The effect of three commonly used endodontic materials on the strength and hardness of root dentin.
The purpose of this study was to determine if calcium hydroxide, mineral trioxide aggregate, or sodium hypochlorite caused a change in the force required to fracture root dentin. Ten bovine central and lateral incisors were machined using various saws and drills to produce a cylinder of dentin with a 6.0-mm outer diameter 3.5-mm inner diameter and a length of 10 mm. The cylinders were cut lengthwise into four symmetrical pieces. The canal sides of the sections were then placed into Petri dishes containing a 1-mm depth of calcium hydroxide, mineral trioxide aggregate, sodium hypochlorite, or physiologic saline (control). The samples remained in the dishes for 5 weeks and were then shear tested by using an Instron machine. Data were analyzed using an ANOVA test for comparison of the groups as a whole, and a t test was used to compare each quarter section with its control from the same tooth. A 32% mean decrease in strength was discovered for calcium hydroxide, a 33% decrease in strength for mineral trioxide aggregate, and a 59% decrease for sodium hypochlorite. All decreases in strength were statistically significant: p < 0.001 for calcium hydroxide, p = 0.027 for mineral trioxide aggregate, and p < 0.001 for sodium hypochlorite. Results indicated that root dentin was weakened after 5 weeks of exposure to calcium hydroxide, mineral trioxide aggregate, or sodium hypochlorite.
White
J Derek
JD
Department of Restorative Dentistry, University of Alabama at Birmingham, 35294-0007, USA.
Lacefield
William R
WR
Chavers
L S
LS
Eleazer
Paul D
PD
D017607:Aluminum Compounds / Q000009:adverse effects*; D000704:Analysis of Variance; D000818:Animals; D017610:Calcium Compounds / Q000009:adverse effects*; D002126:Calcium Hydroxide / Q000009:adverse effects*; D002417:Cattle; D003799:Dental Stress Analysis; D003804:Dentin / Q000187:drug effects*; D004338:Drug Combinations; D006244:Hardness / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D010087:Oxides / Q000009:adverse effects*; D012387:Root Canal Filling Materials / Q000009:adverse effects*; D012388:Root Canal Irrigants / Q000009:adverse effects*; D033081:Shear Strength; D017640:Silicates / Q000009:adverse effects*; D012973:Sodium Hypochlorite / Q000009:adverse effects*; D013718:Tensile Strength / Q000187:drug effects; D014082:Tooth Fractures / Q000209:etiology; D014092:Tooth Root / Q000187:drug effects*
D017607:Aluminum Compounds; D017610:Calcium Compounds; D004338:Drug Combinations; D010087:Oxides; D012387:Root Canal Filling Materials; D012388:Root Canal Irrigants; D017640:Silicates; C086631:mineral trioxide aggregate; D012973:Sodium Hypochlorite; D002126:Calcium Hydroxide