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Objective The aim was to investigate the effect of mechanical vibration on root resorption with or without orthodontic force application. Material and methods Twenty patients who required maxillary premolar extractions as part of orthodontic treatment were randomly divided into two groups of 10: no-force group and force group. Using a split-mouth procedure, each patient’s maxillary first premolar teeth were randomly assigned as either vibration or control side for both groups. A buccally directed vibration of 50 Hz, with an Oral-B HummingBird device, was applied to the maxillary first premolar for 10 min/day for 12 weeks. After the force application period, the maxillary first premolars were extracted and scanned with micro-computed tomography. Fiji (ImageJ), performing slice-by-slice quantitative volumetric measurements, was used for resorption crater calculation. Total crater volumes were compared with the Wilcoxon and Mann–Whitney U tests. Results The total crater volumes in the force and no-force groups were 0.476 mm3 and 0.017 mm3 on the vibration side and 0.462 mm3 and 0.031 mm3 on the control side, respectively. There was no statistical difference between the vibration and control sides (P > 0.05). There was more resorption by volume in the force group when compared to the no-force group (P < 0.05). Conclusion Mechanical vibration did not have a beneficial effect on reducing root resorption; however, force application caused significant root resorption.

Loofa sponge is a naturally-grown and decomposable material providing high specific surface area and high porosity for potential application as an environmentally-friendly catalyst carrier. In this work, cellular samples of various loofa types cut from different fiber network regions of the fruits were studied in detail using non-invasive imaging techniques. Digital microscopy was applied to characterize the cellular fiber network, which revealed a honeycomb structure in the core region and a sandwich structure in the wall region. Furthermore, reconstructed three-dimensional (3D) morphological images of the loofa samples obtained via micro-tomography (micro-CT) were utilized to extract the geometrical properties cell size, window diameter and strut thickness as well as porosity and volume-specific surface area. The reconstructed loofa samples revealed porosities of about 92% and specific surface areas up to 2057 m2/m3. In addition, the geometrical properties of manufactured solid foams (ceramic and polyurethane) were also determined via micro-CT and compared with loofa sponge. Finally, the different characteristic cell dimensions were employed to predict the porosity and specific surface area with available geometrical correlations. Deviations between correlation and measurement data (±16%) can be attributed to the peculiarity of the loofa cellular fiber network, which is somewhat different from the tetradecahedral-shaped geometry commonly used as the basis for most of the available correlations.

Objective to determine the presence of marginal bacterial microfiltration in the IAI in different implant/abutment systems, in vitro. Material and methods Fifty‐six implants from seven different brand names, 4 with cone and 3 with straight connections were used, implant and abutment were connected using the Ncm tightening as indicated by each of the manufacturers and then were sealed. The samples were subjected occlusal load and thermal cycling, a first sample of each group was observed by micro CT and in a second sample (both samples randomly selected) length of connection was measured, while the rest of the samples were mounted on devices according to the bacterial microfiltration model with Porphyromonas gingivalis. Results Two of the conical connection system groups did not present bacterial microfiltration, one of the three straight connection groups only microfiltered in one sample, while the other two conical as well as the two straight connection samples showed different and important levels of bacterial microfiltration, all groups presented a direct relationship between the implant‐abutment adjustment determined by micro‐CT and bacterial microfiltration levels, not related to the connection length. Conclusion: Only two conical connection systems presented no bacterial microfiltration.

This study evaluated the shaping ability of XP-endo Shaper and Mtwo systems in long-oval-shaped canals of extracted human mandibular molars using micro-computed tomography (micro-CT). Images recorded before and after preparation were evaluated for morphometric measures regarding increase in canal volume, dentin removed, surface area, untouched walls and structure model index (SMI). Data were statistically analysed using the Mann-Whitney test with 5% of significance. On both groups, the root canal preparation significantly increased all analysed parameters (P > 0.05). There was no statistical difference between XP-endo Shaper and Mtwo systems in the increase of the canal volume (30.50%-27.82%), in volume of dentin removed (2.77%-2.40%), in the increase of the canal surface area (11.30%-8.86%), in canal untouched surfaces (9.57%-8.51%) and in the SMI (2.59%-2.68%), respectively. XP-endo Shaper and Mtwo systems showed similar shaping efficiency and were not able to completely prepare the walls of long-oval-shaped canals of extracted human mandibular molars.

Jackstone calculi, having arms that extend out from the body of the stone, were first described over a century ago, but this morphology of stones has been little studied. We examined 98 jackstones from 50 different patient specimens using micro-computed tomography (micro CT) and infrared (IR) spectroscopy. Micro CT showed that jackstone arms consisted of an X-ray lucent core within each arm. This X-ray lucent core frequently showed sporadic, thin layers of apatite arranged transversely to the axis of the arm. The shells of the jackstones were always composed of calcium oxalate (CaOx), and with the monohydrate form the majority or sole mineral. Study of layering in the shell regions by micro CT showed that growth lines extended from the body of the stone out onto jack arms and that the thickness of the shell covering of jack arms often thinned with distance from the stone body, suggesting that the arms grew at a faster radial rate than did the stone body. Histological cross-sections of decalcified jackstone arms showed the core to be more highly autofluorescent than was the CaOx shell, and immunohistochemistry showed the core to be enriched in Tamm-Horsfall protein. We hypothesize that the protein-rich core of a jack arm might preferentially bind more protein from the urine and resist deposition of CaOx, such that the arm grows in a linear manner and at a faster rate than the bulk of the stone. This hypothesis thus predicts an enrichment of certain urine proteins in the core of the jack arm, a theory that is testable by appropriate analysis.

The shaping outcomes after instrumentation with rotary and reciprocating glide path and shaping systems were evaluated through micro-computed tomography (Micro-CT). Thirty extracted maxillary first molars were selected. Mesio-buccal canals were randomized into two groups (n = 15): rotary system ProGlider and ProTaper Next X1, X2 (PG-PTN) and reciprocating system WaveOne Gold Glider and WaveOne Gold Primary (WOGG-WOG). Specimens were micro-CT scanned before, after glide path and after shaping. Increase in canal volume and surface area, percentage of removed dentin from the inner curvature, centroid shift and canal geometry variation through ratio of diameter ratios (RDR) and ratio of cross-sectional areas (RA) were measured in the apical and coronal levels and at the point of maximum curvature. The number of pecking motions needed to reach the working length (WL) was recorded. One-way ANOVA and post hoc Turkey–Kramer tests were used (p

Purpose The presence of a persistent primitive maxillary artery is described in the literature dealing with the development of the cavernous carotid inferolateral trunk, and the relevant similarities of the cranial circulation of the human and dog. The literature includes no dissection photographs of the above-mentioned two human fetal arteries, only diagrammatic representations. This study’s objectives were to analyze photographs of fetal dissections for the presence of these two arteries, and also investigate the possibility of obtaining, in preserved dog specimens, high-resolution micro-CT imaging of arteries homologous with the above-mentioned two human arteries. Methods The literature describing the embryologic development of the cavernous carotid inferolateral trunk, the persistent primitive maxillary arteries, and their homologies in the dog was reviewed. Relevant dissections of fetal specimens were analyzed. High-resolution micro-CT images of un-dissected dog arteries were produced and analyzed. Results Photographs of fetal specimen dissections demonstrate the cavernous carotid inferolateral trunk. A separate persistent primitive maxillary artery was not present in the dissected specimens. High-resolution micro-CT images of the dog demonstrate homologous arteries with segments of the human inferolateral trunk, and other skull base and brain arteries. Conclusion This investigation provides the only photographs in the literature of dissected human fetal cavernous carotid inferolateral trunks. A persistent primitive maxillary artery was not present in the dissected specimens and is a non-existent structure, likely a previously misidentified carotid inferolateral trunk. High-resolution micro-CT images of the dog visualized arteries that are homologous to segments of the human cavernous carotid inferolateral trunk artery.

Bone diseases are a widely spread problem in the human ageing process. Early recognition is essential to an optimal treatment and deceleration of the etiopathology. Implementing a functional working automated software tool for analysing bone image data of radiographs could lead to an accurate and precise diagnoses and treatment. This Master Thesis aimed to examine the clinical applicability of the TX-Analyzer. The evaluation of the proper functionality as well as the effects on the outcome of the TX-Analyzer by changing the exposure parameters of the examined radiographs was the focus. The outcome of the TX-Analyzer was also compared with micro-CT image data to evaluate a possible correlation. 7 human femoral head bone samples were examined in 175 radiographs. The acquired radiographs were annotated and analysed by the TX-Analyzer. For every bone sample a dedicated spiral micro CT was performed and evaluated with the RadiAnt Viewer. The resulting data was further analysed and statistically prepared with GraphPad Prism 9. The Pearson correlation and a regression analysis were performed to evaluate correlation between the gained micro CT data and the BEV. Furthermore, a multifactorial ANOVA analysis was done to show the significance of the parameter changes to the effect of the data gained by the TX-Analyzer. The results of the Pearson correlation and the regression analysis show that HU values do not have a significant correlation to the BEV. However, the BEV is the most stable value evaluated by the TX-Analyzer according to the results of this study. With the acquired radiographs and the evaluation of the data instability of BSV and BVV could be discovered.The results of the repeated measures ANOVA show that the change of flattening filter has highly significant effect on the BSV (p value < 0,0001). Moreover, the impact of changes of the mAs value are also shown with the dedicated ANOVA (p value 0,0361). According to the measurements the only rather negligible expos

Periodontitis is a common oral disease mainly caused by bacterial infection and inflammation of the gingiva. In the prevention or treatment of periodontitis, anti-bacterial agents are used to inhibit pathogen growth, despite increasing levels of bacterial resistance. Sapindus mukorossi Gaertn (SM) seed oil has proven anti-bacterial and anti-inflammation properties. However, the possibility of using this plant to prevent or treat periodontitis has not been reported previously. The aim of this study was to evaluate the effects of SM oil on experimental periodontitis in rats by using micro-CT and microbiota analysis. The distance between cementoenamel junction (CEJ) and alveolar bone crest (ABC) on the sagittal micro-CT slide showed that total bone loss (TBL) was significantly lower in CEJ-ABC distances between SM oil and SM oil-free groups on Day 14. Histology data also showed less alveolar bone resorption, a result consistent result with micro-CT imaging. The microbiota analyzed at phylum and class levels were compared between the SM oil and SM oil-free groups on Day 7 and Day 14. At the phylum level, Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria were the dominant bacterium. Firmicutes in box plot analysis was significantly less in the SM oil group than in the SM oil-free group on Day 7. At the class level, Bacteroidia, Gammaproteobacteria, Bacilli, Clostridia, and Erysipelotrichia were the dominant bacteria. The bacteria composition proportion of Bacilli, Clostridiay, and Erysipelotrichia could be seen in the SM oil group significantly less than in t SM oil-free group on Day 7. Overall, the present results show that topical application of SM oil can reduce bone resorption and change bacteria composition in the ligature-induced periodontitis model. According to these results, it is reasonable to suggest SM oil as a potential material for preventing oral disease.

Statement of problem Whether the precision of fit of computer-aided design and computer-aided manufacturing (CAD-CAM) complete crowns is affected by the finish line configuration is unclear. Purpose The purpose of this in vitro study was to evaluate the marginal and internal fit of CAD-CAM ceramic crowns made from lithium disilicate based on 3 different finish lines (rounded shoulder, chamfer, feather-edge). Materials and methods Thirty anterior lithium disilicate complete crowns (n=10 per finish line group) were fabricated by following a completely digital workflow based on digital scans made with the TRIOS scanner. The crowns were adhesively cemented on duplicate dies of the respective prepared Typodont teeth, and the marginal gap, absolute marginal discrepancy, and internal gap were evaluated by using microcomputed tomography (μCT). A total of 66 values were obtained for each specimen from sagittal and transaxial sections, and a rendering software program was used to calculate the volume of the cement gap for each specimen by means of 3D region growing. Two-way ANOVA, Tukey post hoc tests with Bonferroni correction, and the Kruskal-Wallis test were used to compare the values between the experimental groups (α=.05). Results Marginal gap and absolute marginal discrepancy values were statistically significantly different between groups. In ascending order, marginal gap values were 23 ±14 μm for rounded shoulder, 54 ±28 μm for chamfer, and 96 ±36 μm for feather-edge finish lines. Absolute marginal discrepancy values were 96 ±34 μm for rounded shoulder, 124 ±37 μm for chamfer, and 157 ±34 μm for feather-edge finish lines. Internal gap values were 111 ±14 μm for feather-edge, 136 ±22 μm for chamfer, and 168 ±25 μm for rounded shoulder finish lines. The differences in cement volume between groups were not statistically significant (P=.200). Conclusions All 3 finish lines produced marginal gaps within the range of clinically accep table values. Lithium disilicate CAD crowns with a rounded shoulder finish line had the best marginal fit but the poorest internal fit, and lithium disilicate CAD crowns with a feather-edge finish line had the best internal fit but the poorest marginal fit.

Military personnel use protective armor systems that are frequently exposed to low-level damage, such as non-ballistic impact, wear-and-tear from everyday use, and damage during storage of equipment. The extent to which such low-level pre-damage could affect the performance of an armor system is unknown. In this work, low-level pre-damage has been introduced into a Kevlar/phenolic resin-starved composite panel using tensile loading. The tensile stress–strain behavior of this eight-layer material has been investigated and has been found to have two distinct regions; these have been understood in terms of the microstructure and damage within the composite panels investigated using micro-computed tomography and digital image correlation. Ballistic testing carried out on pristine (control) and pre-damaged panels did not indicate any difference in the V50 ballistic performance. However, an indication of a difference in response to ballistic impact was observed; the area of maximal local out-of-plane deformation for the pre-damaged panels was found to be twice that of the control panels, and the global out-of-plane deformation across the panel was also larger.

Although single-file rotary systems are accepted in the field of paediatric dentistry in terms of providing time advantage, research works continue due to the variable anatomical structure of the root canal.This study aimed to evaluate rotary systems in different kinematics in terms of microcracks and the shaping of the danger zone in primary molars by micro-CT.The mesial canals of primary molars (n = 30) were used. Root canals in each group (n = 10) were prepared with single-file rotary systems (One Shape®, OS; XP-endo® Shaper, XP-ES; WaveOne Gold, WOG). The images were evaluated for dentin thickness in the danger zone and microcrack formation.WOG caused the highest dentin reduction in the danger zone area. OS led to significantly less dentin reduction than XP-ES and WOG (P .05). The XP-ES showed the highest number of microcracks (P .05). No statistically significant difference was found between WOG and OS (P .05). In all systems, more microcracks were observed in the middle third than coronal and apical.Within the limitations of this study, the rotary systems were superior to reciprocating in terms of shaping ability in the danger zone. It is thought that further studies with different systems should be designed considering the anatomical variations and chemical composition of primary teeth.

Background: The typical imaging finding of MM is bone destruction in the form of diffuse patchy osteolytic lesions or punctate destruction. However, it is difficult to accurately determine the fine structure of bone affected by MM with these techniques due to low specificity and sensitivity. Introduction: This study aimed to investigate the microscopic anatomical morphology and analyze the microstructure changes of trabeculae affected by multiple myeloma (MM) based on micro-CT. Methods: MM-affected and normal trabecular bone samples were imaged by micro-CT to obtain bone structure parameters to assess statistical differences between them and evaluate the degree of microstructural damage of MMaffected trabeculae. Methods: MM-affected and normal trabecular bone samples were imaged by micro-CT to obtain bone structure parameters to assess statistical differences between them and evaluate the degree of microstructural damage of MM-affected trabeculae. Results: Micro CT images clearly showed the microstructure of MM-affected trabeculae. The degree of trabecular osteoporosis varied with the severity of MM. There were significant differences in the structural parameters between MM-affected and normal trabeculae (P < 0.05). Conclusions: Micro-CT clearly reveals the microstructure of MM-affected trabeculae. The obtained bone structure data will help to determine the degree of bone damage caused by MM and assess the efficacy.

Polymer-ceramic composites are widely used in biomedical applications. This paper presents the results of an experimental investigation on the crack extension inside epoxy-alumina. Specimens with 5 vol.%, 10 vol.%, …, 25 vol.% fillers fractions were fabricated. Three-point bending on single-edge notched bend specimens were performed using conventional mechanical tester and in situ mechanical tester coupled with micro-CT, respectively. Fracture toughness was measured to be 2.10–2.51 $${\text{MPa}}\sqrt {\text{m}} $$ , and it decreased with increasing filler fraction. When cracks were shorter than 0.88 mm, crack resistance for 5 and 25 vol.% epoxy-alumina was similar. Beyond 0.88 mm, 25 vol.% epoxy-alumina exhibited no crack resistance, whereas stress intensity factor kept increasing in 5 vol.% epoxy-alumina. The matrix-particle interfaces were the weakest link, where cracks often initiated from. Crack bridging by uncracked ligament and crack deflection were commonly observed toughening mechanisms. To design robust epoxy-alumina composites, increasing matrix-particle interface strength is recommended for future work.

For materials characterization, obtaining insight through 3D imaging has been extremely helpful in improving our understanding of complex systems. X-ray computed tomography (CT) has proven to be an extremely useful technique in this field, allowing for non-destructive interrogation of samples of all types across many length scales. In this article we look at how micro-CT is moving from static 3D imaging into the realm of 4D data collection through dynamic CT, where CT data are collected on samples undergoing change in an uninterrupted matter.

Purpose To evaluate the marginal and internal adaptation of all-ceramic crowns and inlays fabricated by different scanners of the same CAD/CAM system. Materials and methods All-ceramic crown preparations were performed on typodont maxillary first premolars, and mandibular first molars were prepared for ceramic Class II mesio-occlusal inlays. Two intraoral scanners (CEREC Bluecam and Omnicam, Dentsply Sirona) and one model scanner (CEREC inEos X5, Dentsply Sirona) were used to scan the preparations. All restorations were fabricated by milling single-feldspathic ceramic blocks (CEREC Blocks). The marginal and internal discrepancies of restorations were evaluated via micro-CT analyses. Results For linear crown measurements, the marginal gaps were 63.75 μm, 88.24 μm, and 90.89 μm for Bluecam, Omnicam, and inEos X5, respectively. For crowns at central groove areas, the maximum values for Bluecam, Omnicam, and inEos X5 were found to be 144.78 μm, 165.19 μm, and 129.49 μm, respectively. For inlays, the highest range at the midpoint of the axiopulpal line angle for Bluecam, Omnicam, and inEos X5 were determined as 138.57 μm, 184.33 μm, and 179.71 μm, respectively. In volumetric measurements, inEos X5 showed lower gap for both crowns (11.47 mm3) and inlays (5.65 mm3) compared to both intraoral scanners. These results are within a clinically acceptable range. Conclusion When all-ceramic crowns were evaluated, there were generally no significant differences found between scanners for the regional linear measurements, but more gaps occurred in restorations obtained with intraoral scanners for volumetric measurements. On the other hand, when the inlay restorations were evaluated, significant differences were found between groups except for the midpoint of the axio-pulpal line angle and the midpoint of the mesio-gingival margin. However, marginal and internal gaps of both crowns and inlays presented mean values less than 150 μm in many surfaces, which could be considered clinically acceptable.

Aim. This study aimed to determine the residual filling material and the reestablishment of working length and apical patency after retreatment of TotalFill® BC Sealer.Materials and methods. Thirty maxillary incisors were used in a single cone obturation technique with TotalFill BC Sealer (FKG, Switzerland) and randomly divided into 6 groups according to the retreatment technique. The samples were scanned by micro-CT before and after retreatment in order to evaluate the residual filling material on the root dentin walls. Data were analyzed statistically with the Kruskal-Wallis tests (p < 0.05).Results. No instrumental protocol was able to remove all obturation material from the root canals. The differences in reduction in the total volume of filling material percentage were statistically significant (p < 0.05) among groups with and without ultrasound or sound activation in retreatment protocol.Conclusions. The most effective root canal retreatment was determined with D-Race + XP-endo Shaper + XP-Endo Finisher R + US (3.0 W) protocol; it was found that the efficiency of filling material removal was more than 92%.

BackgroundThe objective of the present micro-computed tomography (micro-CT) study was to assess the presence of voids in band-shaped isthmuses obturated using three different filling techniques.MethodsTwenty-four artificial molar teeth with a band-shaped isthmus were allocated to three groups (n = 8) for obturation, according to the filling technique: single-cone (SC), continuous wave of condensation (CWC) or lateral condensation (LC). Obturation was performed with gutta-percha (GP) cones and iRoot SP (Innovative Bioceramix, Vancouver, Canada). Post-filling micro-CT scanning was performed. The percentage of filling materials and void volumes were calculated in the isthmus areas and data were analyzed using one-way ANOVA and Tukey tests.ResultsThe mean percentage of void volumes and corresponding filling percentages in the isthmus areas after obturation in the SC groups was 22.98 % ± 1.19 %, 77.02 % ± 1.19 %; in the CWC groups 10.46 % ± 2.28 %, 89.54 % ± 2.28 %; and in the LC groups was 13.14 % ± 1.85 %, 86.86 % ± 1.85 %, respectively.ConclusionsIn band-shaped isthmus area, the obturation quality of CWC was superior to SC and LC techniques.

Vertebral compression fractures rank among the most frequent injuries to the musculoskeletal system, with more than 1 million fractures per annum worldwide. The past decade has seen a considerable increase in the utilisation of surgical procedures such as balloon kyphoplasty to treat these injuries. While many kyphoplasty studies have examined the risk of damage to adjacent vertebra after treatment, recent case reports have also emerged to indicate the potential for the treated vertebra itself to re-collapse after surgery. The following study presents a combined experimental and computational study of balloon kyphoplasty which aims to establish a methodology capable of evaluating these cases of vertebral re-collapse. Results from both the experimental tests and computational models showed significant increases in strength and stiffness after treatment, by factors ranging from 1.44 to 1.93, respectively. Fatigue tests on treated specimens showed a 37% drop in the rate of stiffness loss compared to the untreated baseline case. Further analysis of the computational models concluded that inhibited PMMA interdigitation at the interface during kyphoplasty could reverse improvements in strength and stiffness that could otherwise be gained by the treatment.

The pore habits of gas hydrate in natural sediment matrices provide essential clues for understanding physical (mechanical, thermal, hydraulic, and electrical) properties of hydrate-bearing sediments, yet there are no tools that can directly visualize the pore habits of natural gas hydrate other than indirect interpretation based on core-scale or field-scale observations. A significant challenge is to obtain a mini-core from pressure cores retrieved from natural reservoirs for high-resolution micro-CT (computed tomography) scans while maintaining pressure and temperature conditions required for stability of gas hydrate during all operational steps including manipulation, cutting, transferring, sub-coring and CT scanning. We present a new set of tools for pore-scale micro-CT imaging of natural hydrate-bearing sediments while maintaining pressure and temperature control. The tests with laboratory-prepared cores and pressure cores successfully demonstrate the capability of this set of tools to subsample a mini-core from pressure cores, transfer the mini-core to an X-ray transparent core holder, and conduct micro-CT scans. Successfully obtained CT images prove the functionality of this set of tools.

AIM To evaluate the precision of the orthodontic bracket slot dimensions of 0.022 inch and to compare them with those of the manufacturers' specifications. MATERIALS AND METHODS The slots of upper-right central incisor brackets (n = 5) from 11 commercial bracket systems of three different manufacturers (3M Unitek: Victory Mini Metal, Clarity, SmartClip, Clarity SL; ORMCO/SYBRON: Mini Diamond Twin, Damon Q, Damon Clear; Dentsply/GAC: Ovation, Mystique, In-Ovation R, In-Ovation C) were measured. The orthodontic brackets were scanned using micro-computed tomography (micro-CT), and the bracket slots were measured using micro-CT images. The slot was measured at four different surfaces (occlusal, gingival, base, and face) for both mesial and distal sites. Data were subjected to ANOVA and unpaired t-tests. A p-value of ≤0.05 was considered statistically significant. RESULTS All brackets had slot dimensions that were significantly larger (p < 0.05) than the stated 0.022 inch. 3M-victory were 11.99% larger (0.02509 inch) and the closest to the stated dimension and the ORM-Damon C were 24.07% larger (0.02948 inch) than the quoted slot size of 0.022 inch. Comparison between mesial and distal sides showed that 91% of the bracket slots were asymmetrical at their bases and 100% asymmetrical at their faces. All of the bracket system showed divergent walls from base to face with values ranging from 1.96 (3M-SmartClip) to 26.58% (ORM-Damon C). CONCLUSION The actual measurements of 11 bracket systems from three different manufacturers were more substantial than the manufacturers' specifications, and the walls of the slots diverged from the bracket bases in all of the tested bracket system. CLINICAL SIGNIFICANCE Orthodontic bracket slots vary significantly from that of the manufacturers' specification. The orthodontist should anticipate such shortcomings and be able to modify treatment mechanics through additional wire bending in three spatial planes.

This work presents a statistical approach to establish the refined meso-scale model for angle-interlock (2.5D) woven SiCf/SiC composites considering various pore defects. This method firstly extracted the regions of interest to obtain the original data of yarn and pores from X-rays computed tomography (Micro-CT). Then, the geometric parameters of the collected yarns and pores were statistically analyzed based on the scanning tomograms. Consequently, a non-uniform pore distribution model (N-model) was established by introducing the virtual small pores and giant pores construction. Furthermore, for the validation of N-model, the traditional ideal model without pore defects (I-model) and uniform small pore distributing model (U-model) were reconstructed. Also, the tensile tests were carried out. The elastic modulus of composite obtained from the N-model, U-model, and I-model are 44,354.58 MPa, 42,932.23 MPa and 40,477.25 MPa respectively, while that of experimental result exhibit 41,659.85 MPa, the prediction accuracy rate of the N-model could reach up to 95%. The results showed that the proposed N-model is capable of accurately predicting the mechanical behaviors, full-field stress distribution and damage of 2.5-dimensional (2.5D) woven SiCf/SiC composites, validated by the experimental tests.

Background: During the past decade there has been a significant increase in the number of vertebral fractures being treated with the balloon kyphoplasty procedure. Although previous investigations have found kyphoplasty to be an effective treatment for reducing patient pain and lowering cement-leakage risk, there have been reports of vertebral recollapse following the procedure. These reports have indicated evidence of in vivo bone-cement separation leading to collapse of the treated vertebra. Methods: The following study documents a multiscale analysis capable of evaluating the risk of bone-cement interface separation during lying, standing, and walking activities following balloon kyphoplasty. Results: Results from the analysis found that instances of reduced cement interlock could initiate both tensile and shear separation of the interface region at up to 7 times the failure threshold during walking or up to 1.9 times the threshold during some cases for standing. Lying prone offered the best protection from interface failure in all cases, with a minimum safety factor of 2.95. Conclusions: The results of the multiscale analysis show it is essential for kyphoplasty simulations to take account of the micromechanical behavior of the bone-cement interface to be truly representative of the in vivo situation after the treatment. The results further illustrate the importance of ensuring adequate cement infiltration into the compacted bone periphery during kyphoplasty through a combination of new techniques, tools, and biomaterials in a multifaceted approach to solve this complex challenge.

The estimation of the post-traumatic survival time (PTST) in case of bone injuries remains a tricky issue in the forensic field, especially when dealing with dry bones. Newer high-resolution imaging, and in particular microcomputed tomography (micro-CT), has the potential to significantly improve our abilities to interpret antemortem and perimortem lesions and accurately date fractures in a less destructive analysis. In this paper, nine costal fractures of known post-traumatic ages were analyzed through gross examination, conventional radiography, and microcomputed tomography, in order to test the potential of microcomputed tomography for dating fractures. As a result, microcomputed tomography provided images of high quality and definition and allowed the observation of the internal microarchitecture of the fractures and calluses. While microcomputed tomography cannot substitute histological examination for the estimation of the post-traumatic survival time, it constitutes a potent and helpful complementary tool for the analysis of bone trauma.

Stripping perforation is a possible complication in instrumentation of C-shaped canals. This study evaluated the minimum thickness of the root canal wall in C-shaped teeth after instrumentation. Twelve extracted C-shaped mandibular second molars (four teeth of type I, II and III each) were examined by CBCT (voxel size 90 μm) before and after instrumentation with WOG primary file. Micro-CT scans (voxel size 30 μm) were obtained after instrumentation. Percentage of canal wall area touched by the file and minimum thickness of dentine were measured and compared between CBCT and micro-CT. In type I C-shape canals, less than 10% of the canal wall area was touched by the instrument. In ten teeth, the shortest distance to root surface was from the instrumented area; no perforations occurred. CBCT and micro-CT measurements were in good agreement in ten cases; in two teeth, micro-CT revealed considerably shorter distance to root surface. The two shortest distances were 0.27 and 0.41 mm.

Amyloid plaques are small (~50 μm), highly-dense aggregates of amyloid beta (Aβ) protein in brain tissue, supposed to play a key role in pathogenesis of Alzheimer’s disease (AD). Plaques´ in vivo detection, spatial distribution and quantitative characterization could be an essential marker in diagnostics and evaluation of AD progress. However, current imaging methods in clinics possess substantial limits in sensitivity towards Aβ plaques to play a considerable role in AD screening. Contrast enhanced X-ray micro computed tomography (micro CT) is an emerging highly sensitive imaging technique capable of high resolution visualization of rodent brain. In this study we show the absorption based contrast enhanced X-ray micro CT imaging is viable method for detection and 3D analysis of Aβ plaques in transgenic rodent models of Alzheimer’s disease. Using iodine contrasted brain tissue isolated from the Tg-F344-AD rat model we show the micro CT imaging is capable of precise imaging of Aβ plaques, making possible to further analyze various aspects of their 3D spatial distribution and other properties.

Objective: To reconstruct the etiology of a perimortem injury observed on a Neolithic – Chalcolithic cranium (5060 – 4400 yrs cal. BP). Materials: A cranium of an old adult male individual belonging to a collective burial from Cova Foradada site (Calafell, Tarragona, Spain). Methods: The cranium was analyzed macroscopically and microscopically using micro-CT scan. Results: The fracture on the right parietal bone presents characteristics of perimortem trauma. The morphology of the point of impact allows for the interpretation of this fracture as a result of impact by an object with a straight and sharp edge. In addition, the same cranium presents two healed antemortem injuries. Conclusions: The object that most likely caused the cranial fracture was a stone adze. The blow occurred from behind the individual, possibly by a right-handed attacker. Significance: The potential to link cranial fractures with specific tools increases our understanding of interpersonal violence during the Neolithic. Limitations: It is not possible to infer if this cranial injury was related to a large-scale intergroup confrontation or an intragroup violent event. Suggestions for further research: To investigate additional similar sites in the northeastern Iberian Peninsula to better characterize the fracture pattern caused by stone axes and adzes as well as other objects used as weapons during the Neolithic – Chalcolithic ages., This work was supported by the Ministerio de Ciencia, Innovación y Universidades (FPU18-02291 scholar-ship); Ministerio de Ciencia, Innovación y Universidades/Fondo Europeo de Desarrollo Regional [PGC2018-093925-B-C32]; Agència de Gestió d’Ajuts Universitaris i de Recerca [SGR 2017-1040]; Departament de Cultura de la Generalitat de Catalunya [CLT009-18-00024]; and Universitat Rovira i Virgili, projects [2014, 2015 and 2016 PFR-URV-B2- 17] and [2018 PFR-URV-B2-91], framed in the Programa de Centros de Recerca de Catalunya (CERCA), Generalitat de Catalunya.

This current paper aims to review the literature on the root canal configuration (RCC) and root structure of permanent mandibular premolars. To find the published scientific literature on the RCC of mandibular premolars up to July 2022, a systematic search of four electronic databases was performed. The studies were selected, rendering to a predetermined point of reference: “mandibular 2nd premolar”, “root and canal system”, “morphology of root and canal”, “root and canal configuration”, and “morphology”, along with “anatomy” and “mandibular premolars”. Cross-referencing along with screening through the bibliographies of the chosen articles resulted in the identification of further studies. In the current study, we examined 30 different articles, and we chose them based on the quality of research investigations. From 3471 retrieved studies, a total of 15981 mandibular 2nd premolars were observed in 30 studies. The mean JBI score for studies assessing the structure of the root, as well as the root canal of the mandibular 2nd premolar, was 7.78 ± 0.81. We have found a pooled prevalence of 91.82% for Vertucci class I root canal morphology and 78.63% pooled prevalence of single-rooted mandibular second premolar. A total of 8677 mandibular 1st premolars were observed in 22 studies. The mean JBI score for studies assessing the structure and anatomy of the root, as well as root canal of mandibular 1st premolar, was 7. 95 ± 0.85. We have found a pooled prevalence of 74.34% for Vertucci class I root canal morphology and 85.20% pooled prevalence of single-rooted mandibular 1st premolar. Mandibular first and second premolars were mostly single-rooted teeth (89.5–100%). The most frequently seen RCC is a 1-1-2-/2 (type V–Vertucci’s), followed by 1-1-2-/1 (type IV– Vertucci’s; type III–Weine’s), and finally RCC 2-2-2-1 (type IV–Vertucci’s; type III–Weine’s). Presently, the imaging of CBCT is the most used research approach for studying Mn2Ps’ structural characteristics.

Additive manufactured light components are desirable for airspace and automobile applications where failure resistance under contact is important. To date, understanding the nature of subsurface damage in contact is still lacking. In this research, we investigated 3D-printed aluminum-silicon (Al-Si) alloys in the lattice structure under a rolling contact condition. Using the microtomography technique, we were able to construct a 3D image of the lattice structure being plastically deformed. Finite element analysis was conducted about the strain and stress on struts of different dimensions. Results showed that morphology dominated the deformation. The significant factors affecting the deformation were the strut aspect ratio, and their relative diameter. When the aspect ratio of a strut is smaller than 0.5, the plastic deformation is distributed in the subsurface region and when it is larger than 0.5, the deformation concentrates on the top layer of struts. This research indicates that the dimensional parameters of lattice structures can be designed for optimization to achieve higher resistance to deformation.

Background: Generally, after tooth extraction, trauma is caused by bone damage, which leads to a decreased bone density. Bone damage repair should be conducted using a bone graft containing hydroxyapatite (HA). HA can be synthesised from gypsum puger powder, which is abundant and easy to obtain. Hydroxyapatite gypsum puger (HAGP) was successful with 100% hydroxyapatite purity level. Purpose: To compare the ratio of trabecular bone density in Wistar rats between HAGP scaffold application and bovine hydroxyapatite (BHA) scaffold application. Methods: This study is a laboratory experiment using 6 treatment groups, namely K (-) polyethylene glycol (PEG) 7, K (-) PEG 28, HAGP + PEG 7, HAGP + PEG 28, BHA + PEG 7, and BHA + PEG 28. HAGP scaffold freeze-drying. The rats were anaesthetised intramuscularly, and their left mandibular incisor was removed. The scaffold was applied to the mouse socket, followed by tissue decapitation after 7 and 28 days. The examination was carried out with micro-computed tomography (Micro-CT). Next, statistical analysis using a one-way analysis of variance (ANOVA) test was conducted (p

Many studies have analyzed different tooth demineralization models, which generate artificial incipient lesions; however, most of them are complex, slow, not clear and results could not be employed in both primary and permanent teeth because of chemical content differences among them. This study evaluates a demineralization model on primary enamel, under three incubation periods; quantifying artificial incipient lesions formation, and depth by micro-CT, complementing with SEM for morphological characterization. Sixteen healthy human anterior primary teeth extracted for prolonged retention and orthopedic/orthodontic reasons were included in this study, previous informed consent. The sample was randomly assigned to four groups n = 4: G_Control, G_2D, G_4D, and G_7D. Micro-CT and SEM were performed during two stages: before demineralization (BD) and after demineralization (AD). A t-student test was carried out to determine differences among groups (p ≤ .05). No incipient lesions were observed in control group. Artificial lesion depth was similar among experimental groups; values were from 38.16 ± 05.40 μm to 42.61 ± 04.75 μm. An amount of 14 to 17 artificial incipient lesions were formed per group, the extension and distribution were different for each incubation period. Five erosive lesions were produced in G_7D. All experimental groups were able to form incipient artificial lesions in primary enamel. SEM characterization revealed more pronounced changes on the enamel surface, as the days of immersion in the demineralization solution increased. The 4-day incubation period is the most recommended for the demineralization model, due to the formation of incipient lesions only and its extension, which facilitates their assessment.

Carbon fiber reinforced polymer (CFRP) composites have been gathering a lot of interest in several engineering applications because of their favorable properties including lightweight and ease of m...

The internal structure and mechanics of the fibre materials, such as yarn or woven textile, are highly complex. Exploring the fibre structure is an essential step in material engineering either from the experimental or computational point of view. In this study, a new method to extract geometrical and morphological parameters of fibre structures is proposed. The method benefits from standard image analysis and machine learning technique to efficiently extract fibre segments from microcomputer tomography data. The proposed algorithm is tested on the yarn and woven textile materials with different resolution and quality. The developed method can extract the individual fibres with varying accuracy from 73-100% with processing time 2-5s on the tested samples.