<b>Integrative Assessments of Clinico–Operative Procedures: Microbial Shifts in Peri-Implant Sulcular Fluid as Predictors of Early Implant Failure</b>

Background: Early implant failure is a serious clinical problem due to the mechanical stability as well as peri-implant microbial composing. The purpose of this research was to assess the correlations between clinico-operative variables and changes of microbial at the peri-implant level as predictors of early implant failure. Methods: This prospective cohort study (February 2023 to July 2023) included 120 systemically healthy adults that received single tooth implant placement were enrolled. They were classified into Group A (successful osseointegration, n = 90) and Group B (early implant failure, n = 30). The samples of peri-implant sulcular fluid (PISF) were taken at baseline, Week 2, Week 4, and Week 8. The 16S rRNA gene sequencing was used to measure microbial profiling of peri-implant sulcular fluid to assess the α-diversity and relative abundance of the main periopathogens such as Porphyromonas gingivalis (P. gingivalis), Tannerella forsythia (T. forsythia), Treponema denticola (T. denticola), and Fusobacterium nucleatum (F. nucleatum) along with the presence of commensal streptococci (p<0.05). Results: Group B had lower insertion torque (34.8 ± 6.2 Ncm vs. 38.6 ± 5.1 Ncm, p = 0.03) and longer operative time (32.9 ± 6.5 min vs. 27.8 ± 5.4 min, p = 0.01) than Group A. The level of relative abundance of periopathogens was greater in Group B, and commensal streptococci were higher in Group A. Conclusion: Early implant failure is related to less mechanical stability and dysbiotic peri-implant microbiota. Early monitoring of microbial changes and clinical/operative optimization can enhance the prognosis of implants and direct preventive measures.