The influence of restorations and prosthetic crowns finishing lines on inflammatory levels after non-surgical periodontal therapy.

Objective: The aim of the present study was to evaluate the inflammatory response in sites where crowns were placed supragingivally, at the level of the gingival margin and subgingivally. These were measured clinically and through the levels of interleukin-1 3 and matrix metalloproteinase-2, inflammatory mediators, before and after periodontal therapy.
Methods: From 68 patients analyzed, 10 were selected for this study. The gingival crevicular fluid of the patients was collected and analyzed using standard enzyme-linked immunosorbent assay (ELISA). The clinical parameters were measured and correlated with interleukin-1beta and matrix metalloproteinase-2. Both analyses were realized before (baseline) and 2 months after non-surgical periodontal therapy. The two-way variance analysis (two-way ANOVA), Tukey-Kramer multiple comparisons test (post hoc) and Pearson parametric correlation test were performed in statistical analysis.
Results: There were statistically significant differences before and after nonsurgical periodontal therapy when comparing supra- and subgingival margins for the plaque and bleeding indexes (p < 0.05). There was a tendency toward correlation between the reduction of plaque index and the reduction of interleukin-1beta levels, both for supragingival (r = 0.694, p = 0.026) and subgingival margins (r = 0.715, p = 0.020) post non-surgical periodontal therapy. The levels of matrix metalloproteinase-2 were not detectable by ELISA because they were below the detection threshold of the assay.
Conclusion: Supragingival restorations appeared to be more adequate in promoting periodontal health when compared with the other possible marginal finish lines. They also presented a better response to basic periodontal treatment, according to clinical and inflammatory findings.