Composite resin restoration and postoperative sensitivity: Clinical follow-up in an undergraduate program

Objectives: To analyze the relationship between the cavity depth and liners with postoperative sensitivity of resin composite restorations. Methods: A clinical follow-up was conducted on 319 resin composite restorations made in the final year of an undergraduate program over a 3-year period. Along with the analyses of cavity type, cavity depth, type of pulpal protection and the materials used, the postoperative sensitivity was also examined on each restoration. Results: Thirty-nine percent of the restorations had no protective layer (Group 1). As the depth of the prepared cavities increased, the restorations received one of the three pulpal protection methods; a calcium hydroxide base (Group 2), glass ionomer cement (Group 3), or protection with a calcium hydroxide base in combination with glass ionomer cement (Group 4). The incidence of postoperative sensitivity showed no significant difference among Groups 1, 2 and 3, but was significantly lower in Group 1 than in Group 4. The restorations made in shallow and medium depth cavities demonstrated significantly less-postoperative sensitivity than those made in deep cavities. The newer generation dentine-bonding agents showed a significantly lower incidence of postoperative sensitivity than the early generation group. Conclusions: Postoperative sensitivity in resin composite restorations was not related to the absence of protective layers but increased with the depth of cavities restored with the resin composite. The type of dentine-bonding agents could also be responsible for postoperative sensitivity.