Microbiology Flashcards
Bacteria is a major etiological factor factor in the progression of pulpal inflammation to apical periodontitis. (germ-free rats).
Kakehashi et al
Bacteria present in necrotic pulps with apical periodontitis but not in necrotic pulps without apical disease.
Sundqvist
Focal infection theory in endodontics – bacteria trapped in dentinal tubules could leak and cause systemic disease.
Weston Price 1925
Refuted the focal infection theory in endodontics.
Easlick 1952
A basis for the success of RCT
“The Zones of Fish” – If the nidus of infection is removed, then the body can recover.
Gram-positive Bacteria
Streptococcus, enterococcus, lactobacillus, actinomyces. Thick petidoglycan cell walls. Stain crystal violet.
Gram-negative Bacteria
Fusobacterium, treponema, porphyromonas, tannarella, campylobacter. Cell walls contain LPS. Less affinity for crystal violet.
_______ is important in progression of pulpal and periapical inflammation – stimulate cytokine production in macrophages.
LPS
Torabinejad and Dwyer
________ caused by trauma allow bacterial ingress.
Microcracks
Bergenholtz
Anachoresis – homing of bacteria to traumatized, unexposed pulps proposed by ______
Gier and Mitchell
Disproved anachoresis
Delivanis et al
Endodontic infections require _____ and are ______ in nature
Disruption of protective barrier
Polymicrobial
A microbial derived, sessile community characterized by cells irreversibly attached to a substratum, or interface, or to one another, embedded in a self-produced matrix of extracellular polymeric substances, and exhibiting an altered phenotype with respect to growth rate and gene transcription compared to planktonic counterparts.
Biofilm defined by Donlan and Costerton
Svensater and Bergenholtz qualities unique to biofilms. (4)
Metabolic diversity
Concentration gradient
genetic exchange
quorum sensiing
Abscesses are not sterile, supports the validity of _________.
Extraradicular infections
Tronstad – anaerobes present in extraradicular infections
Sunde – molecular techniques (Agreggatibacter, actino, tanerella)
________ present in sinus tracts
Bacteria
Haapasalo
Cytomegalovirus and EBV in AP
Sabeti
More _____ and ______ when parulis present
Fusobacterium
P ging
Sassone
______ can occur despite pulpal necrosis in luxated teeth without contamination.
Healing
Andreasen
_____% of necrotic teeth are infected
64%
Wittgow and Sabiston
Typically isolated species types (oxygen need)
Facultative and obligate anaerobes
Typically isolated species
Strep, enterrococcus, porphyromonas, prevotella
Infection profiles vary _______
Geographically
Baumgartner
________ strep more common in endo infections
Beta-hemolytic
Winkler and Van Amerongen
E faecalis is of particular interest due to
Antimicrobial resistance
E Faecalis unique properties (3)
Proton pump – Evans
Survives in dentinal tubules – Love
Can form bioflims – Distel
E Faecalis proton pump provides resistance to
CaOH. Prevents the ionization that is required for it mechanism of action. Bystrom.
“Black Pigmented Bacteroides” split into (use of sugar)
Prevotella (sacchrolytic)
Porphyromonas (asacchrolytic)
Atypical species in endodontic infections (4)
Actinomyces
Spirochetes
Fungi
Arachaea
Actinomyces is associated with _____ and are common cause of ______
Sulfur granules – Sunde
persistent endodontic infections (survives and thrives in periapical area) – Nair
Spirochetes have ____
flagella for motility. Treponema detected by Siqueira.
Archaea present in pulp
Vianna
Candida present in primary endodontic infections
Baumgartner
________ have not been detected in dental pulp
Prions
Azarpazhooh and Fillery
HSV 1 and 2, HHV, VZV present in acute apical abscesses
Ferreira
Viruses may play an active role in pulpal death
Goon and Jacobsen. Devitalization of pulps associated with trigeminal VZV infection.
Association between feline herpesvirus and invasive cervical root resorption.
Von arx
HPV in endodontic abscesses
Ferreira
_______ in pulps of patients with clinical AIDS
HIV
Glick
______ in periapical lesions of HIV+ patients
HIV
Elkins
Greater number of bacterial species present in
Primary infections
20 in primary vs 3 in secondary
Rocas and Siqueria
Primary infection composition
Equal mix of gram-positive and gram-negative. Mostly obligate anaerobes.
Sundqvist
Secondary infection composition
Mostly gram-positive. More equal distribution of facultative and obligate anaerobes.
Sundqvist
Progression of primary infections from aerobic and anaerobic species as oxygen tension decreases.
Microbial Succession.
Fabricius
_________ frequently associated with secondary infections.
E faecalis
Siqueira
________ with symptomatic infections
Fusobacterium — Siqueira
T forsythia — Sassone
T forsythia with painful infections
Sassone
EBV and CMV with painful infections
Sabeti
Buccal Vestibule
Defined by buccinators and the alveolar mucosa. Mx posterior apices inferior to insertion and Mn posterior apices superior to insertion will spread to this space.
Buccal Space
Defined by buccinators and cheek mucosa. Mx posterior apices superior to insertion and Mn posterior apices inferior to insertion will spread to this space. Can spread to periorbital space.
Pterygomandibular Space
Defined by the medial pterygoid and the mandibular ramus inferior to the lateral pterygoid. Mn second and third molar infections can spread here.
Canine Space
Superior to the levator anguli oris muscle and inferior to the levator labii superioris. Mx canines and first premolar infections disrupting the buccal cortex can spread to this space.
Periorbital Space
Deep to the orbicularis occuli. Infections from Mx canines and large buccal space infections can spread to this space.
Submandibular Space
Superior to the platysma and inferior to the mylohyoid muscle. Mn posterior infections disrupting the lingual cortex can spread to this space. Continuous with the submental space across the digastric muscle.
Submental Space
Superior to the platysma and inferior to the mylohyoid muscle. Mn anterior infections can spread here.
Mental Space
Below the mentalis muscle. Mn anterior infections can spread here.
Sublingual Space
Superior to the mylohyoid and inferior to the floor of the mouth. Mn infections that disrupt the lingual cortex can spread here. This space is bilateral without midline separation.
Lateral pharyngeal space infection
Mn second or third molar infection spreads beyond to pterygomandibular space. Can cause inner jugular thrombosis.
Ludwig angina
Combination of submental, sublingual, and submandibular space infections
Cavernous sinus thrombosis
Periorbital space infection spreads via valveless facial veins.
Danger space
Alar and pre-vertebral fascia. Continuous with mediastinum. Infections that spread beyond the lateral pharyngeal space.
