Background: Self‑ disinfecting impression materials would reduce time and energy needed for impression disinfecting process in clinic. The aim of this study was to evaluate the antimicrobial effect of alginate mixed with nanosilver solution at a concentration of 500 ppm and 1000 ppm on common oral microorganisms and assess changes in working time, setting time, and surface detail reproduction. Materials and Methods: In this in vitro study, three groups were assigned. The first group was alginate, the second group was alginate mixed with 500 ppm nanosilver, and the third group was alginate mixed with 1000 ppm nanosilver. Antimicrobial effect on Escherichia coli, Staphylococcus aureus, and Candida albicans was studied using direct contact test in each group (n = 10). Working time (n = 10), setting time (n = 10), and surface detail reproduction (n = 10) were evaluated separately using the ISO 21563 protocol. Descriptive tables were used to describe the data. Kruskal– Wallis test used to determine significant differences in the number of colonies was counted in antimicrobial test (α = 0. 05). Results: No adverse effects observed in working time, setting time, and surface detail reproduction of alginate impressions. Alginate mixed with silver nanoparticles showed no inhibitory effect on S. aureus and C. albicans, but the number of E. coli colonies were counted in the group 1000 ppm was significantly lower than 500 ppm (P = 0. 001). Conclusion: Antimicrobial effect of alginate mixed with silver nanoparticles is not clinically indicated. Nevertheless, its physical features did not change significantly.

Dental impression materials are fundamental to the production of accurate dental prostheses and restorations. This study focused on the formulation and characterization of a novel, plasticizer-free condensation silicone paste, comparing its performance to a commercial benchmark, Speedex. A specific laboratory paste was developed using 39 vol% hydroxy-terminated polydimethylsiloxanes (PDMS-OH), a high concentration of inorganic fillers (60 vol% silica and calcite), and 1 vol% tetraethyl orthosilicate (TEOS). In contrast, characterization of Speedex revealed a lower inorganic filler content of approximately 40 wt% and the likely presence of plasticizers. A detailed comparative analysis of physicochemical, rheological, and mechanical properties was conducted. The high-filler laboratory formulation demonstrated significantly improved dimensional stability, exhibiting less shrinkage over 12 hours compared to Speedex. This enhancement, however, resulted in a predictable trade-off in mechanical properties. The formulated paste was substantially stiffer, with a higher elastic modulus (4. 8 ± 0. 2 MPa vs. 3. 63 ± 0. 12 MPa) and a slightly greater Shore A hardness (62 vs. 60), but it showed markedly reduced ductility, with a lower elongation at break (36. 69% vs. 51. 82%) than the more flexible commercial material. Rheological profiles also differed notably, reflecting their distinct compositions. These findings highlight that a high-filler, plasticizer-free formulation strategy can significantly improve dimensional accuracy, albeit at the cost of reduced flexibility, providing valuable insights into the structure–property relationships that govern the performance of condensation silicone impression materials.

A novel dust free alginate impression material was formulated and prepared, comprising an alginate polyvinylpyrrolidone and tetraflouroethylene resins, a mixture of liquid paraffin and dimethylpolysiloxane oil as the dust generation controlling agents and processed diatomaceous earth filler which was obtained from Iranian ore. No dusting was detected during the mixing of the powder and the conventional properties of the impression material, like working and setting times and compressive strength were in the range of the required specifications for alginate dental impressions. The compressive strength was measured to be 2.6 times of the minimum requirement for such fast setting impressions.

Dental impression can be contaminated through contact with patient's saliva, blood, or plaque and cross-contamination is avoided by disinfecting impression materials. Nevertheless, the disinfectants may affect the wettability and surface roughness qualities. This study aimed to investigate how the wettability and surface roughness of polyether impression material changed after being immersed in two disinfectants (2% glutaraldehyde for 10 min and 200 ppm hypochlorous acid for 15 min.). 60 polyether dental impression material specimens (Monophase Impregum, 3MESPE, Germany) were randomly categoried into three test groups of ten specimens for each test. A ring mold with a diameter of 30 mm and a thickness of 6 mm was used to prepare the specimens. The specimens were submerged in two disinfection solutions: 2% glutaraldehyde and 200 ppm hypochlorous acid. The control group did not get any disinfection. The wettability of the specimens was determined by measuring the contact angle with a Goniometer, while surface roughness was determined using a digital Profilometer. The data were submitted to a 5% variance significance analysis threshold. The results of this study show that wettability and surface roughness of polyether impression material indicate a non-significant difference as compared with the control group (P>0.05). Within the study's limits, 2% glutaraldehyde showed safe for 10 minutes of immersion disinfection, whereas immersion in 200 ppm hypochlorous acid for 15 minutes shows promise as an efficient disinfectant without compromising the polyether's wettability or surface roughness.