|
| | Interest | Limits |
|
| Saliva | | |
| Human | (i) Contains a complex & complete blend of proteins, glycosaminoglycans, and ions that form a pellicle on tooth surface | (i) Quality: need healthy volunteers
(ii) Quantity: need many volunteers
(iii) Limited reproducibility |
| Artificial | (i) Reproducibility
(ii) Low cost | (i) Less complex blend of molecules
(ii) Do not mimic in vivo conditions |
|
| Substrates | | |
| Glass | (i) Allows a simple and fast screening
(ii) Low cost | (i) Direct bacterial adherence: no EAP creation
(ii) Scoring could be operator dependent |
| Dentin/enamel | (i) Study of cariogenic, periodontal, endodontic, and Dentin/Composite interface specific biofilms
(ii) Close to in vivo condition | Need for human or bovine teeth |
| Polystyrene (96-well plates) | (i) Can be coated with collagen, saliva, and/or different substances
(ii) Allows many simultaneous studies: comparison of different stains, media, and substances in the same array | (i) When not coated: only direct bacterial adherence
(ii) Far from in vivo conditions |
| Hydroxyapatite | (i) Best synthetic substrate mimicking human dental tissues
(ii) Avoid the search of extracted teeth and their sterilization
(iii) Can be coated with collagen, saliva & different substances | (i) Cost
(ii) When not coated: only direct bacterial adherence (no EAP creation) |
|
| Incubation conditions | | |
| Batch models | (i) Multispecies biofilms
(ii) Allows the study of interactions in bacterial communities and the effect of various substances | (i) Far from in vivo conditions: does not integrate the changing environmental conditions occurring during biofilm growth |
| Continuous culture | | |
| Constant depth fermentor | (i) Allows the control of environmental factors: gas flow, real time medium and waste monitoring, biofilm thickness, temperature, and pH
(ii) Allows the formation of multispecies biofilms | (i) Cost
(ii) Complexity of protocol
(iii) No vast simultaneous studies allowed
(iv) Can only handle up to 2 experiments at a time |
| Flow cell chamber | (i) Allows the control of environmental factors
(ii) Allows real time microscope observation |
|
| Biofilm collection | | |
| Scrapping | Allows the removal of almost all the biofilm | (i) Operator-dependent |
| Vortexing & sonification | (i) Reproducibility
(ii) Fast and easy | The first (deeper) bacterial layer can remain on the medium |
|
| Biofilm analysis | | |
| Cultivation on agar media | (i) Simple
(ii) Allows further identification methods
(iii) Selection of sustainable strains | (i) Delayed results
(ii) Only for culturable species
(iii) Time consuming |
| Gram staining | (i) Low cost
(ii) Fast and easy | (i) Limited identification based on colony and bacterial morphology |
| FISH | (i) Can focus on targeted bacteria in a multispecies biofilm
(ii) Possible to combine consecutive FISH with multiple rRNA
(iii) Can be combined with CLSM and PCR | (i) Cost
(ii) Complexity of protocol
(iii) Inability to discriminate live and dead bacteria |
| CLSM | (i) Allows discriminating between live and dead bacteria
(ii) Can determine the distribution of all the different species within the biofilm at different development times
(iii) Can be combined with FISH and PCR | (i) Cost
(ii) Complexity of protocol
(iii) Inability to discriminate stains (only on morphology)
(iv) Inability to assess gene expression |
| SEM | (i) Can determine the distribution of all the different species within the biofilm | (i) Cost
(ii) Complexity of protocol
(iii) Inability to discriminate live and dead bacteria |
| PCR | (i) Allows identifying and counting bacterial stains directly
(ii) Can be combined with culture on specific media
FISH: better results than CFU counts
CLSM | (i) Cost
(ii) Multispecies biofilms need a cultivation and isolation of every colony prior to PCR
(iii) Inability to discriminate live and dead bacteria |
|
