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Purpose: Bone tissue is a dynamic tissue, possessing different functional requirements at different scales. This layered organization indicates the existence of a hierarchical structure, which can be characterized to distinguish macro-scale from micro-scale levels. Structurally, both scales can be linked by the use of classic multiscale homogenization techniques. Since in bone tissue each micro-scale domain is distinct form its neighbour, applying a classic multiscale homogenization technique to a complete bone structure could represent an inadmissible computational cost. Thus, this work proposes a homogenization methodology that is computationally efficient, presenting a reduced computational cost, and is capable to define the homogenized microscale mechanical properties of the trabecular bone highly heterogeneous medium. Methods: The methodology uses the fabric tensor concept in order to define the material principal directions. Then, using an anisotropic phenomenological law for bone tissue correlating the local apparent density with directional elasticity moduli, the anisotropic homogenized material properties of the micro-scale patch are fully defined. To validate the developed methodology, several numerical tests were performed, measuring the sensitivity of the technique to changes in the micro-patch size and preferential orientation. Results: The results show that the developed technique is robust and capable to provide a consistent material homogenization. Additionally, the technique was combined with two discrete numerical techniques: the finite element method and radial point interpolation meshless method. Conclusions: Structural analyses were performed using real trabecular patches, showing that the proposed methodology is capable to accurately predict the micro-scale patch mechanical behavior in a fraction of the time required by classic homogenization techniques. [ABSTRACT FROM AUTHOR]

Background: One of the most frequent complications in guided bone regeneration (GBR) is wound dehiscence, which compromises treatment outcomes. Thus, primary tension-free suture is essential to avoid wound dehiscence. The purpose of this study was to compare the extension of 2 different mandibular flaps in human cadaveric specimens, and to measure the size of the supraperiosteal blood vessels., Material and Methods: Five freshly unfrozen human cadaveric specimens were used. Arteries and veins were marked and bilateral classical lingual flaps (extending from the second premolar to the retromolar area) were prepared. In one side, the mylohyoid muscle was detached to increase the coronal extension of the flap. An implant drill was used to measure the extension of the flap after exerting 30 g of traction, before and after detaching the mylohyoid muscle. The size of the largest vascular structures of the flap was measured using a periodontal probe., Results: The classical flap extension was 5.99 mm (95% confidence interval (CI): 5.08 to 6.90), while the coronally advanced flap extension with mylohyoid muscle detachment was 14.96 mm (95%CI: 10.81 - 19.11). A statistically significant difference was found between the 2 groups (p= 0.0002), with a mean extension difference was 8.97 mm (95%CI: 5.02 to 12.91). The mean largest artery had 0.20 mm of diameter (95%CI: 0.15 - 0.26)., Conclusions: The detachment of the mylohyoid muscle from the lingual flap allows to significantly increase its extension by 2.5 times. The superficial arteries found in the lingual flap have a small diameter (around 0.2mm).

Background: The goal of the current study is to assess the difference in connective tissue adherence to laser microtextured versus machined titanium abutments., Material and Methods: Six patients were selected and each of them received 2 implants, one combined with a laser treated abutment and one with a machined abutment. After three months, the abutments were retrieved together with their surrounding gingival tissue for histological analysis. Qualitative and quantitative evaluation of microscopical images was performed to assess the presence or absence of adherence between the soft tissues and the abutment, and the percentage of soft tissue adhered to the two different surfaces., Results: Intimate adherence between connective tissue and the laser treated abutments, while on machined abutments no adherence was detected. A significant difference was found in the percentage of surface in contact with soft tissue between both implant abutments p=0.03., Conclusions: Within the limitation of the current study, it can be concluded that connective tissues show enhanced adherence to microtextured abutments compared to machined abutments.