Effects of cleaning methods for custom abutment surfaces on gene expression of human gingival fibroblasts

Abstract

The aim of this study was to develop an effective method for cleaning implant abutments made by computer-aided design and computer-aided manufacturing techniques and to investigate the effect of decontamination in vitro. Briefly, a newly developed reagent (PK) and/or vacuum plasma (Plasma) were used to clean the surfaces of zirconia disks, and the effects of this decontamination were evaluated by X-ray photoelectron spectroscopy. Human gingival fibroblasts (HGFs) were cultured on sample disks for 6, 24, and 48 h. We evaluated cell attachment and gene expression of the acute inflammatory cytokines interleukin-6 and vascular endothelial growth factor A, and type 1 collagen. In the PK and PK+Plasma groups, surface contaminants were reduced by washing. In addition, HGF attachments was increased in the PK and PK+Plasma groups. Gene expressions of interleukin-6 and vascular endothelial growth factor A were lower at 6 h. Gene expression of type 1 collagen was increased at all time points after seeding. These results suggest that decontamination of implant abutment surfaces is important in initial HGF attachment and may improve the biological seal of peri-implant soft tissue.

The Influence of an Ultrasonic Cleaning Protocol for CAD/CAM Abutment Surfaces on Cell Viability and Inflammatory ResponseIn Vitro

“…By contrast, another recent study showed enhanced numbers and cell spreading areas of adherent osteoblasts on plasma treated surfaces in vitro (28). Nakajima et al also reported significantly reduced mRNA levels of IL-6 and VEGFA by either surface-treatment (11). By way of comparison, we did not find such effects with ultrasonically cleaned surfaces.…”

“…It is well possible that gingival fibroblasts are not sensitive to contaminants on the surfaces of these specimens. In a previous study (11), the surfaces of zirconia and titanium samples were ultrasonically cleaned with a special washing reagent containing proteinase, detergent and EDTA, and/ or a vacuum plasma protocol. While the washing reagent led to an increased cell number on the suface, the plasma treatment did not seem to have any effect.…”

“…affect the surface-cell interaction (9)(10)(11). CAD/CAM fabrication procedures for customized implant abutments made of titanium and zirconia may contaminate abutment surfaces through lubricants, waxes, generic pollutants, and wear microparticles.…”

Qualitative and Semi-Quantitative Assessment of Processing-Related Surface Contamination of One- and Two-Piece CAD/CAM Abutments before and after Ultrasonic Cleaning

“…These acids and semi-metals were already correlated to CAD/CAM implant manufacturing processes in earlier studies and can be assigned to cleaning attempts after industrial milling [35]. Such particulate debris, if not removed, might act detrimental and provoke inflammatory reactions in peri-implant tissues [21][22][23]36]. Although regulatory guidelines for adequate cleaning, disinfection or sterilization exist, there does not appear to be a consistent application and data on the amount and extent of such contaminants is lacking [37].…”

“…Debris have been found on the external and internal surfaces of custom implant abutments after laboratory procedures. Such debris, present at the critical implant-tissue interface, could trigger an inflammatory response of peri-implant tissues [20][21][22][23]. From a mechanical point of view, micro residues at the basal platform of an abutment could negatively impair the stability of the implant-abutment connection [24].…”