Fluorapatite Enhances Mineralization of Mesenchymal/Endothelial Cocultures

In addition to the widely used mesenchymal stem cells (MSCs), endothelial cells appear to be a favorable cell source for hard tissue regeneration. Previously, fluorapatite was shown to stimulate and enhance mineralization of MSCs. This study aims to investigate the growth of endothelial cells on synthesized ordered fluorapatite surfaces and their effect on the mineralization of adipose-derived stem cells (ASCs) through coculture. Endothelial cells were grown on fluorapatite surfaces and characterized by cell counting, flow cytometry, scanning electron microscopy, and enzyme-linked immunosorbent assay (ELISA). Cells were then cocultured with ASCs and stained for alkaline phosphatase and mineral formation. Fibroblast growth factor (FGF) pathway perturbation and basic FGF (bFGF) treatment of the ASCs were also conducted to observe their effects on differentiation and mineralization of these cells. Fluorapatite surfaces showed good biocompatibility in supporting endothelial cells. Without a mineralization supplement, coculture with endothelial cells induced osteogenic differentiation of ASCs, which was further enhanced by the fluorapatite surfaces. This suggested a combined stimulating effect of endothelial cells and fluorapatite surfaces on the enhanced mineralization of ASCs. Greater amounts of bFGF release by endothelial cells alone or cocultures with ASCs stimulated by fluorapatite surfaces, together with FGF pathway perturbation and bFGF treatment results, suggested that the FGF signaling pathway may function in this process.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140224/1/ten.tea.2013.0113.pd

Enamel crystals of mice susceptible or resistant to dental fluorosis: an AFM study

Objective: This study aimed to assess the overall apatite crystals profile in the enamel matrix of mice susceptible (A/J strain) or resistant (129P3/J strain) to dental fluorosis through analyses by atomic force microscopy (AFM). Material and Methods: Samples from the enamel matrix in the early stages of secretion and maturation were obtained from the incisors of mice from both strains. All detectable traces of matrix protein were removed from the samples by a sequential extraction procedure. The purified crystals (n=13 per strain) were analyzed qualitatively in the AFM. Surface roughness profile (Ra) was measured. Results: The mean (±SD) Ra of the crystals of A/J strain (0.58±0.15 nm) was lower than the one found for the 129P3/J strain (0.66±0.21 nm) but the difference did not reach statistical significance (t=1.187, p=0.247). Crystals of the 129P3/J strain (70.42±6.79 nm) were found to be significantly narrower (t=4.013, p=0.0013) than the same parameter measured for the A/J strain (90.42±15.86 nm). Conclusion: enamel crystals of the 129P3/J strain are narrower, which is indicative of slower crystal growth and could interfere in the occurrence of dental fluorosis

In Vitro Differentiation and Mineralization of Dental Pulp Stem Cells on Enamel-Like Fluorapatite Surfaces

Our previous studies have shown good biocompatibility of fluorapatite (FA) crystal surfaces in providing a favorable environment for functional cell?matrix interactions of human dental pulp stem cells (DPSCs) and also in supporting their long-term growth. The aim of the current study was to further investigate whether this enamel-like surface can support the differentiation and mineralization of DPSCs, and, therefore, act as a potential model for studying the enamel/dentin interface and, perhaps, dentine/pulp regeneration in tooth tissue engineering. The human pathway-focused osteogenesis polymerase chain reaction (PCR) array demonstrated that the expression of osteogenesis-related genes of human DPSCs was increased on FA surfaces compared with that on etched stainless steel (SSE). Consistent with the PCR array, FA promoted mineralization compared with the SSE surface with or without the addition of a mineralization promoting supplement (MS). This was confirmed by alkaline phosphatase (ALP) staining, Alizarin red staining, and tetracycline staining for mineral formation. In conclusion, FA crystal surfaces, especially ordered (OR) FA surfaces, which mimicked the physical architecture of enamel, provided a favorable extracellular matrix microenvironment for the cells. This resulted in the differentiation of human DPSCs and mineralized tissue formation, and, thus, demonstrated that it may be a promising biomimetic model for dentin-pulp tissue engineering.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98483/1/ten%2Etec%2E2011%2E0624.pd

A Comparison between the Implant Stability Quotient and the Fractal Dimension of Alveolar Bone at the Implant Site

Objectives. Fractal analysis of the radiographic pattern of bone has been used to evaluate its quantitative properties. However, the relation between initial implant stability and quality of bone remains unclear. The objective of this study was to evaluate RFA values in relation to the fractal dimension of bone where the implant was inserted. Material and Methods. A total of 50 two-stage dental implants were placed in the maxilla and mandible of 32 patients. After implant placement, an implant stability quotient (ISQ) was measured in two perpendicular planes. On intraoral digital periapical radiographs, three 35x35 pixels’ regions of interest (ROIs) were chosen covering the bone adjacent to the neck (ROI 1), middle (ROI 2), and apical (ROI 3) part of the implant, respectively. For every ROI, a fractal dimension (FD) was calculated. A linear correlation, as well as a logistic regression analysis, was used to identify a possible relation between the ISQ and FD values for every ROI in the maxilla and mandible. Results. The ISQ and FD values were found to be correlated at ROI 1 for the maxilla. There was no linear correlation between ISQ and FD values in any of the three ROIs in the mandible. However, logistic regression analysis showed that in ROI 1 and ROI 3 the values of FD and ISQ are statistically important and may be used to express the difference between maxilla and mandible. Conclusion. The fractal dimension of alveolar bone measured from intraoral digital radiographs alone may be an insufficient parameter to determine initial implant stability

Management of the Oral Health of Children During the COVID-19 Pandemic in Poland

Managing the oral health of children during the time of a health emergency linked to the current COVID-19 pandemic presents specific problems. A high number of non-specific effective infection control protocols are available in dental settings. It is of fundamental importance to implement specific protocols relating to those clinical situations that normally do not represent an emergency but which now fall into that category. The aim of this study was the comparison of data obtained from the Regional National Health Fund (NFZ) relating to the number and the type of procedures in the oral health management of children aged 0-18 years from the Wielkopolska region, with the months of March and April of 2019 being compared with those of the, respective, pandemic period of 2020. The results showed statistical differences in the number of performed procedures when comparing 2019 and 2020; especially in April

Gender-Related Biomechanical Properties of Masseter Muscle among Patients with Self-Assessment of Bruxism: A Comparative Study

It seems extremely important to know the biomechanical properties of the orofacial tissues among patients with increased activity of masticatory muscles, such as bruxism. The aim of this study was to evaluate biomechanical properties of the masseter muscle by using MyotonPRO in adults with probable bruxism and to define gender relations. This study was conducted in the Temporomandibular Disorders Department at Poznan University of Medical Sciences, Poland (June 2021–November 2021) among patients that reported bruxism symptoms The patients underwent a clinical examination, then the biomechanical properties of the masseter muscles were assessed. The MyotonPro measured masseter tone, stiffness and elasticity in 36 patients with a self-assessment of bruxism (18 women and 18 men). Data were collected from relaxed and contracted muscles. In relaxed masseter muscles there were no statistically significant differences between the sexes in muscle tone, stiffness and elasticity. During contraction significant differences were found between the sexes in the tension and the stiffness of the masseter muscles. Moreover, women often experienced headaches in the temporal region and pain in the masseter muscles during palpation. Among patients with a self-assessment of bruxism, accompanying pain was significantly more frequent in women. Male gender was associated with increased muscle tension and stiffness of the contracted masseter muscle

Computed Tomography versus Optical Scanning: A Comparison of Different Methods of 3D Data Acquisition for Tooth Replication

Objectives. The study aimed to compare the accuracy of different methods of data acquisition and data reconstruction and to assess their usefulness for 3D printing of tooth replicas. Methods. 3-dimensional models of molar and canine teeth obtain utilizing CBCT examination with different protocols, and optical scanning was compared with models derived from micro-computed (micro-CT) examination using Geomagic Studio Qualify software. A pairwise comparison of 3D models with analysis of standard deviation and the value of the mean distance of given surfaces was performed. Results. Standard deviation and the value of the mean distance were lowest for optical scanning followed by CBC in high and standard resolution in all tested protocols. Models, obtained with high-resolution CBCT protocols, of teeth in and outside of alveolar bone showed similar average distance parameters, but standard deviation parameter was significantly lower for models of teeth scanned outside of the socket. Good surface representation on all models was seen at relatively smooth areas while in areas of high changes in the geometry CBCT based models performed inferiorly to those obtained from an optical scanner. Conclusions. In case of teeth of noncomplicated texture, independently from a position (within or outside the alveolar socket), the high-resolution CBCT seems to be a sufficient method to obtain data for 3D printed tooth replica. Optical scanning performs better when a detailed replica is necessary

The Association between Maxillary Sinus Dimensions and Midface Parameters during Human Postnatal Growth

Objective. The aim of the study based on CT images was to assess the age-related changes in maxillary sinus diameters in relation to diameters of the facial skeleton. Materials and Methods. The retrospective analysis of CT images of the head of 170 patients aged 0–18 years (85 females and 85 males) was performed. Specific orientation points (zy, zm, pr, ns, n, and P) were identified in every patient and the following distances were measured: zy-zy, maximum facial width; zm-zm, midfacial width; n-pr, upper facial height; ns-pr, alveolar facial height; and ns-P, distance not indicated in craniometry. Results. The maxillary sinuses of every patient were bilaterally measured in three planes. Three diameters were obtained: maximum transverse (horizontal) diameter called MSW, maximum vertical diameter called MSH, and maximum anteroposterior diameter (length) called MSL. In females, the correlation of MSW, MSH, and MSL and zy-zy, as well as n-pr distances, is very strong. Moreover, the significant correlation was found between all measurements of maxillary sinus and ns-pr as well as ns-P distances in females. The correlation between MSL and all measurements of midface as well as MSH and MSW and all measurements except ns-P is stronger in females than in males. In males, all measurements of maxillary sinus correlate with ns-P distance very strongly. Conclusions. The statistical analysis (correlation and determination coefficient) showed that all measurements of maxillary sinuses correlate with midface dimensions

Acellular Synthesis of a Human Enamel-like Microstructure This investigation was supported by a USPHS Research Grant DE015599 from the National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892. The JEOL-2010F SEM/TEM used for this investigation was funded by a National Science Foundation Grant DMR-9871177. Supporting information is available online from Wiley InterScience or from the author.

No abstract.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/55794/1/1846_ftp.pd