay of elevation with plant growth and plant‐plant interactions should never be neglected.
A well-polished cement surface increases the viability and spreading of gingival fibroblasts. The tested resin composite cements did not reveal any cytotoxic effects.
Objective: This in vitro study ...aimed to investigate the effect of cement type and roughness on the viability and cell morphology of human gingival fibroblasts (HGF-1).Methods and Materials: Discs of three adhesive (Panavia V5 PV5, Multilink Automix MLA, RelyX Ultimate RUL and three self-adhesive (Panavia SA plus PSA, SpeedCem plus SCP, RelyX Unicem RUN) resin composite cements were prepared with three different roughnesses using silica paper grit P180, P400, or P2500. The cement specimens were characterized by surface roughness and energy-dispersive X-ray spectroscopic mapping. A viability assay was performed after 24 hours of incubation of HGF-1 cells on cement specimens. Cell morphology was examined with scanning electron microscopy.Results: The roughness of the specimens did not differ significantly among the different resin composite cements. Mean Ra values for the three surface treatments were 1.62 ± 0.34 μm for P180, 0.79 ± 0.20 μm for P400, and 0.17 ± 0.08 μm for P2500. HGF-1 viability was significantly influenced by the cement material and the specimens' roughness, with the highest viability for PSA ≥ RUN = MLA ≥ SCP = PV5 > RUL (p<0.05) and for P2500 = P400 > P180 (p<0.001). Cell morphology did not vary among the materials but was affected by the surface roughness.Conclusion: The composition of resin composite cements significantly affects the cell viability of HGF-1. Smooth resin composite cement surfaces with an Ra of 0.2-0.8 μm accelerate flat cell spreading and formation of filopodia.
Abstract Background Radical local treatment of pulmonary metastases is practiced with increasing frequency due to acknowledgment and better understanding of oligo-metastatic disease. This study aimed ...to develop a nomogram predicting overall survival (OS) after stereotactic body radiotherapy (SBRT) for pulmonary metastases. Patients and methods A multi-institutional database of 670 patients treated with SBRT for pulmonary metastases was used as training cohort. Cox regression analysis with bidirectional variable elimination was performed to identify factors to be included into the nomogram model to predict 2-year OS. The calibration rate of the nomogram was assessed by plotting the actual Kaplan–Meier 2-year OS against the nomogram predicted survival. The nomogram was externally validated using two separate monocentric databases of 145 and 92 patients treated with SBRT for pulmonary metastases. Results The median follow up of the trainings cohort was 14.3 months, the 2-year and 5-year OS was 52.6% and 23.7%, respectively. Karnofsky performance index, type of the primary tumor, control of the primary tumor, maximum diameter of the largest treated metastasis and number of metastases (1 versus >1) were significant prognostic factors in the Cox model (all p < 0.05). The calculated concordance-index for the nomogram was 0.73 (concordance indexes of all prognostic factors between 0.54 and 0.6). Based on the nomogram the training cohort was divided into 4 groups and 2-year OS ranged between 24.2% and 76.1% (predicted OS between 30.2% and 78.4%). The nomogram discriminated between risk groups in the two validation cohorts (concordance index 0.68 and 0.67). Conclusions A nomogram for prediction of OS after SBRT for pulmonary metastases was generated and externally validated. This tool might be helpful for interdisciplinary discussion and evaluation of local and systemic treatment options in the oligo-metastatic setting. Key message A nomogram for prediction of overall survival after stereotactic body radiotherapy (SBRT) for pulmonary metastases was developed and externally validated. This tool might be helpful for interdisciplinary discussion and evaluation of local and systemic treatment options in the oligo-metastatic setting.
PDF
