.  2022 Dec;26(4):222-233. 10.32542/implantology.2022022.

Survival Rate of Single Implant When Replacing the Mandibular Second Molars: Importance of Implant Length

• Kim MJ
• Chang HJ
• Ahn KM

• KMID: 2538533
• DOI: http://doi.org/10.32542/implantology.2022022

Abstract

Purpose
Restoration of the mandibular second molar with single implants has many limitations. This includes poor bone quality, reduced alveolar bone, large occlusal force, and difficulty in surgical approach. The purpose of this study was to analyze the survival rate of single implants in second molar restoration and evaluate the effect of associated factors regarding implant length, diameter, and guided bone regeneration (GBR).
Materials and Methods
Altogether, 137 patients (77 males and 60 females; age range: 19 to 81 years; mean age 53.6 years) were treated with 147 single implants in the mandibular second molar region by an experienced surgeon between 2006 and 2019. The cumulative survival rate (CSR) was analyzed using a life-table analysis and the effect of associated factors on the survival was compared using Log Rank Test.
Results
Four of the 147 implants failed. Thus, the five-year cumulative survival rate was 97.1%. In three out of four cases, implant failed after the 4th, 6th, and 8th year of implantation. In one of the four cases, the implant failed within four months of implantation. A significant change was observed in CSR with respect to the implant length. However, no difference was observed in CSR with respect to the implant diameter and GBR.
Conclusion
This study reveals that replacing the mandibular second molar with a single implant is an effective and reliable treatment. However, the implant length over 10mm is recommended for successful result if there is sufficient residual alveolar bone.

Keyword

Diameter; Guided bone regeneration; Length; Mandibular second molar; Single implant