Reproducibility of a digital method to evaluate soft tissue modifications: A study of inter and intra-operative measurement concordance

Background: The soft tissue healing and quality around dental implant is a current debated topic in the recent literature. The free gingival margin and the quantity and quality of the mucosa around teeth and surrounding dental implants still determine the hard and soft tissue healing status. Objective: The aim of this study is to assess inter and intra-operative measurement concordance of a method aimed at evaluating the apicocoronal migration of free gingival margin, using intra-oral photography. Methods: The method was tested on peri-implant tissues that were treated with a connective tissue graft on the second stage surgery. Thirtyeight measurements on 13 implants in 8 patients were recorded. An intra-oral photograph was taken for the graft and the provisional crown, which enclosed a circular landmark with a previously determined diameter. The landmark was prepared with a red-resin by the same technician. Before crown cementation, the landmark was calibrated with a digital calibrator by the main investigator, to determine the precise diameter up to two decimal numbers. Results: On the intra-oral photograph, the distance was measured from the most apical point of the determined landmark to the zenith of the gingiva, using an image-processing program designed for scientific multidimensional images (Image J). Three independent examiners took these measurements. Conclusion: The main advantage of the present non-invasive technique is that the spatial plane of the prosthetic landmarks is the same of the tooth unlike the utilization of periodontal probe, which is generally positioned on different plans in the space (generally more vestibular).