I am working on Dental Implants and i want to define interaction in abaqus between an implant and the bone surrunding it. I am using Abaqus CAE to do it and i want to define frictional interaction with penalty method but I have problem with the penetration of implant in the bone. I've tried all the possible contact definitions such as surface to surface or node to surface. Sometimes Abaqus gives me some incredible answers for example pulling out the implant!!!! Please help me with this problem. Thank you....