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One essential energy vector for building a sustainable bioeconomy is hydrogen, which may be obtained from renewable biomass sources. This study discusses many biological routes used in the conversion of biomass to hydrogen, as well as a variety of thermochemical routes such as pyrolysis and gasification. Thermochemical routes include fast pyrolysis, steam and supercritical water gasification, and related processes; biological routes include photo, dark, and mixed fermentation techniques in addition to bio-photolysis processes. Notwithstanding its promise, improving the reliability and selectivity of hydrogen processing is necessary for economically viable industrial uses in the hydrogen economy. The importance of operating conditions, process parameters, variables influencing hydrogen production, parameters of storage methods, hydrogen transportation, separation, and difficulties in producing hydrogen through thermochemical and biological routes are all covered in this paper. It looks at the problems that come with these procedures, highlighting important knowledge gaps that need for more investigation. Combining biological processes with thermochemical pathways can ensure economic sustainability. Both thermochemical and biological routes can help fulfilling future demand for a hydrogen based society.

Hydrothermal carbonization (HTC) has emerged as a pivotal technology in the battle against climate change and fosters circular economies. Operating within a unique reaction environment characterized by water as a solvent and moderate temperatures at self-generated pressures, HTC efficiently converts biomass residues into valuable bio-based products. Despite HTC’s potential—from the management of challenging biomass wastes to the synthesis of advanced carbons and the implementation of biorefineries—it encounters hurdles transitioning from academic exploration to industrial implementation. Gaps persist, from a general comprehension of reaction intricacies to the difficulty of large-scale integration with wastewater treatments, to the management of process water, to the absence of standardized assessment techniques for HTC products. Addressing these challenges demands collaboration to bridge the many scientific sectors touched by HTC. Thus, this article reviews the current state of some hot topics considered crucial for HTC development: It emphasizes the role of HTC as a cornerstone for waste management and biorefineries, highlighting potentialities and challenges for its development. In particular, it surveys fundamental research aspects, delving into reaction pathways, predictive models, analytical techniques, and HTC modifications while exploring HTC’s crucial technological applications and challenges, with a peculiar focus on combined HTC, wastewater integration, and plant energy efficiency.

Bioplastics are steadily replacing fossil-based plastics due to their renewable origin and biodegradability. However, their end-of-life can be problematic: they are often collected with the organic fraction of municipal solid waste (OFMSW) but can be not satisfactorily biodegradable in plants that treat it, leading to their rejection at the entrance. This work focuses on five different commercial bioplastics employed in the eyewear industry: two based on cellulose acetate, one on galalithe, one on corn starch and one on polyamide. The aim was to assess their treatability via hydrothermal carbonization (HTC), which was never reported in the literature for these materials. Under HTC at 180 and 220 °C for 1 h, four of the tested bioplastics show significant degrees of degradation, leading to the formation of different solid and liquid products, which were respectively characterised according to their elemental composition and pH. The interesting different behaviours may be ascribed to the different compositions and structures of the materials. HTC appears as a viable route to facilitate the degradation of these recalcitrant materials and may be followed by a material recovery or an energetic valorisation through anaerobic digestion or thermochemical pathways, depending on the purity of the waste stream.

Chlorella vulgaris is an inexpensive microalga that could be employed for environmental remediation, but further investigations are needed to assess its suitability and optimal treatment methodology. With this aim in mind, this study focused on the raw biomass and the biochar and hydrochar obtained from it, analyzing their physicochemical properties and testing them to capture cadmium from an aqueous environment. The adsorption/absorption tests assessed the effect of adsorbent dosage, pH, Cd concentration, and contact time, and the results were analyzed through a structural equation model. Biochar and hydrochar performed similarly and better than the raw biomass, with the highest Cd removal observed at an adsorbent dosage of 0.8 g L−1, an initial concentration of Cd solution of 30 mg L−1, a pH of 6, and a contact time of 30 min. The adsorption isotherm data for Cd could be well-described by the Langmuir and Temkin models. The results from the structural equation modeling revealed that the variables material type, dosage, and concentration all contributed to Cd removal in water, with time mediating these effects.

In recent years, increasing attention has been paid to the problem of sewage sludge management and the relevant energy consumption, which represent the main cost items in wastewater treatment plants. Therefore, implementation of technologies that can reduce sludge production and ensure a positive impact on the energy of the entire sewage treatment plant has gained considerable importance in the scientific and technical community. The objective of this study was thus to screen full-scale sludge reduction technologies integrated into both the water line and the sludge line of a municipal sewage treatment plant with a sustainable impact on the overall balance of the plant. The results showed that, within the water line, ultrasound in the recirculation line of the activated sludge allowed for greater reductions in sludge production than the Cannibal and UTN systems, despite the higher energy consumption. CAMBITM, BioThelysTM, ExelysTM and TurboTec® enabled the greatest reductions in sludge production among the technologies integrated into the sludge line, and although they required a large amount of energy, this was partially offset by energy recovery in terms of additional biogas production.

This study examines the kinetics of pyrolysis and oxidation of hydrochars through thermal analysis. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) techniques were used to investigate the decomposition profiles and develop two distributed activation energy models (DAEM) of hydrochars derived from the hydrothermal carbonization of grape seeds produced at different temperatures (180, 220, and 250 °C). Data were collected at 1, 3, and 10 °C/min between 30 and 700 °C. TGA data highlighted a decomposition profile similar to that of the raw biomass for hydrochars obtained at 180 and 220 °C (with a clear distinction between oil, cellulosic, hemicellulosic, and lignin-like compounds), while presenting a more stable profile for the 250 °C hydrochar. DSC showed a certain exothermic behavior during pyrolysis of hydrochars, an aspect also investigated through thermodynamic simulations in Aspen Plus. Regarding the DAEM, according to a Gaussian model, the severity of the treatment slightly affects kinetic parameters, with average activation energies between 193 and 220 kJ/mol. Meanwhile, the Miura–Maki model highlights the distributions of the activation energy and the pre-exponential factor during the decomposition.

Hydrothermal carbonization (HTC) of sewage sludge has been investigated in this study to demonstrate its capability to segregate phosphorous element and produce a solid energy dense material, i.e. hydrochar, which could find application as solid bio-fuel and/or soil amendment. In this study, centrifuged anaerobically digested sewage sludge (total solid content: 21 wt.%) from Trento North (Italy) waste water treatment plant was hydrothermally carbonized at 190 and 210 °C at 1 and 3 h of residence time. Hydrochars, recovered via filtration, were leached using 4 M HCl solution at room temperature to transfer phosphorous (P) and inorganic elements into the aqueous solution. Recovery of P was achieved via phosphate salt precipitation by alkalinisation, up to pH 9, of the acidic leachate using a 5 M NaOH solution. Sewage sludge and the corresponding hydrochars, before and after acid leaching, were characterized in terms of energy properties (HHV) by calorimetric analysis, P and inorganic elements content via ICP-OES. Results showed that HTC promotes segregation of P element in the hydrochar (up to 90 wt.% of the initial content on a dry basis at 190 °C, 1 h). The study demonstrated that P can be effectively recovered via precipitation via acidic leaching and subsequent alkalization with total recovery yields higher than 70 wt.%. The hydrochar residues, after leaching, showed inorganic elements content and energy properties compatible with their possible use as soil amendment in agriculture and/or as solid biofuel.

Hydrothermal processes enable an effective conversion of waste biomasses into fuels and carbonaceous materials. Covering the heat requirements with concentrated solar energy is a clever strategy to increase the plant efficiency and pursue the principles of circular economy. With the purpose of producing liquid and solid biofuels through zero-energy routes, this work presents two conceptual designs for integrating a concentration solar system (CSS) with a hydrothermal liquefaction (HTL) and a hydrothermal carbonization (HTC) plant. The solar configuration used to cover hydrothermal heat requirements consists of a set of parabolic trough collectors operating with molten salts, which are used as both thermal carrier fluid and thermal energy storage medium. Two different scenarios were modelled to continuously process wood and organic wastes. In the first scenario, the CSS is coupled with a continuous HTL reactor (operating at 400 °C and 300 bar) followed by thermal cracking and hydroprocessing for upgrading bio-crude to a saleable liquid biofuel. The second scenario considers the CSS operating with a continuous HTC reactor (working at 220 °C and 24 bar) for the conversion of organic wastes into a solid fuel (hydrochar). The CSS and both the hydrothermal plants were modelled based on experimental data. Energy consumptions and techno-economic aspects were investigated.

Prickly pear (Opuntia ficus-indica L.) is a member of the Cactaceae family originally grown in South America, and the plant is now distributed to many parts of the world, including the Middle East. The chemical composition and biological activities of different parts of prickly pear, including cladodes, flowers, fruit, seeds and seed oil, were previously investigated. Oil from the seeds has been known for its nutritive value and can be potentially used for health promotion. This review is an effort to cover what is actually known to date about the prickly pear seeds oil extraction, characteristics, chemical composition and potential health benefits to provide inspiration for the need of further investigation and future research. Prickly pear seeds oil has been extracted using different extraction techniques from conventional to advanced. Chemical characterization of the oil has been sufficiently studied, and it is sufficiently understood that the oil is a high linoleic oil. Its composition is influenced by the variety and environment and also by the method of extraction. The health benefits of the prickly pear seed oil were reported by many researchers. For future research, additional studies are warranted on mechanisms of action of the reported biological activities to develop nutraceutical products for the prevention of various chronic human diseases.

An increasing number of industrial plants integrate the anaerobic digestion (AD) of the organic fraction of municipal solid waste (OFMSW) with a subsequent composting phase. To improve the plant productivity, a fraction of OFMSW digestate can be converted into a carbonaceous material, called hydrocar (HC), through Hydrothermal Carbonization (HTC), and then composted together with the OFMSW digestate itself, to produce “hydrochar co-compost”. The aim of this paper is to present the design and assembly of batch bioreactors, built in-house to investigate the co-composting process of OFMSW digestate and its HC, and to provide some preliminary results. The OFMSW digestate from an industrial plant was carbonized at 200 °C for 3 h in a 2 L HTC reactor, to produce wet HC after filtration. The ratio of OFMSW digestate and green waste (1:1) used as bulking medium was reproduced in four bioreactors with an increasing percentage of HC substituting the OFMSW digestate (0, 25, 50, 75%). The bioreactors managed to effectively compost the solid wet biomasses in a wet environment with temperature and oxygen control, while measuring online the oxygen consumption and thus the dynamic respirometric index (DRI). The DRI24,max measured with AIR-nl solid respirometer (standardized offline measurement) started from values above 800 mg O2 kgVS−1 h−1 before composting and dropped at the end of the process to values in the range 124–340 mg O2 kgVS−1 h−1 for the four mixes, well below the recommended limit of 500 mg O2 kgVS−1 h−1 for high-quality compost stability. These offline DRI values were confirmed by the online DRI measurements. This research is part of the international C2Land Project funded by the European Institute of Innovation and Technology Climate Knowledge and Innovation Community (EIT Climate-KIC), which is greatly acknowledged.

The present study addresses the coupling of hydrothermal carbonization (HTC) with anaerobic digestion (AD) in wastewater treatment plants. The improvement in biomethane production due to the recycling back to the anaerobic digester of HTC liquor and hydrochar generated from digested sludge is investigated and proved. Mixtures of different compositions of HTC liquor and hydrochar, as well as individual substrates, were tested. The biomethane yield reached 102 ± 3 mL CH4 g−1 COD when the HTC liquor was cycled back to the AD and treated together with primary and secondary sludge. Thus, the biomethane production was almost doubled compared to that of the AD of primary and secondary sludge (55 ± 20 mL CH4 g−1 COD). The benefit is even more significant when both the HTC liquor and the hydrochar were fed to the AD of primary and secondary sludge. The biomethane yield increased up to 187 ± 18 mL CH4 g−1 COD when 45% of hydrochar, with respect to the total feedstock, was added. These results highlight the improvement that the HTC process can bring to AD, enhancing biomethane production and promoting a sustainable solution for the treatment of the HTC liquor and possibly the hydrochar itself.

With the increasing needs of clean water supplies, the use of biomass wastes and residues for environmental remediation is essential for environmental sustainability. In this study, the residues from winery and citrus juice industries, namely grape skin and orange peel, respectively, were first converted to hydrochars by hydrothermal carbonization (HTC) and then a cationic dye (methylene blue) adsorption was studied on hydrochars. Hydrochars from both feedstocks were produced at three different temperatures (180, 220, and 250 °C) and a fixed residence time (1 h) to evaluate the hydrochar’s performance on the dye adsorption. The hydrochars were characterized in terms of their pH, pH at point of zero charge (pHPZC), surface functionalities, and surface area. A batch adsorption study of the dye was carried out with variable adsorbate concentration, pH, and temperature. Two adsorption isotherms namely Langmuir and Freundlich models were fitted at 4, 20, and 36 °C. The thermodynamic properties of adsorption (Gibbs free energy (ΔG), enthalpy (ΔH) and entropy (ΔS)) were evaluated from the isotherms fittings. Results showed that the dye adsorption on both hydrochars was significant and followed Langmuir isotherm. The maximum adsorption capacity on citrus waste hydrochar was higher than the winery waste hydrochar at any corresponding HTC temperature. Although hydrochars showed the lowest surface area (46.16 ± 0.11 and 34.08 ± 1.23 m2/g for citrus and winery wastes, respectively) at 180 °C, their adsorption was the highest, owing to their maximum density of total oxygen functional groups (23.24 ± 0.22 and 32.69 ± 1.39 µmol/m2 for citrus and winery wastes, respectively), which decreased with the increase in HTC temperature. This research shows a sustainable route for the production of highly effective adsorbent materials at lower HTC temperatures from citrus and winery wastes.

The growing importance of bio-based products, combined with the desire to decrease the production of wastes, boosts the necessity to use wastes as raw materials for bio-based products. A waste material with a large potential is spent sugar beets, which are mainly used as animal feeds or fertilizers. After hydrothermal treatment, the produced chars exhibited an H/C ratio of 1.2 and a higher heating value of 22.7 MJ/kg, which were similar to that of subbituminous coal and higher than that of lignite. Moreover, the treatment of 25 g/L of glucose and 22 g/L of fructose by heating up to 160 °C led to a possible application of spent sugar beets for the production of 5-hydroxymethylfurfural. In the present study, the maximum concentration of 5-hydroxymethylfurfural was 3.4 g/L after heating up to 200 °C.

Conventional activated sludge systems, still widely used to treat wastewater, produce large amounts of solid waste that is commonly landfilled or incinerated. This study addresses the potential use of Hydrothermal Carbonization (HTC) to valorize sewage sludge residues examining the properties of hydrochars depending on HTC process conditions and sewage sludge withdrawal point. With increasing HTC severity (process residence time and temperature), solid yield, total Chemical Oxygen Demand (COD) and solid pH decrease while ash content increases. Hydrochars produced from primary (thickened) and secondary (digested and dewatered) sludge show peculiar distinct properties. Hydrochars produced from thickened sludge show good fuel properties in terms of Higher Heating Value (HHV) and reduced ash content. However, relatively high volatile matter and O:C and H:C ratios result in thermal reactivity significantly higher than typical coals. Both series of carbonized secondary sludges show neutral pH, low COD, enhanced phosphorous content and low heavy metals concentration: as a whole, they show properties compatible with their use as soil amendments.

Municipal sewage sludge was subjected to a hydrothermal carbonization (HTC) process for developing a hydrochar with high adsorption capacity for water remediation in terms of dye removal. Three hydrochars were produced from municipal sewage sludge by performing HTC at 190, 220 and 250 °C, with a 3 h reaction time. Moreover, a portion of each hydrochar was subjected to a post-treatment with KOH in order to increase the adsorption capacity. Physicochemical properties of sludge samples, raw hydrochars and KOH-modified hydrochars were measured and batch adsorption studies were performed using methylene blue (MB) as a reference dye. Data revealed that both raw and modified hydrochars reached good MB removal efficiency for solutions with low MB concentrations; on the contrary, MB in high concentration solutions was efficiently removed only by modified hydrochars. Interestingly, the KOH treatment greatly improved the MB adsorption rate; the modified hydrochars were capable of capturing above 95% of the initial MB amount in less than 15 min. The physicochemical characterization indicates that alkali modification caused a change in the hydrochar surface making it more chemically homogeneous, which is particularly evident for the 250 °C hydrochar. Thus, the adsorption process can be regarded as a complex result of various phenomena, including physi- and chemi-sorption, acid–base and redox equilibria.

Olive trimmings (OT) were used as feedstock for an in-depth experimental study on the reaction kinetics controlling hydrothermal carbonization (HTC). OT were hydrothermally carbonized for a residence time τ of up to 8 h at temperatures between 180 and 250 °C to systematically investigate the chemical and energy properties changes of hydrochars during HTC. Additional experiments at 120 and 150 °C at τ = 0 h were carried out to analyze the heat-up transient phase required to reach the HTC set-point temperature. Furthermore, an original HTC reaction kinetics model was developed. The HTC reaction pathway was described through a lumped model, in which biomass is converted into solid (distinguished between primary and secondary char), liquid, and gaseous products. The kinetics model, written in MATLABTM, was used in best fitting routines with HTC experimental data obtained using OT and two other agro-wastes previously tested: grape marc and Opuntia Ficus Indica. The HTC kinetics model effectively predicts carbon distribution among HTC products versus time with the thermal transient phase included; it represents an effective tool for R&D in the HTC field. Importantly, both modeling and experimental data suggest that already during the heat-up phase, biomass greatly carbonizes, in particular at the highest temperature tested of 250 °C.

Grape marc is a residue of the wine-making industry, nowadays not always effectively valorized. It consists of grape seeds (mostly lignocellulosic) and grape skins (mostly holocellulosic). In order to understand possible correlations between seeds and skins in forming hydrochar for it to be used as a solid biofuel, hydrothermal carbonization (HTC) was applied separately to grape marc and its constituents. HTC was performed at several process conditions (temperature: 180, 220 and 250 °C; reaction time: 0.5, 1, 3 and 8 h), in order to collect data on the three phases formed downstream of the process: solid (hydrochar), liquid and gas. An in deep analytical characterization was performed: ultimate analysis and calorific value for hydrochar, Total Organic Carbon (TOC) and Inductively Coupled Plasma (IPC) analyses for liquid phase, composition for gas phase. In previous works, the same experimental apparatus was used to treat residual biomass, obtaining interesting results in terms of possible hydrochar exploitation as a solid biofuel. Thus, the main objectives of this work were both to get results for validating the hypothesis to apply HTC to this feedstock, and to collect data for subsequent theoretical investigations. Moreover, a severity model was developed to allow a predictive description of the hydrochar yield as a function of a unique parameter condensing both temperature and reaction time effects. The results obtained demonstrate that this process can upgrade wet residues into a solid biofuel ad that the process can be satisfactorily described in terms of a severity factor.

A two-stage conversion process for the production of a valuable product from biomass waste, i.e., grape seeds activated carbon (GSAC) was investigated. Such process involved hydrothermal carbonization (HTC) of grape seeds, followed by chemical activation with potassium hydroxide (KOH). Different HTC temperatures (THTC = 180–250 °C), as well as different KOH:hydrochar ratios (R = 0.25:1–1:1), were explored. The samples that were obtained from both stages of the biomass conversion process were analyzed in terms of textural characterization (apparent total and micro-pore surface areas, total and micro-pore volumes, pore size distribution), proximate and ultimate compositions, thermal stability, surface morphology (via SEM), and surface chemistry characterization (via FTIR). Overall yields of approximately 35% were achieved, which are comparable to those obtained with the state-of-art one-stage process. In a wide range of operating conditions, the higher THTC and R, the higher was the surface area of the GSAC, which was maximal (above 1000 m2/g) for THTC = 250 °C and R = 0.5. At such optimal conditions, around 90% of the total porosity was due to micro-pores. Such a trend was not fulfilled at the most severe operating conditions (THTC = 250 °C; R = 1), which resulted in larger pore size, causing surface area reduction. A proper selection of the process parameters of both the process stages gives great opportunities of tuning and optimizing the overall process. The produced GSACs showed a remarkable thermal stability, and their surface appeared rather free of functional groups.

Supercritical water gasification (SCWG) is an emerging technology for the valorization of (wet) biomass into a valuable fuel gas composed of hydrogen and/or methane. The harsh temperature and pressure conditions involved in SCWG (T > 375 °C, p > 22 MPa) are definitely a challenge for the manufacturing of the reactors. Metal surfaces are indeed subject to corrosion under hydrothermal conditions, and expensive special alloys are needed to overcome such drawbacks. A ceramic reactor could be a potential solution to this issue. Finding a suitable material is, however, complex because the catalytic effect of the material can influence the gas yield and composition. In this work, a research reactor featuring an internal alumina inlay was utilized to conduct long-time (16 h) batch tests with real biomasses and model compounds. The same experiments were also conducted in batch reactors made of stainless steel and Inconel 625. The results show that the three devices have similar performance patterns in terms of gas production, although in the ceramic reactor higher yields of C2+ hydrocarbons were obtained. The SEM observation of the reacted alumina surface revealed a good resistance of such material to supercritical conditions, even though some intergranular corrosion was observed.

In this paper, a hydrothermal carbonization (HTC) process is designed and modeled on the basis of experimental data previously obtained for two representative organic waste materials: off-specification compost and grape marc. The process accounts for all the steps and equipment necessary to convert raw moist biomass into dry and pelletized hydrochar. By means of mass and thermal balances and based on common equations specific to the various equipment, thermal energy and power consumption were calculated at variable process conditions: HTC reactor temperature T: 180, 220, 250 °C; reaction time θ: 1, 3, 8 h. When operating the HTC plant with grape marc (65% moisture content) at optimized process conditions (T = 220 °C; θ = 1 h; dry biomass to water ratio = 0.19), thermal energy and power consumption were equal to 1170 kWh and 160 kWh per ton of hydrochar produced, respectively. Correspondingly, plant efficiency was 78%. In addition, the techno-economical aspects of the HTC process were analyzed in detail, considering both investment and production costs. The production cost of pelletized hydrochar and its break-even point were determined to be 157 €/ton and 200 €/ton, respectively. Such values make the use of hydrochar as a CO2 neutral biofuel attractive.

Background: Dental implant rehabilitation has significantly advanced prosthodontics by providing a reliable, long-lasting solution for missing teeth. This systematic review compares the clinical, technical, and biological outcomes of cemented versus screw-retained single dental implant restorations based on randomized clinical trials (RCTs). Materials and Methods: This review included recent human and in vitro studies focusing on the keywords “cemented vs. screw-retained” and “dental implant”. Eight studies met the inclusion criteria, which investigated parameters, including implant survival rate, bleeding on probing (BOP), probing depth, plaque index, marginal bone loss (MBL), cytokine concentrations, mechanical complications, esthetic outcomes, patient satisfaction, treatment time, and technical failures. Results: The primary outcomes, BOP and MBL, did not statistically differ between cemented and screw-retained implants (p-values for MBL and BOP are 0.5813 and 0.8093, respectively). The reviewed studies, including RCTs, split-mouth studies, and clinical evaluations, demonstrated comparable clinical, technical, and biological outcomes between the two restoration methods. Conclusions: Screw-retained and cemented dental implant restorations exhibit similar clinical, technical, and biological outcomes. Screw-retained restorations offer advantages such as retrievability, ease of repair, and predictable passive fit, while cemented restorations provide superior esthetics. The risk of peri-implant complications due to residual cement in cemented restorations must be considered. Future research should explore long-term stability and the impact of different prosthetic protocols on peri-implant health.

Background: This systematic review aims to critically assess the literature on the debonding process of orthodontic brackets from enamel surfaces. The review evaluates Randomized Controlled Trials (RCTs) to determine the effectiveness and implications of various debonding techniques and materials. Methods: The study followed PRISMA guidelines, selecting RCTs published from 1999 onwards that compared the outcomes of various orthodontic bracket debonding techniques. Selection criteria included studies utilizing human teeth, with outcomes such as enamel surface roughness and Adhesive Remnant Index (ARI) analyzed. Data sources included PubMed, Scopus, Web of Science, and the Cochrane Library. Results: Out of 1,587 records identified, five studies met the inclusion criteria. These studies provided comparative data on the effectiveness of various debonding techniques, including tungsten carbide and diamond burs, in minimizing enamel damage and optimizing adhesive removal. Findings indicated that tungsten carbide burs produced the least enamel roughness. Discussion: Utilizing tungsten carbide burs for debonding orthodontic brackets significantly minimizes enamel surface roughness and potential damage, thereby enhancing the preservation of enamel integrity post-treatment. The systematic review highlights current debonding techniques are effective in adhesive removal, and the choice of instrument significantly affects enamel integrity and clinical outcomes. The findings support the need for continuous improvement and innovation in removing braces to improve orthodontic treatment results and patient satisfaction.

This manuscript introduces a novel two-step technique for fabricating mobile dentures post-extraction to streamline prosthodontic rehabilitation. The study utilizes various materials, including dental polymers, metals, ceramics, and composite materials, each chosen for their unique properties that contribute to the final prosthesis’s functionality, durability, and esthetics. The detailed procedure involves an initial occlusal registration immediately following tooth extraction, capturing precise occlusal relationships and a comprehensive dental impression. This approach reduces clinical visits and leverages optimal alveolar ridge morphology. The expected results highlight the efficiency of the technique, reducing treatment time without compromising quality and potentially improving patient satisfaction and prosthodontic outcomes. This innovative method conclusively promises rapid, efficient, and patient-centered dental rehabilitation, emphasizing the need for future research to validate its effectiveness and explore long-term outcomes.

A 65-year-old Caucasian male was referred to an endodontic specialist practice in a private clinic in December 2019 for the management of an asymptomatic, radiolucent lesion located at the cervical level of the distal root of his right lower first molar, noticed during a routine periapical radiograph. After an accurate evaluation with cone-beam computed tomography (CBCT), the subgingival lesion was diagnosed as a supracrestal external cervical resorption (ECR), with a circumferential spread ⩽90°, confined to dentine without pulp involvement. The lesion was treated with the following sequence: (1) a full flap accessed the ECR, (2) the granulomatous tissue was removed from the root area, (3) the cavity was refreshed and filled with a well-refined and polished resin composite, (4) the flap was sutured at the cemento-enamel junction. A mandibular CBCT scan was performed before treatment, right after treatment, and 3 years postoperatively. Compared to the 3-year posttreatment CBCT scan, the immediate posttreatment one, revealed the absence of bone loss and an unexpected coronal bone remodeling with new bone formation over the treated lesion.

Charles William Macfarlane (1852-1931) represents an almost unique and completely forgotten economist during the Progressive Era: although he was outside Academis, he was able to take an active part in the theoretical debate of the time by proposing a peculiar version of marginalism far away from the Austrian school version and close the classical approach. This paper deals with Macfarlane’s theory of value and distribution, by discussing its influence in the discipline, and it presents an archival appendix which reproduces an unpublished response by Clark to Macfarlane which provides further evidence on the reception of Macfarlane’s work among his contemporaries.

This case report focuses on applying a protocol for dental implant restoration in aesthetic zones, specifically the anterior sectors. The protocol aims to achieve optimal results with minimal complexity, reducing the number of sessions and impressions required for transferring clinical information to the laboratory. The historical development of dental implantology and the evolution of dental implant restoration workflows are discussed, highlighting the significance of osseointegration and advancements in materials, surgical techniques, and prosthetic components. The case report describes rehabilitating congenitally missing lateral incisors using fibre-reinforced composite Maryland bridges for provisional restoration and Osstem TSIII (Osstem®, Seoul, South Korea) implants, zirconia abutments, and disilicate lithium crowns for definitive repair. The discussion covers essential aspects of aesthetic dental implant restoration, including materials, types of dental implants, surgical techniques for soft tissue enhancement, and prosthetic and impression techniques. The study emphasises the importance of selecting appropriate materials, employing advanced surgical procedures, and utilising accurate prosthetic and impression techniques to enhance the aesthetic outcomes of dental implant restorations. A multidisciplinary approach and patient-centred care are essential for successful aesthetic dental implant restorations. The methodology presented in this manuscript demonstrates its effectiveness in achieving optimal outcomes while minimising stress on soft tissues and improving patient comfort and satisfaction. This case report contributes to dental implant restoration, providing evidence-based techniques for achieving aesthetic and functional success.