Supragingival Relocation of Subgingivally Located Margins for Adhesive Inlays/Onlays with Different Materials

Purpose: This study evaluated the marginal adaptation of supragingivally relocated cervical margins. Newly developed and reference materials were compared. Materials and Methods: Eighty-eight extracted human teeth were divided into 11 groups. A standardized boxshaped cavity (4.0 mm mesiodistal width, 1.5 mm axial depth) was prepared on each tooth with the cervical margin 1.3 mm below the cementoenamel junction. Seven different restorative materials (Filtek Silorane [Sil], Clearfil AP-X [APX], Clearfil Majesty Posterior [CMP], Clearfil Majesty Flow [CMFlow], RelyX Unicem [RelyX], SDR [SDR], Vertise Flow [VertFlow]) were applied in a layer of 1.5 mm, combined with different adhesive systems (Filtek Silorane Primer + Bond [SilPB], Clearfil Profect Bond [ClePB], Filtek Silorane Bond [SilB]). No indirect restorations (ie, inlays/onlays) were placed on these restorations. SEM analysis was performed to evaluate marginal adaptation in enamel and dentin. The results were subjected to statistical analysis by Kruskal Wallis and Duncan post-hoc tests. Results: In both dentin and enamel, statistically significant differences were present between groups (p 0.001). In enamel, the lowest percentage of continuous margin was observed for SilPB/CMP, SilPB/APX, and ClePB/SDR, while SilPB/Sil exhibited the highest percentage of continuous margin, although this was not statistically different from other groups except for SilPB/CMP, SilPB/APX, and ClePB/SDR. In dentin, a higher percentage of continuous margin was observed for all materials than in enamel (p 0.002). Statistically significant differences were found between ClePB/SilB/Sil, ClePB/SDR, and RelyX, SilPB/APX, ClePB/APX, and ClePB/Sil. ClePB/Sil showed the lowest marginal adaptation. Considering the overall marginal length, the best marginal adaptation was exhibited by ClePB/SilB/Sil, followed by SilPB/Sil, ClePB/SDR, and ClePB/CMP. Conclusion: Marginal adaptation of supragingivally relocated cervical margins is significantly influenced by the materials used. Keywords: subgingival, marginal adaptation, silorane, relocation, inlays, onlays, resin composite, resin coating