Immediate, Early, and Late Implant Placement in First-Molar Sites: A Retrospective Case Series

Purpose: To review the clinical outcomes of immediate, early, and conventional single-tooth implant placement in mandibular or maxillary first molar sites. Materials and Methods: The charts of patients treated consecutively for first molar replacement according to unconventional (immediate = group 1, early = group 2) or conventional (late = group 3) surgical protocols were examined. All available clinical parameters were reviewed to calculate implant survival and success rates according to well-established criteria. Periapical radiographs obtained upon delivery of the definitive crown (T2) and 1 year later (T3) were digitized and assessed to evaluate marginal bone loss (MBL). Clinical photographs were evaluated to determine soft tissue health. Results: Forty-seven patients were treated with a total of 53 immediate, early, or late single implants. The last follow-up examination was at 38.84 ± 16.14 months (mean ± SD) for group 1, 32.91 ± 18.49 months for group 2, and 42.66 ± 12.41 months for group 3. The implant survival rate was 100% for all groups. The success rates were 91.7% for early implants, 95.0% for immediate postextraction implants, and 100% for implants placed in healed sites. MBL and soft tissue parameters did not differ significantly among the three groups at definitive restoration delivery or 1 year later; a thin gingival biotype, irrespective of treatment timing, was the only covariate that was able to slightly affect the outcome variables. Conclusions: Short-term implant survival and success rates, as well as MBL values for immediate, early, and conventional implants, appear similar for maxillary and mandibular first molar sites. Early placement should be considered as a suitable alternative to immediate placement when unfavorable conditions at the time of extraction could affect the clinical outcome of immediate placement. Palabras clave: clinical study, dental implants, early placement, first molar site, immediate placement, marginal bone loss