Bone‐level changes around implants with 1‐ or 3‐mm‐high abutments and their relation to crestal mucosal thickness: A 1‐year randomized clinical trial

Abstract Aim To evaluate 1‐year bone‐level changes around subcrestal platform‐switching implants with 1 or 3 mm definitive abutments. The influence of mucosal thickness on bone‐level alterations was further analysed. Materials and methods Implants were placed in the posterior sextants and positioned 1.5 mm subcrestally with an abutment of 1 or 3 mm height. Final restorations were delivered after 16 weeks. Radiographic measurements of inter‐proximal bone level were the primary outcome and were adjusted by vertical mucosal thickness. Peri‐implant clinical conditions and resonance frequency analysis were also compared. Results A total of 65 subjects with 99 implants were analysed. The overall 1‐year implant survival rate between the 1‐ and 3‐mm groups was 96.4% and 94.4%, respectively. Statistically significant lower inter‐proximal marginal bone‐level changes were observed in the 3‐mm group (1 mm: −0.17 ± 0.02 mm at mesial and −0.21 ± 0.02 mm distal; 3 mm: −0.03 ± 0.02 mm at mesial and −0.03 ± 0.02 mm and distal; mesial: p = .001; distal: p < .001). Initial vertical mucosal thickness was not correlated with inter‐proximal marginal bone loss. Conclusions Subcrestal implants with 3‐mm abutment were associated with minimal inter‐proximal bone loss. Independent of the abutment height, crestal mucosal thickness was not correlated with bone loss.