Effect of argon plasma pre-treatment of healing abutments on peri-implant microbiome and soft tissue integration: a proof-of-concept randomized study

Abstract

Purpose Biofilm-free implant surface is ultimate prerequisite for successful soft and bone tissue integration. Objective of the study was to estimate the effects of argon plasma healing abutment pre-treatment (PT) on peri-implant soft-tissue phenotype (PiSP), inflammation, plaque accumulation and the microbiome (PiM) between non-treated (NPT) and treated (PT) abutments following 3-months healing period. The hypothesis was that cell-conductive and antimicrobial properties of PT would yield optimal conditions for soft tissue integration. Material and Methods Two months following second-phase surgery, microbiological and clinical parameters were assessed around thirty-six healing abutments with two types of microtopography, smooth surface (MACHINED) and ultrathin threaded microsurface (ROUGH). A two level randomization schema was used to achieve equal distribution and abutments were randomly divided into rough and machined groups, and then divided into PT and NPT groups. PiM was assessed using next-generation DNA sequencing. Results PiM bacterial composition was highly diverse already two months post-implantation, consisting of key-stone pathogens, early and late colonizers, while the mycobiome was less diverse. PT was associated with lower plaque accumulation and inflammation without significant impact on PiSP, while in NPT clinical parameters were increased and associated with periopathogens. NPT mostly harbored late colonizers, while PT exerted higher abundance of early colonizers suggesting less advanced plaque formation. Interaction analysis in PT demonstrated S. mitis co-occurrence with pro-healthy Rothia dentocariosa and co-exclusion with Parvimonas micra, Porphyromonas endodontalis and Prevotella oris. PiSP parameters were generally similar between the groups, but significant association between PiM and keratinized mucosa width was observed in both groups, with remarkably more expressed diversity in NPT compared to PT. PT resulted in significantly lower BOP and PI around rough and machined abutments, respectively, without specific effect on PiM and PiSP. Conclusions PT contributed to significantly the less advanced biofilm accumulation and inflammation without specific effects on PiSP.

Effect of argon plasma abutment activation on soft tissue healing: RCT with histological assessment

“…The present study showed that PT helped to reduce plaque accumulation and inflammation, in accordance with the study previously reported by this group. 28 Briefly, the previous study showed the same clinical results between the groups, while demonstrating that bacterial biofilms around PT were dominated by pioneer colonizers in contrast to NPT which was associated rather with late colonizers characteristic to mature biofilms. 28 This is important because infection, even in its sub-clinical grade, is considered the most devastating complication of biomaterials 46 due to its immediate interference with healing processes and far-reaching role in the development of future implant infections.…”

“…Sample size calculation was performed for the PI values estimated in the previous study with a similar design. 28 According to that, a total sample of 30 participants using α of 0.05 would result in a power of 0.8 with a drop-out of 25%. Demographic characteristics between the groups were analyzed using Fisher's exact test.…”

“…[25][26][27] Additionally, the anti-biofilm effects of the PT abutment pretreatment at the clinical and microbiome levels were previously demonstrated in the proof-of-concept study reported by this group. 28 Nevertheless, although a great number of in vitro and pre-clinical studies reported on the beneficial effects of argon plasma treatment of soft tissues, respective clinical confirmation is still lacking. Thus, the working hypothesis was that argon plasma abutment pre-treatment would provide pro-stimulative effects on peri-implant soft tissue healing compared to no treatment.…”

Effects of Zn–ZnO Core–Shell Nanoparticles on Antimicrobial Mechanisms and Immune Cell Activation

“…During the period that the gap between the implant surface and host bone is filled by bone ingrowth (osteogenesis), there is a probability of the microorganisms entering into this gap and adhering to the implant surface . This microbiota (bacteria, fungi) from the mucosal flora can induce the appearance of infections and consequent complications, , such as peri-implantitis. , Peri-implantitis is currently qualified as an emerging public health problem without an effective and predictive treatment …”

“…7,8 Peri-implantitis is currently qualified as an emerging public health problem without an effective and predictive treatment. 9 The initial biological response to a biomaterial is modulated by the immune system, 10 composed of macrophages. Macrophages play two crucial roles as they are responsible for inflammation and bone healing regulation 11 and avoid infection.…”