Purpose: to compare marginal bone level (MBL), modified sulcus bleeding index (mSBI),, simplified gingival index (sGI), modified plaque index (mPI) and prosthetic maintenance in conical and trilobe implant-abutment connections (IACs) in mandibular implant assisted overdenture during 3 years in service.
Materials and method: 14 completely edentulous patients received 28 implants to assist overdentures inserted in the mandibular canine region such that 14 implants with conical IAC (group I) and 14 implants with trilobe IAC (group II) assigned randomly. Split mouth design was used. After 3 months, each patient received two ball and socket attachments; and pick up was done to the denture fitting surface. The MBL, mSBI , sGI, mPI, and prosthetic complications for each group of implants were evaluated at loading time, after 6, 12, 24, and 36 months follow up visits. Data were collected, statistically analyzed.
Results:On comparing MBL in both groups, no significant difference was found at 0-6 months, while at the 0-12 and 0-36 follow up periods a significant difference was found.. No significant difference was found in the mSBI, sGI and mPI scores of both IAC groups at all follow up visits. the technical complications and prosthetic maintenance requirements were fewer and less frequent in conical (12 (22%)) than in trilobe IAC (38 (78%)).
Conclusion:
Within this study limitations , The conical IAC can be associated with significantly less marginal bone loss and prosthetic maintenance requirements offering a more stable implant system compared to the trilobe IAC.