Fracture resistance of human teeth with mesial-occlusal-distal cavities prepared with sharp and round internal line forms.
Conservative MOD amalgam-type preparations of similar dimensions were cut in extracted contralateral maxillary first premolars; one preparation for each pair had sharp internal line angles and the other had a rounded internal form. The data do not demonstrate a statistically significant difference in resistance to fracture between the two groups. The difference in preparation produced by the use of a flat-end bur vs. a rounded-end bur does not appear to produce a great enough concentration of stress to significantly weaken teeth with conservative preparations.
D000293:Adolescent; D000328:Adult; D001641:Bicuspid / Q000033:anatomy & histology*; D002648:Child; D003737:Dental Cavity Preparation / Q000379:methods*; D006801:Humans; D013314:Stress, Mechanical; D013718:Tensile Strength; D014082:Tooth Fractures / Q000517:prevention & control*