Diederik Hentenaar

15 General introduction To date, most promising in cleansing the implant surface seems the use of particle beam devices i.e . air-polishing / air abrasion (Louropoulou et al. 2014). The superiority of air-polishing methods over the use of rigid instruments with regard to cleaning efficacy and surface damage in non-surgical/covered and surgical/open in vitro models, has been repeatedly proven (Keim et al. 2019, Ronay et al. 2017, Sahrmann et al. 2015). As described by Petersilka (2011), the powder-water ejection of air-polishing is subject to the additional so-called ricochet effect. For particles that hit a hard surface, this effect describes an uncontrolled rebound, bounce, or skip off a surface which may have an influence on the cleaning efficacy. According to the mode of clinical application (supra- or subgingival) tip designs vary since these require different angulations for applying the particle beam at the appropriate working distance from the surface being cleaned. Previous clinical non-surgical peri-implantitis treatment studies using air-polishing reported small sample sizes, different peri-implantitis case definitions and primarily the use of a single type of investigative powder (i.e., glycine) ( John et al. 2015, Karring et al. 2005, Renvert et al.2011). From these studies it was concluded that non-surgical therapy shows modest improvements and limited predictability in the resolution of mucosal inflammation (Heitz-Mayfield & Mombelli 2014, Suárez-López del Amo et al. 2016, Schwarz et al. 2016). One of the challenges clinicians are facing when trying to effectively detoxify the implant surface, in order for the implant tissues to re-integrate, is to preserve the implant topographical and chemical composition. In the search for an air-polishing powder that does not or hardly alters the implant surface and maintains the biocompatibility, a new low-abrasive powder, i.e. erythritol, was introduced to the dental field. This powder, which is a sugar alcohol similar to xylitol and used as sugar substitute, is non-caloric, has a high gastrointestinal tolerance and does not increase blood glucose or insulin levels (de Cock 1999, de Cock 2018). In vitro studies report that erythritol seems to be more effective in terms of cleaning efficacy compared to previously used powders (e.g., glycine and natriumbicarbonate) (Drago et al. 2014, Moharrami et al. 2018). Moreover, studies describe a more effective reduction in the bacterial biofilm and inhibition of post-treatment biofilm re-growth, improved cell attachment, cell viability, and proliferation of osteoblasts, anticipating promising effects of this powder in a clinical setting (Drago et al., 2017, Matthes et al. 2017, Mensi et al. 2018, Tastepe et al. 2018). Clinical periodontal maintenance studies on subgingival air-polishing with erythritol powder, report comparable clinical and microbiological effects to ultrasonic therapy (Müller et al. 2014). However, thus far, studies on the treatment of peri-implantitis with eythritol air-polishing are lacking. 1