Inherent difference between the tooth and implants is that an endosseous implant is in direct contact with the bone while a natural tooth is suspended by PDL. The mean values of axial displacement of tooth in the socket are 25∼100 μm, whereas the range of motion of osseoingegrated implants implants has been reported approximately 3∼5 μm. For this difference of motional range, occlusal concepts are applied differently for each restorations. Occlusal adjustments of natural teeth are based on three occlusal concepts (balanced, group function, and mutually protected occlusion). In the case of dental implants, occlusal overload is one of the main causes for peri-implant bone loss and implant prosthesis failure. So implant-protected occlusion is applied for occlusal adjustments of implant restorations. This concept is designed to reduce occlusal force on implant prostheses and thus protect implants. Working and non-working contacts should be avoided in a single implant restoration. For full-arch fixed implant prostheses, bilateral balanced occlusion has been utilized for an opposing complete denture, while group- function occlusion has been adopted for opposing natural dentition. Mutually protected occlusion with a shallow anterior guidance was also recommended for opposing natural dentition. In this case, mandibular multiple implant restorations opposing maxillary full-arch fixed prostheses are restored with group-function in right working side and shallow canine guidance in left working side for reducing overload to implants. Six month follow-up has been done and implant complications such as peri-implant bone loss and implant prosthetic failure are not shown. (JOURNAL OF DENTAL IMPLANT RESEARCH 2013;32(2): 51-54)