Long- term effectiveness of 6Â mm micro- rough implants in various indications: A 4.6- to 18.2- year retrospective study

Abstract

ObjectivesTo evaluate the long- term effectiveness of 6Â mm implants in various indications with a micro- rough surface after 4.6- 18.2Â years in function and to assess key factors associated with implant survival, success, and biologic/technical complications.Materials and methodsFifty- five patients with seventy- four 6Â mm implants placed from 2000 to 2013 attended the re- examination assessing well- established clinical and radiographic parameters, biologic and prosthetic complications, and patient- reported outcome measures.ResultsFive implants were lost after a mean follow- up period of 9.1Â years resulting in a survival rate of 93.2%. All losses occurred in free- end situations in the mandible. Smoking habit significantly reduced implant survival (hazard ratio 36.25). Two implants exhibited a history of peri- implantitis, and one implant showed progressive marginal bone loss (MBL) resulting in a success rate of 89.2%. The mean MBL amounted to 0.029Â mm. Increased MBL was found for implants placed in the maxilla (0.057Â mm) and for implants with a diameter of 4.1Â mm (0.043Â mm). Soft tissue thickness (1.39Â mm) and width of keratinized mucosa (1.91Â mm) had no effect on MBL. Patient- reported outcome measures showed high satisfaction (mean VAS scores 88%) and high quality of life (mean OHIP- G14 score 2.2).ConclusionThe present study demonstrated survival and success rates of 93.2% and 89.2% for 6Â mm implants used in various indications. A factor leading to higher implant failure was smoking, whereas modulating factors increasing annual MBL included implants placed in the maxilla and implants with a diameter of 4.1Â mm compared to 4.8Â mm.