The microwaveable resins displayed better adaptation, greater stiffness, and greater surface hardness than other denture base resins included in this investigation. Elastomeric toughening agents yielded decreased stiffness, decreased surface hardness, and decreased glass transition temperatures.

No abstract

Purpose: When restoring facial defects, maxillofacial prosthodontists and anaplastologists are often limited by material deficiencies. Silicone elastomers bonded to a polyurethane liner best satisfy the functional and esthetic requirements necessary for facial prostheses; however, patients using silicone prostheses with polyurethane liners often experience varying degrees of debonding at the polyurethane-silicone interfaces. This may result in failure of such prostheses. The purpose of this investigation was to evaluate the effects of five primers on bonding between polyurethane and two commonly used silicone elastomers. Following fabrication, specimens were attached to a universal testing machine and separated in tension at a crosshead speed of 25.4 mm/min. One examiner performed the assessment of T-peel strength (N/mm), peak load (N), and peel distance (mm) for all specimens. Mean data were analyzed using one-way ANOVA followed by Fisher's protected significant difference multiple comparison of the means (α = 0.05). Results: A statistically significant difference (p < 0.05) in T-peel strength was found among specimen groups. Post hoc analysis indicated that Sofreliner MS primer (1.32 ± 0.13 N/mm) and Sofreliner T primer (1.25 ± 0.11 N/mm) increased the bond strengths significantly compared to A-330-G primer (0.91 ± 0.10 N/mm) and Udagama's technique (0.13 ± 0.02 N/mm). Cohesive failure between silicone A-2000 and polyurethane liner was observed when Sofreliner MS primer and Sofreliner T were used. Conclusion: Within the limitations of this study, the use of Sofreliner MS primer and Sofreliner T primer produced significant increases in the bond strength of silicone elastomer to polyurethane liner material. Based on T-peel strength, peel distance, and peak load data, the combination of silicone A-2000 and Sofreliner MS primer resulted in the greatest mean bond strength for silicone-to-polyurethane applications.According to the American Cancer Society, head and neck cancers account for 3 to 5% of all cancers in the United States. These cancers are more commonly found in males and in persons over age 50. Moreover, an estimated 40,500 U.S. citizens develop head and neck cancers each year.1 Because many head and neck cancers are treated surgically, the resulting defects can be esthetically compromising and emotionally devastating. Advances in prosthetic therapy and reconstructive surgery have yielded significant improvements in function and appearance. Facial prostheses can be constructed using elastomers

No abstract

No abstract