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.

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.

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.

The current pilot study investigates the effects following removal of excessive gingival tissue, which is often necessary in fixed prosthodontic cases. The aim of the study is to assess gingival healing after diode laser gingivectomy prior to prosthetic procedures. Materials and methods: The healing process of the gingiva after the diode laser gingivectomy of 41 teeth was assessed. The following parameters were examined: recovery time of the gingiva, possibility to take the impression at the same visit, duration of the manipulation, bleeding during the procedure, tissue adherence to the instrument, postoperative hemorrhage on probing, postoperative pain, and wound healing in regard to tissue color, tissue contour, and appearance of the wound. Results: At the 24th hour, all gingival wounds were covered with fibrinous plaque and an erythematous halo. At the 72nd hour, in two cases (4.9%), this wound’s characteristic had already passed through to the next healing stage—granulated surface and normal pale pink color. A granulated surface in the 1st week was reported in 10 (24.4%) cases, and in all of the other 31 (75.6%) cases, complete healing was reported. In the second week, all wound surfaces had a normal pale pink color. Bleeding was self-limiting in most of the cases and negligible from a clinical point of view. The postoperative pain levels were low or nonexistent. There was lack of postoperative hemorrhage on probing after the first week in all examined cases. Tissue recovery in terms of tissue contour, color, and appearance of the wound was asymptomatic. Conclusion: within the limitations of this pilot study, the outcomes of the wound healing after laser gingivectomy aided the clinicians to perform the prosthetic procedures in the same visit.

The aim of the current article is to analyze and compare post-retraction gingival height changes resulting from six different types of gingival-displacement methods, encompassing both conventional and surgical approaches. The study involved a comparative analysis of 263 teeth (consisting of 128 front teeth, 69 premolars, and 66 molars) from 23 patients. For the investigation, three classic retraction methods were utilized, namely the single-cord technique, retraction paste Expasyl, and retraction paste Astringent. Additionally, three surgical techniques were employed, which included ceramic bur rotary curettage, Er:YAG laser troughing, and diode laser troughing. A randomized split-mouth design was implemented, and a significance level of 0.05 was used for the study. The recovery of the free gingival margin height was assessed on gypsum models that were scanned using an intraoral scanner during the first and second week after the retraction procedure. The results revealed that all retraction methods, except for ceramic bur rotary curettage, led to clinically insignificant levels of gingival recession. The article provides insights into the effectiveness and safety of various gingival-displacement techniques, highlighting that most methods tested in the study resulted in minimal or negligible gingival recession post-retraction.

Three-dimensional printed denture base resins are relatively new materials, and their properties need to be thoroughly investigated to assess whether they can be used clinically. The aim of the current study was to evaluate the colour stability of 3D printed and conventional denture base resins after immersion in different staining solutions. A total of 200 specimens were manufactured from two types of materials: 3D printed dental resin NextDent Denture 3D+ (NextDent, 3D Systems, the Netherlands) and heat-polymerized PMMA Vertex (3D Systems, the Netherlands), which were immersed in four types of colourants—artificial saliva, coffee, red wine and coke (n = 25). For measuring the colour changes (CIE-L*a*b* system), a SpectroShade Micro spectrophotometer (SpectroShade, Oxnard, CA, USA) was used. After seven days (T1), 14 days (T2) and 21 days (T3), the mean ∆E values were calculated and compared by the Bonferonni post hoc test. The data were processed using the statistical software SPSS 26. The level of significance for rejecting the null hypothesis was fixed at p < 0.05. The highest mean values for ∆E were found for both types of dental resin in red wine, and the lowest mean values for ∆E were found for 3D printed specimens in artificial saliva. The 3D printed denture base resin demonstrated better colour stability than the conventional acrylic materials. The staining effect correlated with the immersion time, with the red wine and coke having the strongest chromogenic impact and the period with the highest colour changes being 21 days.