Soft tissue histomorphology at implants with a transmucosal modified surface. A study in minipigs

ObjectivesTo investigate soft tissue histomorphology and quality around implants with a modified transgingival collar surface comparatively to a machined. Material and methodsTwenty-seven Straumann Standard Tissue Level implants belonging to the following groups (nine of each group): Ti modSLA with machined collar (Ti-M), Ti modSLA with machined, acid-etched surface collar (Ti-modMA), and TiZr modSLA with machined, acid-etched surface collar (TiZr-modMA) were placed in the mandible of six minipigs. After 8weeks of healing, buccal sections were obtained and processed for histological evaluation. ResultsHistometric soft tissue outcomes were similar for the three types of implants. The percentage of connective tissue attached to implant surface and its length was longer at TiZr-modMA with respect to Ti-M implants. The number of inflammatory cells was slightly higher at the TiZr-modMA with respect to Ti-M implant. The percentage of area occupied by perpendicular collagen fibers was slightly higher for the modified surfaces in comparison with the machined. ConclusionsModified implant collar surfaces at Ti and TiZr implants showed a soft tissue interface similar to machined. A tendency of increasing number of perpendicular collagen fibers and improved connective tissue contact was found at the modified implant surfaces.