CHAPTER 2 - HIGH YIELD

What protects the normal pulp and dentin to keep them sterile?

Enamel and cementum

What is the most common route of root canal infection?

Direct pulp exposure (caused by deep caries, trauma, or restorative procedures)

How do microbes enter the root canal via dentinal tubules?

Usually not significant unless dentin is very thin, posing more risk in deep caries or trauma

How do microbes enter the root canal in relation to periodontal disease?

Via apical foramen, lateral canals, or exposed tubules after pulp necrosis

What is anachoresis?

The spread of microorganisms through the bloodstream to an inflamed pulp

Is there strong evidence supporting anachoresis as a route of infection in humans?

No strong evidence supports this in humans

What defines a primary intradenticular infection?

First-time infection of a necrotic pulp occurring before any treatment

What microorganisms primarily cause primary endodontic infections?

Mostly anaerobic, Gram-negative bacteria (Treponema, Fusobacterium, Porphyromonas, Prevotella, Tannerella)

Gram+ve: Streptococcus (S. Angiosus group), Actinomyces, Peptostreptococcus.

Where are primary endodontic infections most common?

In untreated necrotic pulps

What defines a secondary intradenticular infection?

New infection introduced during or after root canal treatment

What microorganisms primarily cause secondary endodontic infections?

Mostly Gram-positive bacteria (Enterococcus faecalis, Streptococci, Lactobacilli, Propionibacterium) and rare Candida albicans

What causes secondary endodontic infections?

Contamination during or after root canal treatment

What defines a persistent intradenticular infection?

Microbes from the original infection that survived root canal treatment

What microorganisms primarily cause persistent endodontic infections?

Gram-positive facultative or anaerobic bacteria (E. faecalis) and Candida albicans

Why do microbes causing persistent infections survive treatment?

Due to resistance or adaptation

What condition is frequently caused by persistent intradenticular infections?

Post-treatment apical periodontitis

Which specific bacterial species is highly resistant and strongly associated with secondary and persistent root canal infections?

Enterococcus faecalis

Which two infections are clinically similar?

Secondary and persistent

What symptom can occur with persistent or secondary infection?

Persistent symptoms

Exudate

Flare-up

Apical radiolucency

How much more frequently is E. faecalis found in treated teeth than primary infections?

9-fold

What structure can E. faecalis invade?

Dentinal tubules

What makes E. faecalis difficult to eliminate?

Irrigant resistance

Which bacteria is rarely involved in failed endodontic cases?

Prevotella intermedia

What is the classic radiographic sign associated with failed endodontic treatment?

Apical radiolucency