The document discusses different materials used in dentistry and their affinity for biofilm formation. It states that metals generally have smooth, polished surfaces and low biofilm affinity. Ceramics also have low affinity unless roughness is present from machining without reglazing. Polymers are rougher with pores, allowing easier biofilm penetration and higher affinity. Specific examples discussed include biofilm formation around dental implants, on crown margins due to microgaps, and below dentures leading to conditions like denture stomatitis.