Occlusion Design Of Crown Upon Implant In Posterior Tooth

Dental implant has been a most important part of prosthodontics, and restorations will be comfortable when it is supported by implants. In the process of using fixed implant-supported restorations, it would produce different stresses distributing to peri-implant bone when contacts with the corresponding teeth take place at different spots on the occlusion surface, which would influence the longevity of implants. Recently, most of the researches about fixed implant-supported restorations are concentrated on the shape of restorations, but few about occlusal situation of the fixed implant-supported restorations. Therefore, the study was aimed to analyze stress in bone around the mandible posterior implant by the three-dimension finite element analysis.In this study, models were created by data from modelling via data and CT image processing.The mandible first molar model was created by the three dimensions finite element analysis method. Stress of bone surrounding the fixed implant-supported restoration was analyzed in two situations. Firstly, under different implant-bed qualities, the stresses were analyzed in different contact-spots and different occlusions. Secondly, in the samequality bone, the stresses were observed under different contacting areas.The results indicated that: 1 > It is an accurate, visual and practical way to create models by modellingvia data and CT image processing. 2, Stress in bone surrounding implant is small when the maxillary teeth bitthe mesial ,central and distal fossa on occlusal surface of the fixedimplant-supported restoration. 3^ It is better when maxillary teeth bit occlusal surface of the implantrestoration by two contacting types, as one is cusp with ovoid fossa, theother is coupled contract. Tripod contract tends to result in high stress inbone, and makes stress asymmetric in bone. 4^ With the increase of occlusal area, stress in bone surrounding implantdecreased. However, few changes of the stress could be observed whenthe occlusal surface area reached to some extent. 5 -. With the decrease of bone quality, stress in bone increased, especiallythe Type Bland Type IV bone quality. In order to keep bone tissuehealthy, it's important to make the implant restoration light contact andreduce the occlusion force.