Influence of different instrumentation modalities on the surface characteristics and biofilm formation on dental implant neck, in vitro.

OBJECTIVES: To evaluate surface characteristics of implants after using different instruments and biofilm formation following instrumentation.

MATERIAL AND METHODS: Thirty-five commercially available dental implants were embedded into seven plastic models, attached to a phantom head and randomly assigned to seven instrumentation groups: (1) stainless steel (SSC) or (2) titanium curettes (TC); air-polisher using glycine-based (3) perio (PP) or (4) soft (SP) powders or (5) erythritol powder (EP); and an ultrasonic device using (6) stainless steel (PS) or (7) plastic-coated instruments (PI). Half of each implant neck in each group (n = 5) was treated once (30 s), while the other half was left uninstrumented (control). An eighth (8) treatment group used a bur/polisher to smooth two implants (SM). Following instrumentation implants were rinsed (5 ml Ringer's solution), analysed under a scanning electron microscope (SEM) and subjected twice (separately) to bacterial colonization with Streptococcus gordonii (2 h) and a mixed culture (S. gordonii, Actinomyces naeslundii, Fusobacterium nucleatum, Porphyromonas gingivalis and Tannerella forsythia; 24 h).

RESULTS: Visual assessment of SEM pictures revealed surface modifications (smoothening to roughening) following instrumentation. These alterations differed between the instrument groups and from the control. Quantitative scoring of the photographs revealed that SSC caused a significantly rougher surface compared to other instruments (P < 0.05), except for SP (P = 0.057) and PP (P = 0.108). After bacterial colonization no significant differences (P > 0.05) were evident between instrumented or control surfaces in either culture.

CONCLUSIONS: Overall, no significant differences were observed in the surface characteristics (except for SSC) or bacterial colonization based on one-time instrumentation.