Is there a maximum number of replacing dental filling?

Depends on tooth : The more you drill and fill, the less tooth structure you have left. Then fillings wont hold well, margins will be ill fitting and more recurrent cavities will happen, and possibly gingivitis or bone loss due to trapping food between teeth. Then you would consider a laboratory fabricated tooth crown to properly restore tooth structure, contacts and tooth anatomy and function.

No, but...: There is no maximum number of times to replace a filling but after a while one has to determine why it needs to be redone. There may be an underlying occlusal (bite) problem or insufficient tooth structure to support a filling over time. A more permanent ceramic onlay or crown might be indicated and a more long term solution is such cases. No limit to #\fillings replaced at same visit either.

No: If you mean the number that can be replaced at one time then , no. I would be concerned if amalgam fillings are being replaced. You do not want to replace too many of those as mercury is released when they are being taken out.

No: It is usually a matter of time for the patient and the dentist.