title: Modification of the resistance form of amalgam coronal-radicular restorations.
abstract: Three groups of 10 extracted endodontically treated mandibular molars were mounted in acrylic resin. The occlusal surface was reduced until a 4 mm pulp chamber height remained. A peripheral shelf 2 mm deep and 1.4 mm wide was placed on one group, while four TMS Minim pins were placed 45 degrees to the long axis of the tooth into the facial and lingual walls of the second group. The final group served as the control and had no further treatment. All teeth were then restored with amalgam. An Instron testing machine was used to apply a controlled force to the beveled amalgam at a crosshead speed of 2 mm/min until fracture occurred. A peripheral shelf did not improve the fracture resistance of the coronal-radicular restorations tested. The specimens with semihorizontal pins were significantly stronger than specimens from the other groups. Placement of pins into the pulp chamber is recommended when adequate dentin remains.
authors.affiliation: Department of General Dentistry, Wilford Hall USAF Medical Center, Lackland Air Force Base, San Antonio, Texas.
authors.forename: J J
authors.initials: JJ
authors.lastname: Kane
authors.forename: J O
authors.initials: JO
authors.lastname: Burgess
mesh_terms: D000704:Analysis of Variance; D003723:Dental Amalgam / Q000737:chemistry; D003737:Dental Cavity Preparation / Q000379:methods; D003772:Dental Pins; D003779:Denture Design; D006801:Humans; D008434:Matrix Bands; D011176:Post and Core Technique; D012390:Root Canal Therapy; D013314:Stress, Mechanical; D013499:Surface Properties; D014082:Tooth Fractures / Q000503:physiopathology
chemical_list: D003723:Dental Amalgam