Biocompatibility of All-ceramic Implant-supported Restorations Using Molecular Indicators of Inflammation

Objectives: The aim of this prospective in vivo study was to measure the concentration of inflammation indicators in the gingival crevicular fluid (GCF), in order to quantify a reaction of inflammation triggered by monolithic lithium-disilicate implant-supported ceramic restorations.
Methods: In this study, 24 patients received 30 implants (Camlog Screw-Line Implants) in the premolar and molar region of the lower and upper jaw. The single-crown-restorations were made of lithium-disilicate ceramic either cement-retained (n=18) or screw-retained (n=12). A caries-free natural tooth was chosen as a control. Samples of the GCF were taken mesio-orally and disto-bucally using PerioPaper for 30 seconds each. The concentration of IL-1ra, IL1-beta und aMMP-8 were determined using Elisa tests. The periodontal status was evaluated clinically by measurement of the pocket depth, gingiva index, plaque index and bleeding on probing (BOP). Statistically analysis were performed with Wilcoxon-Test and Mann-Whitney-Test.
Results: One year after insertion of the crown, the mean pocket depth were 3.1±0.9mm for the implant group and 3.2±0.8mm for the control teeth. The mean Gingiva index was 0.8±1.0 (implant) and 1.7±0.8 (control), the mean plaque index was 0.3±0.6 (implant) and 0.6±0.7 (control), and the mean BOP was 0.4±0.5 (implant) and 0.8±0.4 (control). Significant differences were shown for Gingiva index (p=0.001), plaque index (p=0.02) and BOP (p=0.001). There were significant lower concentrations of IL1-beta (p=0.036) and aMMP-8 (p=0.017) in the GCF for the restored implants in contrast to the control-teeth. However, for IL-1ra no significant differences were found. Further, there were no significant differences between cemented and screw-retained crowns for none of the indicators.
Conclusions: The plaque, gingiva index and BOP showed, that the cleaning conditions are better in the implant than in the control group. Further, the treatment of monolithic lithium-disilicate implant-supported ceramic restorations did not influence the concentration of inflammation indicators in the GCF negatively.