Diederik Hentenaar

82 Chapter 4 A promising new low abrasive air-polishing powder, i.e., erythritol, has recently been introduced on the market. In-vitro studies on erythritol have shown stronger antimicrobial and antibiofilm activity than glycine (Drago, et al., 2014) and inhibitory effects on Streptococcus gordonii and Porphyromonas gingivalis (Hashino, et al., 2013). In addition, erythritol suppresses biofilm regrowth and improves cell attachment, cell viability, and proliferation of osteoblasts (Drago et al. 2017, Matthes, et al., 2017, Mensi, et al., 2018). Moreover, promising effects in terms of titanium cleaning efficacy were seen (Tastepe, et al., 2018; Drago, et al., 2017). When erythritol air-polishing was compared to scaling and rootplaning in periodontal maintenance studies and in non-surgical periodontitis treatment studies, comparable clinical and microbiological results were found (Müller, et al., 2014; Hägi, et al., 2015; Park, et al. 2018; Jentsch, et al., 2020; Mensi, et al., 2021). More recently, a study by Cosgarea et al. (2021) showed that erythritol air-polishing during periodontal surgery may represent a valuable adjunct following calculus removal or as minimally invasive treatment for root surfaces without calculus. However, clinical studies on the effect of erythritol air-polishing during the surgical treatment of peri-implantitis are lacking. The aim of the present randomized clinical trial was to evaluate the clinical, radiographical and microbiological effect of erythritol air-polishing as implant debridement method and compare this with saline-soaked cotton gauzes as control intervention. Hence, the null-hypothesis of erythritol air-polishing being not better than saline soaked gauzes in terms of clinical, radiographical and microbiological parameters was tested. MATERIALS AND METHODS Trial design This two-armed, investigator-blind randomized controlled trial is the surgical part of a two-staged peri-implantitis therapy protocol. Prior to participation, all patients received a non-surgical treatment (Hentenaar, et al., 2021). If signs of inflammation persisted 3 months after the non-surgical intervention, a surgical treatment was rendered. The study was approved by the Medical Ethical Committee of the University Medical Center Groningen (METc, UMCG with study number 2016/356) and registered in the Dutch national trial register (https://www.trialregister.nl/) with number NL8621. The CONSORT (Consolidated Standards of Reporting Trials) guidelines for reporting a randomized controlled trial were followed (Schulz, Altman, Moher, 2010).