This 3-month study aimed to demonstrate the efficacy of an electric toothbrush in reducing plaque and gingival inflammation around dental implants and natural teeth. To better understand the different data collected around two different anatomical structures, we decided to collect data separately. Analyzing our results, it is possible to observe how the mean values for probing, bleeding, and plaque index were bigger for dental implants. According to literature, it was expected to find deeper probing for dental implants [20]. Many authors associated this to the different kind of attachment and the different orientation of periodontal fiber around dental implants [21,22,23]. The electric toothbrush has widely been described as a preventive option in the maintenance of peri-implant tissues [24,25,26,27,28]. However, many authors did not observe any differences between the manual and electric toothbrush, and for this reason, the topic is still controversial [17, 19]. In the present study, the manual toothbrush seemed to maintain the values achieved with the professional prophylaxes; however, a mild increase of both PI and BoP was detected after 3 months. The choice to perform prophylaxis on all patients after baseline index recording was done in order to bring the patients at the same level and reduce the variability of the study according to several authors [29, 30]. As a direct consequence, all the values recorded in both groups resulted to be extremely decreased at the second time point, after 1 month. However, the data collection at the third time point 3 months after the baseline made possible to analyze the new plaque formation trend in both groups and verify the different devices’ efficacy on both teeth and implant. The evolution observed over time can be related also to the presence of peri-implant and periodontal pockets. Despite that the average values of PPD were lower than 3 mm, patients presenting deeper pockets were included, which might represent a limit of the study. The prophylaxis performed at the beginning of the study, in fact, could not remove adequately the plaque present in the deepest area of these pockets. This prevented the achievement of a “level 0” of PI and BoP and, at the same time, promoted a faster re-colonization. During this time, patients also improved their skills with the electric toothbrush, which have also might influence their motivation. These factors could explain the reduction of PI observed in the second part of the study on the electric toothbrush groups and, sequentially, of the BoP as inflammatory index caused by the presence of plaque itself. The efficacy of the electric toothbrush can be related to the easiness of use and the complexity of artificial movement (rotating-oscillatory), which has been demonstrated to be more effective in plaque removal with respect to the manual toothbrush as reported by many authors [14, 25, 27]. Many authors observed a 0.3-mm reduction of probing depth after at least 12-month observation period in the patients using the electric toothbrush [26, 28]. Despite in the present study it was observed only 0.15 mm of mean probing reduction for dental implants, our observation was limited only to a 3-month period. This trend could be comparable to a 0.3-mm reduction in 12 months, as observed in the previous studies. However, a similar trend was also detected in the control group so the electric toothbrush cannot be directly related to the PPD reduction.