immediate versus delayed loading of dental implants in the maxillae of minipigs followup of implant stability and implant failures purpose to assess the course of the stability and the failure rate of dental implants placed in the partially edentulous maxillae of minipigsmaterials and methods three months after tooth removal implants were placed in 9 minipigs six implants xive friadent mannheim germany were placed on each side of the posterior maxilla after preparation of the implant sites either by an osteotome technique or with spiral drills implant stability was assessed by resonance frequency analysis rfa at the time of placement at secondstage surgery which took place after a healing periods of 1 2 3 4 or 5 months and after a loading period of 6 monthsresults implant stability was significantly influenced by the healing period p 007 implant stability decreased after 1 to 3 months of healing for both of the placement techniques and increased after a healing period of 4 months after implant site preparation by an osteotome technique 6 of 12 immediately loaded implants 18 of 24 implants loaded after healing periods of 1 to 3 months and 1 of 18 implants loaded after a healing period of 4 or 5 months were lost after implant site preparation using spiral drills 7 of 12 immediately loaded implants 12 of 24 implants loaded after healing periods of 1 to 3 months and 2 of 18 implants loaded after healing periods of 4 or 5 months were lost broad overlapping of confidence intervals for the number of implant failures revealed that there was no relevant difference between immediate and early functional loading for either of the 2 techniquesdiscussion and conclusion implant loading after healing periods of 1 to 3 months did not improve implant survival compared to immediate loading in the posterior maxillae of minipigs not until a healing period of 4 months was reached did implant stability begin to increase only when functional loading was started at this point in time was maximal implant survival achieved