Introduction: A unilateral partial denture is a treatment option for unmodified Kennedy class II cases. But from a biomechanical point of view regarding stability and stress distribution possibly insufficient. The incorporation of the glass abutment in the unilateral partial denture may add to the design; by improving the stress distribution hence, decrease the exaggerated loads conducted to the supporting structures.
Objectives: This study aimed at measuring and comparing the strain on the supporting structures of class II tooth-tissue supported telescopic partial denture with different prosthetic designs.
Materials and Methods: Three groups of class II maxillary telescopic partial dentures were constructed of BioHPP using CAD/CAM. Each group contained six specimens. Using a universal testing machine and strain gauge, stress around the abutment teeth and the distal extension saddle was measured on an epoxy model missing first and second molars under 200N vertical and oblique loads.
Results: There was a statistically significant difference in the microstrains developed at all the examined sites between the three groups (ANOVA test p < 0.001). During vertical and oblique loading, the highest mean microstrains were recorded distal to the second premolar, in all groups. The use of glass abutment in groups B and C had reduced the microstrains transmitted to the distal aspect of the abutments significantly than in group A.
Conclusions: Reduction of stress to the abutment teeth was observed when using the glass abutment, which has allowed redistribution of load between the abutments and the ridge.