Immediate definitive individualized abutments reduce peri-implant bone loss: a randomized controlled split-mouth study on 16 patients

Objectives This paper aims to observe peri-implant time-related vertical bone level and soft tissue changes with immediate, non-detached glass-ceramic (lithium-disilicate) individualized abutments and dis-/reconnections. Materials and methods Sixteen split-mouth patients received provisionalized immediate definitive individualized abutments (test T) versus dis-/reconnected individualized abutments (control C). In group T, digital impressions were made by using titanium bases (Conelog, Camlog), and individualized abutments (E.maxCAD) and temporary crowns (TelioCAD) were designed and milled (CerecMCXL). Lithium-disilicate abutments were crystallized and luted (Multilink Hybrid Abutment) to titanium bases. Non-occluding temporary crowns were connected to abutments. After 16 weeks, definitive digital restorations were delivered. In group C, 8 weeks were allowed after healing cap mounting for conventional impressions. Lithium-disilicate individualized abutments were produced, try-ins were performed by dis-/reconnections. Crowns were luted. Cone beam computed tomography (CBCT) images were obtained at restoration delivery, 12 months and 24 months. Pink esthetic scoring was made, plaque-gingival index measurements were done and statistical analyses (Shapiro-Wilk, Mann-Whitney U , Wilcoxon’s, Spearman’s rank, α = 0.05) were completed. Results No implant failures occurred. At 12 months, T (−0.1 ± 0.14 mm) exhibited significantly reduced vertical bone loss only on the labial side than C (−0.24 ± 0.13 mm) ( p