Significance: Recent generation of bioengineered human skin allowed the efficient treatment of patients with severe skin defects. However, the optical and biomechanical properties of these models are not known. Aim: Three models of bioengineered human skin based on fibrin-agarose biomaterials (acellular, dermal skin substitutes, and complete dermoepidermal skin substitutes) were generated and analyzed. Approach: Optical and biomechanical properties of these artificial human skin substitutes were investigated using the inverse adding-doubling method and tensile tests, respectively. Results: The analysis of the optical properties revealed that the model that most resembled the optical behavior of the native human skin in terms of absorption and scattering properties was the dermoepidermal human skin substitutes after 7 to 14 days in culture. The time-course evaluation of the biomechanical parameters showed that the dermoepidermal substitutes displayed significant higher values than acellular and dermal skin substitutes for all parameters analyzed and did not differ from the control skin for traction deformation, stress, and strain at fracture break. Conclusions: We demonstrate the crucial role of the cells from a physical point of view, confirming that a bioengineered dermoepidermal human skin substitute based on fibrin-agarose biomaterials is able to fulfill the minimal requirements for skin transplants for future clinical use at early stages of in vitro development.

Introduction: The success of endodontic treatment depends on a good knowledge of the root canal system. Aim: The purpose of this study was to describe the anatomical configuration of mandibular first premolars using cone-beam computed tomography (CBCT) in a group of Colombian population according to Vertucci's classification, as well as the frequency of the presence of anatomical variations. Materials and Methods: A descriptive study was carried out using 100 mandibular first premolars to obtain CBCT images. The root length, root curvature, configuration of the root canals, number and location of the apical foramen, and shape of the entrance orifice to the root canal were analyzed. Results: The average length of the mandibular first premolars was 21.16 mm, and 33% showed different grades of the curvature. The most frequent configuration was type I (53%), and the least common were types VII and VIII (1%). Eighty-three teeth had some anatomical variations, and the apical foramen was located laterally in 38%. There was a high incidence of oval canals 1C1 (67%), followed by 1A1 (27%). Conclusion: A mixture of phenotypes leads to multiple anatomical variations in mandibular first premolars between individuals within a population. Herein, CBCT provided useful information about root canal anatomical variations of mandibular first premolars in Colombian population. Type I was the most frequently found configuration, and anatomical variations occurred more frequently in the middle third.