Absence of Pulpal Sensitivity Using Ultra-rapid Polymerizing Resin Composites

Objectives: Ultra-rapid polymerization (3 second) of composite resin offers advantages to clinical dentistry. However, the risk of rapid polymerization includes pulpal trauma and sensitivity. The goal of this prospective, randomized, split mouth comparative study was to investigate the incidence of tooth sensitivity, and restoration outcomes of an ultra-rapid polymerizing resin composite compared to a conventional composite restorative procedure.
Methods: Under an IRB approved protocol, 52 subjects were recruited for Cl I or Cl II caries treatment or replacement of existing restorations in two opposing quadrants. Following IRB consent and inclusion, subjects’ two restorations were randomized to be treated with the ultra-rapid (UP) or conventional (c) composite restoration using a total etch protocol. Restorations were evaluated at 1 week, and 6 months to assess the primary outcome, tooth sensitivity and secondary measures of restoration retention, tooth integrity, proximal contact, marginal adaptation, luster, staining, color match, wear, and subject satisfaction.
Results: 17 male and 35 female subjects were treated for 46 Cl I and 58 Cl II restorations. There were 26 UP and 22 C premolar restorations and 26UP and 22 C molar restorations. Of the 104 restorations, 37 were placed for caries treatment and 67 for restoration replacement, respectively. 46 UP and 47 C restorations evaluated. Regarding post-op sensitivity, 2 UP teeth recorded minor sensitivity and 1 C treated tooth had moderate sensitivity and required endodontic therapy (p=0.544, ns). Regarding the aforementioned secondary measures, there were no statistical differences in the positive clinical performance of UP and C restorations. However, luster differed. 13/46 UP restorations scored slightly dull compared to 0/47 for C restorations (p < 0.0004).
Conclusions: This study demonstrates that an ultra-rapid polymerizing resin composite and associated high power curing light can be used with similar positive biologic and clinical outcomes as a conventional composite resin and curing light system.