This review examined the current state of knowledge on the modifications of commercial soft lining materials (SLMs) with a variety of antifungal compounds: (i) polyene antibiotics, including nystatin and amphotericin B, (ii) azole drugs, including fluconazole, itraconazole, clotrimazole, ketoconazole, and miconazole, and (iii) antiseptics, including chlorhexidine salts to give them anti-Candida albicans properties. The effect of such modifications on the SLMs’ physical properties, such as drug release, water sorption, surface properties, bond strength, tensile strength, and hardness, was also analyzed. In effect, this study provided a unique compilation of research results obtained for numerous properties of SLM modified with antifungal compounds that differ in their chemical structure and mechanism of antifungal action. These results might also be useful for prosthetic dentistry, where SLMs are used to prevent and treat candidiasis, the most common disease among denture wearers.

The colonizing of temporary soft lining materials in the oral cavity by yeast-like fungi, particularly Candida albicans, poses a significant risk of complications during prosthetic treatment. Various experimental materials incorporating antimicrobial additives, such as drugs, natural oils, and inorganic particles, have been tested. However, these components are not chemically bonded to a polymer network, making them prone to being easily released into the surrounding environment. This study aimed to evaluate experimental soft lining materials containing liquid components with 2-(methacryloyloxy)ethyl-2-decylhydroxyethylmethylammonium bromide, a monomethacrylate monomer with a quaternary ammonium group, added at concentrations of 8.54%, 8.75%, and 14.90% by weight. The adherence of Candida albicans, cytotoxicity, glass transition temperature (Tg), sorption (WS), solubility (WSL), Shore A hardness (SHA), tensile strength (TS), and tensile bond strength (TBS) were tested. Two tested materials did not show cytotoxicity for the 2-day undiluted extracts. The Candida albicans adhesions were reduced for two materials. The SHA values compared to the control were varied but all decreased with time. WS and WSL increased compared to the control. The TBS values were at an acceptable level.

Background: This study aimed to assess the impact of methacrylate-functionalized polyhedral oligomeric silsesquioxanes dispersed in nanosilica (MA/Ns-POSS) on the mechanical properties of light-curable dental resins and composites. The primary goal was to evaluate how different concentrations of MA/Ns-POSS (0.5–20 wt.%) affect the hardness, flexural strength, modulus, diametral tensile strength, polymerization shrinkage stress, and degree of conversion of these materials. Methods: A mixture of Bis-GMA, UDMA, TEGDMA, HEMA, and camphorquinone, with a tertiary amine as the photoinitiator, was used to create resin and composite samples, incorporating 45 wt.% silanized silica for the composites. Hardness (Vickers method, HV), flexural strength (FS), and flexural modulus (E_f) were assessed using three-point bending tests, while diametral tensile strength (DTS) polymerization shrinkage stresses (PSS), and degree of conversion (DC) analysis were analyzed for the composites. Results: The results showed that resins with 10 wt.% MA/Ns-POSS exhibited the highest E_f and FS values. Composite hardness peaked at 20 wt.% MA/Ns-POSS, while DTS increased up to 2.5 wt.% MA/Ns-POSS but declined at higher concentrations. PSS values decreased with increasing MA/Ns-POSS concentration, with the lowest values recorded at 15–20 wt.%. DC analysis also showed substantial improvement for 15–20 wt.% Conclusion: Incorporating MA/Ns-POSS improves the mechanical properties of both resins and composites, with 20 wt.% showing the best results. Further studies are needed to explore the influence of higher additive concentrations.

Six novel urethane-dimethacrylates with quaternary ammonium groups (QAUDMAs) were successfully synthesized from 2-(methacryloyloxy)ethyl-2-hydroxyethylmethylalkylammonium bromide (QAHAMA-n, where n was 8 and 10) and diisocyanate (isophorone diisocyanate (IPDI), 4,4′-methylenedicyclohexyl diisocyanate (CHMDI), and 4,4′-diphenylmethane diisocyanate (MDI)). Their chemical structures were confirmed through nuclear magnetic resonance spectroscopy (NMR) and Fourier transform infrared spectroscopy (FTIR). The refractive index (RI) and density (d_m) were also determined. The novel QAUDMAs were compounded with common dental dimethacrylates and subsequently photopolymerized. The resulting copolymers, comprising QAUDMA 40 wt.%, bisphenol A glycerolate dimethacrylate (Bis-GMA) 40 wt.%, and triethylene glycol dimethacrylate (TEGDMA) 20 wt.%, were tested for water sorption (WS) and solubility (SL). The WS and SL values decreased following these orderings based on the diisocyanate: IPDI > CHMDI > MDI for WS, and MDI > CHMDI > IPDI for SL. The WS values ranged from 11.50 to 13.82 µg/mm³, and were significantly lower than the recommended maximum for dental materials, 40 µg/mm³. The SL values that met the recommended maximum, 7.5 µg/mm³, ranged from 2.67 to 6.75 µg/mm³. Only the copolymer having the QAHAMA-8- and MDI-derived QAUDMA had the SL slightly exceeding 7.5 µg/mm³, at 7.89 µg/mm³.

This review examines strategies to enhance the antifungal properties of commercial soft lining materials (SLMs) through modification with plant-derived oils, extracts, and powders. These natural bioactive compounds act via multiple mechanisms, including disruption of fungal cell membranes, inhibition of biofilm formation, and interference with Candida albicans metabolism, the pathogen causing denture-associated candidiasis. Their incorporation into SLM provides localized antifungal activity at the denture–mucosa interface. The review highlights Aloe vera (aloe), Azadirachta indica (neem), Ocimum basilicum (basil), Melaleuca alternifolia (tea tree), Cocos nucifera (coconut), Allium sativum (garlic), Thymus vulgaris (thyme), and chitosan as notable sources of phytotherapeutics that consistently inhibit C. albicans growth. In addition to antimicrobial effects, studies assessed both intrinsic (hardness, tensile strength, tear strength) and interfacial (bond strength) mechanical properties, as well as surface roughness. Most formulations maintained acceptable mechanical performance and improved surface smoothness. Key limitations include rapid leaching of active compounds, variability in testing methods, and insufficient in vivo and cytotoxicity data. Future research should prioritize the high-quality purification of natural extracts, the isolation of well-defined bioactive compounds, and the design of systems enabling selective and sustained release of these agents, ensuring reproducibility, enhanced stability, and clinical reliability of next-generation bioactive SLMs.

Poly(acrylamide) (PAM) hydrogels offer biomedical potential, but bacterial colonization limits their long-term use. This study examines PAM hydrogels modified with quaternary ammonium monomethacrylate (QAHAMA-10) for antimicrobial properties. Five formulations with QAHAMA-10 to acrylamide (AA) molar ratios ranging from 2.5 to 30 mol.% and crosslinked with 1 mol.% N,N′-methylenebisacrylamide (bis-AA) were evaluated. QAHAMA-10 improved hydrogel stability, especially at 10 mol.%, which showed the best structural integrity and transparency. The degree of swelling (DS) decreased with increasing QAHAMA-10 content, from 394.4% (2.5 mol%) to 180.0% (30 mol%), versus 938.4% for the reference. No bacterial growth was detected in suspensions recovered from wells with experimental hydrogels. The hydrogels inhibited Staphylococcus aureus ATCC 25923, with inhibition zones ranging from 16.2 to 23.1 mm depending on the QAHAMA-10 content, while the reference showed no inhibition. In contrast, no activity was observed against Escherichia coli ATCC 25922 in the disk diffusion assay. Alamar Blue reduction in fibroblast L929 cells decreased with higher QAHAMA-10 content, ranging from 70.8% to 27.7% after 24 h and 74.4% to 26.1% after 48 h, compared to 78.1% and 94.2% for the reference. Overall, 2.5 mol.% QAHAMA-10 offered the best balance of anti-S. aureus activity and cytocompatibility, while 10 mol.% provided optimal physicochemical properties.