Bridge Restorations Research Articles

Bridge and transport network resilience – a perspective

Bridges and critical transport infrastructure are primary assets and systems that underpin human mobility and activities. Loss of bridge functionality has consequences on entire transport networks, which are also interconnected with other networks. Cascading events then unfold in the entire system of systems, leading to significant economic losses and societal disruption to business and society. Recent natural disasters have revealed the vulnerabilities of bridges and critical assets to diverse hazards (e.g. floods, blasts, earthquakes), some of which are exacerbated due to climate change. The assessment of bridge and network vulnerabilities by quantifying their capacity and functionality loss and adaptation to new requirements and stressors is thus of paramount importance. The aim of this work was try to understand the main compound hazards, stressors and threats that have short- and long-term impacts on the structural capacity and functionality of bridges and the impact of bridge closures on network operability. The main drivers of bridge restoration and reinstatement were also considered. Loss of performance, driven by redundancy and robustness of a bridge, is the first step to be considered in the overall process of resilience quantification. Resourcefulness is the other main component of resilience analysed in this work.

A multi-attribute approach to select the best method for repairing river bridge columns

PurposePier scour is one of the main causes of damage to the columns of the river bridges. It is essential to select the best method among various repair methods based on different evaluation indices. However, there is no procedure for ranking these repair methods based on their attributes. The present study seeks to set an approach for this ranking.Design/methodology/approachIn this paper, a multi-attribute decision-making (MADM) model is presented for ranking the repair techniques, in which alternatives are examined using the most important evaluation criteria. In addition, a combination of entropy and eigenvector methods has been proposed for weighting these attributes. A case study is then used to demonstrate the applicability and the validity of the method.FindingsThe execution of the model using two multi-criteria methods yielded similar results, which confirms its accuracy and precision. Moreover, the research findings showed the consistency of the objective and subjective weighting methods and the conformity of the weights obtained for the attributes from the combination of these methods to the nature of the problem.Originality/valueThe selection of the proper method for repairing the bridge columns plays an essential role in success of the bridge restoration. The proposed model introduces an approach for ranking repair methods and selecting the best one that has not been presented so far. Also, the weighing method for attributes is an innovative method for ranking restoration methods that has been proven in a case study.

Temporary adhesive bridge restoration of the upper anterior teeth lost due to trauma: Three case reports

Aim: Traumatic dental injuries at the anterior region of the maxilla occur frequently in children and adults. In this case report, we aimed to describe the temporary aesthetic restoration of the upper lateral incisor with a fiber-reinforced bridge by using the original tooth crown, which had avulsed after dental trauma.
 Methodology: Case 1: A 14-year-old girl with an avulsion in tooth #11 due to trauma visited our clinic. During the examination, it was seen that the wound had healed, and there was no luxation in teeth #21 and #12. Since the patient could not undergo prosthetic procedures, for reasons including implants, and did not want a removable prosthesis, a single crown supported by acrylic tooth fibers was constructed.
 Case 2: A 17-year-old male patient was referred to our clinic because of an avulsed left lateral incisor tooth, which was traumatized 15 days before visiting the clinic. His medical history revealed that his parents had found the tooth two hours after the trauma. However, the emergency clinic that he had previously visited did reimplant that tooth and repaired it with fiber-reinforced composite.
 Case 3: In the examination of a 12-year-old male patient who applied to our clinic due to trauma, it was observed that tooth #11 had an avulsion and tooth #12 had a crown fracture. Root canal treatment was performed. A crown was made for the patient by supporting the fiber inside the canals of tooth #11 and tooth #21. It was revised aesthetically with the support of the crown of the other tooth.
 Conclusion: Avulsion after anterior trauma affects patients’ appearance aesthetically; thus, patients want to be treated as soon as possible. Function, phonation, and aesthetics must be quickly provided for a loose anterior tooth. Fiber-reinforced adhesive bridge techniques may be considered as a temporary treatment for providing an aesthetically appealing appearance until the completion of permanent prosthetic treatment.
 
 How to cite this article: Şahin M, Toptancı İR. Temporary adhesive bridge restoration of the upper anterior teeth lost due to trauma: Three case reports. Int Dent Res 2021;11(Suppl.1):285-91. https://doi.org/10.5577/intdentres.2021.vol11.suppl1.42
 
 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Clinical application of fully digital self-glazed ultra-thin zirconia veneers

ABSTRACT Monolithic self-glazed zirconia is a new type of biomimetic zirconia that has been successfully used as crown and bridge restorations in the anterior and posterior regions. It exhibits excellent biomechanics and aesthetic properties through completely digital processing technology. This case presents a young patient’s aesthetic rehabilitation with self-glazed ultra-thin zirconia veneers by closing the scattered diastema in the aesthetic zone of the anterior teeth with a fully digital workflow. The restorations exhibited excellent aesthetic outcomes with a minimally invasive concept and superior mechanical properties over glass-based ceramic veneers. The application of full-contour monolithic ultra-thin self-glazed zirconia restorations in the anterior aesthetic zone constitutes a reliable, fully digital clinical workflow.

Finite element simulation of fixed dental prostheses made from PMMA -Part I: Experimental investigation under quasi-static loading and chewing velocities.

Material properties are of high clinical relevance, even though in vitro laboratory setups may differ from clinical conditions. Therefore, the aim of the present study was to investigate the fracture behavior of three-unit bridge restoration (Telio CAD) with different test velocities (1.0 mm/min International Organization for Standardization (ISO) standard speed/ 130 mm/s mean chewing velocity) and to provide crucial validation experiments for the upcoming Part 2 of our study, in which FEA on such temporary restorations will be conducted. Local strains were detected using digital image correlation (DIC). The material exhibited significantly different responses at different test velocities, and the forces at fracture were found to be much smaller at chewing velocity (130 mm/s) than in the quasi-static test. Overall, the results of the present study show that characteristics pertaining to material behavior can change significantly with increasing chewing velocity, and that fracture forces decrease with increasing test velocity.

Color and Translucency Stability of Three-Dimensional Printable Dental Materials for Crown and Bridge Restorations.

The purpose of this study was to examine and compare color and translucency stability of three-dimensional (3D) printable dental materials for crown and bridge restorations. Five different materials were investigated, and twelve disc-shaped specimens of two different thicknesses (1 and 2 mm) were prepared using a digital light processing 3D printer. Color measurements were made according to the CIELAB color scale (L*, a*, and b*) using a spectrophotometer 1 h, 1 day, 1 week, one month, and six months after post-curing of the materials, and the translucency parameter (TP) was calculated. The L*, a*, b*, and TP values were compared among the different materials and storage periods using repeated measures analysis of variance. Color and translucency changes of the specimens after the different storage periods were compared with 1 h measurements to determine whether they exceeded clinically perceivable thresholds. The L*, a*, b*, and TP values showed significant differences according to the storage periods, as well as among the materials. Until one month, some materials demonstrated distinct color differences, while others showed small color differences below a clinically perceivable threshold. The translucency differences were not clinically perceivable for any specimen. After six months, all specimens demonstrated large color changes, whereas the changes in translucency were relatively small. In conclusion, the color of 3D printable dental materials changed with time, and the differences varied with the materials used. On the contrary, the changes in translucency were small. Overall, the materials became darker, more yellowish, and more opaque after six months of water storage.

Optimal decision making in post-hazard bridge recovery strategies for transportation networks after seismic events

In this study, optimal post-hazard bridge recovery strategies were proposed for transportation networks under seismic conditions. To predict the performance of the transportation network, a robust performance measure, total system travel time (TSTT), was employed, and an artificial neural network (ANN)-based surrogate model was developed to enable an accelerated Monte Carlo analysis. In addition, a sensitivity analysis based on the benefit–cost ratio was proposed to support optimal decision making immediately after an earthquake. To demonstrate the proposed methodology, an actual transportation network in South Korea was adopted, and a network map was reconstructed based on geographic information system (GIS) data. A surrogate model for network performance evaluation was constructed using training data generated based on historical earthquake epicenters. In addition, the damage ratio and required recovery days according to the damage states of bridges were employed to perform network recovery analysis. For the numerical analysis, a limited budget was set for each scenario, and the recovery and damage curve were compared with existing priority strategy. The numerical results showed that the priority strategy of bridge restoration determined through the benefit–cost analysis generated a faster recovery curve and significantly reduced the damage, as compared to existing strategy. Therefore, it is concluded that the proposed methodology enables optimal decision making and also helps risk management that can minimize the economic damage.

РОЗРОБКА МЕТОДИКИ ОПТИМІЗАЦІЇ ВІДНОВЛЕННЯ МОСТІВ

Abstract. The biggest part of the bridges in Ukraine requires serious restoration works. However, in the literature sources there are no recommendations for choosing effective organizational and technological solutions for the reconstruction of bridges and overpasses. Therefore, the design of methods for optimizing bridge restoration is an urgent task. The working optimization hypothesis is formulated in the article. A general research technique is developed. The algorithm of multicriteria analysis is presented to determine the most effective structural and technological solutions for the restoration of the main structural elements of the studied structures. As a result of the analysis, the most significant indicators of restoration efficiency were determined. These were the cost of restoration of m2 of the bridge and the duration of restoration of the bridge. As factors affecting performance indicators ‒ the intensity of the use of working time and the combination of construction processes, the size of the roadway and the operational condition of the bridge were selected. The planning of the experiment is based on the well-known theory of experimental planning. A 25-point D-optimal plan was selected, which will provide adequate results with significantly fewer experiments than in a full-factor experiment. For calculations is used the program software COMPEX, which is developed at the Odessa State Academy of Civil Engineering and Architecture under the direction of Professor V. Voznesensky. Modelling allows to find the dependencies between the input (intensity use of working time, combination of construction processes, size of the carriageway of the bridge, operational condition of the bridge) and output (cost of restoration of m2 of the bridge, duration of restoration of the bridge) parameters. Dependences data is described with usage of second-degree polynomials obtained by processing the results of a numerical experiment. These dependencies will allow to determine the cost and duration of the restoration of the bridge for varying degrees of damage and the size of the bridge. In addition, to change indicators by choosing the optimal production modes (combination of processes, the intensity of the use of working time). The analysis of the results of a numerical experiment will allow us to assess the influence of organizational and technological factors on the performance indicators of restoration technologies and find areas of factor space that provide optimization of organizational and technological solutions for the restoration of damaged bridges. At the last stage of the numerical experiment, limits are introduced into graphic models (by cost, duration, combination, etc.) and the optimal organizational and technological solutions are determined taking into account the introduced restrictions.

Evaluation of Metal Artifacts in Cone Beam Computed Tomography by Metal Supported Porcelain Crowns Using Different FOV and Localizations: An In Vitro Study

Introduction: Metal-supported porcelain crowns (MSPC) and bridge restorations may be present in the mouths of patients undergoing CBCT imaging. Artifacts that are caused by these MSPCs may adversely affect image quality. The aim of this study is to determine the effect of different FOV (field of view) and localization in FOV on metal artifacts caused by MSPC. Methods: Twenty MSPCs scanned with CBCT at central and peripheral localization at 18x16 and 8x8 cm FOV. The 2.5 mm periphery area of the MSPC cross-sectional image was evaluated. The metal artefact-area within this area was measured. Then, the artifact-area to total-area ratio was converted to form of a percentage. In addition to evaluation of crown periphery area, the lengths of the metal streaks artifacts were measured. The maximum linear dimension of the metal artifact was recorded from the crown margin for each MSPC in cross-sectional image in the bucco-lingual direction. All data collected were evaluated by Kruskal-Wallis analysis and Mann Whitney U test (P˂0,05). Results: No statistically significant differences were found in the artifacts-area measured (P=0.121). However, there was a statistically significant difference in linear dimension measurements of artifacts (P=0.000). In 18x16 cm FOV localization peripheral linear dimension measurements were higher than other FOV and localizations. Conclusion: Linear size artifacts of MSPC were found to be higher in peripheral positioning in wide FOV. However, according to this study, areas evaluated for metal artifacts caused by MSPCs are not affected by FOV and localization.

Utilization of 3D measurement in bridge restoration design

Utilization of 3D measurement in bridge restoration design

Preliminary study on the elimination of artifacts of five kinds of dental prosthetic materials by energy spectrum CT multi-material artifact reduction technology

Objective: To investigate the effect of the multi-material artifact reduction (MMAR) algorithm of spectral CT in reducing the beam hardening artifacts in dental restoration material. Methods: Three-unit fixed bridge restorations were fabricated on the first to third molars in pig jaw. Gold alloy, zirconia, cobalt chromium alloy, nickel chromium alloy and pure titanium were used as materials for these fixed bridges. After restoration delivery, the pig jaw was scaned using energy spectrum CT machines. Images in regular 120 kVp scan mode were used as conventional group, and reconstructed single-energy horizontal images of 80, 90, 100, 110, 120, 130 and 140 keV in energy spectrum scanning mode were used as energy spectrum group, and reconstructed images applied MMAR technology in energy spectrum scanning mode were used as energy spectrum MMAR group. Each group was scanned 10 times to measure CT value and noise of muscles around dental prosthetic materials and adjacent non-artifact layers. Artifact index was calculated. Two radiologists scored the image quality of each group subjectively. Kruskal Wallis rank sum test was used to compare the difference of image noise, artifact index and subjective score among the control group and the best keV condition in the energy spectrum group and the energy spectrum MMAR group. Results: The image noise of energy spectrum group and energy spectrum MMAR group decreased gradually with the increase of single energy level. The artifact index of pure titanium restorations in conventional group, energy spectrum group and energy spectrum MMAR group were 71.0±8.0, 21.4±2.7 and 14.7±2.7 respectively, and these values were significantly lower than those of other materials in the same group (P<0.05). The subjective image quality scores in energy spectrum MMAR group were as follows: 3.0±0.2 for gold alloy, 4.3±0.5 for zirconia, 3.0±0.4 for cobalt chromium alloy, 3.1±0.4 for cobalt chromium alloy, and 4.6±0.5 for pure titanium. These scores were significantly smaller than those in the conventional group (P<0.05). There was no significant difference in noise between energy spectrum group and energy spectrum MMAR group (P>0.05), and the noise values in energy spectrum group and energy spectrum MMAR group were significantly lower than that in the conventional group (P<0.05). Conclusions: Artifacts of pure titanium is minimal. Energy spectrum CT combined with MMAR technology can effectively reduce the artifacts of gold, zirconia, cobalt-chromium alloy, nickel-titanium alloy and pure titanium. This technique can be used as an effective method to remove artifacts of dental prosthesis.

Comparing the marginal leakage and retention of implant-supported restorations cemented by four different dental cements.

Despite the wide use of implants in dentistry, there is insufficient information about the ideal cement for retention. To determine the cement bond strength and marginal leakage of crown and partial denture cemented to implant abutments by four different types of cement. Eighty-four direct abutments were divided into eight groups (n = 7). Fifty-six crown and bridge restorations were cemented using zinc phosphate (ZM), temporary cement (TM), resin-modified glass-ionomer cement (GM), and self-adhesive resin cement (RM). After cementation, thermal cycling and incubation in basic fuchsin dye was applied. The maximum load to failure, marginal leakage, and fracture modes were evaluated. The mean of retention strength for the bridges (874 N) was higher than the crown samples (705 N) (P = .005). The mean of retention strength for each cement group was ZM = 1298, RM = 1027, GM = 646, and TM = 187 N (P ≤ .0001). Marginal leakage was recorded in majority of the samples; the highest incidence was detected for ZM samples. The cement fracture was mostly adhesive in nature. Self-adhesive resin and resin-modified glass ionomer cement had better mechanical properties to retain implant supported restorations.

The bridge restoration made by self-glazed zirconia with a digital processes

ABSTRACT Self-glazed zirconia has been recently developed and widely used in crowns owing to its high strength, low wear on opposite teeth, and aesthetic appearance. This clinical study was to explore the application prospect of the bridge restoration made by self-glazed zirconia with a digital process. The results demonstrated that self-glazed zirconia could meet both the aesthetics and functional requirements of anterior and molar teeth in a time-saving and efficient manner.

Decision tree based bridge restoration models for extreme event performance assessment of regional road networks

Bridge restoration models are essential for assessing the functionality of bridges after extreme events, emergency response planning, and evaluating resilience and indirect losses. Most of the existing restoration models lack explicit evaluation of anticipated bridge functionality in terms of traffic restrictions on bridges, which is necessary for realistic road network modeling. Therefore, this paper proposes a decision tree based approach to determine potential traffic restrictions and their durations using empirical and expert opinion survey data on restrictions imposed on bridges after extreme events. The proposed methodology is applied in this paper to obtain seismic restoration models for bridges. Herein, three separate decision trees are developed to determine various traffic restrictions, anticipated for different levels of damage to bridge components, including bridge closure, lane closure, and speed/load restriction. Corresponding to each of the three traffic restriction decision trees, another decision tree is developed which determines the duration of the traffic restriction. The probabilistic seismic performance of a regional highway network in Memphis, Tennessee, is studied using the proposed decision trees. Additionally, HAZUS bridge restoration functions are also applied and the differences in the time evolving bridge level functionality estimates and their impacts on network performance are highlighted.

Apps can help bridge restoration science and restoration practice

Scientists need to find innovative ways to communicate their findings with restoration practitioners in an era of global change. Apps are a promising bridge between restoration science and practice because they apply broad scientific concepts to specific situations. For example, habitat connectivity promotes ecological function, but practitioners lack ways to incorporate connectivity into decision‐making. We created an app where users calculate how habitat restoration or loss affects connectivity. By providing our app as an example and discussing the benefits and challenges in creating apps for practitioners, we encourage other restoration ecologists to similarly create apps that bridge science with practice.

Effect of Pretreatment Process on the Metal-Porcelain Bonding Mechanism and Properties of CoCr Alloy Dental Crown and Bridge Manufactured by SLM

This paper aims to investigate the influential mechanism of grinding and sand blasting pretreatment of CoCr alloy manufactured by SLM (selective laser melting) process on the metal-porcelain bonding of the restorations, and then provides references for SLM manufacturing CoCr alloy dental crown and bridge restorations with good mechanical properties. Three groups of CoCr alloy substrates were manufactured by SLM process with optimal parameters. The samples were subjected to different grinding and sand blasting pretreatment, and the porcelain sintering was carried out with the same parameters. The samples of different groups were analyzed by three-point bending test, roughness test, SEM and EDS. Results show that the metal-porcelain bonding strength of samples in group a with grinding and sand blasting is 36.79±0.49 MPa, which is obviously higher than those of group b with no grinding but sand blasting and group c with only grinding. The average metal-porcelain bonding strength of the three group samples is higher than the ISO9693: 1999 standard minimum 25 MPa. The metal-porcelain bonding effect of group a and c is better than that of group b, and the element diffusion on metal-porcelain interface is observed in all three groups. The results also show that there are significant differences among the three groups on residues and element distribution of metal-porcelain peeling surface. The final conclusion is that the surface roughness obtained by the pretreatment of sand blasting and grinding can ensure the strong chemical combination of metal and porcelain and considerable mechanical properties combination, which can improve the performance of metal-porcelain restorations manufactured by SLM.

3D printed versus conventionally cured provisional crown and bridge dental materials

ObjectivesTo optimize the 3D printing of a dental material for provisional crown and bridge restorations using a low-cost stereolithography 3D printer; and compare its mechanical properties against conventionally cured provisional dental materials. MethodsSamples were 3D printed (25×2×2mm) using a commercial printable resin (NextDent C&B Vertex Dental) in a FormLabs1+ stereolithography 3D printer. The printing accuracy of printed bars was determined by comparing the width, length and thickness of samples for different printer settings (printing orientation and resin color) versus the set dimensions of CAD designs. The degree of conversion of the resin was measured with FTIR, and both the elastic modulus and peak stress of 3D printed bars was determined using a 3-point being test for different printing layer thicknesses. The results were compared to those for two conventionally cured provisional materials (Integrity®, Dentsply; and Jet®, Lang Dental Inc.). ResultsSamples printed at 90° orientation and in a white resin color setting was chosen as the most optimal combination of printing parameters, due to the comparatively higher printing accuracy (up to 22% error), reproducibility and material usage. There was no direct correlation between printing layer thickness and elastic modulus or peak stress. 3D printed samples had comparable modulus to Jet®, but significantly lower than Integrity®. Peak stress for 3D printed samples was comparable to Integrity®, and significantly higher than Jet®. The degree of conversion of 3D printed samples also appeared higher than that of Integrity® or Jet®. SignificanceOur results suggest that a 3D printable provisional restorative material allows for sufficient mechanical properties for intraoral use, despite the limited 3D printing accuracy of the printing system of choice.

The Zlatné bridge - condition survey, temporary remedial works required due to dangerous condition and bridge restoration project

Bridges are and have been designed on lifetime basis, as given in standards applicable at the time of design. The design lifetime for newly designed bridges as given in Eurocodes is 100 years and according to the old Slovak standard it was 80 years only. The first generation of prestressed concrete bridges have been used in Slovakia (formerly part of Czechoslovakia) starting from 1950s, and thus, according to old standards, they approach the end of their design lifetime. Nowadays, due to insufficient maintenance, many of them are in unsatisfactory condition. This paper focuses on the condition survey of the bridge on the road No. I/18 - in the part “Zlatné” of village Strečno and on the design of immediate remedial works which were necessary due to its potentially dangerous condition. Moreover, the design of restoration is also described.

Lung Function Disturbance Based on Student Characteristic in Surabaya Dental Laboratory

The dental technician program of Airlangga University teaches and trains aspiring dental technicians. During three years of study, students manufacture dental prostheses such as cobalt chromium coping and acrylic dentures and perform other procedures, such as crown and bridge restoration. However, the use of dental prostheses material might cause respiratory diseases, skin problems, and neurotoxicity. Few respiratory diseases have been reported related to the occupation of dental technician, and epidemiology studies have shown high prevalence of pneumoconiosis linked with exposure duration. Lung function disturbance severity in dental laboratories is affected by some factors, such as the characteristics of workers in such a setting. This study aims to investigate the lung function representation of students of the dental technician program of Airlangga University in relation to student characteristics in the dental laboratory. This study is an observational decriptive study. Data are obtained by using a questionnaire and a literature review, and lung physiological examination is conducted using spirometry. Examination data results are presented in the form of a ratio scale and analyzed by using descriptive statistics. Conclusion: No significant difference in lung function was observed between smokers and non-smokers and between mask-wearers and non-mask-wearers.

Del Cusco renace la integración andina: La restauración del Puente de la Almudena

Este artículo presenta una crítica arquitectónica al resultado de la obra de Recuperación y Puesta en Valor del Puente de La Almudena en la ciudad de Cusco, culminada el año 2006. Dicho proyecto parte de la idea general de recuperar físicamente la trayectoria histórica de los caminos pertenecientes al sistema vial inca Qhapaq Ñan, que alguna vez fue la primordial herramienta de integración del entonces Tawantinsuyu. La ejecución de este proyecto significó la renovación de un espacio en franco proceso de deterioro e insalubridad, así como la reapertura del acceso por medio del cual el centro histórico de la ciudad de Cusco se comunica con los territorios del Kuntisuyu o territorios hacia la costa, intervención durante la cual tuvieron lugar nuevos retos y experiencias metodológicas, además de que se gestó una nueva forma de concebir el valor del patrimonio civil público de carácter vial, hasta entonces poco apreciado.