Failure of dental bridges. IV. Effect of supporting periodontal ligament.

The relationship between bridge failure and the periodontal ligament area of their abutments was studied in 156 dental bridges constructed for 132 patients. Of the bridges constructed at the College of Dentistry, King Saud University, 26.9% did not meet the published criteria of Ante's Law while 50.0% of those made in general dental practice did not meet the same criteria. However, radiographic evaluation of abutment teeth in 56 failed bridges revealed that there were only two cases with evidence of overloading the abutments.