Bacterial culture and DNA Checkerboard for the detection of internal contamination in dental implants.
OBJECTIVE
The aim of this in vitro study was to evaluate the bacterial leakage along the implant-abutment interface by the conventional bacterial culture and DNA Checkerboard hybridization method.


METHODS
Twenty Branemark-compatible implants with a 3.75-mm diameter and external hexagonal platform were randomly placed in two groups of ten implant-abutment assemblies each. One group was used to analyze bacterial counts by DNA Checkerboard hybridization and the other by a conventional bacterial culture. Suspensions of Fusobacterium nucleatum (3 microl) were injected into the grooved internal cylinders of each implant assembly, and the abutment was connected by a 32 Ncm torque. The combined implant-abutments were individually placed in tubes containing the CaSaB culture medium and incubated in a bacteriological constant temperature oven for 14 days. The samples were observed daily as to the presence of turbidity, and after the designated time the microorganisms were collected from the implant interiors and analyzed by the two methods.


RESULTS
After 14 days, six implant-abutment assemblies showed turbidity. Both methods indicated reduced microorganism counts in samples from the interior of the implant-abutment assemblies after incubation in the culture medium; however, the number of counts of F. nucleatum was higher by the DNA Checkerboard method when compared to the group analyzed by conventional bacterial cultures (p < 0.05).


CONCLUSIONS
The DNA Checkerboard method was shown to be more sensitive than conventional cultures in the detection of microorganisms.
Faculty of Dentistry of Ribeirão Preto, Department of Dental Materials and Prosthodontics, University of São Paulo, Brazil.
Rodrigo Edson Santos
RE
Barbosa
Cássio
C
do Nascimento
João Paulo Mardegan
JP
Issa
Evandro
E
Watanabe
Izabel Yoko
IY
Ito
Rubens Ferreira
RF
de Albuquerque
D015373:Bacterial Typing Techniques / Q000379:methods*; D004269:DNA, Bacterial / Q000032:analysis; D000044:Dental Abutments / Q000382:microbiology*; D015921:Dental Implants / Q000382:microbiology*; D003763:Dental Leakage / Q000382:microbiology*; D017267:Dental Prosthesis Design; D004866:Equipment Contamination; D016967:Fusobacterium nucleatum / Q000235:genetics; D006801:Humans
D004269:DNA, Bacterial; D015921:Dental Implants