Purpose: To determine the level of bacterial contamination in immediate implantation or augmentation sites vs pristine bone, before and after saline rinses. Materials and Methods: Bacterial samples were taken from fresh extraction sites (17 patients) and pristine bone (15 patients) before performing implant dentistry surgical procedures. Levels of bacterial contamination were estimated before and after saline rinses. Samples from the socket were placed on an agar plate for total bacterial account and on selective plates for Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis counts. Results: The level of bacterial contamination before saline rinse was 1.2 × 104 units of bacterial colony (CFU)/mL in fresh extraction sites (study group) and 5 × 102 CFU/mL in pristine bone sites (control group). After a saline rinse, the bacterial level was lowered significantly to 5.2 × 103 CFU/mL in the study group and to zero in the control group (P .05). Levels of bacterial contamination were higher in the mandibular sockets (7.5 × 103 CFU/ml) than in the maxillary sockets (5.6 × 103 CFU/mL), and the difference was statistically significant (P = .034). All implanted/augmented fresh or pristine sites survived in the followup period. Conclusion: Fresh extraction sockets with clinical signs of infection show bacterial presence. Pristine bone shows a lower bacterial level. Saline rinse in addition to a decontamination protocol may reduce the level of bacterial contamination significantly both in fresh extraction sites and pristine bone. Schlagwörter: bacterial contamination, immediate implantation and augmentation sites, pristine bone sites