Method: Restorations of class I, II or V of Black were included in the study. The Equia™ restorative system (GC Corporation, Japan), was selected for this trial. Integrity of restorations and margins have been evaluated through visual observation with 4x magnification loupes and status of all restorations has been classified using Frencken’s evaluation criteria for glassionomer restorations. Follow-ups were planned at 3, 6, 12, and then every 12 months.
Results: 304 restorations were performed in 202 patients. At 48 months of follow-up (82 Class I, 150 Class II, 72 Class V), 39 restorations reported chipping of margins (Criteria 1 or 2, successful); 35 restorations were lost or seriously damaged or lost (Criteria > 3, failures). This is equal to an overall general success rate, at 48 months, of 91,45%, and a general integrity rate (only Criteria =0) of 79,61%. The highest number of failures (code >3) has been reported in class II (24) in respect to Class I (1 failure) and Class V (10).
Conclusion: These results suggest that the restorative system used in this trial can be a reliable choice for permanent dental restorations, even in load-bearing tooth surfaces of molars and premolars. The number of walls of restoration seems to be more important for Class II in premolars (more walls = more failures) in respect to molars (no differences if 2 or more walls). Retention of class V seems to be the worst in time. This leads to consider that flexural forces are more important than occlusal forces for the evaluated restorative material. Optimal performances for Class I (1 failure over 82 restorations).