PURPOSE: The purpose of this in vitro study was to determine the wetting properties of 3 different commercially available denture base resin materials with artificial salivary substitute by using contact angle measurements and to compare these properties before and after thermocycling.
MATERIAL AND METHODS: A total 120 specimens were fabricated with 3 different denture base materials (n=40): heat-polymerized polymethylmethacrylate (DenTek), injection-molded nylon polyamide (Valplast), and microwave polymerized (VIPI WAVE). The advancing and receding contact angles were measured with a goniometer by using the WinDrop++ software program. The contact angle hysteresis was calculated from the advancing and receding contact angles values. The same specimens were subjected to thermocycling to measure the advancing and receding contact angles values. The comparative evaluation was carried out before and after thermocycling.
RESULTS: The mean ±standard deviation contact angles of the microwave-polymerized material were (62.40 ±1.21 degrees) advancing contact angle, (32.12 ±0.66 degrees) receding contact angle, and (30.28 ±1.40 degrees) contact angle of hysteresis. It was followed by the injection-molded nylon polyamide material, whose mean ±standard deviation contact angle values were (68.57 ±1.72 degrees) advancing contact angle, (43.02 ±1.39 degrees) receding contact angle, (26.27 ±2.05 degrees) contact angle hysteresis and high impact strength heat-polymerized polymethylmethacrylate material, whose mean ±standard deviation contact angle values were (69.81 ±0.16 degrees) advancing contact angle, (41.90 ±1.02 degrees) receding contact angle, and (27.91 ±0.97 degrees) contact angle hysteresis. The statistical analysis showed significant differences among contact angle values of the microwave-polymerized material as compared with the heat-polymerized polymethylmethacrylate and injection-molded nylon polyamide materials (P
Materials and methods: QOS collagen nanofibers were electrospun by incorporating various concentrations of QOS (0.1%-10% w/w) and were cross-linked in situ after exposure to ammonium carbonate. The QOS cross-linked scaffolds were characterized and their biological properties were evaluated in terms of their biocompatibility, cellular adhesion and metabolic activity for primary human dermal fibroblasts and human fetal osteoblasts.
Results and discussion: The study revealed that 1) QOS cross-linking increased the flexibility of otherwise rigid collagen nanofibers and improved the thermal stability; 2) QOS cross-linked mats displayed potent antibacterial activity and 3) the biocompatibility of the composite mats depended on the amount of QOS present in dope solution - at low QOS concentrations (0.1% w/w), the mats promoted mammalian cell proliferation and growth, whereas at higher QOS concentrations, cytotoxic effect was observed.
Conclusion: This study demonstrates that QOS cross-linked mats possess anti-infective properties and confer niches for cellular growth and proliferation, thus offering a useful approach, which is important for hard and soft tissue engineering and regenerative medicine.