Repair or Observation of Resin Margin Defects: Clinical Trial After Five Years.

OBJECTIVE: To assess the effectiveness of repair/resealing of stained composite margins as an alternative to controlled observation without treatment in a randomized clinical trial after five years. METHODS AND MATERIALS: Each patient recruited had from one to three composite restorations with visible margin discoloration. Initially, the characteristics of each defect were recorded with direct vision through a surgical microscope at 20x magnification. Clinical evaluation was done by two independent examiners using modified USPHS criteria for color, margin discoloration, and margin adaptation. Each restoration was then randomly assigned to a control or treatment group. Control restorations were observed yearly for the presence of recurrent caries; treatment restorations were resealed by exposing the margin with a (1/4) round bur, removing all interfacial stain, acid etching, placing an adhesive bonding agent, and a flowable composite to restore margin integrity. There were 152 patients recruited, with 360 restorations (180 control and 180 treatment). RESULTS: At five years, 104 patients were recalled (68%) with 271 restorations (76%): 136 untreated control and 135 resealed restorations. At that time, 61 restorations had been lost or replaced for nonrelated reasons. Clinical evaluation of the remaining 210 restorations determined penetrating discoloration (control = 81%, resealed = 46%) and margin crevice formation (control = 21%, resealed = 11%). Recurrent caries was diagnosed cumulatively in only six control and five treatment restorations (<5%). Microscopically, 49 control restorations (49%) and 36 resealed restorations (33%) had crevice formation. Discoloration was distributed as follows: 9% vs 47% with no discoloration, 30% vs 33% in the composite, 49% vs 18% in the interface, and 12% vs 2% in tooth structure. CONCLUSIONS: Resealing of restorations with margin discoloration reduced the occurrence of penetrating stain from 81% in controls to 46% in resealed margins and crevicing from 21% to 11% after five years. Both controlled observation and resealing of margins resulted in a similar very low incidence (<6%) of recurrent caries.