Survival of periodontal ligament myofibroblasts after short-term mechanical strain in rats and in vitro: Could myofibroblasts contribute to orthodontic relapse?

Objectives: To investigate in vivo whether myofibroblasts formed in the PDL after exposure to short-term high experimental orthodontic forces in rats survive. To study in vitro whether human PDL fibroblasts can differentiate into myofibroblasts and survive when chemical or mechanical stimuli are removed.

Design: Nine 6-week-old male Wistar rats were used in this experiment.

Cisplatin-functionalized dual-functional bone substitute granules for bone defect treatment after bone tumor resection.

Invasive bone tumors pose a significant healthcare challenge, often requiring systemic chemotherapy and limb salvage surgery. However, these strategies are hampered by severe side effects, complex post-resection bone defects, and high local recurrence rates. To address this, we developed dual-functional bone substitute biomaterials by functionalizing commercially available bone substitute granules (Bio-Oss® and MBCP®+) with the established anticancer agent cisplatin.

foxe1 mutant zebrafish show indications of a hypothyroid phenotype and increased sensitivity to ethanol for craniofacial malformations.

Background: FOXE1 mutations in humans are associated with cleft palate and hypothyroidism. We previously developed a foxe1 mutant zebrafish demonstrating mineralization defects in larvae. In the present study, we investigate the thyroid status and skeletal phenotype of adult foxe1 mutants.

Histomorphometric Analysis of Flaplessly Placed and Early Loaded One-Piece Mini Dental Implants in Overdenture Patients.

Mini dental implants (MDIs) are an affordable alternative for overdentures in medically compromised patients with reduced bone volume. This human study reports the histomorphometric analysis of early loaded and flaplessly placed tapered, one-piece MDIs (ILZ, Southern Implants; Sa: 1.5 μm) after 7 to 11 months in function.

Do dental implants facilitate bone invasion in patients with oral squamous cell carcinoma? A case series.

Osseointegrated dental implants in the vicinity of oral squamous cell carcinoma (OSCC) will become more common given the increasing popularity of dental implants. Reports and studies of OSCC around dental implants are rare, as is the topic of how to handle OSCC surgically when implants are in contact with the tumour. In view of this uncertainty, a histological study was performed to assess tumour behaviour around implants.

Early bone ingrowth and segmental stability of a trussed titanium cage versus a polyether ether ketone cage in an ovine lumbar interbody fusion model.

Background Context: Lumbar interbody fusion is an effective treatment for unstable spinal segments. However, the time needed to establish a solid bony interbody fusion between the two vertebrae may be longer than twelve months after surgery. During this time window, the instrumented spinal segment is assumed to be at increased risk for instability related complications such as cage migration or subsidence.

Combined effect of undersized surgical technique and axial compression on the primary implant stability and host bone architecture.

Aim: The aim of this study was to investigate the combined effect of the lateral-compression of host-bone (undersized-osteotomy-preparation) and axial-compression of host-bone (not drilling the full length of the implant) on the primary-implant-stability and the host-bone-architecture.

Materials And Methods: In this experimental-study, 44 dental implants (diameter-4.2 mm; length-10 mm; Dyna®) were installed in the femoral-condyles of four cadaver-goats using four different surgical approaches (11 implant/surgical approach; n = 11).

Three-dimensional evaluation of marginal and internal fit of 3D-printed interim restorations fabricated on different finish line designs.

PurposeTo evaluate the influence of fabrication method and finish line design on marginal and internal fit of full-coverage interim restorations. MethodsFour typodont models of maxillary central-incisor were prepared for full-coverage restorations. Four groups were defined; knife-edge (KE), chamfer (C), rounded-shoulder (RS), rounded-shoulder with bevel (RSB).

Osteogenesis around CaP-coated titanium implants visualized using 3D histology and micro-computed tomography.

Calcium phosphate (CaP) coatings can enhance the performance of bone implants in compromised conditions, such as osteoporosis. Therefore, this study compared non-coated vs. CaP-coated (n = 8) titanium implants in osteoporotic ovariectomized (OVX) rats.

Injectable self-gelling composites for bone tissue engineering based on gellan gum hydrogel enriched with different bioglasses.

Hydrogels of biocompatible calcium-crosslinkable polysaccharide gellan gum (GG) were enriched with bioglass particles to enhance (i) mineralization with calcium phosphate (CaP); (ii) antibacterial properties and (iii) growth of bone-forming cells for future bone regeneration applications. Three bioglasses were compared, namely one calcium-rich and one calcium-poor preparation both produced by a sol-gel technique (hereafter referred to as A2 and S2, respectively) and one preparation of composition close to that of the commonly used 45S5 type (hereafter referred to as NBG). Incubation in SBF for 7 d, 14 d and 21 d caused apatite formation in bioglass-containing but not in bioglass-free samples, as confirmed by FTIR, XRD, SEM, ICP-OES, and measurements of dry mass, i.

Osseointegration of oral implants after delayed placement in rabbits: a microcomputed tomography and histomorphometric study.

Purpose: This study compared osseointegration of implants placed 14 days after implant site preparation with that of immediately placed implants in rabbit femurs.

Materials And Methods: Implants were placed bilaterally in the femoral condyles of 12 rabbits. On one side, the implants were placed 14 days after osteotomy, and the other side received implants immediately after osteotomy.

Calcium-phosphate-coated oral implants promote osseointegration in osteoporosis.

Osteoporotic conditions are anticipated to affect the osseointegration of dental implants. This study aimed to evaluate the effect of a radiofrequent magnetron-sputtered calcium phosphate (CaP) coating on dental implant integration upon installment in the femoral condyles of both healthy and osteoporotic rats. At 8 weeks post-implantation, bone volume and histomorphometric bone area were lower around non-coated implants in osteoporotic rats compared with healthy rats.

The biological performance of injectable calcium phosphate/PLGA cement in osteoporotic rats.

Calcium phosphate cements (CPCs) including poly(D,L-lactic-co-glycolic) acid (PLGA) microparticles are promising candidates for bone regenerative applications. Previous studies with CPC/PLGA demonstrated that the material is non-toxic, biocompatible and osteoconductive. However, the outcome of these studies was based on healthy individuals and consequently does not provide information on bone substitute material performance in a compromised situation, such as osteoporosis.

Resolution, sensitivity, and in vivo application of high-resolution computed tomography for titanium-coated polymethyl methacrylate (PMMA) dental implants.

Objectives: The aims of this study were (i) to determine the spatial resolution and sensitivity of micro- versus nano-computed tomography (CT) techniques and (ii) to validate micro- versus nano-CT in a dog dental implant model, comparative to histological analysis.

Material And Methods: To determine spatial resolution and sensitivity, standardized reference samples containing standardized nano- and microspheres were prepared in polymer and ceramic matrices. Thereafter, 10 titanium-coated polymer dental implants (3.

Processing and in vivo evaluation of multiphasic calcium phosphate cements with dual tricalcium phosphate phases.

Calcium phosphate cements (CPCs) use the simultaneous presence of several calcium phosphates phases. This is done to generate specific bulk and in vivo properties. This work has processed and evaluated novel multiphasic CPCs containing dual tricalcium phosphate (TCPs) phases.

Validation of micro-CT against the section method regarding the assessment of marginal leakage of sealants.

Background: The aim of this study was to validate the micro-CT and related software against the section method using the stereomicroscope for marginal leakage assessment along the sealant-enamel interface.

Methods: Pits and fissures of the occlusal surface of 10 teeth were sealed with a resin-fissure sealant material without acid etching, thermocycled for 5000 cycles, immersed in 50% silver nitrate for three hours and scanned using micro-CT. Teeth were embedded in epoxy resin and cut in three sections.

Bone formation analysis: effect of quantification procedures on the study outcome.

Quantification of the amount of newly formed bone is an essential part of bone regeneration studies. Histomorphometry, based on histological sections of plastic-embedded specimens, is the most frequently applied technique in this assessment. Before performing image analysis, a specific region of interest (ROI) has to be determined.

Scanning electron microscopy stereoimaging for three-dimensional visualization and analysis of cells in tissue-engineered constructs: technical note.

In tissue engineering research, various three-dimensional (3D) techniques are available to study cell morphology, biomaterials, and their relations. To overcome disadvantages of frequently used imaging techniques, in the current study stereoimaging scanning electron microscopy (SEM) is proposed. First, the 3D SEM application was validated using a series of standardized microspheres.

In-vivo generation of bone via endochondral ossification by in-vitro chondrogenic priming of adult human and rat mesenchymal stem cells.

Background: Bone grafts are required to repair large bone defects after tumour resection or large trauma. The availability of patients' own bone tissue that can be used for these procedures is limited. Thus far bone tissue engineering has not lead to an implant which could be used as alternative in bone replacement surgery.

Controlled fabrication of triple layered and molecularly defined collagen/elastin vascular grafts resembling the native blood vessel.

There is a consistent need for a suitable natural biomaterial to function as an arterial prosthesis in achieving arterial regeneration. Natural grafts are generally obtained by decellularization of native blood vessels, but batch to batch variations may occur and the nature/content of remaining contaminants is generally unknown. In this study we fabricated a molecularly defined natural arterial graft from scratch resembling the native three layered architecture from the fibrillar extracellular matrix components collagen and elastin.

Marginal leakage of two newer glass-ionomer-based sealant materials assessed using micro-CT.

Objectives: To test newer glass-ionomer-based materials as sealant materials. One glass-ionomer sealant was light-cured to obtain an early setting reaction. The null-hypothesis tested was: there is no difference in marginal leakage of sealants produced with high-viscosity glass-ionomer, with and without energy supplied, and that of glass-carbomer, in comparison with resin composite sealants in vitro.

Optimal use of silver nitrate and marginal leakage at the sealant-enamel interface using micro-CT.

Purpose: To investigate the optimal silver nitrate concentration and tooth immersion period for assessing marginal leakage at the sealant-enamel interface, using micro-CT.

Methods: Two experiments were conducted, using eight teeth sealed with a resin composite without etching, in dried but not desiccated, pits and fissures. Five teeth were immersed in 50% silver nitrate for 0, 1, 2, 3, and 4 hours and scanned, using micro-CT, and two evaluators using a newly developed index assessed marginal leakage at the sealant-enamel interface (Experiment A).

Micro-computed tomographical imaging of soft biological materials using contrast techniques.

The aim of this work was to introduce high-resolution computed tomography (micro-CT) for scaffolds made from soft natural biomaterials, and to compare these data with the conventional techniques scanning electron microscopy and light microscopy. Collagen-based scaffolds were used as examples. Unlike mineralized tissues, collagen scaffolds do not provide enough X-ray attenuation for micro-CT imaging.

Three-dimensional localization of implanted biomaterials in anatomical and histological specimens using combined X-ray computed tomography and three-dimensional surface reconstruction: a technical note.

For adequate histological processing of implanted biomaterials or tissue-engineered constructs, it is sometimes essential to obtain insight into the localization of structures inside the tissue samples. Observation of three-dimensional (3D) surface reconstruction, including basic photorealistic texture characteristics as surface pattern and color combined with X-ray computed tomography 3D reconstruction at different levels, is a useful approach to localize anatomical or implanted structures within experimental tissue samples. Because of the possible observation of structures of interest in a 3D environment, fusion of these techniques can greatly facilitate histological processing.

Micro-CT for measuring marginal leakage of Class II resin composite restorations in primary molars prepared in vivo.

Purpose: To evaluate the reliability of marginal leakage assessment of self-etch adhesive Class II resin composite restorations in primary molars prepared in vivo using the micro-CT.

Methods: Fourteen primary molars, divided over seven ART and seven traditional resin composite Class II restorations, were subjected to marginal leakage test using a 50% (w/v) silver nitrate solution for 4 hours by a micro-CT. Two evaluators selected the image with the deepest marginal dye penetration for each restoration from the occlusal and approximal surfaces on consensus.