Learn tooth anatomy at first.



In short tooh is piece of relatively soft bone(dentin) covered with natural crown which is called enamel, this enamel is hard like epoxy, but it cracks easily. Enamel is dead like nails and hair so it cant repair itself. dentin is not so absolutely dead, but still cant repair itself.



Tooth also has blood supply system which is called nerve, its purpose is to provide water to the tooth bone and enamel without nerve tooth will crack and disintegrate easily.

Dentists like to remove nerve because it my cause problems sometimes, but in reality it is not that dangerous if timely help is available. Without nerve tooth will crack for sure if not protected by crown.



Tooth structure is quite interesting, it is not like other bones but lots of small parallel tubes coming from the nerve to the edges of tooth, because of that tooth has very high tensile strength but it is prone to cracking.



To repair tooth you mostly need to restore missing enamel. However if decay progressed for long enough dentin is usually badly damaged, decaying bone spreads and makes pressure to the nerve, in some cases infection may happen.

If you feel dental pain it means that somewhere you have decaying dentin which makes pressure on the nerve.



So before beginning repair works it is necessary to remove damaged dentin. or else decay will spread. Also damaged dentin cause lots of pain for no visible reasons just cleaning it is enough to relieve dental pain.

Damaged dentin is quite soft and it is easy to scrape with some sharp tool. Usually there is no pain unless you reach healthy tooth surface.

Also it is quite easy to see if everything is ok , because decaying bone becomes darker. It is necessary to scrape away all dark spots until everything is clean and hard.



In case of open nerve work becomes more complex because inflammation may happen.

usually dentist will perform root canal procedure then, but it is also possible to save nerve by cleaning it up and placing CaOH on it. Pulp has one interesting unknown feature: it can regrow tooth. Under stimulation pulp will turn into dentin, however if there are lots or bacteria around that will not work and inflammation will happen instead

CaOH can do that stimulation and somehow kill bacteria too.



The big problem with dental work is that you work in very wet area so it will be hard to glue something to wet surfaces.

And even worse is that dentin is something like calcium reinforced fabric made of tiny threads of collagen. Cleaning will mess up that surface and make it into something like greased chalk. Obviously it is nearly impossible to glue something to such surface properly.

thats why most of DIY dentistry will fail.

lots of people try to use super glue or epoxy to glue back pieces of tooth but that is quite useless. they will fall off even under minimal load. gluing teeth is about same as trying to glue Teflon



Currently pharmacists invented new materials to fight with that problem. for example Clearfil SE bonding agent seems to be good but very expensive. one pack costs about 200$



Another problem is that all epoxies will shrink, simple epoxy will shrink about 1-3% and so it will detach from tooth surface and let contaminants enter inside.



Usage of costly filing material with quartz particles will help a little. Seems ebay sells one for about 75$



Cheap DIY dentistry without these exotic materials is quite primitive. All attempts to use pure epoxy filings will fail. Amalgam is quite worthless to because it needs special preparation which scraps away too much bone. Even if filling will not fall out decay will start again.



Gluing crowns is another story, because you can glue them to enamel (however dentists prefer to scrap enamel way to make crown smaller.)because of little amount of glue there is no shrinkage.

and bonds to enamel are very strong and can be made even stronger if you etch it with some acid.



Before doing any of filings or gluing it is vital to dry surface.

and in case of epoxy application it is good idea to scrap surface with small hadrd steel brush to mix collagen threads with your epoxy. It may increase bonding strength quite much and aslo it will clean away some of remaining bacteria and decayed cells



Even if job is done perfectly there are some more dangers. crown shape must be correct. in the lower area of tooth some gap between teeth must exist bigger gap = better, top surfaces sides must touch nearby teeth and have as little gap as possible.



Without proper gap , food particles will go down and there will be no way to clean them, finally they will be pushed between gums and tooth which will cause decay, inflammation abscess or other nasty things. so that must be taken into account during repair.



If there is no gap between teeth like often happens with wisdom teeth it is nearly impossible to do repairs

Primitive gluing may cause closing of gap between teeth and some of glue may enter between gums ant tooth what may cause inflammation.

it is quite hard to remove that glue, because unlike dentin bonds to enamel are stronger and it is possible to cause damage to the bone while trying to scrub excessive hardened epoxy away and you may accidentally implant contaminated piece of glue between bone and tooth, which probably will cause some problems.



To avoid these problems rubber barrier is used sometimes so that you protect gum line from contamination and damage



So my recommendation is to leave all heavy damage repair to dentist. And only work on light cracks that do not reach gums or pulp.

Also remember that faulty work will do lots of damage.

