Influence of Mandibular Residual Ridge Morphology on Pressure Distribution During Impression Procedures: A Model Experiment

Purpose: To clarify the relationship between residual ridge morphology and pressure distribution of the alveolar bone surface during dental impression procedures. Materials and Methods: Seven experimental models of the mandibular posterior residual ridge with the same ridge morphology but different mucosa (ie, silicone material) thicknesses and bone (ie, plaster) shapes and sizes were fabricated. The pressure on the bone surface was recorded using a pressure sensor sheet. The data from each model were compared using the Kruskal-Wallis test, and P .05 was considered statistically significant. Results: Even with the same ridge morphology, the distribution of the impression pressure on the bone surface differed according to the mucosal thickness and bone shape and size. Pressure tended to concentrate on sharp edges and prominences of a slope and became more widely distributed as the mucosal thickness increased. Conclusion: Within the limitations of this experimental study, the morphology of the residual alveolar ridge (bone and mucosa) appears to be a significant influencing factor for the pressure distribution during impression procedures.