sybraloy and Dental-Leakage

Previous dye leakage studies have shown that mineral trioxide aggregate leaks significantly less than other commonly used root-end filling materials. This study determined the time needed for Staphylococcus epidermidis to penetrate a 3-mm thickness of amalgam, Super-EBA, Intermediate Restorative Material (IRM), or mineral trioxide aggregate (MTA) as root-end filling materials. Fifty-six single-rooted extracted human teeth were cleaned and shaped using a step-back technique. Following root-end resection, 48 root-end cavities were filled with amalgam, Super-EBA, IRM, or MTA. Four root-end cavities were filled with thermoplasticized gutta-percha without a root canal sealer (+ control), and another four were filled with sticky wax covered with two layers of nail polish (- control). After attaching the teeth to plastic caps of 12-ml plastic vials and placing the root ends into phenol red broth, the set-ups were sterilized overnight with ethylene dioxide gas. A tenth of a microliter of broth containing S. epidermidis was placed into the root canal of 46 teeth (40 experimental, 3 positive, and 3 negative control groups). In addition, the root canals of two teeth with test root-end filling materials and one tooth from the positive and negative control groups were filled with sterile saline. The number of days required for the test bacteria to penetrate various root-end filling materials was determined. Most samples whose apical 3 mm were filled with amalgam, Super-EBA, or IRM began leaking at 6 to 57 days.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Aluminum Compounds; Analysis of Variance; Calcium Compounds; Dental Alloys; Dental Amalgam; Dental Leakage; Dentin-Bonding Agents; Drug Combinations; Drug Evaluation; Humans; Methylmethacrylates; Oxides; Retrograde Obturation; Root Canal Filling Materials; Silicates; Streptococcus; Zinc Oxide-Eugenol Cement

The sealing ability of amalgam and Gallium Alloy Gallium Filling (GF) root-end fillings was evaluated in vitro using a highly uniform collection of sheep incisor roots. Following ultrasonic canal debridement and orthograde obturation with gutta-percha and sealer, root-end cavities were prepared in 100 roots and filled with amalgam (50 teeth) or Gallium Alloy GF (50 teeth), Twenty-five teeth from each group were subjected to immediate dye leakage assessment under vacuum conditions with methylene blue dye (2%), pH 7. Linear dye penetration was measured following longitudinal splitting. The other 25 teeth from each group were incubated in Ringer's solution for 12 weeks before leakage assessment by the same method. Control teeth were included in each component of the study. Mean linear dye penetration was: amalgam--5.17 mm at baseline, 2.33 mm after 12 week's incubation; Gallium Alloy GF--2.21 mm at baseline, 1.41 mm after 12 week's incubation. The apical marginal seal of both materials improved significantly following storage in Ringer's solution (P<0.001). Gallium Alloy GF provided a better apical seal than amalgam, both at baseline and following storage (P<0.001). Subjective evaluation of the general handling characteristics of Gallium Alloy GF revealed that it was a more difficult material to manipulate than amalgam, largely because of its wetting ability and consequent adhesion to dental instruments.

Topics: Alloys; Analysis of Variance; Animals; Dental Alloys; Dental Amalgam; Dental Leakage; Evaluation Studies as Topic; Gallium; Isotonic Solutions; Retrograde Obturation; Ringer's Solution; Root Canal Filling Materials; Sheep; Time Factors; Water; Wettability

In the past, measurement of microleakage has been based on measurement of dye or radioactive isotope penetration. A method has been developed to allow electronic monitoring of microflow in the same specimen over a period of time. This method was used to compare previously reported retrograde materials with an amalgam/sealer combination. The material that performed best was amalgam/sealer, particularly in the first week. The role of cavity varnish in limiting leakage has been controversial, and the results in the present study do not indicate any significant benefit. The range of leakage measured for specimens in the same group suggests that in vivo the expected leakage could be considerable for the materials tested and that small differences in experimental leakage between groups may not have any practical significance.

Topics: Calcium Sulfate; Dental Alloys; Dental Cavity Lining; Dental Cements; Dental Leakage; Dental Materials; Drug Combinations; Gutta-Percha; Humans; Materials Testing; Polyvinyls; Resins, Plant; Retrograde Obturation; Rheology; Root Canal Filling Materials; Zinc Oxide; Zinc Oxide-Eugenol Cement