Periapical Test



The probing test is a helpful test to diagnose if any are teeth present with periapical inflammation or periodontal involvement.




under construction!.png


Before you begin: select which teeth you will be testing. 

Unless you suspect more generalized periodontitis or wish to gauge the patient’s overall periodontal status, it should be sufficient to only probe the tooth or teeth that are of interest (symptomatic or suspected involvement).

  • Every situation is different, so you will need to adjust your selection based on your patient’s symptoms and natural dentition

Using your periodontal probe, check the depth of the periodontal pocket surrounding the teeth you are examining. Record the pocket depths (DB, B, MB, ML, L, DL) and note any pockets that are greater than or equal to 4 mm.

Record the probing depths in a record keeping table.

  • Probing shows a normal sulci except in one area -> primary defect of endodontic origin

  • Probing shows a normal crest and then “steps down” into a really deep pocket -> primary defect of periodontal origin

  • Probing shows extensive plaque, calculus, periodontitis, and wide pockets -> primary defect of endodontic-periodontic origin (combined defect)

For multi-rooted teeth with bone loss, assess for furcation involvement. In the area of the expected furcation, probe carefully. If you detect the ability of the probe to travel through the furcation, this indicates furcal involvement. If an explorer can pass all the way through or if the furcation is visible then this indicates severe furcal involvement.

  • If there is furcation involvement, this should be considered when assessing the overall prognosis of the tooth in question

  • It is possible that furcal involvement may be a result of perio-endo infection or periodontal disease


Torabinejad M, Fouad A, Shabahang S. Endodontics: Principles and Practice. 6th ed. London, United Kingdom: Elsevier, 2020.

Blicher B, Pryles RL, Lin J. Endodontics Review: A Study Guide. Hanover Park, IL: Quintessence Publishing Co, Inc, 2019.