Regular Maintenance Research Articles

Experimental investigation on the restart characterization of shale oil-water flow in a horizontal pipe

ABSTRACT With the dwindling conventional oil resources and increasing energy demand, shale oil development has gradually become a hot spot in the global energy industry. Moreover, the shale oil pipeline also inevitably experiences abnormal operations, such as shutdown and restart during regular maintenance or emergency accident repairs. However, previous restart research primarily focused on conventional crude oil pipelines, and there is still a research gap on shale oil-water flow. Therefore, this work conducted the shale oil-water restart flow experiment in the multi-test section pipe flow loop, considering the temperature (20–50℃), starting frequency (15–25 hz), and water content (0–80%). Based on the restart pressure and volume flow rate change, the response characteristics of start pressure are studied. Moreover, the changing rules of restart pressure are explored with starting frequency, temperature, and water content. Eventually, the variation trend of the restart pressure absolute errors between the calculated value and the experimental data with the starting frequency is analyzed. The results show that the restart pressure reaches the maximum around 10 s after the pump starts, and the maximum restart pressure is approximately 1.5 times the stabilized restart pressure. Moreover, the restart pressure increases linearly with the starting frequency and decays exponentially with the temperature and water content (after the inversion point). With the starting frequency reduced from 45 hz to 15 hz, the restart pressure reduces from 24.6 kPa to 10.0 kPa at 20°C. Furthermore, the empirical formulas can predict the starting pressure at low frequencies. This research lays a theoretical foundation for the safe restart of shale oil-water flow.

Temporal and Spatial Dynamics of Carbon, Nitrogen, and Phosphorus in a Subtropical Urban River (Tamanduateí River, São Paulo, Brazil)

Water quality in urban streams often reflects the broader environmental challenges posed by dense population centers, where pollution from untreated sewage and runoff can significantly degrade ecosystems. This study examines the spatial and temporal variations of carbon, nitrogen, and phosphorus concentrations in the Tamanduateí River, which runs through the Metropolitan Region of São Paulo, Brazil. Data were sourced from the annual reports of the Environmental Company of the State of São Paulo (CETESB) covering the period from 2011 to 2022. Between 2011 and 2017, carbon and phosphorus concentrations declined, likely due to sanitation improvements. However, since 2017, these concentrations have been rising again, indicating renewed pollution inputs, primarily from untreated sewage. Nitrogen levels remained consistently high, with elevated concentrations observed upstream, linked especially to domestic effluent discharges. The recent increase in phosphorus levels is also of concern. The absence of spatial variation in phosphorus suggests diffuse pollution from urban areas, while nitrogen decreases downstream, possibly due to biological assimilation. The study underscores the pressing need for enhanced sewage management. Drawing from the successful revitalization of the Cheonggyecheon stream in Seoul, implementing nature-based solutions and regular maintenance could effectively reduce nutrient pollution and improve water quality, facilitating the restoration of the Tamanduateí River.

ASSESSMENT OF THE PROBABILITY OF OCCURRENCE OF EMERGENCY SITUATIONS DURING OPERATION OF THE PYROLYSIS PLANT

The article discusses the issues of reliability and safety of operation of a pyrolysis plant for the disposal of used tires, which, in the context of an increasing volume of waste and the need for their effective disposal, is an urgent topic. The problem statement is related to the identification of factors affecting the reliability of the installation and the development of methods to prevent emergencies.The purpose of the study is to analyz the reliability of the pyrolysis plant and develop recommendations for its improvement. To achieve this goal, the causes and probabilities of failures of system elements are investigated, an analysis using the failure tree method is carried out. This method made it possible to identify the weaknesses of the system and assess the probability of their failures, which is critical to prevent emergencies.An assessment of the reliability of the installation showed that the greatest contribution to the probability of accidents is made by a malfunction of the gas separation system. This element is the most vulnerable due to its complexity and importance in the pyrolysis process, as it is responsible for the safe and effective separation of pyrolysis products. Any malfunction of the gas separation system can lead to the accumulation of dangerous gases, increasing the risk of explosions and fires. The identified emergencies require special attention to the development of effective measures to minimize them.The article proposes methods to improve the reliability of the system, the main of which is the redundancy of the most vulnerable elements. This will significantly reduce the probability of failures and increase the overall reliability of the installation. In addition, it is recommended to carry out regular inspections and maintenance of all elements of the system. These measures will help to identify and eliminate potential malfunctions in a timely manner, which will significantly reduce the likelihood of failures that can lead to emergencies.Thus, ensuring the reliability and safety of a pyrolysis plant for the disposal of used tires requires an integrated approach. Enabling redundancy of vulnerable elements and regular maintenance will minimize the likelihood of failures that can lead to emergencies and guarantee stable and safe operation of the system. These measures will not only increase the efficiency of disposal, but also ensure reliable and long-term operation of the installation.This article focuses on the importance of identifying vulnerable elements of the system and conducting regular maintenance to improve the reliability and safety of operation of the pyrolysis plant.

Framework of Scan to Building Information Modeling for Geometric Defect Localization in Railway Track Maintenance

Railway transportation plays a vital role in modern society, enabling the safe and efficient movement of people and goods over long distances. To ensure the longevity and safety of a railway infrastructure, the regular maintenance of tracks is crucial. Traditional track inspections, conducted manually to monitor geometric parameters and to identify defects, are time-consuming, labor-intensive, and prone to human error. Current Scan-to-BIM frameworks for railway maintenance also lack standardized methods for extracting geometric parameters that can be easily integrated into Building Information Modeling (BIM). Additionally, the Industry Foundation Classes (IFC) standard, used for BIM data exchange, does not support storing parameter values at specific chainage points along the track, limiting defect localization. A framework is proposed to address these challenges by standardizing the extraction of geometric parameters from point cloud data and ensuring seamless integration with BIM. The framework calculates parameters at station chainage points and generates additional chainage points along the track, associating the data with the corresponding chainage. A case study demonstrates the framework’s ability to enhance defect localization, using the EN 13848-5 European Standard to identify defects at specific chainages. Ultimately, this approach contributes to the more effective lifecycle management of railway tracks.

Web Presence and Search Engine Optimization on Hotel Patronage in Akwa Ibom State, Nigeria

This study examined the effect of web presence and search engine optimization on hotel patronage in Akwa Ibom State, Nigeria. Web presence, search engine optimization and hotel patronage formed the specific objectives of the study. 1122 employees that had access to information of customers who made hotel reservations from forty-one hotels registered with Akwa Ibom State Hotels Management and Tourism Board formed the population. The study employed a census sampling technique. Primary data were gathered through a structured questionnaire. Simple percentages and charts were employed for the demographic analyses, leveraging the Statistical Package for Social Sciences (SPSS) version 25 to facilitate the data analyses. The univariate analyses were done using means and standard deviations to provide insights into the central tendencies and variability of the data. To test the study hypotheses, the researchers employed Partial Least Square-Structural Equation Modelling (PLS-SEM), facilitated by the SmartPLS version 3.2.9 software. Findings of the study showed that web presence (β = 0.713, t- value = 10.156, p-value = 0.011 < 0.05) had positive significant effect on hotel patronage in Akwa Ibom State and search engine optimization (β = 0.613, t-value = 8.046, p-value = 0.003 < 0.05, a statistically significant and positive effect on hotel patronage. Based on the empirical findings, we recommended that management of hotels in Akwa Ibom State should ensure that they have a well- designed, user-friendly, and informative website that showcase their offerings and provides a seamless booking experience for customers. Regular updates and maintenance of the website should be a priority to keep it relevant and engaging. The hotel owners and operators should prioritize the implementation of effective search engine optimization strategies to improve their visibility on search engine results pages. This should include optimizing their website content, improving website structure and navigation, and leveraging relevant keywords to attract potential customers.

Increasing the Wear Resistance of the Impellers of Electrical Centrifugal Submersible Pumps Through Repair

Objective: This research investigates the challenges of maintaining electrical submersible pumps (ESP) and develop effective repair techniques to enhance their reliability and efficiency. Theoretical Framework: The research draws upon theories and models related to pump maintenance, materials science, and corrosion prevention. Methodology: A case study approach was adopted, focusing on a Weir VTP submersible pump in continuous operation for 15 years. The pump's condition was assessed, and the root causes of erosion and corrosion were identified. Laser cladding with a TiC coating was applied to the damaged areas. Results and Discussion: The results demonstrated a significant improvement in the pump's wear resistance and overall efficiency following the laser cladding treatment. The TiC coating effectively mitigated the effects of erosion and corrosion, extending the pump's lifespan and reducing maintenance costs. Research Implications: The findings of this research contribute to the development of more effective maintenance strategies for submersible centrifugal pumps. The use of laser cladding with TiC coatings can be applied to other types of pumps and machinery operating in harsh environments. This research also highlights the importance of regular inspections and preventive maintenance. Originality/Value: This study provides a practical solution to the problem of erosion and corrosion in submersible centrifugal pumps. The application of laser cladding with a TiC coating is a relatively novel approach, offering a more effective repair method compared to traditional techniques. The results can be applied to improve the reliability and efficiency of pumps in various industries.

Optimizing Energy Renovation in Building Portfolios: Approach and Decision-Making Platform

The building sector contributes significantly to energy consumption and greenhouse gas emissions, with many buildings being energy inefficient. In response, the European Green Deal promotes improving energy efficiency to support decarbonization goals. However, managing energy consumption and integrating data from multiple sources presents challenges, especially for large building portfolios. This study introduces a novel methodology designed to optimize energy renovation strategies, balancing technical, financial, and maintenance considerations. The methodology is implemented in CERPlan 1.0, a web-based decision-support platform that combines data on building energy performance, renovation costs, and maintenance needs. Through simulations, CERPlan 1.0 helps decision-makers prioritize retrofit interventions based on economic criteria while leveraging synergies between energy improvements and regular maintenance. Application of this methodology to real estate portfolios reveals opportunities to enhance cost-effectiveness and energy savings. The results show that integrating maintenance into renovation planning reduces payback times and allows for more comprehensive renovation strategies. The conclusions highlight CERPlan 1.0’s potential to improve decision-making, making building renovations more efficient and sustainable.

Challenges and Future Directions in Evaporative Cooling: Balancing Sustainable Cooling with Microbial Safety

Evaporative cooling systems are gaining popularity due to their environmental benefits, particularly in reducing energy consumption and utilizing air (R-729) and water (R-718) as refrigerants. However, these systems are susceptible to microbial contamination, posing significant health risks, especially in environments where air is in direct contact with water. The article provides an in-depth analysis of the microbial risks associated with evaporative cooling systems, focusing on bacteria such as Legionella pneumophila, fungi, and other pathogens that can proliferate in the moist environments these systems create. While Legionella contamination is well-documented and frequently addressed, this study highlights the need for more comprehensive evaluation of other microbial risks. The research compares the microbial safety of evaporative cooling systems with that of traditional vapor compression cooling and examines the role of cooling pad materials and water quality in promoting microbial growth. It also underscores the limitations of current maintenance practices, which often overlook non-Legionella risks. To improve microbial safety, the paper proposes several mitigation strategies, including UV water treatment and heat exchanger surface modifications, to reduce microbial contamination. Additionally, the study calls for more detailed and consistent maintenance guidelines that cover a broader spectrum of microbial threats beyond Legionella, as well as regular monitoring of indoor air quality to ensure the safe operation of these systems in human-occupied spaces.Ultimately, the findings emphasize that, with improved microbial safety protocols and regular maintenance, evaporative cooling systems can become a sustainable and safe alternative to conventional cooling technologies in various environments.

Investigating the Catastrophic Roof Failure of a Fatty Acid Storage Tank: Causes, Mechanisms, and Safety Implications

This paper investigates the catastrophic failure of the roof weld on a carbon steel storage tank at a Fatty Acids plant, which was attributed to pressure overload. The incident resulted in the tank's roof, weighing over 5 tons and spanning 8 meters in diameter, being propelled 25 meters from the tank. Despite installing several safety devices, including pressure regulating valves, pressure indicator controls, and pressure vacuum relief valves, inadequate maintenance led to their malfunction. This study examines the mechanisms and causes behind the failure, highlighting the crucial role of regular maintenance in ensuring the functionality of safety instruments. While neither toxic nor flammable, the plant's compressed air system poses a significant hazard due to the energy stored at slight overpressure, necessitating vigilant management by the safety department. The findings underscore the importance of robust maintenance strategies and procedural adherence to prevent similar incidents, enhancing industrial storage systems' overall safety and reliability.

Investigating Fuel Reduction Methods Through Propeller Optimization on Coastal Ro-Ro Liner Vessels

In light of efforts to reduce GHG emissions, liner ship operators in coastal navigation are undertaking numerous activities to contribute to the reduction of fossil fuel consumption during the transitional period toward environmentally friendly propulsion systems without compromising their regular operations. Regular ship overhauls, which include removing fouling from the underwater part of the hull and optimizing propellers, also contribute to this goal and are the focus of this research. The ship propeller, as a key component of the propulsion system, plays a significant role in ensuring reliable, safe, and economical navigation. Proper selection and regular maintenance of the propeller are essential for achieving optimal performance. This paper presents the optimization of a fixed-pitch propeller according to the ISO 484/2 standard to Class I using Metrascan 3D technology. This technology enables a detailed analysis of the propeller geometry, identification of irregularities, correction, and adjustment to achieve better hydrodynamic characteristics. The pitch corrections of the propeller resulted in improved overall vessel performance and fuel consumption, as demonstrated by comparing the consumption before and after the optimization.

New Approaches for Regeneration of an Outstanding Baroque Living Heritage, the Széchenyi Linden Allée in Hungary

Allées used to be the essential artistic tools and indispensable parts of the strictly architectural, formal Baroque gardens. Beyond the practical purposes of edging paths and garden ways for walking, hunting, or horse and carriage riding, allées played a vital role in marking visual and landscape connections and thus the spatial projection of the noble estate, its wealth, and social rank. In Historical Hungary, Baroque architecture and garden art appeared in German-Austrian and French examples in the 18th century. The Széchenyi Linden Allée is an outstanding linear garden space of Baroque Garden art at Nagycenk, West Hungary. The generous composition, created by the prominent Count Széchenyi family in the mid-18th century, has remained a magnificent entity in the landscape ever since. Despite barely two hundred years of detected or unknown environmental or habitat changes, as early as 1942, the allée received a nature conservation nomination. More than a half-century later, in 2002, the allée became a historical and landscape aesthetical heritage within the Fertő-Hanság Cultural Landscape World Heritage site. Unfortunately, the once magnificent tree lines have severely eroded in recent decades due to mature trees’ subsequent death, inadequate replacement, lack of regular maintenance and tree care, and effects of climate change. In recent years (2011, 2018), landscape and horticultural analyses and visual and instrumental tree assessments were performed to help the conservation and rebirth of the allée, maintain the mature trees, and restore the landscape within a long-term renewal plan. Along with the 2018 survey and plan, the short-term maintenance works were completed in 2019–2020. This study, based on site surveys in 2022 and 2024, aims to identify the results of the primary management, analyses the vitality of mature trees after crown reductions, and then proposes a resilient and sustainable regeneration method with the habitat, cultural, natural, and genetic heritage, and the feasible maintenance contexts in focus. As proposed in the 2018 plan, the reproduction of mature trees started in 2020 and resulted in well-developing grafts for a later allée restoration. Due to the challenges of climate change, the regeneration project requires a special, long-term restoration management plan with a special focus on the still vital and possible remaining mature trees, the well-growing individuals from previous replanting, and the nursery school seedlings conserving the genetic heritage of the Széchenyi lime trees with long-viability capacity.

Damage analysis and restoring of structural integrity of Pelton runner after repair welding: case study

This paper presents the repair welding technology of a Pelton runner blade, including an analysis of damage caused by cavitation. Extreme exploitation conditions resulted in crack initiation followed by its propagation, with a length 200 mm, detected during regular annual maintenance, compromising Peltron turbine’s structural integrity. The base material of the Pelton turbine was steel X3CrNiMo13-4, and as well as the blade geometry itself, required special attention during the process of defining repair welding technology. An austenitic electrode was used for this purpose along with a welding technology defined in a way to counter the initiation of new cracks at the same location. Following the NDT, the Pelton runner was put back into exploitation, along with recommendations for its further monitoring.

Survey on Patient Perception of At-Home Bacterial Biofilm Control in Relation to Peri-Implant Soft Tissue Health.

Bacterial biofilm control around dental implants is critical for the health of the peri-implant soft tissue and longevity of dental implants. The patient's role in regular biofilm removal around dental implants is just as important as that of the dental hygienist. The purpose of this study is to identify the relationship between at-home dental implant care and patients' perceptions of peri-implant soft tissue health. A 15-item paper survey was distributed to adult patients undergoing professional dental hygiene maintenance at a specialty dental practice within a 3-month period and had at least one dental implant. Survey items included participant demographics, patient-reported adjunctive aids for dental implants and patient perceptions of dental implant oral hygiene practices and peri-implant soft tissue health. There was a statistical difference between time spent cleaning dental implants and peri-implant soft tissue health. An association was found between patients who reported spending more time cleaning their dental implants and less bleeding (p = 0.046/54%), gingival inflammation (p = 0.026/58%) and gingival tissue redness (p = 0.036/53%). Additionally, patients who more frequently underwent professional dental hygiene maintenance perceived less gingival inflammation (p = 0.001/66%). To promote peri-implant soft tissue health and reduce oral biological complications, best practice guidelines should be implemented, including optimal at-home dental implant care and regular professional dental hygiene maintenance.

How Artificial Intelligence (AI) Is Powering New Tourism Marketing and the Future Agenda for Smart Tourist Destinations

Artificial intelligence (AI) is a disruptive technology that is being used by smart tourist destinations (STDs) to develop new business models and marketing services to increase tourists’ experiences and sales, revenue, productivity, and efficiency and STDs. However, the adoption of AI applications and platforms requires a high economic budget for STDs that want to integrate this digital tool into their future agenda and tourism development plans, especially when they set them up for marketing plans and operational processes. This iterative technology needs regular maintenance as well, leading to recurring costs and specialised crews in advanced technologies and marketing activities. This study aims to show the impact of AI advancements on STDs’ tourism marketing to enhance the quality of services and illustrate their future agenda to improve tourists’ experiences. A comprehensive literature review on AI technology and STDs has been conducted to illustrate new tourism marketing in their future agenda. Moreover, this study presents real examples of AI technology in a tourism context to better understand the potential of this digital tool. The findings of the current study support the idea that AI is a multipurpose tool that helps manage, monitor, and analyse sales information; revenue management; minimise prediction errors; streamline operations; and develop better marketing strategies, optimising economic resources, reducing marketing costs, and responding dynamically to changing needs for tourists and residents in STDs. Furthermore, the investment in AI technologies by STDs helps enhance the quality of products and services, and attract new investments, which benefit the regional economies and population’s quality of life. This study is the first to address the use of AI to improve tourist marketing in STDs, which is its primary uniqueness. Also, this study identifies new opportunities and initiatives through AI that can be developed to help tourism marketing in STDs.

Effect of Management Information System on Growth of Agro-Firms in Anambra State

The study examined the effect of management information systems on the growth of agro-firms in Anambra State. The objectives were to: determine the effect of decision-making information systems on the Return on Investment (ROI) of agro-businesses in Anambra State, Nigeria, and ascertain the extent to which database management systems affect the ROI of agro-businesses in Anambra State, Nigeria. The study adopted a survey research design, with data generated from both primary and secondary sources. The data collection method was a questionnaire, which was randomly administered to staff of selected agro-firms. The population of the study was 6,727, while the sample size was 1,293, out of which 929 questionnaires were retrieved. The hypotheses were tested using the multiple regression analysis method at a 0.05% level of significance. The findings revealed that decision-making information systems had a significant effect on the ROI of agro-businesses in Anambra State, with a t-statistic of 7.743 and a probability value of 0.000. Additionally, database information systems had a significant effect on the ROI of agro-businesses in Anambra State, with a t-statistic of 2.476 and a probability value of 0.013. The study concluded that management information systems have a significant positive effect on agro-firms in Anambra State. It recommended that agricultural firms should invest in advanced decision support tools to aid data-driven decisions that maximize ROI. Furthermore, agro-business managers should focus on optimizing their database information systems to improve data organization and accessibility. Regular maintenance and updates of the database systems are crucial for ensuring accurate and timely information, which can positively impact ROI.

Performance Effects of Different Shutdown Methods on Three Electrode Materials for Electromethanogenesis

AbstractIndustrial applications of microbial electrochemical systems will require regular maintenance shutdowns, involving inspections and component replacements to extend the lifespan of the system. Here, we examined the impact of such shutdowns on the performance of three electrode materials (i. e., platinized titanium, graphite, and nickel) as cathodes in a microbial electrochemical system that would be used for electromethanogenesis in power‐to‐gas applications. We focused on methane (CH4) production from hydrogen (H2) and carbon dioxide (CO2) using Methanothermobacter thermautotrophicus. We showed that the platinized titanium cathode resulted in high volumetric CH4 production rates and Coulombic efficiencies. Using a graphite cathode would be more cost‐effective than using the platinized titanium cathode in microbial electrochemical systems, but showed an inferior performance. The microbial electrochemical system with the nickel cathode showed improvements compared to the graphite cathode. Additionally, this system with a nickel cathode demonstrated the fastest recovery during a shutdown experiment compared to the other two cathodes. Fluctuations in pH and nickel concentrations in the catholyte during power interruptions affected CH4 production recovery in the system with the nickel cathode. This research enhances understanding of the integration of biological and electrochemical processes in microbial electrochemical systems, providing insights into electrode selection and operating strategies for effective and sustainable CH4 production.

Impact of restorative dental procedures on periodontal health: A comprehensive review

Restorative dental procedures play a crucial role in restoring function and aesthetics to damaged teeth, yet their impact on the periodontium—comprising the gingiva, periodontal ligament, cementum, and alveolar bone—cannot be overlooked. This review aims to explore the relationship between restorative dental treatments and periodontal health, emphasizing the potential risks and considerations involved. Factors such as improper crown placement, overhanging restorations, subgingival margin placement, and inadequate proximal contact can lead to periodontal inflammation, tissue damage, and bone loss. The integration of restorative and periodontal care is essential to ensure long-term success and to prevent adverse outcomes such as gingival recession, periodontal pocket formation, and compromised periodontal support. This review highlights the importance of precise clinical techniques, appropriate material selection, and careful case planning to minimize detrimental effects on the periodontium. Additionally, the role of regular periodontal maintenance and patient education in preserving periodontal health following restorative procedures is underscored. Understanding the delicate interplay between restorative interventions and periodontal health is vital for clinicians to achieve optimal treatment outcomes and maintain the integrity of both the teeth and supporting structures.

Movable VOC Removal System

In this study, we develop a mobile VOCs gas removal system that can remove volatile organic compound (VOCs) emissions from petrochemical facilities, metal painting factories, and surroundings of life, and can efficiently cope with situations occurring in the field. Regular repairs to petrochemical plants and semiconductor plants are carried out for a month every four to five years, and work such as replacing old pipes and repairing aging facilities, cleaning, removing residual gas, checking pipe connections and valves, and improving processes are carried out while the plant is shut down. During regular maintenance, a large-scale accident occurs in which gas remaining in the facility leaks or explodes due to rising pressure, and even after internal gas discharge and purge work is performed, it is scattered by the characteristics of raw materials remaining inside the pipe and reactor and discharged into the atmosphere. Therefore, there is always a possibility of causing safety accidents, and such accidents have a great socioeconomic impact as they are directly connected to the safety of workers as well as the safety of local residents. This system is designed to be adaptable according to the size of a number of outlets, and it is proposed to minimize the impact of VOCs harmful gases on the surroundings by developing it as a mobile type. The efficiency of collecting scattered VOCs gas is more than 90%, and the integrated operating system is demonstrated for 50 CMM class movable VOCs adsorption device, 5 CMM class treatment gas recirculation type non-flame waste heat recovery adsorbent regeneration treatment device, and two or more business sites.

PELATIHAN PERAWATAN KENDARAAN SEPEDA MOTOR BAGI MASYARAKAT DESA SIRNAJAYA

A motorcycle is an engine-driven two-wheeled vehicle composed of different parts that are subjected to different loads during operation, such as heat load, chemical load, impact, bump, twist, push-pull-bend force, friction, pressure. The precision of vehicle components will vary from their original and standard conditions over time such as becoming looser, weaker, or finer. To ensure it is always in top condition, cars require regular maintenance which can be done by a garage or by yourself. In improving the ability to maintain motorcycles and make an income through their own business, especially in the field of motorcycle maintenance services. Through this community service project, counseling on business management and training on motorcycle maintenance skills, including the correct adjustment and use of repair equipment, are provided. The service method applies socialization of motorcycle maintenance theory and direct assistance on how to perform motor vehicle maintenance for Sirnajaya Village youth. The results of this service activity are the increased knowledge, understanding, and abilities of the participants in the field of motorcycle maintenance and repair, besides that this service program supports the success of the community in establishing their own business.

Maintenance Costs, Time, and Efforts Following Implant Therapy With Fixed Restorations Over an Observation Period of 10 Years: A Randomized Controlled Clinical Trial.

To assess the costs and efforts of maintenance therapy following implant treatment with fixed restoration over an observation period of 10 years. This randomized controlled clinical trial included 64 patients who were randomly assigned to receive one of two implant systems (AST or STM) and fixed restoration. Patients were included in a regular maintenance program and were examined at loading, 1, 3, 5, 8, and 10 years. Outcome measures included technical and biological complications, time, efforts, and costs to resolve them. A total of 97 implants were placed in 64 patients (AST: 54, STM: 43). Patient recall rates at 5 and 10 years were 89% and 67%. In general, technical complications were resolved within one to two appointments (mean = 1.5), and biological complications required a mean of 1.3 appointments. The overall regular maintenance time for the period of 10 years amounted to 77 min per year. Technical complications occurred in 39.5% of the patients, with screw-loosening being the most common one (43.4% of all complications). The most time-consuming technical complication was abutment fracture (94 min ± 68), followed by screw fracture (84 min ± 38). The prevalence of peri-implant mucositis on the patient level was 30.2%, and it was 9.3% for peri-implantitis. The average annual maintenance costs amounted to 9% of the initial cost of the implant treatment over the period of 10 years. Additional regular maintenance costs and costs due to the treatment of potential complications have to be taken into consideration when placing dental implants. The majority of technical complications could be resolved within one appointment, whereas the time needed to treat biological complications varied between one and three appointments for peri-implantitis.