The relationship between failure and design in conventional bridgework from general dental practice

Abstract

A total of 142 failed bridges constructed in general dental practice were assessed for design factors that might relate to failure. The overall mean age of the bridges at failure was 6.2 years; anterior and complex bridgework had a mean age of about 5 years, compared with 7.5 years for posterior bridges. The lifespan of the bridgework was significantly correlated with the number of retainers but not with the number of units. Bridges with one or two retainers had an average lifespan of just over 7 years, whilst those with three or more retainers had been in service for, on average, only 4 years. The practical difficulties of constructing multi-abutment bridgework could account for this difference. One hundred and ninety-one of the 346 retainers were porcelain bonded to semi non-precious metal crowns, and had a mean lifespan of 3.7 years, whilst those that were gold based lasted at least twice as long. Post crowns as retainers survived on average for 6.2 years.

Complications and primary failures related to fixed metal ceramic bridge prostheses made by dental students

“…Demands for the necessary parallelism of the abutment teeth, especially in the bridges with multi‐abutments, can be too difficult to perform for the students and complications of this kind are predictable. The same problem has been observed in a study concerning the relationship between failure and design in conventional bridgework in general dental practice ( Foster 1991). Two perforations of the root canal noted during the preparation phase of cast cores in one upper incisor and canine might also be due to the inexperience of the students.…”

Tooth‐related risk factors for tooth loss in community‐dwelling elderly people

“…Thus, the effect of these abutment teeth on tooth loss could vary according to the characteristics of study population. Moreover, FPDs with more units were found to increase the risk of retention loss or even the loss of the restoration altogether because the alignment of multiple tooth preparations is complex and may result in excessive taper, which will jeopardize retention (20). However, unfortunately, this study did not examine span length of FPDs.…”

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

“…To fulfill the criteria in Ante's Law, dentists commonly increase the number ni retainers and this may accelerate bridge failure with reduced embrasures spaces, plaque retention, etc. Foster (1991) stated that the longevity ol bridgework would be prolonged by using only retainers that are strategic for bridge support. Double or multiple abutments in long-span bridges do not always increase survival times, but may predispose the prostheses to biological deterioration because of such matters as tissue stagnation and biological width violation.…”