Crown vs. filling

It depends on how much sound tooth is left and whether any cusps are undermined or cracked. A filling replaces missing structure but does not hold the remaining walls together, and a very large filling can actually contribute to a cusp fracturing. If the walls are sound, a filling may be appropriate; if they are not, cuspal coverage is the more durable answer. It is entirely reasonable to ask what specifically about your tooth makes a crown necessary.

An onlay covers one or more cusps to protect a weakened tooth while conserving the sound structure that a full crown would remove. It costs about the same as a crown, so there is no financial reason to prefer one, and for many teeth it is the better-judged option. Not every practice uses them routinely. If a crown has been proposed and an onlay has not been discussed, asking whether it would work in your case is a fair question.

Where the tooth is substantially broken down or the cusps are undermined, cuspal coverage generally outlasts a very large direct filling, so yes in that situation. Where the walls are sound and the cavity is moderate, a filling removes less tooth and keeps more options open. The judgment is about the specific tooth instead of a general ranking, and it should be explainable in terms of what remains and what is at risk of fracturing.

Because it involves an additional stage. The restoration is made outside the mouth in a laboratory or by chairside milling, which adds material and technical cost, and the sequence usually includes a temporary and a separate bonding or cementation visit that is time-consuming. What you are buying is a restoration that fits and performs more predictably than a very large direct filling, plus protection against the tooth splitting.

Often, yes, and that progression is common. Teeth are restored repeatedly until a direct filling no longer holds them together. The caution is that if the walls are already undermined, a large filling may fail or the tooth may fracture in the interim, and a cusp fracture can occasionally extend below the gum and make the tooth harder to save. Ask what the risk of waiting is for your specific tooth instead of assuming it is neutral.

Back teeth commonly do, because they lose structure both to the original problem and to the access opening, and they become more prone to splitting. Front teeth with minimal structural loss are sometimes restored without one. Where coverage is needed, an onlay may achieve it while conserving more tooth than a full crown. It should be explained in terms of your specific tooth, not presented as an automatic rule.

A filling is typically a single, relatively quick appointment. A crown or onlay usually requires at least two visits, preparation and a temporary at the first, then fitting the final restoration at the second, unless the practice mills the restoration chairside in one visit, which some do.

Yes: they are billed under different procedure codes with different allowed amounts and different likelihoods of an alternate-benefit downgrade. Crowns in particular are the most common target of a downgrade toward a filling. A pretreatment estimate is worth obtaining for anything beyond a straightforward filling.

It depends on the tooth's location and load instead of one material being universally best: high-strength ceramics or metal alloys suit heavy-load back teeth, while materials chosen for translucency suit visible front teeth where appearance matters most. Ask why a specific material is being proposed for your specific tooth.

Sometimes: a small chip or marginal defect in an existing filling can occasionally be repaired directly without removing and replacing the whole restoration, which is more conservative. Whether repair is appropriate depends on the extent of the problem and the material involved; ask specifically whether repair was considered before a full replacement is proposed.

Not automatically: size alone is one factor among several, including how much sound wall remains, whether cusps are undermined, and the bite forces on that specific tooth. A large but well-contained cavity with sound surrounding walls can sometimes still be filled; the assessment should be tooth-specific instead of based on cavity size alone.

A true temporary is not designed to serve indefinitely and should be followed by a definitive restoration on a timeline the practice states explicitly: ask directly how long the temporary is expected to hold and what happens if the follow-up appointment is delayed.