An acrylic educational model with missing 6, 7 was used to represent a Kennedy class I situation. The first and second premolars of the right and left sides were prepared to receive full coverage porcelain fused to metal splinted crowns with the studied attachments included. The study was divided into two major stages: Stage I: The removable partial denture was retained by resilient extra- coronal attachment. Stage II: The removable partial denture was retained by rigid intra- coronal attachment combined by resilient versacryl layer. After constructing the partial dentures with their corresponding attachment counterparts, the edentulous areas of the acrylic model were modified by removing 2 mm of it and replacing them by heat cured silicone based soft liner to stimulate the mucosa. The acrylic resin around the terminal abutments was then reduced to create box shaped areas of acrylic resin. The strain gauges were then adhered to the buccal and distal surfaces of the box shaped preparation and the wires of strain gauges were allowed to pass through channels created in the base of the model. A metal bar was attached to acrylic resin teeth of the partial denture so that it extended from the first molar of one side to the first molar at the other side. Two dimples were created in the metal bar, one at the center of the bar and the other one at the center of the first molar area to accommodate the tip of the universal testing machine. The latter was used to apply a load starting from 0 to 70 N. Once the load was applied, the micro-strain readings transferred to the strainmeter were captured on a monitor screen, saved and printed. The data were collected, tabulated and presented as means and standard deviation and then statistically analyzed. The results of the study showed a statistically significant difference between the two stages, where the mean micro-strain values recorded for the intra-coronal attachment combined by the versacryl layer (SII) were significantly higher than those recorded for the extra-coronal attachment (SI).