If the wisdom tooth has erupted fully and in a proper position then we can save it by dental cement filling.
If the cavity is deep and near or into the pulp then we can save it by root canal
Ideally we should save natural tooth structure if its fits in above criterias.
If the wisdom teeth
has erupted in a such way that it's disturbing other tooth structures and we don't have any option left for saving it then only you should go for removal.
The wisdom tooth usually causes pain
because of its uneven position distrubing adjacent teeth and some times swelling of the tissues around the tooth causing pericoronitis ( i.e inflamation of the surrounding soft tissues ) causing pain.
Wisdom tooth which is usually considered as an extra tooth having no role in mastication (i.e chewing of food)
On other hand removal of wisdom tooth have much advantages rather than any disadvantage..
Retaining wisdom tooth some times results in food lodgement within and between adjacent tooth ,results in caries ( decay ) of the adjacent tooth.
So for improper erupted wisdom tooth, removal is the only and best available option to the date.
Which in turn also helps in preserving other tooth structures.wisdom tooth removal