AAE Home > JOE > Abstracts > March 1983, Volume 9, Number 3
March 1983, Volume 9, Number 3
Effect of Sterilization and Irrigants on the Cutting Ability of Stainless Steel Files
Neal, Craig and Powers
New Principle and Method for Measuring the Root Canal Length
Ushiyama
Micropuncture Measurements of Interstitial Fluid Pressure in Normal and Inflamed Dental Pulp in Cats
Tonder and Kvinnsland
Effect of Sterilization and Irrigants on the Cutting Ability of Stainless Steel Files
Richard G. Neal, Robert G. Craig and John M. Powers
The effect of sterilization and irrigants on the cutting ability of stainless steel files was determined. Dry heat or salt sterilization had no effect, but autoclave sterilization caused a reduction in their cutting ability. Sodium hypochlorite, hydrogen peroxide, and EDTA-ures peroxide (UP) irrigants caused a decrease in the cutting ability of the files, but the saline irrigant had no effect.
New Principle and Method for Measuring the Root Canal Length
Junji Ushiyama
A new method for locating the apical constriction and foramen in vivo has been developed and tested on an in vitro model prepared with an extracted human tooth. The results indicate the feasibility of this method for clinical use.
Comment: The device described permits length determination in an electrolyte-filled canal. The problem with such devices seems to be that prior to instrumentation (when length determination is usually desired), the exact degree and nature of canal hydration are unpredictable. After instrumentation, canals likely have to be open to at least a #35 instrument before a solution of any kind can be predictably delivered throughout the canal. This may be too large a size to take the apical several millimeters of a fine or tortous canal.
Nevertheless, the device seems an advance over previous electrical gadgets.
Micropuncture Measurements of Interstitial Fluid Pressure in Normal and Inflamed Dental Pulp in Cats
Karin J. K. Tonder and Inger Kvinnsland
Interstitial fluid pressure (IFP) in cat dental pulp has been measured by glass capillaries (diameter, 2 to 4 μm) connected to a servocontrolled counterpressure system (Wiederheilm). Measurements were made in control teeth and in teeth 7 days after experimentally induced pulpitis. Control IFP averaged 5.5 (SD, 0.95) and 16.3 mm Hg (SD, 2.8) in the inflamed pulp. Measurements of IFP at a site 1 to 2 mm distant to the induced inflammation averaged 7.0 mm Hg (SD, 1.9). The measurements indicate that increased IFP due to inflammation is a local phenomenon which is not conveyed to the rest of the pulp.
Increased venous pressure resulted in an immediate rise in pulp IFP whereas mannitol infusion caused a reduction in pulp IFP.
The micropuncture technique for measurement of pulp IFP has the advantage of being practically atraumatic and pressure measurements are obtained rapidly, within seconds. This method allows IFP measurements at different sites in small organs, like the dental pulp.