Abstract Aim: To evaluate stresses transmitted to abutment teeth and residual ridges by using modified and conventional attachment types. Materials and methods: Ten ready-made mandibular epoxy resin models were used. Two types of attachments were placed on each side of the models. Group A received conventional attachment type on the left side of each model (34 abutment tooth) while group B received modified attachment type on the right side of each model (44 abutment tooth). The final constructed attachment types connecting between removable partial denture and fixed porcelain fused to metal crown. Strain gauge technology was used in this study to measure the stresses applied on the models with final restorations. The models were subjected to 300 N bilateral static vertical load. The stresses transmitted to abutment teeth and residual ridges were measured using universal testing machine. Results: The modified attachment showed decreased in the mean of stresses around the abutment teeth and residual ridges. Large decreases in the mean of stresses on the crest of the ridge under the first molar of partial denture were recorded compared to the conventional type of attachment. Results showed also that removable partial denture retained by modified attachment demonstrated reduction in the microstrains around abutment teeth and residual ridges. Statistically significant differences in the stresses between the two attachment types were reported. Conclusions: The residual ridge in group A exposed to a lot of stresses than group B Therefore, the residual ridge at conventional attachment side exposed to a greater bone resorption especially at the crest of the ridge. The modified attachment is getting a better distribution of forces than conventional type. Removable partial dentures fabricated with precision attachments were the viable options for patients in whom fixed prosthesis and implants were contraindicated.
Oma et al. (Thu,) studied this question.