Marginal integrity in minimally invasive molar resin composite restorations: Impact of polymerization shrinkage.

Objectives: This study utilized non-linear finite element (FE) models to explore polymerization shrinkage and its impact on marginal integrity in molars following both selective caries removal (SCR) and conventional treatment. Specifically, we performed 2D in silico simulations to study residual stresses post-resin polymerization shrinkage and their influence on the marginal integrity of various restoration types.

Methods: Initially, FE models were developed based on a cohesive zone framework to simulate crack propagation along the bonded interfaces between restoration and tooth structure in SCR-treated molars with class I and class II restorations.

Bamboo's tissue structure facilitates large bending deflections.

Bamboo is becoming increasingly popular as an engineering material and source of bio-inspiration for instance in architecture and for the manufacture of a variety of woven products. Besides the properties of bamboo products for construction purposes, the bending deformability of thin bamboo slivers is of interest, as it appears that extraordinary large deflection can be achieved. To unravel the underlying mechanisms that may contribute to the high deformability at the tissue and cell level, bending deflection tests and additionalexperiments were performed to record the deflection of bamboo slivers in dependence of the tissue composition and the deformations of individual cells.

Substantial regional differences in the biomechanical behavior of molar treated with selective caries tissue removal technique: a finite element study.

Objectives: Selective caries removal (SCR) is recommended over non-selective removal for managing deep carious lesions to avoid pulp exposure and maintain pulp vitality. During SCR, residual carious dentin is left behind and sealed beneath the restoration. The biomechanical effects of such residual lesions on the restored tooth remain unclear and were assessed using finite element modeling (FEM).

The mechanoresponse of bone is closely related to the osteocyte lacunocanalicular network architecture.

Organisms rely on mechanosensing mechanisms to adapt to changes in their mechanical environment. Fluid-filled network structures not only ensure efficient transport but can also be employed for mechanosensation. The lacunocanalicular network (LCN) is a fluid-filled network structure, which pervades our bones and accommodates a cell network of osteocytes.

Lasting organ-level bone mechanoadaptation is unrelated to local strain.

Bones adapt to mechanical forces according to strict principles predicting straight shape. Most bones are, however, paradoxically curved. To solve this paradox, we used computed tomography-based, four-dimensional imaging methods and computational analysis to monitor acute and chronic whole-bone shape adaptation and remodeling in vivo.

Damage tolerance of lamellar bone.

Lamellar bone is known to be the most typical structure of cortical bone in large mammals including humans. This type of tissue provides a good combination of strength and fracture toughness. As has been shown by John D Currey and other researchers, large deformations are associated with the appearance of microdamage that optically whitens the tissue, a process that has been identified as a contribution to bone toughness.

Mechanobiologically optimized 3D titanium-mesh scaffolds enhance bone regeneration in critical segmental defects in sheep.

Three-dimensional (3D) titanium-mesh scaffolds offer many advantages over autologous bone grafting for the regeneration of challenging large segmental bone defects. Our study supports the hypothesis that endogenous bone defect regeneration can be promoted by mechanobiologically optimized Ti-mesh scaffolds. Using finite element techniques, two mechanically distinct Ti-mesh scaffolds were designed in a honeycomb-like configuration to minimize stress shielding while ensuring resistance against mechanical failure.

Scaffold curvature-mediated novel biomineralization process originates a continuous soft tissue-to-bone interface.

Unlabelled: A myriad of shapes are found in biological tissues, often naturally evolved to fulfill a particular function. In the field of tissue engineering, substrate geometry influences cell behavior and tissue formation in vitro, yet little is known how this translates to an in vivo scenario. Here we investigate scaffold curvature-induced tissue growth, without additional growth factors or cells, in an ovine animal model.

Tomography-Based Quantification of Regional Differences in Cortical Bone Surface Remodeling and Mechano-Response.

Bone has an adaptive capacity to maintain structural integrity. However, there seems to be a heterogeneous cortical (re)modeling response to loading at different regions within the same bone, which may lead to inconsistent findings since most studies analyze only one region. It remains unclear if the local mechanical environment is responsible for this heterogeneous response and whether both formation and resorption are affected.

The Periosteal Bone Surface is Less Mechano-Responsive than the Endocortical.

Dynamic processes modify bone micro-structure to adapt to external loading and avoid mechanical failure. Age-related cortical bone loss is thought to occur because of increased endocortical resorption and reduced periosteal formation. Differences in the (re)modeling response to loading on both surfaces, however, are poorly understood.

Aging Leads to a Dysregulation in Mechanically Driven Bone Formation and Resorption.

Physical activity is essential to maintain skeletal mass and structure, but its effect seems to diminish with age. To test the hypothesis that bone becomes less sensitive to mechanical strain with age, we used a combined in vivo/in silico approach. We investigated how maturation and aging influence the mechanical regulation of bone formation and resorption to 2 weeks of noninvasive in vivo controlled loading in mice.

Monitoring in vivo (re)modeling: a computational approach using 4D microCT data to quantify bone surface movements.

Bone undergoes continual damage repair and structural adaptation to changing external loads with the aim of maintaining skeletal integrity throughout life. The ability to monitor bone (re)modeling would allow for a better understanding in how various pathologies and interventions affect bone turnover and subsequent bone strength. To date, however, current methods to monitor bone (re)modeling over time and in space are limited.

Skeletal maturity leads to a reduction in the strain magnitudes induced within the bone: a murine tibia study.

Bone adapts to changes in the local mechanical environment (e.g. strains) through formation and resorption processes.

The influence of age on adaptive bone formation and bone resorption.

Bone is a tissue with enormous adaptive capacity, balancing resorption and formation processes. It is known that mechanical loading shifts this balance towards an increased formation, leading to enhanced bone mass and mechanical performance. What is not known is how this adaptive response to mechanical loading changes with age.

Mineralizing surface is the main target of mechanical stimulation independent of age: 3D dynamic in vivo morphometry.

Mechanical loading can increase cortical bone mass by shifting the balance between bone formation and resorption towards increased formation. With advancing age resorption outpaces formation resulting in a net loss in cortical bone mass. How cortical bone (re)modeling - especially resorption - responds to mechanical loading with aging remains unclear.

Diminished response to in vivo mechanical loading in trabecular and not cortical bone in adulthood of female C57Bl/6 mice coincides with a reduction in deformation to load.

Bone loss occurs during adulthood in both women and men and affects trabecular bone more than cortical bone. The mechanism responsible for trabecular bone loss during adulthood remains unexplained, but may be due at least in part to a reduced mechanoresponsiveness. We hypothesized that trabecular and cortical bone would respond anabolically to loading and that the bone response to mechanical loading would be reduced and the onset delayed in adult compared to postpubescent mice.

Shaping scaffold structures in rapid manufacturing implants: a modeling approach toward mechano-biologically optimized configurations for large bone defect.

Large segmental bone defects remain a clinical challenge. Titanium lattice-structured implants in combination with laser sintering technology promises to be an alternative to bone grafting in the treatment of critical sized bone defects. Laser sintering allows the rapid manufacturing of patient specific 3D-structured scaffolds with highly interconnected macroporous networks and tunable mechanical properties.