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Dentin-Pulp Complex Regeneration
Published in Vincenzo Guarino, Marco Antonio Alvarez-Pérez, Current Advances in Oral and Craniofacial Tissue Engineering, 2020
Amaury Pozos-Guillén, Héctor Flores
Another type of apexification named ‘apical MTA plug’ was described using Mineral Trioxide Aggregate (MTA). MTA is a repair material made of fine hydrophilic particles of tri/dicalcium silicate, tricalcium aluminate, tricalcium oxide and silicate oxide (Parirokh and Torabinejad 2010). MTA is placed into the root canal space and acts as a mechanical barrier to prevent coronal leakage and penetration of microorganisms. Some disadvantages of this material are difficulty to manipulate, the possibility of tooth discoloration and difficulty to remove from the root canal However, neither calcium hydroxide nor MTA barrier technique allow further root growth in length, maturation of the apex or root wall thickening. New calcium silicate-based materials have recently been developed with the purpose of improving clinical use and overcoming MTA limits BiodentineTM is a bioceramic made of tricalcium silicate, dicalcium silicate, zirconium oxide, calcium carbonate, calcium oxide and iron oxide. It is mixed with a hydrosoluble polymer and calcium chloride to decrease the setting time (Rajasekharan et al. 2014). This biomaterial has shown reduced setting time with interesting physical and biological properties as a dentine restorative material (Koubi et al. 2013; Topçuoglu and Topçuoğlu 2016).
A new class of efficient and debiased two-step shrinkage estimators: method and application
Published in Journal of Applied Statistics, 2022
Muhammad Qasim, Kristofer Månsson, Pär Sjölander, B. M. Golam Kibria
The Portland dataset, which was initially adopted by Woods et al. (1932) and also used in Lukman et al. [21] is used as a first illustration in this paper to demonstrate the performance of the new estimator. The dependent variable is defined as the heat evolved after 180 days of curing measured in calories per gram of cement. This variable is modeled using four correlated explanatory variables corresponding to x1 that represents tricalcium aluminate, x2 that represents tricalcium silicate, x3 that represents tetracalcium aluminoferrite, and x4 that represents β-dicalcium silicate. In Table 7, the correlation matrix is shown that indicates a multicollinearity problem since the pairwise correlations reach up to an absolute value of 0.9730. Also, the condition index defined as Table 8 the result is shown. We can see that among the unbiased and the almost unbiased estimators the