current concepts in endodontics

lecture given 5/11/2026

what are the classifications of pulpal pathosis?

reversible pulpitis, irreversible pulpitis, pulp necrosis, previously treated, previously initiated therapy

what are the classifications for periradicular pathoses?

symptomatic periradicular periodontitis, acute periradicular abscess, asymptomatic periradicular periodontitis, chronic periradicular abscess, phoenix abscess, focal sclerosing osteomyelitis (condensing osteitis)

what is the systematic approach to a final diagnosis?

medical history

dental history

clinical exam

radiographic exam

diagnostic tests

what questions should you ask when doing case selection and treatment planning?

can the tooth be endodontically treated- are the canals negotiable, can the tooth be isolated, nonsurgical (retreatment) or surgical root canal treatment case?

should the tooth be endodontically treated- restorability of the tooth, periodontal status of the tooth, strategic value of the tooth, health status of the patient, motivation of the patient?

pathophysiology of reversible pulpitis

hyperemia

transient vasodilation

increased hydrostatic pressure within the pulp

is reversible if the etiology of the inflammatory response is removed

dental history for reversible pulpitis

no prior history of pain

sharp, hyper-response to thermal change (cold/hot), but pain does not linger after stimulus is removed

pain is not spontaneous, pain has to be provoked

recently placed restoration or carious lesion

clinical examination of reversible pulpitis

recently placed restoration (with or without wear facets), carious lesion, defective restoration, cervical erosion/abrasion

radiographic examination of reversible pulpitis

deep restoration (with or without a base), carious lesion, periodontal ligament space WNL (no break in lamina dura)

diagnostic tests for reversible pulpitis

positive electric pulp test

hyper response but pain disappears upon removal of stimulus thermal test

negative percussion

negative palpation

emergency treatment for reversible pulpitis

occlusal adjustment

removal of restoration- placement of temporary restoration, zinc oxide eugenol based restoration

pathophysiology of symptomatic irreversible pulpitis

circumferential spread of inflammation

acute inflammatory response within pulp

exudate cannot escape

increased hydrostatic pressure within the pulp (low compliance system)

is not reversible

dental history of irreversible pulpitis

spontaneous pain

history of previous episodes of pain

exaggerated response to cold/hot/sweets (pain lingers after removal of stimulus)

clinical examination of irreversible pulpitis

large restorations approximating pulp

defective restoration

carious lesion approximating pulp

radiographic evidence of irreversible pulpitis

deep restoration with or without a base

carious lesion

periodontal ligament space WNL or slightly widened (may see break in the lamina dura)

diagnostic tests for irreversible pulpitis

positive electric pulp test

hyper response and pain lingers upon removal of stimulus thermal test

negative or positive percussion if periradicular tissue is inflamed

negative or positive palpation if periradicular tissue is inflamed

emergency treatment for symptomatic irreversible pulpitis

nonsurgical root canal treatment- pulpotomy (use of fomocresol and formaldehyde are not advised bc human carcinogen, if immature tooth apexogenesis) / pulpectomy (intracanal medicament (calcium hydroxide), seal the access cavity)

analgesic- NSAIDs

pathophysiology of asymptomatic irreversible pulpitis

acute inflammatory response within pulp, but exudate is able to escape through carious or traumatic exposure

hyperplastic pulpitis- pulp polyp

internal resorption, emergency treatment not needed unless periapical symptoms

pulp necrosis

result of caries, trauma, advanced periodontal disease

can follow reversible pulpitis if etiology is not removed

circumferential spread of inflammation

emergency treatment depends on periapical status

dental history of pulp necrosis

history of trauma, caries, restorations, periodontal disease

previous history of pain

asymptomatic at the present time

no pain when provoked or stimulated

clinical examination of pulp necrosis

carious lesion approximating or exposing pulp

large restoration approximating pulp

tooth discoloration

periodontal diseaes

craze lines

radiographic examination of pulp necrosis

carious lesion approximating or exposing pulp

deep restoration approximating pulp

PDL space WNL or slightly widened- may see a break in lamina dura

diagnostic tests of pulp necrosis

no response electric pulp test

no response for themal test

negative or positive percussion if periradicular tissue is inflamed

negative or positive palpation if periradicular tissue is inflamed

emergency treatment of pulp necrosis

not needed unless periapical symptoms

previously treated or previously initiated root canal therapy

tooth has a history of root canal treatment- pulpotomy, pulpectomy, nonsurgical root canal treatment, surgical root canal treatment

emergency treatment not needed unless periapical symptoms

symptomatic periradicular periodontitis

of endo origin- exluding occlusal trauma and periodontal abscess

inflammation in the pulp has extended through the apical foramen into the periradicular area

dental history of symptomatic periradicular periodontitis

increased pain when chewing

may / may not have increased pain to hot or cold

may / may not have spontaneous and/or continuous pain

past history of pulpal pain

feels like tooth is higher than adjacent teeth

clinical examination of symptomatic periradicular periodontitis

carious lesion approximating or exposing pulp

large restoration approximating pulp

tooth discoloration

periodontal disease

fractured tooth

radiographic examination of symptomatic periradicular periodontitis

carious lesion approximating or exposing pulp

deep restoration approximating pulp

PDL space WNL or slightly widened

diagnostic tests of symptomatic periradicular periodontitis

positive or no response electric pulp test

positive or no response thermal test

positive percussion

positive palpation

emergency treatment of symptomatic periradicular periodontitis

nonsurgical root canal treatment- pulpotomy is contraindicated, pulpectomy (anesthesia, cleansing of the root canal system), intracanal medicament (calcium hydroxide), seal the access cavity, occlusal adjustment, analgesics (NSAIDs)

how can symptomatic periradicular periodontitis present?

spontaneous pain or pain to chewing/brushing

secondary acute periradicular periodontitis

secondary to root canal treatment

overextension of endodontic instruments into periapical area

extrusion of fluids, tissues, bacteria (bacterial products) into periapical area

dental history of secondary acute periradicular periodontitis

history of RCT 1-2 days prior to onset of symptoms

spontaneous/continuous pain

pain to chewing, percussion, palpation

feels like tooth is higher than adjacent teeth?

feels like pressure is building up in my jaw?

emergency treatment of secondary acute periradicular periodontitis

occlusal adjustment

investigate presence of additional canals

intracanal corticosteriod paste

seal the access cavity

trephination of buccal cortical plate

acute periradicular abscess

advanced acute periradicular periodontitis

decreased host resistance

increased virulence of bacteria

a ‘true’ infection

dental history of acute periradicular abscess

pain may/may not be present (pain fibers are located within periosteum)

past history of swelling

systemic system- fever/lymphadenopathy/sweating/chills/GI disturbances

pt looks and feels sick

clinical examination of acute periradicular abscess

extraoral/intraoral swelling, tooth mobility, carious lesion, large restoration, discolored tooth (history of traumatic injury)

radiographic examination of acute periradicular abscess

PDL space WNL or slightly widened- insufficient time for resorption of cancellous bone to inner lining of buccal or lingual cortical plates

should see break in the lamina dura

diagnostic tests for acute periradicular abscess

no response electronic pulp test

no response thermal test

positive percussion

positive palpation

emergency treatment of acute periradicular abscess

management of odontogenic infections- anatomic position of tooth in relation to buccal and lingual cortical plantes, relationship of apex of tooth closest muscle attachment

surgical (incision and drainage / decompression)

surgical phase of odontogenic infection treatment

incision & drainage/decompression

decreases number of bacteria, reduces tissue pressure (alleviates pain/trismus, improves circulation in area), prevents spread of infection, alters oxidation-reduction potential in tissue, accelerates healing

decontamination of site (betadine scrub), anesthesia (regional blocks, infiltration / avoid needle track infections), incision (healthy tissue, subperiosteal, rule of index finger), blunt disection (insert closed curved hemostat with beaks unlocked, open beaks to separate tissues, extend into adjacent spaces), insertion of drain (sterile penrose tubing, suture to healthy tissue, allow to remain in place for 2-7 days), endodontic therapy (at time of surgical phase, while drain is in place), removal of drain (24 hr after cleaning and shaping root canal, after resolution of infection)

indications for antibiotic therapy

compromised host resistance, systemic involvment, fascial space involvement, inadequate surgical drainage

guidelines for antibiotic therapy

select an antibiotic with an anaerobic spectrum, use larger doses for shorter periods of time, collect specimens prior to initiation of antibiotics, if available utilize gram stain results to select initial antibiotics

how should you select the appropriate antibiotic?

gram stain results available- use antibiotic sensitivity charts

culture and sensitivity results available- use antibiotic charts, results of MIC

no gram stain or C&S results available- amoxicillin is antibiotic of choice

amoxicillin

first drug of choice

gram ± aerobic cocci, most anaerobic rods

1-2g loading dose, 500mg every 8 hrs for 5-7 days

what did ashraf fouad find based on JADA article?

beta lactam based antibiotics remain the first line of effective antibiotics for patients in whom antibiotics are indicated

these regimens can be complemented with metronidazole 500mg 3x per day in resistant infections

if pt has fake pencillin allergy- oral cephalexin is indicated

if pts has true penicillin allergy- azithromycin

clindamycin has black box warning for c. dif

clindamycin (cleocin)

third drug of choice if allergic to penicillin and azithromycin or if no improvement in pts after 48 hrs on penicillin or azithromycin

gram - anaerobic rods, gram + aerobic strep

600mg loading dose, 150-300mg 4x a day for 5-7 days

risk of pseudomembraneous colitis

pseudomembraneous colitis

overgrowth of c. dif (gram + spore forming anaerobic rod)

growth is inhibited by lactobacillus, porphyromonas, psptostreptococcus

approx 5% of healthy adults carry c. dif in their intestines

20% of adults in hospitals are asymptomatic carries

pts at risk are elderly, inpatient, and immunosuppressed

most often associated with cephalosporins > ampicillin > clindamycin

produces 2 toxins a (enterotoxin) and b (cytotocin)

what are the 3 forms of GI complications

antibiotic asociated diarrhea without colitis- not caused by overgrowth of c. dif

antibiotic associated with colitis without pseudomembrane formation- overgrowth of c. dif without production of toxins

antibiotic associated colitis with production of pseudomembranes

metronidazole (flagyl)

oral absorption, renal excretion

bacteriocidal- disrupts DNA synthesis

antabuse effect

all anaerobic gram - rods, anaerobic gram + cocci, facultative aerobes are resistant

500mg 4x a day for 5-7 days

t/f antibiotics can interact with oral contraceptives

true

ibuprofen as analgesic post op

600mg tablets, 1 tablet 1 hr pre op, 1 tablet every 6 hrs post op, not prn

applied heat post operative

intraoral warm rinses, extraoral warm moist heat compresses

aid the body’s defenses- vasodilation, increased circulation into the infected area, removal of tissue products, increased inflammatory cells into the infected area

not used to regulate localization of infection

20-30min per hour

monitoring patient progress

close follow up- minimizes risk of severe complications, allows for modification of treatment or referral of patient, severity of infection determines frequency of follow-up

asymptomatic periradicular periodontitis

periapical inflammation/infection with resultant resorption of the bone

lesion of endodontic origin

histological diagnosis of periapical granuloma or cyst

dental history of asymptomatic periradicular periodontitis

asymptomatic at present time

past history of pain

restorations / caries / trauma

clinical exam of asymptomatic periradicular periodontitis

restoration, caries, trauma

radiographic exam of asymptomatic periradicular periodontitis

periradicular radiolucency

diagnostic tests for asymptomatic periradicular periodontitis

no response

emergency treatment for asymptomatic periradicular periodontitis

not needed

chronic apical abscess

asymptomatic periradicular periodontitis with the presence of an intraoral sinus tract or extraoral fistula

emergency treatment is not needed but be cautious

phoenix abscess

recrudescence of an asymptomatic periradicular periodontitis

asympatomatic periradicular periodontitis that becomes an acute periradicular abscess- decreased host resistance, increased bacterial virulence

emergency treatment for phoenix abscess

managed the same as an acute periradicular abscess