Comparative evaluation of peri-implant tissues in patients wearing mandibular overdenture with different implant platforms

BACKGROUND: The poor hygiene of peri-implant tissues causes inflammation at tissue-implant interface, which may impair the rehabilitation success. The aim of this study was to evaluate the influence of external hexagon and Morse taper implants on peri-implant health in patients wearing mandibular overdentures for 1 year. MATERIALS AND METHODS: A total of 46 implants were evaluated, 28 external hexagon and 18 Morse taper. Plaque index in the mini-abutment, bleeding index, peri-implant inflammation, keratinized mucosa zone, probing depth, and marginal mucosa level were evaluated after 3 months and 1 year of prostheses insertion. RESULTS: Deeper probing was found in the external hexagon group compared with Morse taper (P = 0.024) after 1 year of rehabilitation. Although the Morse taper group exhibited worse scenario of peri-implant inflammation than the external hexagon group (P = 0.001), both groups showed reduced inflammation after 1 year. A larger keratinized mucosa zone was observed with external hexagon implants (P = 0.020). No significant difference was found between the groups for plaque index in the mini-abutment, bleeding index, and marginal mucosa level. CONCLUSION: In a follow-up period of 1 year, it was concluded that the external hexagon group had a larger probing depth than the Morse taper group. However, better periodontal conditions about inflammation and keratinized mucosa zone were found in external hexagon implants. It was found no influence of implant platform on plaque index in the mini-abutment, bleeding index, and marginal mucosa level.