Diederik Hentenaar

113 Phosphoric acid in surgical peri-implantitis treatment Exclusion criteria were: • Contraindications for the surgical procedures; • A history of local radiotherapy to the head and neck region; • Pregnancy and lactation; • Uncontrolled diabetes; • Systemic use of antibiotics within 3 months before inclusion; • Long-term use of anti-inflammatory drugs; • Incapability of performing basal oral hygiene measures as a result of physical or mental disorders; • Uncontrolled periodontitis (PPD > 5mm); • Implants with bone loss exceeding 2/3 of the length of the implant or implants with bone loss beyond the transverse openings in hollow implants; • Implant mobility; • Implants at which no position could be identified where proper probing measurements could be performed; • Previous surgical treatment of the peri-implantitis lesions. Interventions The study protocol was based on the study protocols of two previous studies evaluating the decontaminating effect of chlorhexidine during surgical peri-implantitis treatment (De Waal et al. 2013; De Waal et al. 2015), and is briefly described below. Within one month before surgical treatment all patients received extensive oral hygiene instructions and mechanical non-surgical debridement of implants and remaining dentition using hand instrumentation and/or an ultrasonic device. Immediately before surgical treatment screw-retained suprastructures were removed. In order to obtain an optimal overview of the peri-implant area during surgery, prior to the procedure only screw-retained suprastructures were removed. Cemented single crowns or bridges on mesostructures were left in place to prevent any damage to these structures. Directly after surgery, the screw-retained suprastructures were placed back. Cemented single crowns or bridges on mesostructures were left in place to prevent any damage to these structures. Vertical releasing incisions extending into the alveolar mucosa were placed using a surgical blade (no. 15) and full thickness mucoperiosteal flaps were raised buccally and lingually. Flaps were designed to allow optimal access to the peri- implant bone defect. Granulation tissue was removed using titanium curettes (Gracey; Hu-Friedy ® , Chicago, IL, USA). The implant surfaces were mechanically cleaned using titanium curettes and gauzes and cotton pellets soaked in saline. Next, the patients were randomly allocated to either the test or control group. Subsequently, implants 5