The included studies reported few , if any , endodontic complications .
Little or no differences emerged between teeth restored with  composite resins  and those restored with amalgam .
Composite resin is used extensively for restoration of teeth with vital pulps .
Although cell culture studies have disclosed harmful effects on pulpal cells , any untoward clinical effects , manifest as adverse pulpal responses , have yet to be determined .
This study comprises a systematic review , design ed to address the question of whether the risk of endodontic complications is greater with  composite resin restorations  than with  other restorative material s  , such as  amalgam .
Endodontic complications after plastic restorations in general practice.
AIM To test the hypothesis that dentine and pulp protection by conditioning- and -sealing is no less effective than using a conventional calcium hydroxide lining . METHODOLOGY A cohort of healthy adults requiring a new or replacement restoration in a posterior tooth was recruited in six general practice s. All procedures received local Ethics Committee approval . Exclusion criteria included signs and symptoms of pulp necrosis or inflammation , and patients unable to commit to a long-term trial . Cavity preparations were r and omized to receive a calcium hydroxide lining or conditioning- and -sealing with a smear-removing bonding system . Choice of bulk restorative material ( composite resin or amalgam ) was at the discretion of the dentist . The key outcome measure was evidence of pulpal breakdown identified at unscheduled ( emergency ) or scheduled recall examinations . Postoperative sensitivity was recorded on 100 mm VAS at 24 h , 4 days and 7 days . Pulp status was assessed at 6 , 12 , 24 and 36 month recall , and at any emergency recall appointment . The relationship between pre-treatment and treatment variables and pulp breakdown was assessed by logistic regression ( P = 0.05 ) . RESULTS A total of 602 teeth were recruited , with comparable numbers of cavities lined ( 288 , 47.8 % ) or conditioned and sealed ( 314 , 52.2 % ) . The majority ( 492 , 81.7 % ) were replacement restorations , and amalgam was the most common bulk restorative material ( 377 , 62.6 % ) . A total of 390 ( 64.8 % ) restored teeth were review ed at 6 months , 307 ( 51 % ) at 12 months , 363 ( 60.3 % ) at 24 months , and 279 ( 46.3 % ) at 36 months post-restoration . Sixteen cases of pulp breakdown were identified within 36 months of restoration placement , 11 presenting as emergencies and five detected at routine recall examination . Logistic regression showed that preoperative pain , cavity treatment by lining or conditioning- and -sealing and the use of rubber dam isolation had no association with pulp breakdown . Pulp breakdown was associated with deep or pulpally exposed cavities ( P < 0.001 , odds ratio 7.8 ) and with composite rather than amalgam restorations ( P = 0.001 , odds ratio 2.13 ) . Re-coding to identify teeth with pulp exposures revealed that pulpal exposure was the key determinant of adverse pulp outcomes ( P < 0.0001 , odds ratio 28.4 ) and that composite resin restorations were again more likely to be associated with pulp breakdown than amalgam ( P = 0.017 , odds ratio 3.92 ) . CONCLUSIONS Considered within the context of routine primary dental care : Dentists can be confident that pulps will be equally well protected from post-restorative breakdown up to 36 months by calcium hydroxide lining and conditioning- and -sealing with adhesive resins .  Residual dentine thickness appears to be a key determinant of pulp responses after restorative dental treatment . In deep and pulpally exposed cavities in posterior teeth , composites were associated with more pulpal breakdown than amalgams
The included studies reported few , if any , endodontic complications .
Little or no differences emerged between teeth restored with  composite resins  and those restored with amalgam .
Composite resin is used extensively for restoration of teeth with vital pulps .
Although cell culture studies have disclosed harmful effects on pulpal cells , any untoward clinical effects , manifest as adverse pulpal responses , have yet to be determined .
This study comprises a systematic review , design ed to address the question of whether the risk of endodontic complications is greater with  composite resin restorations  than with  other restorative material s  , such as  amalgam .