The oral microbiota plays a vital role in the human microbiome and oral health. Imbalances between microbes and their hosts can lead to oral and systemic disorders such as diabetes or cardiovascular disease. The purpose of this review is to investigate the literature evidence of oral microbiota dysbiosis on oral health and discuss current knowledge and emerging mechanisms governing oral polymicrobial synergy and dysbiosis; both have enhanced our understanding of pathogenic mechanisms and aided the design of innovative therapeutic approaches as ORALBIOTICA for oral diseases such as demineralization. PubMed, Web of Science, Google Scholar, Scopus, Cochrane Library, EMBEDDED, Dentistry & Oral Sciences Source via EBSCO, APA PsycINFO, APA PsyArticles, and DRUGS@FDA were searched for publications that matched our topic from January 2017 to 22 April 2022, with an English language constraint using the following Boolean keywords: (“microbio*” and “demineralization*”) AND (“oral microbiota” and “demineralization”). Twenty-two studies were included for qualitative analysis. As seen by the studies included in this review, the balance of the microbiota is unstable and influenced by oral hygiene, the presence of orthodontic devices in the oral cavity and poor eating habits that can modify its composition and behavior in both positive and negative ways, increasing the development of demineralization, caries processes, and periodontal disease. Under conditions of dysbiosis, favored by an acidic environment, the reproduction of specific bacterial strains increases, favoring cariogenic ones such as Bifidobacterium dentium, Bifidobacterium longum, and S. mutans, than S. salivarius and A. viscosus, and increasing of Firmicutes strains to the disadvantage of Bacteroidetes. Microbial balance can be restored by using probiotics and prebiotics to manage and treat oral diseases, as evidenced by mouthwashes or dietary modifications that can influence microbiota balance and prevent or slow disease progression.

The aim of the current paper is to review the available literature reporting on comparative studies of heat-cured resins and three-dimensionally printed biomaterials for denture bases in terms of their composition, properties, fabrication techniques and clinical performance. The methodology included applying a search strategy, defining inclusion and exclusion criteria, selecting studies to summarize the results. Searches of PubMed, Scopus, and Embase databases were performed independently by three reviewers to gather literature published between 2018 and 2021. A total of 135 titles were obtained from the electronic databases, and the application of exclusion criteria resulted in the identification of 42 articles pertaining to conventional and 3D printed technology for removable dentures. The main disadvantages of the heat-cured resins for removable dentures are that they require lots of special equipment, skilled personnel and time. Emerging technologies, such as 3D printed dentures, have the potential to alleviate these problems allowing for faster patient rehabilitation. With the development of digital dentistry, it is becoming increasingly necessary to use 3D printed resin materials for the manufacturing of removable dentures. However, further research is required on the existing and developing materials to allow for advancement and increase its application in removable prosthodontics.

The aim of this study is to report on the oral lesions detected in 123 patients diagnosed at the University Hospital of Bari from October 2020 to December 2020, focusing on the correlation of clinical and pathological features in order to purpose a new classification. Methods. General and specialistic anamnesis were achieved and oral examination was performed. The following data were collected: age/gender, general symptoms and form of Covid-19, presence and features of taste disorders, day of appearance of the oral lesions, type and features of oral lesions and day of beginning of therapies. If ulcerative lesions did not heal, biopsy was performed. Results. Many types of oral lesions were found and classified into four groups considering the timing of appearance and the start of the therapies. Early lesions in the initial stages of Covid-19 before the start of therapies was observed in 65.9% of the patients. In the histopathological analysis of four early lesions, thrombosis of small and middle size vessels was always noticed with necrosis of superficial tissues. Conclusion. The presence of oral lesions in early stages of Covid-19 could represent an initial sign of peripheral thrombosis, a warning sign of possible evolution to severe illness. This suggests that anticoagulant therapies should start as soon as possible.

The number of patients undergoing a surgical resection of the maxilla for oncological reasons is constantly increasing, the most common complication of which remains the communication between oral and nasal cavities. On the basis of data arising from the literature regarding the treatment options of maxillary oncological post-surgical defects, obturator prosthesis remains the most used worldwide. We studied 25 patients (with at least 1-year follow up) rehabilitated by obturator prosthesis after maxillary resection leading to oro-nasal communication, providing data on the objective/subjective evaluation of such rehabilitation and mastication performance measured by a two-color chewing gum test. The type of defect was classified according to the classification system proposed by Aramany. Among the patients in our study, 72% rated a higher score for either stability and retention than for aesthetic appearance, as confirmed by the Kapur score rated by clinicians. The two-color chewing gum test shows similar results as only one patient had insufficient chewing function. Interestingly, we found no correlation between the masticatory function and residual denture, confirming that the maxillary obturator remains a predictable solution in such patients regardless of the anatomical alterations following surgery.

The aim of this paper is to review the available literature on the different methods for color stability determination of CAD/CAM milled and 3D printed resins for denture bases. The methodology included applying a search strategy, defining inclusion and exclusion criteria and selecting studies to summarize the results. Searches of PubMed, Scopus, and Embase databases were performed independently by three reviewers to gather the literature published between 1998 and 2022. A total of 186 titles were obtained from the electronic database, and the application of exclusion criteria resulted in the identification of 66 articles pertaining to the different methods for color stability determination of CAD/CAM acrylic resins for denture bases. Color change in dental materials is clinically very important for the dental operator, as it determines the clinical serviceability of the material. Discoloration of the denture bases can be evaluated with various instruments and methods. Dental resins may undergo color changes over time due to intrinsic and/or extrinsic factors. The extrinsic factors are considered the more frequent causes of color changes. According to a number of studies, CAD/CAM fabricated acrylics have achieved better color stability than the conventional PMMA (polymethyl methacrylate) resins.

Background: This in vitro study aimed to investigate and evaluate the values of water sorption and water solubility of four types of denture base polymers—3D-printed NextDent 3D Denture + (NextDent, 3D Systems, Soesterberg, The Netherlands), CAD/CAM milled Ivotion Base (Ivotion Denture System, Ivoclar Vivadent, Schaan, Liechtenstein), PMMA conventional Vertex BasiQ 20 (Vertex Dental, 3D Systems, Soesterberg, The Netherlands), and conventional heat-cured BMS (BMS Dental Srl, Rome, Italy)—which were subjected to artificial aging. Materials and methods: 200 specimens were created (n = 50), dried, and weighed accurately. They were immersed in artificial saliva (T1 = 7 days, T2 = 14 days, T3 = 1 month) and re-weighed after water absorption. After desiccation at 37 °C for 24 h and then at 23 ± 1 °C for 1 h, samples were weighed again. Next, thermocycling (100 h, 5000 cycles, 5–55 °C) was performed, and the water sorption and solubility were re-measured. IBM SPSS Statistics 0.26 was used for data analysis, revealing a direct correlation between water sorption and material type. Thermocycling at 55 °C increased water sorption for BMS and Vertex BasiQ 20. In conclusion, NextDent’s 3D-printed resin had higher water sorption values throughout the study. Water solubility averages decreased over time, reaching the lowest in the 30-day period for CAD/CAM milled dental resin Ivotion Base. The artificial aging had no effect on Ivotion Base and NextDent’s water sorption. Thermocycling did not affect the solubility of the materials tested. The conducted study acknowledges the great possibilities of dental resins for additive and subtractive manufacturing for the purposes of removable prosthetics in daily dental practice.