Persian leopard (Panthera pardus) attack in Oklahoma: case report.

The authors report a fatal case of a Persian leopard (Panthera pardus) attack in an animal sanctuary in Oklahoma. The victim was a 53-year-old Costa Rican woman who was attempting to feed the animal when she was attacked and killed. Autopsy, radiography, fingerprint analysis, microbiologic cultures, and dental impressions were used to evaluate the case. These simple techniques can be applied to similar cases involving wild and domestic animal attacks.

Interfacial bond strengths of amalgam bonded to amalgam and resin composite bonded to amalgam.

OBJECTIVE: The effects of time, surface preparation, and use of a bonding agent on the ability to bond amalgam or resin composite to amalgam were studied. METHOD AND MATERIALS: Cylindrical amalgam specimens were prepared in a split die (32 groups of 10 each). The 32 groups were divided into two groups of 16 each: amalgam bonded to amalgam and resin composite bonded to amalgam. One half of each group of 16 was bonded within 1 hour after the initial condensation (fresh) and the other half was bonded after 21 days' storage in physiologic saline (old). Four bonding methods (control [no bonding agent], Advance, All-Bond 2, or Amalgambond Plus) were each utilized on one abraded group (air abrasion with 50-microns aluminum oxide) and one unabraded group. After an additional 21 days of storage, bond strengths were measured with a three-point flexure test. Solid amalgam cylinders also tested. RESULTS: Solid amalgam control cylinders exhibited mean bond strengths 10,000 psi greater than any of the bonded specimens. Among specimens of amalgam bonded to amalgam, those that were abraded after 21 days and used no bonding agent showed a significantly greater bond strength than did specimens utilizing any of the other combinations of the selected independent variables. Among specimens of resin composite bonded to amalgam, those bonded after 21 days and utilizing a bonding agent exhibited significantly greater bond strengths than did specimens utilizing any of the other combinations of the selected independent variables. CONCLUSIONS: The results of this in vitro study suggest that the strength of a repaired amalgam is only about 40% of that of an unrepaired amalgam. They also indicate that the strongest repair of amalgam using additional amalgam material may be accomplished without the use of any bonding agents utilized in this study. When adding resin composite material to amalgam, the resin composite should be added after the amalgam has had adequate time to set, and the use of a bonding agent increases the strength of the repair.

Uses and properties of current glass ionomer cements: a review.

Glass ionomer cements have been used for a variety of restorative purposes. Recently, the formulation of these and other restorative materials has changed rapidly, so it is difficult to keep pace with the literature concerning effective use. A major modification to glass ionomer cements has been incorporation of resin components. This and other modifications over the years have changed some handling characteristics and physical properties of glass ionomer cements. A general review of some changes is reported here.

Effects of equivalent abrasive grit sizes utilizing differing polishing motions on selected restorative materials.

The effects on surface roughness of three specific classifications of abrasive motion during the polishing of selected amalgam and resin composite materials were evaluated with a profilometer. Equivalent grit sizes were used to evaluate the character of the surface created by each class of abrasive motion. The motions investigated were rotary (diamond), planar (sandpaper disk), and reciprocal (reciprocating handpiece). Fine, medium, and coarse abrasives were used with each motion. Average roughness values for each abraded specimen were used to compare the effects of the type of motion on the surface. Results indicated that, among all of the combinations of motions and abrasive grits evaluated, the planar motion produced significantly lower surface roughness values on both amalgam and resin composite surfaces.

The diametral tensile strengths of various composite resins.

The products exhibiting the greatest tensile strength values were those systems which provided measuring devices enabling the dentist to more accurately control the amounts of material to be mixed. Statistical analysis supported this finding; the means of the powder/liquid and paste/liquid systems formed a group that was significantly different from the five paste/paste systems. This indicates that accurate measurement of components could represent one important factor in the ultimate strength of a composite resin. There was no apparent correlation between average density and mean diametral tensile strength for the seven systems compared in this study.

Conservative approach to the placement of retentive pins.

A thorough understanding of the basic principles of cavity preparation and knowledge of tooth morphology are necessary for the successful positioning of pin channels in the tooth. Sufficient dentin surrounding the channel is necessary for adequate strength, to avoid external fractures of tooth structure and to protect the pulp. Once the channel location is decided upon, it should be made parallel with the external surface of the tooth rather than its long axis. It is suggested that the operator use only one pin per missing cusp of the tooth and that where possible this pin be placed in the area of the line angles. Optimal length of the pin into the restorative material is 2 mm and in the dentin is 2 to 3 mm for those retained by dentinal elasticity and 3 to 4 mm for those retained by cement. The use of a rubber dam for isolation procedures is encouraged, as well as radiographs and diagnostic casts to aid in the successful placement of retentive pins.