Dental Mechanics Quiz

The imaginary line connecting the points where the clasps on a distal extension partial denture contact the teeth. It's crucial for understanding how the denture will move under different forces.

The imaginary axis around which the distal extension partial denture rotates, caused by forces like chewing.

The imaginary line connecting the rests on the teeth that support a distal extension partial denture. It acts as a stable base.

The imaginary line connecting the points where the denture base contacts the supporting tissue. It helps distribute forces.

A type of fulcrum line formed when there's only one supporting tooth. The denture will rotate around this tooth.

A type of fulcrum line formed when the supporting teeth are on one side of the arch. The denture will rotate around this line.

A type of fulcrum line formed when two supporting teeth are located symmetrically on opposite sides of the arch. The denture will rotate around this line.

A type of fulcrum line formed when two supporting teeth are located asymmetrically on opposite sides of the arch. The denture will rotate around this line.

A stable area formed when there are more than two supporting teeth. The denture won't rotate as easily, increasing stability.

The intersection of two planes forms a linear axis, around which rotational movement of an object occurs in a plane perpendicular to those planes.

Forces generated during function of a removable partial denture are transmitted to the oral tissues based on inclined plane and lever principles.

A rigid bar that rotates around a fixed point (fulcrum) due to applied force, and the leverage type is determined by the position of the fulcrum.

A fulcrum located in the center, force applied at one end, and resistance at the other, like a seesaw. This is commonly seen in distal-occlusal rests and circumferential clasps used in removable partial dentures.

The fulcrum is located at one end, the resistance is in the middle, and the force is applied at the other end, like using a wheelbarrow. An example is a mesio-occlusal rest and a bar clasp used in removable partial dentures.

The fulcrum is at one end, the force is applied in the middle, and the resistance is at the other end. Examples include a fishing rod and a tooth-supported removable partial denture.

The ability of a lever system to amplify force, denoted by the ratio of force arm to resistance arm. Higher mechanical advantage can lead to increased denture movement and potential tissue damage.

A type of partial denture where support comes from teeth on both sides of the edentulous space.

A type of partial denture where support comes from both teeth and tissues.

The area where a partial denture receives support from teeth.

The area where a partial denture receives support from the gums.

A component that transmits occlusal forces to the abutment teeth in a tooth-supported partial denture.

Occlusal rests placed on the abutment teeth adjacent to the edentulous space in Class I and Class II partial dentures.

Occlusal rests placed on the teeth near the edentulous crest in Class III partial dentures.

Occlusal rests attached to the abutment teeth adjacent to the edentulous space in Class IV partial dentures.

Regions that are typically avoided when placing occlusal rests, to ensure proper bite and function.

A strategy to distribute forces across a wider area, especially in mucosa-supported cases, helping to prevent tissue damage.

A type of direct retainer that is placed on the cingulum of a tooth. It's used when the tooth's anatomy doesn't allow for a traditional rest.

A minimum preparation is needed for rest placement when all teeth are in tight occlusal contact. However, this doesn't apply to teeth with thin enamel or abrasions. These teeth need crowns instead.

Direct retainers are the parts of a removable partial denture that attach directly to the abutment teeth. They prevent the denture from displacing and keep it in place.

When placing direct retainers, an ideal arrangement is to place three retainers as far apart as possible, creating a triangle shape. This creates a more stable retention system.

Direct retainers should be able to allow limited movement without transmitting torque to the supporting tooth. This ensures flexibility and reduces stress on the tooth.

If there are limited undercuts or short guiding planes on a tooth, more direct retainers are needed to ensure stability. It compensates for the lack of support.

Direct retainers are placed first, starting from the posterior region of the arch. Anterior placement is minimized to avoid interfering with esthetics.

Placing multiple retainers on the same plane doesn't offer any mechanical advantage. It actually makes it harder to clean and can stress the supporting tooth.

Free-end RPDs (removable partial dentures) need two direct retainers, placed diagonally, to ensure stability. This applies when there are only two abutment teeth.

Occlusal rests placed on teeth that are not clasped act as indirect retainers, providing additional support to the denture and preventing tipping.

The flexible part of a clasp arm that fits into the undercut area of the tooth, providing retention for the partial denture. It is located close to the equator line for aesthetics and mechanical advantages.

The most ideal position for an indirect retainer relative to the fulcrum axis, facilitating stability and minimizing denture movement.

Connectors that link major connectors to other components of the denture, like clasps or artificial teeth.

A key consideration when placing minor connectors to ensure comfort, ease of cleaning, and proper placement of artificial teeth.