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 .
Five-year performance of high-copper content amalgam restorations in a multiclinical trial of a posterior composite.
PURPOSE This paper reports the 5-year performance of the restorations of the high-copper content dental amalgam alloys included in the worldwide programme of clinical trials of Occlusin , including unique data on wear . METHODS The methods employed are common to those previously reported for the multi clinical evaluation of Occlusin . Analysis of the data is limited to simple statistical procedures . RESULTS The findings lend support to existing knowledge concerning the favourable performance of restorations of high-copper content dental amalgam alloys  , notably in relation to restorations in moderate- to large-sized Class II preparations in permanent molar teeth . Analysis of the data sheds new light on the influences of variables , including type of tooth restored , size and class of restoration and the presence or absence of occlusal contact(s ) on performance . CONCLUSION Conclusions are drawn regarding ways in which protocol s for future evaluations of the type reported should be exp and ed , and , together with suggestions for further work , it is concluded that this paper is a timely reminder of the value of existing dental amalgam alloys
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 .