Topographic characterization of multispecies biofilms growing on dental implant surfaces: An in vitro model

Abstract

Objectives To describe the early biofilm formation over whole dental implants with its micro‐ and macrostructure, using an in vitro multispecies biofilm model. Material and methods Six bacterial strains (Streptococcus oralis, Actinomyces naeslundii, Veillonella parvula, Fusobacterium nucleatum, Porphyromonas gingivalis, and Aggregatibacter actinomycetemcomitans) were used to develop in vitro biofilms over whole titanium implants (growth times 12, 24, 48, 72, 96, and 120 hr). The morphology of biofilms was studied by confocal laser scanning microscopy and scanning electron microscopy, and the bacterial dynamics through quantitative polymerase chain reaction. As primary outcome variable, numbers of each species [colony‐forming units per milliliter (CFU/ml)] at different incubation times were compared using the one‐way analysis of variance and post hoc testing with Bonferroni's correction. Furthermore, implants were fixed in methacrylate stents to reproduce the clinical situation and biofilms were developed and analyzed by scanning electron microscopy. Results Bacteria colonized implants in a short period of time. Biofilms reached a mature state at 96 hr, exhibiting different ratios of live/dead cells depending on their location, being the peaks of the threads the areas harboring more live bacteria. The densities of each bacteria fluctuated in time, reaching its maximum at 96 hr. Even though the coefficients of variation were high, percentages were similar to those published previously using implant surface specimens, rather than whole implants. Conclusion Dental implants can be colonized by different bacterial species, developing into a mature and well‐structured biofilm, which depending on the location may exhibit different degree of bacterial vitality.

Biofilm formation on dental implants with different surface micro‐topography: An in vitro study

“…Similarly, the CLSMs patterns described by Sanchez et al () on titanium discs, described bacterial microcolonies spread over the whole surface of the disc, with minimal differences on the bacterial deposition and distribution when different surfaces were compared. In contrast, a recent report from our research group, using a similar methodology (Bermejo et al, ) but on whole dental implants, instead of discs, demonstrated clear differences between the microcolonies deposited at the peaks of the threads from those at the valleys between the threads. It is likely that the differences in the biofilms identified in this investigation, when comparing different microsurface topographies on whole implants, represent a model closer to the clinical reality than when using discs.…”

“…The biofilms were grown on the whole implant surface using the protocol previously reported by our research group (Bermejo et al, ). In brief, the obtained pure cultures of each bacterium were grown anaerobically in a brain–heart infusion (BHI) modified medium, a protein‐rich medium containing BHI (Becton, Dickinson and Company) supplemented with 2.5 g/L mucin (Oxoid), 1.0 g/L yeast extract (Oxoid), 0.1 g/L cysteine (Sigma), 2.0 g/L sodium bicarbonate (Merck), 5.0 mg/L hemin (Sigma), 1.0 mg/L menadione (Merck) and 0.25% (v/v) glutamic acid (Sigma), during 24–48 hr.…”

“…However, most of these studies have not used dental implants, but rather specimens, such as discs or slabs made of the implant surfaces, but without taking into account the implant macroscopic and topographic characteristics, such as the threads and the inter‐thread concavities. In fact, a recent publication from our research group (Bermejo et al, ) has demonstrated different patterns of bacterial colonization and biofilm deposition depending on the topographic area in dental implants.…”

Clinical and radiographic changes at tissue level implants with either a machined or a modified transmucosal neck surface: A 3‐year multicentre randomized controlled proof‐of‐concept study

“…It is well established that modifications of titanium implant surfaces such as acid etching and sandblasting have a significant impact on early biofilm formation (Badihi Hauslich, Sela, Steinberg, Rosen, & Kohavi, ). The findings of a recent in vitro study indicated that a significantly greater bacterial biomass grew on moderately rough implant surfaces compared with minimally rough implant surfaces and that moderately rough surfaces accumulated more bacteria and these bacteria were more pathogenic (Bermejo et al, ). In this context, development of soft tissue recessions at test implants in the present study exposing micro‐rough surfaces to the oral environment combined with insufficient self‐performed biofilm control could even be considered an increased risk for the onset of peri‐implant diseases compared with implants with a machined neck.…”

A systematic review on prevention and management of wound infections from cochlear implantation

“…14 Two studies had reported their experience with biofilm formation on the implant surfaces, 1,17 which would certainly account for the relapsing infections also seen in our experience. The concept of biofilms on implant surfaces is certainly emerging with growing evidence seen in dental 24 and other titanium implants. 25 Despite the relative certainty in causal microorganisms, the intended therapy seemed to vary amongst the different studies.…”