Submerged vs non-submerged reconstructive approach for surgical treatment of peri-implantitis: Re-analysis of two prospective clinical studies.

Abstract

This report stems from a homogeneous patient cohort from two similarly designed prospective controlled studies in the same center on surgical reconstructive treatment of peri-implantitis. The aim of this re-analysis study was exploring prognostic factors associated with surgical outcomes. Individual patient data of both studies were gathered. The initial study employed a submerged healing approach via primary wound closure with implant supra-structure removal and complete coverage of grafted sites. The second study employed a non-submerged healing protocol in which healing abutments were kept in place and the implant was not fully submerged. Both studies measured all outcomes at similar timepoints throughout 1 year, to include clinical and radiographic defect fill (DF and RDF), reduction of pocket depth (PDR) and bleeding on probing (BOP). Multi-level regression was used for statistical assessment of outcomes, relative to the impact of site-/local-, surgical- and patient-related variables. Overall, 59 implants (30 in submerged and 29 in the non-submerged group) were treated. A statistically significant higher DF (on average 0.9 mm higher), RDF (1.7 mm) and PDR (1.3 mm) were observed when a submerged reconstructive approach was performed, whereas BOP reduction was similar. After controlling for treatment (submerged/non-submerged), there were no other significant associations with patient- (age, gender, smoking, prior periodontitis etc.), or implant-related (previous prosthesis type, arch, KTW, etc.) factors. Within its limitations, we conclude that a submerged reconstructive approach for surgical management of peri-implantitis leads to significantly enhanced clinical and radiographic outcomes when compared to a non-submerged approach.