Bacterial communities associated with apical periodontitis and dental implant failure.
BACKGROUND
Previously, we demonstrated that bacteria reside in apparently healed alveolar bone, using culture and Sanger sequencing techniques. Bacteria in apparently healed alveolar bone may have a role in peri-implantitis and dental implant failure.


OBJECTIVE
To compare bacterial communities associated with apical periodontitis, those colonising a failed implant and alveolar bone with reference biofilm samples from healthy teeth.


RESULTS
The study consisted of 196 samples collected from 40 patients undergoing routine dental implant insertion or rehabilitation. The bacterial 16S ribosomal DNA sequences were amplified. Samples yielding sufficient polymerase chain reaction product for further molecular analyses were subjected to terminal restriction fragment length polymorphism (T-RFLP; 31 samples) and next generation DNA sequencing (454 GS FLX Titanium; 8 samples). T-RFLP analysis revealed that the bacterial communities in diseased tissues were more similar to each other (p<0.049) than those from the healthy reference samples. Next generation sequencing detected 13 bacterial phyla and 373 putative bacterial species, revealing an increased abundance of Gram-negative [Prevotella, Fusobacterium(p<0.004), Treponema, Veillonellaceae,TG5(Synergistetes)] bacteria and a decreased abundance of Gram-positive [(Actinomyces,Corynebacterium(p<0.008)] bacteria in the diseased tissue samples (n=5) relative to reference supragingival healthy samples (n=3).


CONCLUSIONS
Increased abundances ofPrevotella, FusobacteriumandTG5(Synergistetes) were associated with apical periodontitis and a failed implant. A larger sample set is needed to confirm these trends and to better define the processes of bacterial pathogenesis in implant failure and apical periodontitis. The application of combined culture-based, microscopic and molecular technique-based approaches is suggested for future studies.
Institute of Dental Research, The Westmead Institute for Medical Research and Centre for Oral Health, Westmead, NSW, Australia.|Faculty of Dentistry, University of Sydney, Sydney, NSW, Australia.
Simon
S
Dingsdag
School of Medical Science, University of Sydney, Sydney, NSW, Australia.
Stephen
S
Nelson
School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia; nicholas.coleman@sydney.edu.au.
Nicholas V
NV
Coleman
T-RFLP; alveolar bone; apical periodontitis; dental implant failure; oral bacterial communities; pyrosequencing