Volumetric assessment of tissue changes following combined surgical therapy of peri‐implantitis: A pilot study

Abstract Aim To assess volumetric tissue changes at peri‐implantitis sites following combined surgical therapy of peri‐implantitis over a 6‐month follow‐up period. Materials and Methods Twenty patients ( n = 28 implants) diagnosed with peri‐implantitis underwent access flap surgery, implantoplasty at supracrestally or bucally exposed implant surfaces and augmentation at intra‐bony components using a natural bone mineral and application of a native collagen membrane during clinical routine treatments. The peri‐implant region of interest (ROI) was intra‐orally scanned pre‐operatively (S0), and after 1 (S1) and 6 (S2) months following surgical therapy. Digital files were converted to standard tessellation language (STL) format for superimposition and assessment of peri‐implant volumetric variations between time points. The change in thickness was assessed at a standardized ROI, subdivided into three equidistant sections (i.e. marginal, medial and apical). Peri‐implant soft tissue contour area (STCA) (mm 2 ) and its corresponding contraction rates (%) were also assessed. Results Peri‐implant tissues revealed a mean thickness change (loss) of −0.11 and −0.28 mm at 1 and 6 months. S0 to S1 volumetric variations pointed to a thickness change of −0.46, 0.08 and 0.4 mm at marginal, medial and apical regions, respectively. S0 to S2 analysis exhibited corresponding thickness changes of −0.61, −0.25 and −0.09 mm, respectively. The thickness differences between the areas were statistically significant at both time periods. The mean peri‐implant STCA totalled to 189.2, 175 and 158.9 mm 2 at S0, S1 and S2, showing a significant STCA contraction rate of 7.9% from S0 to S1 and of 18.5% from S0 to S2. Linear regression analysis revealed a significant association between the pre‐operative width of keratinized mucosa (KM) and STCA contraction rate. Conclusions The peri‐implant mucosa undergoes considerable volumetric changes after combined surgical therapy. However, tissue contraction appears to be influenced by the width of KM.