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Gingiva and Periodontal Tissue Regeneration
Published in Vincenzo Guarino, Marco Antonio Alvarez-Pérez, Current Advances in Oral and Craniofacial Tissue Engineering, 2020
Avita Rath, Preena Sidhu, Priyadarshini Hesarghatta Ramamurthy, Bennete Aloysius Fernandesv, Swapnil Shankargouda, Sultan Orner Sheriff
In an adult, healthy gingiva covers the alveolar bone and tooth root to a level just coronal to the cementoenamel junction. The gingiva is divided anatomically into marginal, attached and interdental areas. Although each type of gingiva exhibits considerable variation in differentiation, histology and thickness according to its functional demands, all types are specifically structured to function appropriately against mechanical and microbial damage (Carranza 2014).
The use of functionally graded dental crowns to improve biocompatibility: a finite element analysis
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2018
Mojtaba Mahmoudi, Ali Reza Saidi, Maryam Alsadat Hashemipour, Parviz Amini
A common method for analyzing inhomogeneous materials by FEM is dividing the model into multi thin layers in which the properties at each layer are considered homogeneous and gradually changed through the layers. Since the crown is formed as an irregular geometry, the modeling of an accurate three dimensional laminated crown for simulation a FGM crown is complex. Therefore, in this study an axisymmetric 3-dimensional model of a premolar tooth was modeled according to the average anatomical dimensions of the buccolingual cross section of a mandibular premolar tooth presented in literature (Nelson 2014). The surrounding tissues of the mandibular tooth were modeled according to the average anatomical dimensions of the bone (Katranji et al. 2007; Watanabe et al. 2010). The periodontal ligament (PDL) and cement layers were considered in all models. Depending on the depth and age, the thickness of the PDL changes in the range of 0.15–0.25 mm, so the average thickness considered for the PDL and the cement was 0.2 and 0.1 mm, respectively (Pietrzak et al. 2002; Dejak and Mlotkowski 2008). The tooth crown was removed 2 mm above the cementoenamel junction; a one-piece post-core and a crown were designed to simulate an endodontically treated tooth that completely lost its coronal and was restored with post-core crown (Figure 1(a)). The crown was divided into 8 equal layers to simulate a FGM crown (Figure 1(b)). The modeling was performed by solidworks software (solidworks ® premium 2013 ×64 Edition SP4.0) and then imported into finite element analysis software, (Abaqus/CAE 6.13) to perform the stress analysis.
In vitro abrasivity and chemical properties of charcoal-containing dentifrices
Published in Biomaterial Investigations in Dentistry, 2020
Foteini Machla, Aida Mulic, Ellen Bruzell, Håkon Valen, Ida Sofia Refsholt Stenhagen
Each tooth was sectioned at the cementoenamel junction using a cutting machine with a diamond blade (Accutom, Stuers, Ballerup, Denmark). To ensure the stabilization of the tooth, the buccal surface of the crown was slightly grinded with a water-cooled instrument (Knuth Rotor, Stuers). The crowns were embedded in epoxy resin (EpoFix, Stuers) in circular containers of specific dimensions, to fit in the sockets of the brushing machine and to protrude approximately 1 mm above the socket’s surface. A grinding machine (Pedemax, Stuers) was used to remove the enamel and to expose the outer part of the dentine of the crowns’ buccal surface. The specimens were polished using grinding papers (Silicon Carbide Paper P500-P1200, Stuers). Two pieces of adhesive tape were placed on the buccal dentine of the teeth parallel to each other to expose a section of dentine of approximately 1 mm width between the tape strips. The exposed buccal dentine section was parallel to the occlusal surface of the tooth. Following preparation, the specimens (n = 30) were randomly divided into five groups: NAO, COCO, MaxWhite (reference), ISO dentifrice slurry (positive control), and DW (negative control). A two-dimensional contact profilometer (Surftest SJ-201P, Mitutoyo, Scandinavia AB, Upplands Väsby, Sweden) was used to ensure initial dentine surface roughness (Ra) of ±0.3 μm. Ra is the mean absolute deviation of the peaks and valleys of the assessed profile from the mean line over a cut-off length and is the most commonly used roughness parameter [26]. The measurements were conducted on three random spots on the dentine, with a stylus tip radius of 5 μm, applying a force of 4 mN, a cut-off length of 0.25 mm and measuring speed of 0.25 mm/s. All specimens were stored in DW at 23 °C in between experiments.