Diederik Hentenaar

150 Chapter 7 underlined by recent study of De Waal et al. 2021, when a full-mouth non-surgical treatment is meticulously performed, combined with a high level of daily oral hygiene and healthy periodontal tissues, the starting position of the subsequent (surgical) peri- implantitis treatment phase can significantly be improved. Overall, a large number of patients having implants with considerable amounts of marginal bone loss, up to two-thirds of the implant length, were included. Hence, the state of disease might have exceeded the capacity of a mechanical decontamination method in a non-surgical as well as a surgical resective approach to be successful. Moreover, one might question whether the extensiveness of disease did not exceed the recoverability capacity of the human body. Considering the low success of treatment approaches described in the literature and a tendency of disease recurrence after more years of observation following surgical treatment of peri-implantitis defects, irrespective of the chosen approach (i.e., reconstructive vs. resective) (Carcuac et al. 2020; La Monaca et al. 2018) a guideline which could help the clinician to decide whether it is still feasible to treat the disease or one should decide to remove the implant, seems urgently needed. Therefore, in contrast to the general goal by dental clinicians of trying to save natural teeth ‘as long as reasonably possible’, one could advocate to explant an implant ‘as soon as reasonably possible’ when diagnosed with multiple unfavorable factors. Factors which might play a role and therefore should be taken into account when making such a decision are for example: amount of marginal bone loss, implant mobility, implant malposition, soft tissue dehiscence and patient preference. Chemical implant surface decontamination: phosphoric acid Considering that implant surface characteristics may compromise an effective mechanical intervention, adjunctive use of chemical agents for implant decontamination has been advocated (Claffey et al. 2008). Previous in-vitro and in-vivo studies have failed to identify one chemotherapeutic agent as the gold standard for implant surface decontamination (Ntrouka et al. 2011) and therefore, we continued the search for other potentially beneficial chemical agents. Hence, in chapter 5 , the effect of phosphoric acid 35% on the composition of the submucosal microbiome and the effect on clinical parameters in a resective surgical peri-implantitis approach was evaluated at 3 months post-treatment. It was concluded that the application of 35% phosphoric acid after mechanical debridement is superior to mechanical debridement combined with sterile saline rinsing for decontamination of the implant surface during surgical peri-implantitis treatment. However, no significant clinical or microbiological effect was found at 3 month follow-up.