However , variability was substantial .
Restoration type , material s , the patient , the operator , the practice environment and type of care system appeared to influence longevity .
Objective To conduct a systematic review of the literature on the longevity of routine dental restorations in permanent posterior teeth , and to identify and examine factors influencing its variability .
The age of restorations in situ.
In a cross-sectional survey the age of restorations in situ was recorded in three patient groups . Group A were r and omly examined regular attenders , group B were irregular attenders r and omly chosen from patient treatment records , and in group C the age of posterior gold and composite resin restorations was recorded in selected regular attenders . The study material included 8310 restorations in group A , 1281 in group B , and 500 restorations in group C. The three material s amalgam , composite , and gold accounted for more than 90 % of all restorations . In group A 3.3 % of the restorations were scheduled for replacement . The most prevalent reasons for replacement were secondary caries , bulk fractures of the restoration , and tooth fractures . The median age of the failed restorations was fairly similar to the median age of the acceptable restorations in situ among the regular patients ( group A ) . The data indicate median ages of 20 years for gold restorations , 12 - 14 years for amalgam restorations , and 7 - 8 years for composite resin restorations . The restoration ages were influenced by the type and size of the restoration , the restorative material used , and possibly also the intra-oral location of the restorations
However , variability was substantial .
Restoration type , material s , the patient , the operator , the practice environment and type of care system appeared to influence longevity .
Objective To conduct a systematic review of the literature on the longevity of routine dental restorations in permanent posterior teeth , and to identify and examine factors influencing its variability .