Evaluating the Peel Bond Strength of Polymethylmethacrylate and Maxillofacial Silicone Elastomer Reinforced with Titanium Oxide Nanoparticles: A Comparative In-vitro Study

Introduction: Maxillofacial prostheses typically last around six months. The facial prostheses are usually provided with an acrylic substructure. This aids in enhanced retention and stability of silicone material. For good results acrylic and silicone materials must bond well with each other. Aim: The aim of the present study was to evaluate and compare the Peel Bond Strength (PBS) of Polymethylmethacrylate (PMMA) acrylic resin and maxillofacial silicone elastomer reinforced with Titanium oxide (TiO2) nanoparticles. Materials and Methods: The present comparative in-vitro study was conducted in the Department of the Prosthodontics and Crown and Bridge in Manubhai Patel Dental College and Hospital, Vadodara, Gujarat, India. for a time period of six months from February to July in the year 2022. A total of 64 rectangular shaped maxillofacial silicone elastomer specimens with well-formed shaped and no visual irregularity were equally divided into two groups. group A silicone was without TiO2 nanoparticles and group B silicone was added with TiO2 nanoparticles. group A was further subdivided into A1 (PMMA acrylic resin and Silicone elastomer bonded with primer) and A2 (PMMA acrylic resin with retentive holes and Silicone elastomer) with 16 specimens in each subgroup. Similarly, group B was subdivided into B1 (PMMA acrylic resin and silicone elastomer reinforced with TiO2 bonded with primer) and B2 (PMMA acrylic resin with retentive holes & Silicone elastomer reinforced with TiO2) with 16 specimens in each subgroup. The acrylic and silicone specimens were bonded together with primer in subgroup A1 and B1 and with retentive holes in A2 and B2. The PBS was assessed through a 180° peel test on a universal testing machine and the mode of failure between the two materials was visually inspected. The data was statistically analysed using Independent t-test and one-way Analysis of Variance (ANOVA) (p=0.05). Results: The difference between A1 and A2 was statistically significant (p=0.05). However, PBS values in other subgroups pairs (A1-B1; A2-B2; B1-B2) did not show a statistical significance. Tests indicated that specimens bonded with primer A-330 Gold platinum experienced adhesive bond failure. Conclusion: Within the limitations of this study, retentive holes offer significantly stronger PBS between PMMA acrylic resin and maxillofacial silicone compared to primer alone. However, incorporating nanoparticles into maxillofacial silicone does not enhance the PBS between the given two materials.