Evaluation of stress distribution in edentulous complete cleft maxillae constructed by different implant plannings under occlusal loading with finite element analysis

Stress distributions in cortical bone around conventional andmini dental implants which were located in edentulous unilateral completecleft maxilla with different plannings was evaluated in our study.Implants were placed in 1. premolar, 2. premolar and 1.molar regions and two, four and six implant retained overdentures werecreated. Attachment system was determined as ball attachment and oring/ball attachment for conventional and mini dental implants,respectively. Maximum and minimum principal stress distributions wereevaluated in all models under six different loading conditions. Occlusalforce value of 100 N was applied both vertically and horizontaly on firstmolar teeth and vertically on central incisors.In all occlusal loading conditions model with six mini dentalimplants found advantageous to the other models in terms of stressdistribution. Maximum and minimum principal stress values increased inmodel which conventional and mini dental implants were used together.And also stress values of vertical loading conditions were found lower thanvalues of horizontal loading conditions. It is considered that the reason ofthe lowest stress values in models with mini dental implants were relatedto the stress breaking characteristic of o ring attachment.