Characterization of cytokine/chemokine and microbiology profiles of peri-implant sulci and implant-supported ridge lap pontics

2012-09-04Background: Some investigators have detected edema, swelling and histological changes in the soft tissue under pontics, while others have demonstrated that exceptional plaque control can lead to healthy soft tissue at pontic sites. A new pontic design by Kim et al. (2009) attempts to address the issue of esthetics and oral hygiene by creating a ridge lap pontic with circumferential pressure, and was hypothesized to be associated with favorable microbiological and inflammatory profiles. ❧ Objective: The aim of this study was to explore the microbiological and cytokine/chemokine profiles of implants as well as the “pressure pontic” site in implantsupported fixed partial dentures and contrast them to that of healthy teeth. ❧ Materials and Methods: Gingival crevicular fluid was sampled from 6 patients, each with an implant-supported fixed prosthesis and a healthy tooth. One implant, the adjacent pontic site, and the contralateral tooth from the implant sampled were sampled whenever possible with Periopaper strips and subgingival plaque was collected with paper points. Both were placed separately into the peri-implant sulcus, periodontal sulcus as well as the pontic-mucosa interface on the mesio- and disto-lingual surfaces. Microbial samples were analyzed for periodontopathic bacteria via selective anaerobic culture techniques. Proinflammatory cytokines were quantified by flow cytometry analysis of GCF with two separate kits. The first kit tested for IL-8, IL-6, IL-1β, TNF-α, and IL-10 while the second one detected the concentration of IL-8, IP-10, RANTES, MCP-1, and MIG. ❧ Results: The number of sites along with the cultivable levels of periodontopathic bacteria detected in pontic sites, implant sulci, and periodontal sulci were similar. There were no significant differences detected in cytokines and chemokines due to a wide range of values and limited number of samples. The results of the chemokine values for patients 5 and 6, who were sampled after one month, appeared higher than those of patients 1-4, who were sampled one year after implant restoration. ❧ Conclusion: The ridge lap pontic with circumferential pressure merits further evaluation. The microbiological profile of the pontic site was comparable to that of other pontic research designs observed by other researchers (Wang et al. 1998). The pontic area also provided esthetic results, a lack of clinical inflammation, as well as a decrease in immune response over time