Effect of frozen storage on preservation of a silicone-based test food material

Aim: This study aimed to evaluate the effect of frozen storage on the physical properties of a silicone-based test food material, highly used to evaluate the masticatory performance in research settings. Methods: A total of 1,666 silicone cubes of Optosil Comfort® with 5.6-mm edges were shaped and stored at -18°C. The cubes were subsequently tested for flexural strength (maximum force, displacement, stress, and strain) before breaking (n = 136), changes in weight and size (n = 170), and masticatory performance (n = 1360) at eight timepoints: immediately after cube preparation (baseline, no freezing), and 1, 2, 3 and 4 weeks, and 2, 4 and 6 months after frozen storage. The cubes were thawed 8 h before each assessment. Results: The maximum force, stress, maximum displacement, and deformation values for the cubes were not affected by freezing (P > 0.05). At all of the time points, the cubes exhibited similar weight (P = 0.366) and size (identical values). The masticatory performance for the cubes also showed no differences from baseline through 6 months (P = 0.061). Conclusion: Freezing Optosil Comfort® silicone cubes did not alter the physical and mechanical properties of the material, being suitable to optimize the assessment of masticatory parameters for research purposes

Mandibular single-implant overdenture as an alternative for full arch rehabilitations: a literature review

Oral rehabilitation with mandibular single-implant overdentures (SIO) has been characterized as a solution to improve retention and stability of conventional complete dentures (CD). Among the benefits of this therapy, it can be mentioned minimally invasive surgery, simple prosthetic technique, better retention, and significantly reduced costs. However, the application of this protocol in daily clinic is still not widespread. Aim: Thus, this study aimed to perform a literature review to address the clinical characteristics of this rehabilitation, when compared to two-implant mandibular overdentures and CD. Methods: For this, a search was conducted in the PubMed database, considering articles published in English language, without date limitation. Results: It was found 243 manuscripts, of which 20 were compatible with the aim of this study after title/abstract reading. The selected papers focused on masticatory muscles function, satisfaction levels and self-reported quality of life, as well as surgical and prosthetic outcomes, such as maintenance, repair and implant failure rates. All evaluated manuscripts showed similar masticatory function and patient's satisfaction with SIO and two-implant overdenture, while results for a SIO were greater when compared to rehabilitations with CD. In addition, SIO have proven to do not damage the implant, being implant loss close to zero. However, the prosthesis fracture adjacent to the implant was a recurrent clinical outcome, which requires further studies to solve this impairment. Conclusion: Thus, it can be concluded that SIO represents an alternative treatment for frail elders or low-income patients, leading to higher masticatory function, as well as improved quality of life