Prosthodontics & Occlusion · single question
The partial prosthesis is loose and moves during chewing — which property is affected?
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Correct answer: A. Stability
Stability (A). In removable prosthodontics:
• Stability: resistance to HORIZONTAL and ROTATIONAL forces — prevents the denture from moving/sliding DURING FUNCTION (chewing, lateral forces). A loose prosthesis that moves laterally/anteroposteriorly during chewing has poor stability.
• Support: resistance to VERTICAL forces directed TOWARD the tissue — prevents denture from sinking into the mucosa when biting. Provided by rests on abutments and the residual ridge.
• Retention: resistance to DISPLACEMENT AWAY from the tissues — prevents the denture from coming out when opening the mouth or yawning. Provided by clasps engaging undercuts.
The key phrase 'moves while chewing' = functional lateral forces = stability problem.
• Stability: resistance to HORIZONTAL and ROTATIONAL forces — prevents the denture from moving/sliding DURING FUNCTION (chewing, lateral forces). A loose prosthesis that moves laterally/anteroposteriorly during chewing has poor stability.
• Support: resistance to VERTICAL forces directed TOWARD the tissue — prevents denture from sinking into the mucosa when biting. Provided by rests on abutments and the residual ridge.
• Retention: resistance to DISPLACEMENT AWAY from the tissues — prevents the denture from coming out when opening the mouth or yawning. Provided by clasps engaging undercuts.
The key phrase 'moves while chewing' = functional lateral forces = stability problem.
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