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Abstract Dynamic wheel–rail contact forces induced by a severe form of wheel tread damage have been measured by a wheel impact load detector during full-scale field tests at different vehicle speeds. Based on laser scanning, the measured three-dimensional damage geometry is employed in simulations of dynamic vehicle–track interaction to calibrate and verify a simulation model. The relation between the magnitude of the impact load and various operational parameters, such as vehicle speed, lateral position of wheel–rail contact, track stiffness and position of impact within a sleeper bay, is investigated. The calibrated model is later employed in simulations featuring other forms of tread damage; their effects on impact load and subsequent fatigue impact on bearings, wheel webs and subsurface initiated rolling contact fatigue of the wheel tread are assessed. The results quantify the effects of wheel tread defects and are valuable in a shift towards condition-based maintenance of running gear, and for general assessment of the severity of different types of railway wheel tread damage.

Intrabony defects can be the result of parodontitis. In this study we aimed to examine how clot stability is affected by different infrabony defect angles and superficial treatments in regenerative surgery. Methods: Thirty single-root extracted teeth were cut to obtain a section from each tooth. This section was placed in an artificial model containing an infrabony defect with three walls in order to achieve 10 models at angles of 25°, 37°, and 50°. Five root samples for every angle were not subjected any treatment (NT) and five were subjected to root conditioning with a neutral pH solution of ethylenediaminetetraacetic acid (EDTA) at 24%, applied for 2 min. Venous blood was put into the artificial models containing the root sections, and these were placed in an incubator at a constant temperature of 37 °C for 2 h. Samples were analyzed by laser confocal microscopy. Results: All samples exhibited signs of retraction. The EDTA group exhibited a plateau trend for infrabony defects, while in the NT group, there was a statistically significant difference between clot retraction and the increase in defect amplitude. Conclusion: The greater the angle of the infraosseous defect, the higher the rate of clot retraction. This showed that EDTA could reduce the influence of the angle of the infraosseous defect.

The approach employed for the site preparation of the dental implant is a variable factor that affects the implant’s primary stability and its ability to integrate with the surrounding bone. The main objective of this in vitro study is to evaluate the influence of different techniques used to prepare the implant site on the primary stability of the implant in two different densities of artificial bone. Materials and Methods: A total of 150 implant sites were prepared in rigid polyurethane blocks to simulate two distinct bone densities of 15 pounds per cubic foot (PCF) and 30 PCF, with a 1-mm-thick simulated cortex. The implant sites were equally distributed among piezoelectric surgery (PES), traditional drills (TD), and black ruby magnetic mallet inserts (MM). Two methods have been employed to evaluate the implant’s primary stability, Osstell and micro-tomography. Results: In the present study, we observed significant variations in the implant stability quotient (ISQ) values. More precisely, our findings indicate that the ISQ values were generally higher for 30 PCF compared to 15 PCF. In terms of the preparation technique, PES exhibited the greatest ISQ values, followed by MM, and finally TD. These findings corresponded for both bone densities of 30 PCF (PES 75.6 ± 1.73, MM 69.8 ± 1.91, and TD 65.8 ± 1.91) and 15 PCF (PES 72.3 ± 1.63, MM 62.4 ± 1.77, and TD 60.6 ± 1.81). By utilizing Micro-CT scans, we were able to determine the ratio of the implant occupation to the preparation site. Furthermore, we could calculate the maximum distance between the implant and the wall of the preparation site. The findings demonstrated that PES had a higher ratio of implant to preparation site occupation, followed by TD, and then the MM, at a bone density of 30 PCF (PES 96 ± 1.95, TD 94 ± 1.88, and MM 90.3 ± 2.11). Nevertheless, there were no statistically significant differences in the occupation ratio among these three approaches in the bone density of 15 PCF (PES 89.6 ± 1.22, TD 90 ± 1.31, and MM 88.4 ± 1.17). Regarding the maximum gap between the implant and the site preparation, the smallest gaps were seen when TD were used, followed by MM, and finally by PES, either in a bone density 15 PCF (PES 318 ± 21, TD 238 ± 17, and MM 301 ± 20 μm) or in a bone density 30 PCF (PES 299 ± 20, TD 221 ± 16, and MM 281 ± 19 μm). A statistical analysis using ANOVA revealed these differences to be significant, with p-values of < 0.05. Conclusion: The outcomes of this study indicate that employing the PES technique and osteo-densification with MM during implant insertion may enhance the primary stability and increase the possibility of early implant loading.

Background: Individuals with pathologic conditions and restorative deficiencies might benefit from a combinatorial approach encompassing stem cells and dental implants; however, due to the various surface textures and coatings, the influence of titanium dental implants on cells exhibits extensive, wide variations. Three-dimensional (3D) cultures of stem cells on whole dental implants are superior in testing implant properties and were used to examine their capabilities thoroughly. Materials and methods: The surface micro-topography of five titanium dental implants manufactured by sandblasting with titanium, aluminum, corundum, or laser sintered and laser machined was compared in this study. After characterization, including particle size distribution and roughness, the adhesion, proliferation, and viability of adipose-derived stem cells (ADSCs) cultured on the whole-body implants were tested at three time points (one to seven days). Finally, the capacity of the implant to induce ADSCs’ spontaneous osteoblastic differentiation was examined at the same time points, assessing the gene expression of collagen type 1 (coll-I), osteonectin (osn), alkaline phosphatase (alp), and osteocalcin (osc). Results: Laser-treated (Laser Mach and Laser Sint) implants exhibited the highest adhesion degree; however, limited proliferation was observed, except for Laser Sint implants, while viability differences were seen throughout the three time points, except for Ti Blast implants. Sandblasted surfaces (Al Blast, Cor Blast, and Ti Blast) outpaced the laser-treated ones, inducing higher amounts of coll-I, osn, and alp, but not osc. Among the sandblasted surfaces, Ti Blast showed moderate roughness and the highest superficial texture density, favoring the most significant spontaneous differentiation relative to all the other implant surfaces. Conclusions: The results indicate that 3D cultures of stem cells on whole-body titanium dental implants is a practical and physiologically appropriate way to test the biological characteristics of the implants, revealing peculiar differences in ADSCs’ adhesion, proliferation, and activity toward osteogenic commitment in the absence of specific osteoinductive cues. In addition, the 3D method would allow researchers to test various implant surfaces more thoroughly. Integrating with preconditioned stem cells would inspire a more substantial combinatorial approach to promote a quicker recovery for patients with restorative impairments.

Background: Although the influence of titanium implants’ micro-surface properties on titanium discs has been extensively investigated, the research has not taken into consideration their whole-body effect, which may be considered possible using a combinatorial approach. Methods: Five titanium dental implants with a similar moderate roughness and different surface textures were thoroughly characterized. The cell adhesion and proliferation were assessed after adipose-tissue-derived stem cells (ADSCs) were seeded on whole-body implants. The implants’ inductive properties were assessed by evaluating the osteoblastic gene expression. Results: The surface micro-topography was analyzed, showing that hydroxyapatite (HA)-blasted and bland acid etching implants had the highest roughness and a lower number of surface particles. Cell adhesion was observed after 24 h on all the implants, with the highest score registered for the HA-blasted and bland acid etching implants. Cell proliferation was observed only on the laser-treated and double-acid-etched surfaces. The ADSCs expressed collagen type I, osteonectin, and alkaline phosphatase on all the implant surfaces, with high levels on the HA-treated surfaces, which also triggered osteocalcin expression on day seven. Conclusions: The findings of this study show that the morphology and treatment of whole titanium dental implants, primarily HA-treated and bland acid etching implants, impact the adherence and activity of ADSCs in osteogenic differentiation in the absence of specific osteo-inductive signals.

Background: Bisphosphonates and receptor activator of nuclear factor kappa-B ligand inhibitors are currently the most widely used antiresorptive therapies in bone metabolism diseases treatment. Unfortunately they can evoke medication-related osteonecrosis of the jaws. The present case series study proposes to evaluate clinical features, evolution and the surgical therapeutic approaches in three patients affected by medication-related osteonecrosis of the jaw and to review the state of art regarding the management of this complication in light of the most recent literature. Methods: Three cases of medication-related osteonecrosis of the jaws are discussed, two related to bisphosphonates therapy (ibandronic acid) and one due to denosumab. Results: All three patients were aged female and had probably a dental trigger agent. The lesions located in posterior mandible were treated in one case with the surgical approach alone and, in the other case, with surgical approach associated with Erb-YAG laser. The lesion related to denosumab was treated with surgical approach and platelet rich fibrin application. A complete healing was always achieved. Conclusions: Dentists should be aware of the potential risk of developing medication-related osteonecrosis of the jaws for patients who take or had taken antiresorptive drugs. The side effects of denosumab and bisphosphonates are partly overlapping and currently there is still no consensus about the therapeutic surgical options. Prevention and early detection of the lesions should be the primary strategy.

Background: The blood wettability of titanium implant surfaces favors primary osseointegration and tissue healing in peri-implantitis. The current study aims to evaluate this property on the main different kinds of surfaces, brand new and after treatments. Methods: grade IV titanium disks were used, five machined, five laser-treated, five sandblasted. The experiment was on four steps. Between each step, specimens were sterilized. At the end of each step, a 4 µL blood drop was put on the samples, and contact angles were calculated. The steps consisted of—1: no treatment; 2: surface instrumentation with an ultrasonic titanium tip; 3: platelet-rich fibrin (PRF) coating and drying with sterile gauze; 4: etching with phosphoric acid, rinse and saline solution and air-drying. At the end of each phase, a blood drop was placed on the surfaces. Blood for PRF preparation and for calculation of contact angles was collected from a single source. Results: average wettability decreased after instrumentation, and increased after the PRF application to a superior level both to the first and second steps. The highest wettability was obtained after etching. This trend is statistically significant for machined and sandblasted surfaces. Conclusions: In the clinical environment, PRF and phosphoric acid used for conditioning exposed implant surfaces can be used for the healing of peri-implant tissues.

Background: Neurological alterations are one of the main complications occurring after the third molar extractions. The aim of this prospective multicenter cohort study was to find out Cone Beam Computed Tomography (CBCT) features and distribution of neurological complications in patients undergoing lower third molar surgery and to determine the radiological and patient-related factors that could be correlated to the occurrence of inferior alveolar and lingual nerves injury. Material and Methods: 378 patients who underwent lower third molar extraction from March 2018 to March 2019 were included. Clinical and radiological data were collected. CBCT features were recorded following Maglione et al. classification. Symptoms and characteristics of patients who experienced neurological alterations were evaluated. Results: 193 patients needed a second-level radiological exam (CBCT). In these patients, the most common feature was Maglione class 3: a higher frequency of apical or buccal mandibular canals in direct contact with the tooth was observed. 3.17% of the patients developed a neurological complication. Maglione class 4, increased age, and operative time were all positively correlated with neurological alterations. Conclusions: while the buccal or apical position of the mandibular canal was the more common findings, the lingual position was found to have a higher correlation with a negative outcome. Age and operative time were also found to be risk factors for developing nerve injury in the considered population.

Aim: To assess preliminarily the potential benefits of the use of the platelet-rich fibrin (PRF) in modern endodontic surgical procedures in terms of radiographic healing acceleration and postoperative discomfort reduction. Methodology: Eleven patients with chronic apical periodontitis were randomly assigned to either the PRF (n = 7) or the control group (n = 4). Postoperative swelling and pain were assessed with a questionnaire. Radiographic healing was scored according to Molven's scale up to a period of one year. Data were statistically analyzed with non-parametric tests. Results: In the PRF group the patients experienced less pain in the 2–6 h postoperatively as well as oedema, which never exceeded the moderate intraoral swelling. Radiographic healing was detectable earlier in the PRF group, with the majority of cases scored as complete healing after 2–3 months. Conclusions: The adjunctive use of PRF might promote the acceleration of the radiographic healing and reduce the postoperative discomfort.

The purpose of this research was to compare the reliability of two different methods for cranial midline localization through cephalometric analysis of mandibular condyle asymmetries. A retrospective cohort study was performed analyzing consecutively the SMV radiograms of 47 patients undergoing oral surgery before orthodontic treatment at the Dental School, University of Trieste (Italy) from 2003 to 2008. Two different cephalometric analyses were used to identify the basicranium midline (Tracing 1: initial landmarks = craniostat ear rods; Tracing 2: initial landmarks = spinosum foramina), and the left/right symmetry ratio (SR) for four parameters (condylar length, condylar angle, intra-condylar hemidistance, extra-condylar hemidistance) was calculated. The main result showed that no significant statistical difference between the SRs of the intra-condylar and extra-condylar hemidistance obtained with the same tracing was found (𝑡-test; 𝑃=NS; C.I. 95%). Conversely, the difference between the SRs obtained with the two different tracings was statistically significant (𝑡-test; 𝑃