Objectives: To compare the removal of simulated biofilm at two different implant-supported restoration designs with various interproximal oral hygiene aids.

Methods: Mandibular models with a missing first molar were fabricated and provided with single implant analogues (centrally or distally placed) and two different crown designs (conventional [CCD] and alternative crown design [ACD]). Occlusion spray was applied to the crowns to simulate artificial biofilm. Thirty participants (dentists, dental hygienists, and laypersons) were equally divided and asked to clean the interproximal areas with five different cleaning devices to further evaluate if there were differences in their cleaning ability. The outcome was measured via standardized photos and the cleaning ratio, representing the cleaned surfaces in relation to the respective crown surface. Statistical analysis was performed by linear mixed-effects model with fixed effects for cleaning tools, surfaces, crown design and type of participant, and random effects for crowns.

Results: The mean cleaning ratio for the investigated tools and crown designs were (in%): Super floss: 76 ± 13/ACD and 57 ± 14/CCD (highest cleaning efficiency), followed by dental floss: 66 ± 13/ACD and 56 ± 15/CCD, interdental brush: 55 ± 10/ACD and 45 ± 9/CCD, electric interspace brush: 31 ± 10/ACD and 30 ± 1/CCD, microdroplet floss: 8 ± 9/ACD and 9 ± 8/CCD. There was evidence of an overall effect of each factor "cleaning tool," "surface," "crown design," and "participant" (p < 0.0001).

Conclusions: ACD allowed more removal of the artificial biofilm than CCD with Super floss, dental floss, and interdental brush. Flossing and interproximal brushing were the most effective cleaning methods. A complete removal of the artificial biofilm could not be achieved in any group.