Microbial biofilm proliferation within sealer-root dentin interfaces is affected by sealer type and aging period.
BACKGROUND
Root canal fillings are intended to prevent microbial proliferation over time in the canal after treatment. The objective of this study was to assess biofilm proliferation within the sealer-dentin interfaces of 2 methacrylate resin-based systems, self-etch (SE) and total-etch (TE), and an epoxy resin-based sealer (EP), aged for up to 6 months.


METHODS
Standardized specimens (n = 45) comprising the coronal 5 mm of human roots were filled with the test materials and gutta-percha. Specimens were either not preincubated (control, n = 9) or were incubated in sterile saline for 1 week, 1 month, 3 months, or 6 months (n = 3/group). Monospecies biofilms of Enterococcus faecalis were grown on the specimens for 7 days in a chemostat-based biofilm fermentor mimicking pathogenic oral conditions. The extent of E. faecalis proliferation within the sealer-dentin interface for each material and incubation period group was assessed by using fluorescence microscopy of dihydroethidium-stained specimens.


RESULTS
TE had less biofilm proliferation than both EP and SE (P < .01). Deeper biofilm proliferation was detected in SE and EP specimens aged for 1 and 3 months than those aged for 1 week or 6 months (P < .05). Maximum depth of biofilm penetration was recorded for SE at 1 month (P < .05).


CONCLUSIONS
Within the test model used, the SE and EP sealers were more susceptible to interfacial biofilm proliferation than the TE restorative material. This susceptibility diminished after aging the materials' interfaces for 6 months.
Discipline of Endodontics, University of Toronto, Toronto, Ontario, Canada.
Karina A
KA
Roth
Shimon
S
Friedman
Céline M
CM
Lévesque
Bettina R
BR
Basrani
Yoav
Y
Finer
D000134:Acid Etching, Dental / Q000379:methods; D058491:Bacterial Load; D018441:Biofilms / Q000254:growth & development*; D003188:Composite Resins / Q000737:chemistry; D003786:Dental Pulp Cavity / Q000382:microbiology*; D003804:Dentin / Q000382:microbiology*; D013293:Enterococcus faecalis / Q000502:physiology; D004853:Epoxy Resins / Q000737:chemistry; D004996:Ethidium / Q000031:analogs & derivatives; D005456:Fluorescent Dyes; D006171:Gutta-Percha / Q000737:chemistry; D006801:Humans; D006813:Humidity; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D050296:Microbial Viability; D010756:Phosphoric Acids / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D012387:Root Canal Filling Materials / Q000737:chemistry* / Q000145:classification; D018915:Root Canal Preparation / Q000379:methods; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors
D003188:Composite Resins; D004853:Epoxy Resins; D005456:Fluorescent Dyes; D008689:Methacrylates; D010756:Phosphoric Acids; C511498:Real Seal composite resin; D019279:Resin Cements; D012387:Root Canal Filling Materials; C084018:Scotchbond Multi-Purpose; C534916:epoxy resin-based root canal sealer; C078905:Bisfil; C067883:dihydroethidium; D006171:Gutta-Percha; C030242:phosphoric acid; D004996:Ethidium