Sleeve crown denture is a kind of restoration developed in the last decade or so, the scientific name is conical sleeve crown, which is mainly made of two layers of crowns, and it is called sleeve because it is a two-layer set. There is mainly a layer of internal sleeve, which is used to connect their teeth, and a layer of external sleeve, both of which are fixed on the teeth by friction, the advantage is that it is more beautiful, without all the exposed rings and so on. And mainly used in the development of loose teeth, loose teeth in the mouth, but there are a lot of patients and do not want to pull, feel that their real teeth or try to retain, this situation is often to consider doing sleeve crowns. Because the socket crown picking instant separation, no force on the tooth, many second degree loose or even third degree loose teeth, are relying on this type of restoration to retain many years. Because according to the original restoration method, the third degree of looseness or the second degree of looseness is very big generally consider extraction. Moreover, this type of restoration is more favorable to patients who have periodontal disease, and the effect of retaining loose teeth after periodontal systematic treatment is very good, which is its advantage. Another is like a fence, so that it is tied together, although loose, but tied into a large tooth or the whole mouth of the teeth are tied together, supporting each other to make its stability effect is better. However, the sleeve crown denture also has certain disadvantages, because you have to do two layers of sleeve crown, so relative to their own remaining teeth grinding more, both to grind the thickness of the normal porcelain teeth, but also to grind the thickness of the inner base crown, about 0.2-0.5mm thickness, is to grind a little bit more, so some of the living pulp teeth may be more sensitive, so it is required to do the living pulp teeth root filling treatment, kill it, and then do it again, the pulp teeth, the pulp of the living pulp of the living pulp of the living pulp of the living pulp of the living pulp of the living pulp of the living pulp of the living pulp of the living pulp of the living pulp of the living pulp of the teeth. Then do the sleeve crown, its destruction of teeth may be relatively more, that is its disadvantage. But even though there is more destruction, at least the tooth is preserved, that is, there is more grinding. And the price is relatively expensive, because of its requirements for precision, inside and outside the crown to rely on friction to fix, so the requirements of the very precise, if you do too loose, there is no fixed role, if you do too tight and can not be removed, this is its advantages and disadvantages.