“Do fillings weaken teeth?”

No, fillings do not weaken teeth. The main cause of a weakened tooth structure is decay, which can grow deeper into the root. Fillings are very important for restoring tooth structure and clearing decay before it becomes worse and bigger procedures become necessary.

Cavities for sure weakens teeth, on the other hand, fillings prevent further teeth deterioration and weakening process.

Yes and no, haha...Older filling such silver filling are place in the tooth after removing decay. They do not bond to the walls of tooth to which they are placed. Composite filling (mostly tooth colored restorations) bind and bond to the wall of the tooth which help strengthen the remaining tooth structure.

It depends on how large they are. If they are too large and there is a shell tooth left to support the fill, yes, a crown would be a better treatment in this situation.

Depends. No - if the filling is small. Yes - if the filling is large.

The larger the filling the weaker the tooth will become. Small little fillings, whether they are silver or composite resin, have a lot of tooth surrounding them to support them. When the fillings get too big, there is not enough tooth to support the filling. Silver fillings expand and contract and as such can create cracks in teeth when they expand and gaps between the filling in the tooth when the silver contracts.

No. If you have cavity requiring a filling it needs to be done, cavities weaken teeth...

Fillings don’t weaken teeth. If anyone is recommended to get a filling, it’s because the tooth either chipped, in which case it’s adding what’s missing, or that person had a cavity, in which the cavity (disease, bacteria) is removed and the empty space is filled with a filling. Placing a filling without a purpose would be wrong and would weaken the tooth.

Dr. Kogan

No. They actually help strengthen teeth that have become week due to cavities.

Anything that removes the original tooth structure "weakens" the tooth. But fillings aren't just put a tooth randomly, they are used to replace tooth structure that is lost due to fracture or decay. Today's materials bond to the tooth to help strengthen the overall result.

They do. All fillings weaken teeth, whether they are silver amalgam or white "bonded" composites. It's not so much the filling that weakens the tooth, however. To be very basic about it, I will assume you are referring to teeth with cavities that then get fillings placed. So the first thing that starts to weaken the tooth is the cavity that starts "eating away" at the tooth. The dentist has to remove all of the cavity, or carious bacteria, to stop it from getting bigger. He or she then drills away the infected part of the tooth, thus weakening it more. Depending on how long this cavity has been in the tooth and how large it has gotten, the dentist may have to drill a lot of the tooth away. Finally a filling is placed. Silver amalgam doesn't "bond" to the tooth; it, sort-of, is just wedged into the space that has been created. The white composite fillings are "bonded' - almost like being glued to the tooth. But, while this is better than the amalgam, it's bond is not as strong as the intact natural tooth, either. That is why it's better not to get any cavities in the first place. Keep your teeth really clean - brush them twice a day, preferably with a battery-operated or electric or sonic toothbrush, floss nightly to remove all the food and plaque from between your teeth, rinse your mouth out with water after eating.

No. Simply defined- a "filling" is a restorative option for sealing a hole in a tooth. There a few variable here but let me try to break it down for you...
The amount of strength of the retaining walls (your tooth structure remaining) around the filling determines how "weak" a tooth might be and it's inherent risk of fracture. If the retaining walls are too thin, because the cavity (hole) was very large other restorative options should be considered. One popular option in this case would be to restore such a tooth with a device called a crown that would fit over a properly shaped tooth and actually make the tooth stronger by acting as a restorative "helmet" for the tooth.