convenience form is a planned shape change to a tooth preparation that improves access and visibility during dental treatment. It is commonly discussed in operative dentistry when preparing a cavity for a filling. The goal is to make it easier to remove decay, place materials, and finish the restoration accurately. How much convenience form is needed varies by clinician and case.

resistance form is a tooth-preparation and restoration design concept used in restorative dentistry. It means shaping the tooth and the restoration so they can withstand chewing forces without breaking. It is most commonly discussed when planning fillings, inlays/onlays, and crowns. It works alongside other concepts like retention (keeping a restoration in place) and adhesion (bonding).

retention form is the shape and design features a dentist creates so a restoration stays in place. It is most often discussed during cavity preparation for fillings and during tooth preparation for crowns. It can rely on tooth geometry (mechanical “lock”) and/or dental bonding (adhesive retention). The exact approach varies by clinician and case.

Rounded internal line angles are gently curved corners inside a tooth preparation. They replace sharp internal corners where two prepared walls meet. They are commonly used when preparing teeth for fillings, inlays/onlays, crowns, and some indirect restorations. The goal is to create a smoother internal shape that supports both the tooth and the restoration.

A chamfer finish is a smooth, sloped edge placed at the margin (border) of a tooth preparation. It creates a gradual transition between natural tooth structure and a restoration. Dentists commonly use a chamfer finish to help restorative materials blend and seal more predictably. It may be used in direct fillings/repairs and in preparations for certain indirect restorations, depending on the case.

A butt joint margin is a restoration edge design where the restorative material meets the tooth at a near 90-degree angle without a bevel. In plain terms, it is a “straight-cut” margin rather than a tapered or sloped one. It is commonly discussed in bonded restorations such as composite fillings, veneer preparations, and some ceramic restorations. The goal is a clean, well-defined margin that can be finished and checked clinically.

An enamel bevel is a small, sloped shaping of the outer enamel at the edge of a tooth preparation. It creates an angled margin rather than a sharp, 90-degree edge. It is commonly used with bonded restorations such as composite fillings, tooth-colored repairs, and some veneer or bonding cases. Its main role is to improve how a restoration blends and seals at the enamel edge.

A bevel is a small, angled surface cut along the edge of a tooth or restorative margin. In dentistry, it is commonly used when preparing teeth for bonded fillings, repairs, veneers, or certain crown margins. The angle changes how a restoration meets tooth structure at the edge. It is often discussed in the context of enamel bonding and aesthetic blending.

tunnel preparation is a conservative cavity design used to treat certain cavities between teeth while keeping much of the chewing surface intact. It creates a small “tunnel” access from the biting surface into the area of decay near the contact point. It is most commonly discussed for back teeth (premolars and molars) with early or moderate proximal caries. The goal is to repair decay while preserving the marginal ridge (the tooth structure at the edge of the chewing surface).

slot preparation is a conservative cavity design used to access and restore decay or defects on the side (proximal surface) of a tooth. It is commonly used for small to moderate lesions between posterior teeth (premolars and molars). The preparation is shaped like a “slot” or box to reach the affected area while preserving as much healthy tooth as possible. It is typically restored with tooth-colored materials such as resin composite, sometimes with a liner or base depending on the case.