Dental restorations (fillings) fail due to excessive wear, fracture of material or tooth, loss of retention, or recurrent decay. The larger the size of the restoration and/or the greater the number of surfaces filled increases the likelihood of failure. Restorative materials have different survival rates and fail for different reasons, but age should not be used as a failure criteria. Drilling to remove and replace fillings can weaken teeth. If feasible, repair of small defects, rather than replacement of a filling, can save tooth structure and increase the lifespan of restorations at a low cost.
Sources:
Blum IR et al. Factors influencing repair of dental restorations with resin composite. Clin Cosmet Investig Dent. 2014 Oct 17;6:81-7. PMID: 25378952.
Gordan VV, et al. Alternative treatments to replacement of defective amalgam restorations: results of a seven-year clinical study. J Am Dent Assoc. 2011 Jul;142(7):842-9. PMID: 21719808.
Lynch CD et al. Student perspectives and opinions on their experience at an undergraduate outreach dental teaching centre at Cardiff: a 5-year study. Eur J Dent Educ. 2010 Feb;14(1):12-6. PMID: 20070794.
Mjör IA et al. Failure, repair, refurbishing and longevity of restorations. Oper Dent. 2002 Sep-Oct;27(5):528-34. PMID: 12216574.