Longevity of Amalgam Build-Up Restorations in Endodontically Treated Teeth

background and aim: restoration of endodontically treated teeth is one of the most important and challenging topics in restorative dentistry. longevity of such restorations is an essential factor in treatment planning. amalgam build-up is a conservative method for restoration of endodontically treated teeth. therefore, this study aimed to assess the longevity of this type of restoration in endodontically treated molar teeth. materials and methods: in this retrospective study, 110 endodontically treated molar teeth of 98 patients that had received amalgam build-up restorations with at least one cusp coverage with 3-10 years of longevity were evaluated. the restorations included mesio-occluso-distal (mod;40%), disto-occlusal (do;23%), mesio-occlusal (mo;17%) and complex amalgam restorations (20%). binary logistic regression and kaplan-meier tests were used for statistical analysis. results: of all restorations, cracks were observed in 22.7% of restorative materials and 10.9% of teeth. secondary caries was found in 29% of the teeth. based on binary logistic regression, mod restorations had significantly higher rate of marginal fracture and recurrent caries (p<0.05). teeth with one or four built-up cusps were significantly more resistant to fracture compared to other groups. patients, who regularly used dental floss had significantly lower rate of secondary caries and restoration fracture (p=0.032). conclusion: the average longevity of amalgam build-up restorations was 8.45 years, which is comparable to minimum longevity of casting restorations. thus, amalgam restorations seem to be an acceptable conservative method for restoration of endodontically treated teeth.