Perio Endo Relationship

Question 1

What is the principal route of communication between root canal system and peri radicular tissues

Answer 1

Apical foramen

Question 2

Diameter of dentinal tubules at the pulp and at CEJ

Answer 2

2. 5um at pulp

0. 9um at DEJ

Question 3

What happens when cementum removed

Answer 3

Cementum on root surface serve as protective barrier to underlying dentin

If cementum removed, there will be direct communication between pulp and periodontium. Open numerous patent channels between pulp and periodontium —> bacteria penetrate into root canal system

Question 4

Non physiological pathways from pulp to periodontium

Answer 4

Iatrogenic root perforation. Inflammation at PDL at site of perforation lead to formation of lesion, which can progress into primary endo lesion

Vertical root fractures. Fracture serve as bridge for pulp contamination. If periodontium previously inflamed —> dissemination of inflammation leading to pulpal necrosis

Question 5

Radiographic representation of direct inflammatory response

Answer 5

Widened PDL space
Loss of lamina dura
Periapical radiolucency

(Furcation radiolucency may be endo and/or perio, confirm clinically using pulp sensitivity test)

Question 6

Chronic inflammatory response will manifest radiographically as

Answer 6

Peri apical radiolucency

Question 7

How does chornic abscess lead to deep probing depth

Answer 7

Chronic periapical drainage through the gingival sulcus -> downgrwoth of epithelium around the sinus tract, resulting in deep and narrow periodontal pocket

Perio and calculus detected within the pocket (Christis and Holthuis 1980) retrograde periodontitis

Question 8

What size gp cone to use fro sinus tract tracing

Answer 8

Size 35-40/30-40

Question 9

Likelihood of perio endo lesion

Answer 9

Pulp unlikely to succumb even with severe periodontitis

Perio to endo happens when attachment and bone loss goes beyond apex and apical foramen

Periodontal disease has no impact on the pulp, pulp remains fully functional even when attachment loss beyond apex —> periodontal infection induce endodontic infection

Question 10

How long does transient increase in pulpal response last for after removal of cementum

Answer 10

Reversible pulpitis resolves after 1-2 weeks

Question 11

What is the chief complaint for pri endo sec perio

Answer 11

Sharp throbbing pain

Question 12

What is the chief complaint for pri perio sec endo

Answer 12

Dull chronic pain with possible acute exacerbation

Question 13

Bite test result characteristic of cracked tooth

Answer 13

Pain upon release

Question 14

How to treat primary endo with secondary perio

Answer 14

RCT. May defer root debridement to later stage. Do cleaning and shaping and hope that bacteria from root canal system will help to resolve periodontal pocket issue, only gross subgingival scaling.

Question 15

Concurrent perio and endo infection. How does perio affect endo

Answer 15

Untreated perio infection will affect post endo healing as bacteria from adjacent infection can reinvade system

Gupta et al 2015: timing of perio intervention no effect on healing as long as performed within 3 months of RCT completion

Question 16

Primary endo pocket is

Answer 16

Deep, solitary or nil

Question 17

Primary endo with perio pocket

Answer 17

Increased PPD

Solitary pocket, wider than primary endo, can sweep probe right and left

See plaque/calculus at gingival margin

Question 18

Primary perio pocket is

Answer 18

Wide. May not go to apex

Question 19

Primary perio with endo pocket

Answer 19

Wide coronally, may extend deep to apex (unless disease progresses to involve apical foramen, negligible effect on pulp)

Question 20

True combined lesion pocket is

Answer 20

Wide and conical