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Structure of Mature Enamel
Published in Colin Robinson, Jennifer Kirkham, Roger Shore, Dental Enamel, 2017
Roger C. Shore, Colin Robinson, Jennifer Kirkham, Steven J. Brookes
Enamel spindles are found predominantly in the region of the cusps65 and may be seen in both transverse and longitudinal ground sections, appearing as discrete, dark, cigarshaped structures, varying between approximately 10 to 15 μm and 200 to 250 μm in length and up to approximately 8 μm in diameter (Figure 16).65 By transmission electron microscopy they appear as electron-lucent, circular channels. Their origins have been ascribed to a number of factors: the remnants of projections of odontoblast processes between secreting ameloblasts,65 dentinal collagen, or the remnants of dead ameloblasts.5
Odontoblasts are cold sensory cells in teeth
Published in Temperature, 2023
Pamela Sotelo-Hitschfeld, Laura Bernal, Katharina Zimmermann
Many kinds of animals possess teeth, but none are as well developed as the teeth of vertebrates. They consist of a main body of a compact bone-like material known as dentin and its outer surface is covered by an even harder material called enamel. Odontoblasts are specialized cells that deposit calcium matrix to form the dentin layer, and their induction occurs only once during tooth development. Once the tooth is completely erupted, odontoblasts maintain their capacity to secrete secondary and reactionary dentin. Each odontoblast has one extension, called odontoblast process or Tomes's fiber, and these processes protrude into a network of fluid-filled microscopic tubules that run through the dentin.
Comparison of clinical efficacy of three different dentin matrix biomaterials obtained from different devices
Published in Expert Review of Medical Devices, 2023
Robert Dłucik, Bogusława Orzechowska-Wylęgała, Daniel Dłucik, Domenico Puzzolo, Giuseppe Santoro, Antonio Micali, Barbara Testagrossa, Giuseppe Acri
When the ultrastructural features of the particles obtained with the different devices were considered, SEM showed that they differed in shape and size. In fact, in the samples from BonMaker, the largest number of particles showed a geometric shape and a rather uniform size, ranging from 500 to 1000 µm. In the samples obtained from Tooth Transformer, the particles were prismatic or lamellar and their size varied from very small (20–40 µm) to larger (1.0–1.2 mm). In Smart Dentin Grinder samples, the particles had a geometric shape and ranged in size from 300 to 1300 µm. The suitable form and size of dentin matrix to be used as a bone substitute were the argument of several studies [38–41]. In fact, while a superior role in bone formation was described with particles of bovine bone about 300 µm in size in highly mineralized tissues [38,40], an optimal bone regeneration from dentin matrix was observed with larger particles around 1000 µm in size obtained from rabbit bone [39] or from human teeth [41]. Therefore, the size of the samples obtained from the three different devices evaluated in our study can be considered adequate for their use as graft material for bone regeneration. SEM exam of the particles obtained with the different devices showed at higher-magnification, well-evident dentinal tubules. These structures move centrifugally from the pulp to the enamel-dentin border and contain odontoblast processes and interstitial fluids to form and maintain the dentine; around each process, the dentine matrix mineralizes, thus forming a dentinal tubule [42]. The presence of well-preserved dentinal tubules in all the examined specimens was an important feature, as it was demonstrated that when the demineralized dentin material is in contact with a bone defect area, mesenchymal cells differentiate into osteoblasts which secrete the matrix, soon mineralized, and then into osteocytes. The processes of osteocytes form a network on the dentinal surface, some of them extend into the dentinal tubules and combine with each other: the degree of dentinal invasion was demonstrated of approximately 5 μm from the interface [43]. Under this aspect, all samples from the examined devices showed morphological features indicating the presence of a structural basis for an adequate bond between dentin and bone.