Measured diagram

Where does an all-ceramic bridge usually break, and how big are its joints?

A close-up of the joint between the premolar's zirconia crown and the false tooth in the step-by-step figure, with a 1 mm scale. The connector measures 3.3 mm tall here, as much as these crowns allow above the margins; beneath it a rounded opening leaves room for floss and small brushes, and the crown's margin sits at the gum.

What the drawing is measured from

Drawn from the bridge in the step-by-step figure: the connector's height is measured off the drawing, 3.3 mm at its thinnest, and the opening beneath it is drawn round. The cement is drawn 0.1 mm thick.
In a clinical study of 20 three-unit zirconia bridges for back teeth, made with connectors of at least 9 mm² in cross-section, 15 were rated perfect in every respect after a mean of 31 months and five showed minor chipping of the veneering porcelain. Raigrodski et al. 2006, The Journal of Prosthetic Dentistry. DOI
In laboratory tests of zirconia bridge frameworks, every framework broke at a connector, and connectors of at least 4 mm were recommended for long spans or where molars are replaced. Larsson et al. 2007, Journal of Oral Rehabilitation. DOI
A systematic review of 29 laboratory and computer-model studies found that larger or taller connectors often made zirconia bridges more resistant to fracture, though connector area alone did not explain every result. Babiuc et al. 2026, Materials. DOI

Use this diagram

Free to use, including commercially, with credit.

This diagram is published under CC BY 4.0. You may reproduce it in articles, teaching material, presentations and patient information, print or online, without asking. The one condition is that you credit Dr. Khalid Aletaibi and link back to this page.

It is published this way on purpose. The measurement in this drawing is not something the people selling the treatment tend to publish, so it is more useful spread than kept.

Credit line

The connector. Dr. Khalid Aletaibi, CC BY 4.0. https://khalidaletaibi.com/en/diagrams/bridge-connector

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  <img src="https://khalidaletaibi.com/figures/bridge-connector-en.svg" alt="The connector" width="100%">
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    The connector. <a href="https://khalidaletaibi.com/en/diagrams/bridge-connector">Dr. Khalid Aletaibi</a>,
    <a href="https://creativecommons.org/licenses/by/4.0/">CC BY 4.0</a>
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