Purpose: The purpose of this study was to compare the clinical outcome of and determine the differences in periodonto-pathogenic microbiota around two types of implant collar surfaces: laser-microtextured (test) vs machined (control). Materials and Methods: Seventeen patients (11 periodontally healthy, and 6 periodontally compromised) were selected to receive the two different implants, placed randomly, in two edentulous sites. Six months following the surgical placement of the dental implants, subgingival plaque samples were collected using paper points from the peri-implant sulcus and from the sulcus of an adjacent tooth. The presence of five putative periodontal pathogens, namely, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Treponema denticola, and Tannerella forsythensis, was assessed using real-time polymerized chain reaction (RT-PCR). Peri-implant parameters and intraoral radiographs were recorded up to 1 year after abutment connection. Results: In the main population, and in the periodontally compromised subgroup, the total number of periodontal pathogens around test implant sites was lower than control implant sites and adjacent tooth sites, with a statistically significant difference (P .05). In periodontally healthy patients, the mean probing pocket depth for the test implant was 1.31 ± 0.51 mm, compared with 2.66 ± 0.83 mm for the control implant, while in periodontally compromised patients, it was 1.61 ± 0.58 mm for the test implant, compared with a mean value of 2.84 ± 1.0 mm for the control implant. Conclusion: Implants with a laser-microtextured collar surface are not more vulnerable to pathogenic microflora colonization than implants with a machined collar surface. In both of the subgroups of patients (periodontally healthy and periodontally compromised), implants with a laser-microtextured collar surface have a better clinical outcome at 1 year of loading, compared with implants with a machined collar surface. Keywords: bacteria, implant, microbiology