Deep sequencing of biofilm microbiomes on dental composite materials

Abstract

Background: The microbiome on dental composites has not been studied in detail before. It has not been conclusively clarified whether restorative materials influence the oral microbiome. Methods: We used Illumina Miseq next-generation sequencing of the 16S V1-V2 region to compare the colonisation patterns of bovine enamel (BE) and the composite materials Grandio Flow (GF) and Grandio Blocs (GB) after 48 h in vivo in 14 volunteers. Applying a new method to maintain the oral microbiome ex vivo for 48 h also, we compared the microbiome on GF alone and with the new antimicrobial substance carolacton (GF+C). Results: All in vitro biofilm communities showed a higher diversity and richness than those grown in vivo but the very different atmospheric conditions must be considered. Contrary to expectations, there were only a few significant differences between BE and the composite materials GB and GF either in vivo or in vitro: Oribacterium, Peptostreptococcaceae [XI][G-1] and Streptococcus mutans were more prevalent and Megasphaera, Prevotella oulorum, Veillonella atypica, V. parvula, Gemella morbillorum, and Fusobacterium periodonticum were less prevalent on BE than on composites. In vivo, such preferences were only significant for Granulicatella adiacens (more prevalent on BE) and Fusobacterium nucleatum subsp. animalis (more prevalent on composites). On DNA sequence level, there were no significant differences between the biofilm communities on GF and GF+C. Conclusion: We found that the oral microbiome showed an increased richness when grown on various composites compared to BE in vitro, but otherwise changed only slightly independent of the in vivo or in vitro condition. Our new ex vivo biofilm model might be useful for pre-clinical testing of preventive strategies.

Early and mature biofilm on four different dental implant materials: An in vivo human study

“…Considering the limitations of this investigation, it can be hypothesized that surface roughness and/or chemical composition of the material are not the most relevant aspects that influence the type of colonizing bacteria. For example, in a recent study, differences in the oral microbiota composition of the individual and in the quality of the surface‐coating pellicle were much more important and interfered to a greater extent than any material‐specific changes (Conrads et al., 2019). The hypothesis that biofilm maturation affects the process of new bacterial adhesion, for example, by compensating or masking the surface characteristics of the implant material (Al‐Ahmad et al., 2010) supports the need for longer testing time intervals.…”

Interaction between the Oral Microbiome and Dental Composite Biomaterials: Where We Are and Where We Should Go

“…The main difference appears to be the abundance of certain microbial species, rather than their presence or absence. The authors also observed a strong correlation between the composition of the in vivo dental material microbiome and an in vitro saliva-derived biofilm model (Conrads et al 2019). Given the dearth of such studies, it is currently unclear whether similar results would be obtained with different commercially available materials.…”

“…For example, gene expression within biofilms can be heavily influenced by neighboring species, nutritional availability, and salivary flow rate as well as the chemistry of dental materials (Shemesh et al 2010). A recent microbiome study of 14 volunteers found only modest changes in the microbial community profiles formed on 2 composite materials (Conrads et al 2019). The main difference appears to be the abundance of certain microbial species, rather than their presence or absence.…”

“…For example, the antimicrobial compound carolacton was reported to induce membrane damage and cell death of S. mutans at low pH (Kunze et al 2010), which theoretically makes it an ideal antimicrobial for the prevention of secondary caries. However, 2 recent studies found that carolacton was unable to prevent secondary caries development (Hetrodt et al 2019) or even affect the microbial composition of in vitro saliva-derived multispecies biofilms (Conrads et al 2019). It was speculated that the poor performance of carolacton in a diverse polymicrobial setting could be due to its biodegradation, sequestration by the EPS, or other resistance mechanisms that may function (Conrads et al 2019; Hetrodt et al 2019).…”

Targeting the oral plaque microbiome with immobilized anti-biofilm peptides at tooth-restoration interfaces

“…Also, different substrates, e.g. ; teeth enamel, HA and dental composites, might affect the biofilm composition [43]. However, we had previously compared biofilm composition grown on HA versus composite resin discs and found no notable differences between these biofilms [42].…”