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 .
Saucer-shaped cavity preparations for posterior approximal resin composite restorations: observations up to 10 years.
OBJECTIVE This clinical trial aim ed at study ing the long-term performance in routine clinical practice of  saucer-shaped Class II resin composite restorations .  METHOD AND MATERIAL S Fifty-one preparations were completed and filled with either of two light-cured posterior composites by seven dentists of the Public Dental Service . The restorations were evaluated annually , using the US Public Health Service criteria , bitewing radiographs , and dies based on replica impressions . At the final evaluation , the recall rate was 100 % . RESULTS After a mean of 7.2 + /- 1.3 years of service ( censored maximum of 9.6 years ) , 70 % of the restorations were acceptable for continued use . Caries and technical deficiencies were the main causes of failure . CONCLUSION The saucer configuration , by respecting and utilizing inherent properties of the resin composites , spares sound dentin and is preferable to the box preparation
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 .