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Bacterial Leakage (bacterial + leakage)
Selected AbstractsA laboratory assessment of coronal bacterial leakage in root canals filled with new and conventional sealersINTERNATIONAL ENDODONTIC JOURNAL, Issue 4 2009A. U. Eldeniz Abstract Aim, To evaluate the resistance to ex vivo bacterial leakage over a 40-day period of root canal fillings with five new root canal sealers: RC Sealer, Epiphany, EndoREZ, GuttaFlow and Acroseal, compared with Apexit, AH Plus and RoekoSeal. Methodology, One hundred and forty-four single rooted human teeth were divided randomly into eight test (n = 15) and two control groups (n = 12). The root canals were filled using a single cone technique with gutta-percha except in the Epiphany and EndoREZ groups. These were filled with Resilon and resin-coated gutta-percha, respectively. The gutta-percha surface of the GuttaFlow group was coated with an experimental primer prior to filling. Positive controls were filled with gutta-percha without sealer and tested with bacteria, whereas negative controls were sealed with wax to test the seal between the chambers. Filled roots were incorporated in a split chamber model system using Streptococcus mutans as a microbial marker. Leakage was assessed for turbidity of the broth in the lower chamber every day for 40 days. Survival analysis was performed using the Kaplan,Meier product limit method and event times were compared using the Log-rank test (, = 0.05). Results, Epiphany, GuttaFlow with test primer and Apexit prevented leakage significantly better than AH Plus, RC Sealer, RoekoSeal, EndoREZ and Acroseal (P < 0.05). None of the specimens in the AH Plus, RC Sealer, RoekoSeal and EndoREZ groups resisted bacterial penetration for 40 days. Conclusion, The new sealers, Epiphany and GuttaFlow with primer, along with Apexit, showed better resistance to bacterial penetration than the other new or traditional sealers tested. [source] Bacterial Culture and DNA Checkerboard for the Detection of Internal Contamination in Dental ImplantsJOURNAL OF PROSTHODONTICS, Issue 5 2009Rodrigo Edson Santos Barbosa DDS Abstract Purpose: 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. Materials and 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 ,l) 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). Conclusion: The DNA Checkerboard method was shown to be more sensitive than conventional cultures in the detection of microorganisms. [source] Influence of repeated screw tightening on bacterial leakage along the implant,abutment interfaceCLINICAL ORAL IMPLANTS RESEARCH, Issue 12 2009Cássio Do Nascimento Abstract Objectives: Bacterial penetration along the implant,abutment interface as a consequence of abutment screw loosening has been reported in a number of recent studies. The aim of this in vitro study was to investigate the influence of repeated tightening of the abutment screw on leakage of Streptococcus mutans along the interface between implants and pre-machined abutments. Materials and methods: Twenty pre-machined abutments with a plastic sleeve were used. The abutment screws were tightened to 32 N cm in group 1 (n=10 , control) and to 32 N cm, loosened and re-tightened with the same torque twice in group 2 (n=10). The assemblies were completely immersed in 5 ml of Tryptic Soy Broth medium inoculated with S. mutans and incubated for 14 days. After this period, contamination of the implant internal threaded chamber was evaluated using the DNA Checkerboard method. Results: Microorganisms were found on the internal surfaces of both groups evaluated. However, bacterial counts in group 2 were significantly higher than that in the control group (P<0.05). Conclusion: These results suggest that bacterial leakage between implants and abutments occurs even under unloaded conditions and at a higher intensity when the abutment screw is tightened and loosened repeatedly. [source] | ||||||||||