Immediate versus delayed single-tooth implants in the posterior mandible – Retrospective survival analysis

Background

Immediate placement of single-tooth implants at the time of tooth extraction has become daily routine in anterior regions of the mandible due to several advantages- less surgical interventions and associated patient morbidity, reduction of total treatment time and the possibility of fixed immediate provisionals within 1 day after tooth removal.

Aim/Hypothesis

The aim of the present retrospective study was to evaluate whether delayed placement should be favoured in posterior regions of the jaw because of higher occlusal forces and reduced need for provisional restoration.

Material and Methods

A total of 4,217 single-tooth implants were placed in mandibular molar positions (i.e. 36, 37, 46 or 47) at the Academy for Oral Implantology in Vienna in the years 2004–2019. Delayed implant placement was performed in 1,230 patients (3,691 implants) and immediate implant placement was performed in 175 patients (526 implants). Implant survival was compared after a mean follow-up of 7 years using chi-squared tests.

Results

The survival rate of delayed implants was 97.1% compared to 94.3% of immediate implants in the posterior maxilla (P = 0.008). No difference between single-tooth gaps and free-end situations could be determined for both delayed (P = 0.811) and immediate (0.419) implants.

Conclusion and Clinical Implications

It can be concluded that immediate placement of single-tooth implants in the posterior mandible may be significantly associated with a 2.8% higher implant failure rate compared to delayed placement.