Objective: The aim of the study was to assess the long-term prognosis of short implants (5 to 6 mm) placed in the posterior region of the atrophic mandible.
Method and materials: The study included 81 patients with severe vertical atrophy of the bone in the posterior region. The patients had 248 short implants (5 to 6 mm) implants placed in the mandibular posterior region and 256 implants with length greater than 10 mm in the mandibular anterior region. Analysis of implant and prosthesis failures, cumulative survival rate, and marginal bone loss was determined at 1 year and 5 years of follow-up (58 ± 7 months).
Results: Mean marginal bone loss after 1 year of prosthetic loading was 0.74 mm for short implants and 0.72 mm for implants with length greater than 10 mm; after 5 years of prosthetic loading this was 1.27 mm for short implants and 1.31 mm for implants with length greater than 10 mm. Of 248 short implants (5 to 6 mm), six failed: four due to peri-implantitis and two due to lack of osseointegration (early rejection). Of 256 implants with length greater than 10 mm, five failed: three due to peri-implantitis and two due to lack of osseointegration (early rejection). On average, over the observation period (58 ± 7 months), the 5-year cumulative implant survival rate was 97.8% in short implants, and 98.1% in longer implants; the prosthesis cumulative survival rate was 98.2%.
Conclusions: Based on the results, it was concluded that the prognosis of the use of short implants for prosthetics in the posterior resorbed mandible can be considered favorable and reasonable.