Fouad – 6 fold increase in TTX-resistant sodium channels in IP cases
Does accessory nerve innervation affect anesthesia?
Frommer – mylohyoid nerve may supply accessory innervation
Pogrel – cross innervation of Mand incisors
What are some supplemental anesthesia techniques and how do they work?
PDL – IO anesthesia (Walton) – 92% effective
Stabident / X-tip – IO anesthesia
Intrapulpal – pressure anesthesia (Birchfield)
What are alternative injection techniques to the IAN block? Are they more successful?
Gow-Gates & Vazirani-Akinosi
Malmed – Gow-Gates is superior to IAN block
Reader, Petrovic – failed to show either GG or V-A is better than IAN block
Compare the efficacy of different anesthetics?
Reader – NSD in 4% prilocaine, 3% mepivicaine & 2% lidocaine with IAN block
Is Articaine the solution?
Reader – NSD between 4% articaine & 2% lidocaine with IAN block & IP
Aritcaine did show increased success if given as a buccal infiltration injection following IAN block (88% vs 71% success rate)
Haas – Articaine has a 5 fold higher incidence of paresthesias compared to lidocaine
Discuss Intraosseous anesthesia success and side effects?
Reader – 67% had an increase in heart rate – ok with healthy pts; consider mepivicaine
- Stabident with 2% lidocaine – 88% effective for IP
- Stabident with 3% mepivicaine for IP– 80% successful x1 injection; 98% x2
What are the anesthetic and epinephrine concentrations in common anesthetics?
2% lidocaine w/ 1:100,000 epi = 36mg lido w/ .018mg epi
3% mepivacaine (Cabocaine, Polocaine) = 54mg mepivacaine
4% articaine w/ 1:100,000 epi = 72mg articaine w/ .018mg epi
0.5% bupivacaine (Marcaine) w/ 1:200,000 epi = 9mg bupivacaine w/ .009mg epi
What drug interactions are a concern with epinephrine?
Tricyclic antidepressants – amitriptyline, doxepin
Nonselective beta blockers – nadolol, propranolol
Recreational drugs - cocaine
Nonselective alpha adrenergic blockers – chropromazine, clozapine, haloperidol
Digitalis - Digoxin
Thyroid hormones – Levothyroxine
What is the max dosage of anesthetic?
Moore – rule of 25 = 1 carp for every 25 pounds of pt weight
Adults 4.4mg /kg
Can Endo pathosis create perio pathology?
Sinai & Soltanoff – rat study showed pulpal disease affects the periodontium quickly with inflammation; perio disease affects the pulp slowly with degenerative changes
Does perio disease cause endo pathosis?
Yes: Seltzer – disease caused through lateral/accessory canals and vice-versa
Langeland, Rodregues & Dowden – if all main apical foramina are involved
Kipioti & Kobayashi (2 sep. studies) – caries free teeth with endo path showed similar microorganisms in perio pockets and root canals
No: Mazur & Massler / Czarneck & Schilder – histo studies showed no correlation
Who discussed endo-perio terminology?
Simon – Primary endo; Primary endo with 2nd perio; Primary perio; Primary perio wth 2nd endo; true combined lesions (ie root fx)
Does perio tx affect the pulp?
Wong & Hirsch – pulpitis was noted adjacent to areas of root planning/scaling
Does endo tx affect future perio tx?
Dunlap – in vitro study found RCT does not interfere with growth of fibroblasts on planed dentin surfaces
What is the biologic width?
Gargiulo, Wentz & Orban – sulcus depth - .7mm
epithelial attachment - 1mm
CT attachment – 1.1mm
What are common perio pathogens?
Red complex Bacteria: P. gingivalis, T. forsythensis & T. denticola
Other bacteria linked to perio disease: Actinobacillus actinomycetemcomitans, B. forsythus & P. intermedia.
Trope – spirochetes common in perio abscesses but less likely in endo abscesses
Discuss Primary tooth anatomy:
Hibbard: Mand incisors – 2 canals 10%
Max 1st molar – 2 MB canals – 75%
Max 2nd molar – 2MB canals – 85-95%
Mand 1st molar – 2 mesial canals – 75%; 2 distal canals – 25%
Mand 2nd molar – 2 mesial canals – 85%
Discuss formocresol pulpotomies: technique, formulation & concerns?
Technique – remove coronal pulp, moist cotton pellet until heme control, place formocresol X5 min, ZOE cement & SSC
Fuks – recommends 1/5 concentration
Pashley – found formocresol systemically (spleen, liver & kidney) after placing in dogs teeth
Are there any other options & compare success rates?
Vargas – NaOCl- & FeSO4 – 100% clinical success; 91% & 64% success radiographically
Fuks – Formocresol success - 84%; Glutaraldehyde - 72%; FeSO4 - 93%; MTA - 97%
How would you obturate primary teeth?
ZOE or Ca(OH)2 paste
Coll – 78% success with ZOE pulpectomies
Who decribed Apexification & what types of repair are seen?
Frank – long term tx with Ca(OH)2
4 types of repair/closure: recession of the root canal
obliterated apex w/out change of canal space
no radiographic evidence of closure / apparent clinically
calcified bridge coronal to the apex
How long does this take?
Kleirer – 1yr +/- 7months
Cvek – Avg 18 months; check q 3-6 months
Are there concerns about long term use of Ca(OH)2?
Andreasen – >30 day use will weaken dentin; ½ strength in 1 yr
Are there other options to manage an open apex?
Apical Bariers: Dentin Chips - Holland
Ca(OH)2 – Weisenseel, Hicks & Pelleu
MTA – Torabinejad
Can orthodontics cause pulp necrosis?
Butcher – extreme ortho forces can cause circulatory interruptions leading to necrosis
Can ortho cause resorption?
Reitan – ortho movement too quickly = resorption
Can you orthodontically move an endo treated tooth?
Wickwire – ok to move endo teeth – no signs of pathologic changes
Who first discussed ortho extrusion?
Heithersay – indicated for transverse root fx 1-4mm subcreastal; 6 wk stabilization
How long should you stabilize an extruded tooth?
Lemon – 1 mo stabilization for every 1mm of movement
Can anything else be done to prevent a relapse?
Malmgren – fiberotomy may help
How is resorption classified?
Tronstad – transient inflammatory (surface), progressive inflammatory, internal & external (progressive external, cervical, and replacement)
How do you differentiate internal from external resorption?
Gartner & Mack – radiographic differences: internal – symmetrical, cannot trace canal through lesion, stays centered in shift shots; external – irregular, can trace the canal through the lesion, moves on shift shots
What causes resorption?
Trope – Two things must happen: 1) the loss or alteration of the protective layer (pre-cementum or pre-dentin); 2) inflammation must occur to the unprotected root surface
Osteoclasts will not adhere to or resorb unmineralized matrix; if the cemental layer is lost or damaged, the inflammatory stimulators can pass from an infected pulp space through the dentinal tubules into the PDL resulting in both bone resorption and root resorption
Discuss internal resorption and tx approach?
Wedenberg – normal pulp is replaced with periodontal-like connective tissue
Turkun - >90% success with non-perforating using 1 wk CaOH2 and warm GP; 25% success with perforating defect
Stamos – ultrasonics & warm GP
Discuss external inflammatory resorption and tx approach?
Johnson – Necrotic teeth with AP had more apical resorption than those with a normal periapex or IP
Trope – Long term (12 wk) CaOH2 tx may be more effective than 1wk for established inflammatory root resorption
Discuss external cervical resorption an tx approach?
Heithersay – strong association with ortho, trauma & bleaching; distinguished class 1-4 defects; recommended topical 90% trichloracetic acid, curettage & GI restoration (endo tx)
Frank – Tx and prognosis based on complete debridement of the defect
Can ortho tx cause resorption?
Reitan – ortho movement too quickly = resorption
Who described internal bleaching?
Spasser – described Na perborate walking bleach
Nutting & Poe – recommended Super oxol + Na Perborate for greater efficacy; change every week
Can bleaching cause resorption?
Madison & Walton – bleaching factors associated with resorption were heat with 30% hydrogen peroxide
Papadopoulos – gaps at the CEJ lead to increased leakage of hydrogen peroxide
What can you do to prevent resorption?
Rotstein – use a 2mm base material at the CEJ; also recommends water instead of super oxol
Can tetracycline stained teeth be bleached?
Walton – only internal bleaching is effective
Does bleaching affect bonding of composite restorations?
Titley & Torneck – H2O2 may inhibit resin polymerization
Demarco – short term use of Ca(OH)2 restores bonding capabilities
Is internal bleaching effective?
Glockner - 5 yrs later; pts are 98% satisfied; 80% subjective success for dentists
Is vital tooth bleaching effective?
Haywood – 92% experience some lightening; 66% experienced transient side effects
Ritter – safe for the pulp up to 10 yrs post-op; bleaching effectiveness may decline
Endodontic Materials Overview
RC Prep: EDTA, Urea Peroxide, Cetyl Alcohol
Gutta Percha: 65% Zinc Oxide; 20% GP; 10% metal sulfites; 5% waxes and resins
AH Plus: epoxy-amine resin (Bisphenol paste A / Amine paste B)
Roth 801 Sealer: ZOE
Cavit: Zinc oxide; calcium sulfate, barium sulfate, talc, ethylene diacetate, zinc sulfate, polyvinyl acetate
MTA: 75% Portland Cement, 20% bismuth oxide, 5% gypsum
Super EBA: Powder – 60% Zinc Oxide, 34% Silicate dioxide, 6% resins
Liquid – 65% Ethylene Benzoic Acid, 35% Eugenol
Are endodontically treated teeth more brittle?
Sedgley – Vital dentin 3.5% harder; biomechanical properties are not significantly altered
Messer – NSD in moisture content
Reeh, Messer & Douglas – RCT reduces cuspal stiffness by 5%; Occl cavity prep. 20%; MOD 63%
Is the seal of the coronal restoration important?
Swanson & Madison – loss of coronal seal = bacterial contamination in as little as 3d
Ray & Trope – Quality of coronal seal more important than quality of endo tx
Berganholtz – GP exposed for up to 3 yrs showed lesions did not worsen
What type of temporary restorations do you use?
Cavit, IRM & Glass ionomer:
Weber – use 3.5mm thickness of Cavit
Beach & Hutter – 3 wk bacterial leakage test: no leakage w/ Cavit
Pashley – Cavit, Term & GI provided leakproof seals for 8wks
Is cuspal coverage important for endodontically treated teeth?
Aquilino – teeth without crown lost at 6X higher rate
When should post space be made? What technique and dimensions?
Immediately due to familiarity to canal anatomy & setting of sealer
Lemon – NSD with immediate or delay
Todd – NSD with heat or rotary removal of GP
Sorensen & Martinoff – post = crown length
Madison – leave at least 4mm GP
Johnson – max post width is 1/3 root width
Does Eugenol affect post cementation?
Yes – Nemetz – with panavia (resin) cement
No - Boone
Can posts cause root fractures?
Akin – Stress patterns are a result of post insertion
Randow – pts detect pressure earlier in vital teeth
Pulpal Histology/Pathology Overview
What the cellular elements of the pulp?
TenCate – Odontoblasts, fibroblasts, undifferentiated mesenchymal cells, macrophages, Lymphocytes & Dendritic cells
Farnoush – found mast cells in both inflamed and normal pulps
Reader – mylenated A-delta fibers 28%; unmylenated C fibers 72% of total
How far do the odontoblastic processes extend into the tubules?
Pashley – 1/3 the length of the tubule
What types of collagen are found in the dental tissues & what cells synthesize collegen?
Pulp – type I & III; Dentin – type I (90% of organic component)
Synthesized by mainly fibroblasts, but also odontoblasts, osteoblasts & cementoblasts
Are lymphatics found in the pulp?
Bernick – demonstrated lymphatics in the pulp
Discuss the pulp vasculature and regulation of blood flow?
Takahashi & Kim – SEM showed AV anastomosis, VVanastomosis, U-shaped arterioles
Kim – PBF increased with C-fiber activation (A-delta insignificant); C-fibers release substance P which increases PBF; the increase in tissue pressure excites both A-delta & C fibers
Describe the ‘strangulation theory’ & does it occur?
As pulpal inflammation ↑, pulpal pressure ↑. With this increased pressure, veins and lymphatics collapse at the apex and strangle the pulp – necrosis results
Tonder – cat study disproved this theory; localized increase in pressure with no strangulation
Discuss calcific metamorphosis? Is RCT indicated?
Pathways - Pulp canal obliteration due to trauma – resembles cememtum or bone
Andreasen – 22% of traumatized teeth undergo CM; only 8.5% developed pulp necrosis
Walton – canal present histologically, although absent radiographically
Holcomb & Gregory – RCT if PARL develops; only 7% require RCT
Discuss the pulpal rxn to caries?
Reeves & Stanley – if caries is < .5mm from the pulp or if it invades reparative dentin, there is irreversible damage; if >1.1mm then little pathosis is seen
Trowbridge – chronic inflammation occurs long before bacteria penetrates the pulp
What is the effect of restorative dentistry on the pulp?
Stanley, White & McCray – tertiary dentin begins to form @ 19 days at 1.49 um/day
Abou-Rass – consider RCT for teeth with stressed pulps
Zach – heat is capable of causing pulp necrosis
Felton & Madison – 13% incidence of pulp necrosis following FCC
How does age affect the pulp?
Bernick – decreased vascularity, nerves & pulp chamber size; increased calcifications
Describe the hydrodynamic theory of dentinal hypersensitivity. Any solutions?
Brannstrom – heat causes inward fluid movement; cold – outward; distortion of odontoblastic processes stimulates nerve response
Pashley – occlude tubules with unfilled resins or oxalate salts
Kim – K+ ions desensitize nerve ending
How does vital bleaching affect the pulp?
Ritter – safe for the pulp up to 10 yrs post-op; bleaching effectiveness may decline
Periapical Pathology Overview
Granulation tissue: healing tissue with fibroblasts, collagen, proliferating capillaries and leukocytes
Granuloma: chronic inflammatory tissue primarily infiltrated with lymphocytes, plasma cells & macrophages
True cyst (bay cyst – Simon): inflammatory lesion with a distinct pathological cavity completely enclosed in an epithelial lining
Pocket cyst: lined with epithelium, but communicates with the root canal
Abscess: acute inflammation consisting primarily of PMNs
Is it possible to differentiate between a granuloma or cyst?
Priebe – No, can’t determine from a radiograph
What is the incidence of a granuloma, cyst & abscess?
Nair – 50% granuloma; 35% abscess; 15% cyst (distinguishes 9%pocket / 6% true)
Rubenstein & Kim – 85% granuloma; 15% cyst
What are the theories of cyst formation?
Breakdown theory – (Toller): Osmotic pressure buildup due to semi-permeable membrane (remnants of cellular debris inside lumen leads to increased osmotic pressure due to Starling’s law)
Cavitational Breakdown theory – (Ten Cate): Continuous growth of epithelial cells (rests of Malassez) removes central cells from their nutrition; innermost cells die & cyst cavity forms
Epithelial Proliferation theory – (Seltzer): epithelial cells proliferate to line the abscess cavity
Immunologic theory – (Torabinejad): Immune rxn (to antigens-bacteria in infected RC) responsible for proliferation of epithelium
Do cysts heal following RCT?
Nair – pocket cysts should heal; true cysts, particularly large ones with cholesterol crystals are less likely to resolve following RCT
What are the histologic features of a sinus tract?
Baumgartner – lined with either epithelium or granulomatous tissue; 67% lined with epithelium to level of rete ridges; 33% were completely lined with epithelium to the PA lesion
Is condensing osteitis a LEO?
Eliasson, Halvarsson & Ljungheimer – tx successfully and resolved with RCT 85%
Provide a differential diagnosis for the following:
Unilocular Periradicular Radiolucency:
PA Fibrous Scar – more frequent with thru & thru lesions or S RCT
Nasopalatine Duct Cyst – max midline; > 6mm between central incisor roots
Traumatic Bone Cyst – not a true cyst; trauma etiology; mand teeth
Benign Fibro-osseous lesions (early stages) – periapical cemental dysplasia
Lateral Periodontal Cyst – mand and max canine & premolar area
Mutiloculary Periapical Radiolucency:
Ameloblastoma – aggressive neoplasm; any tooth-bearing area, but mand most common; peak age 30-40
Central Giant Cell Granuloma – multinucleated giant cells; rule out hyperparathyroidism
Odontogenic Keratocyst – post mand most common but may occur in any tooth bearing area; multiple OKCs associated with Basal cell nevus syndrome
Condensing Osteitis - LEO
Idiopathic Osteosclerosis – idiopathic dense bone; vital pulps
Benign Fibro-osseous lensions – mixed radiolucent/radiopue; ossifying fibroma, cemento-osseous dysplasia, PCD; vital pulps
Cementoblastoma – attached to root with radiolucent rim; neoplasm of cementoblasts
Osteoblastoma – neoplasm of osteoblasts; may occur in any bone; not attached to root
Odontoma - compound (tooth like) or complex
Describe the Nerve supply to the teeth?
The Anatomic Basis of Dentistry
Brain stem → Trigeminal nerve (cranial nerve V) → 3 Divisions (I – Opthalmic; II – Maxillary; III – Mandibular)
Nerve supply to the Maxillary teeth:
Trigeminal nerve → 2nd Div Maxillary nerve (foramen rotundum) →
PSA → Maxillary Molars
MSA → Maxillary Premolars (MB root Max. Molar)
ASA → Maxillary Anteriors
Nerve supply to the Mandibular teeth:
Trigeminal nerve → 3rd Div Mandibular branch (foramen ovale) →
IAN → Mandibular Molars / Premolars → Incisive branches → Canines / Incisors
Describe the blood supply to the teeth?
The Anatomic Basis of Dentistry
R atrium/R ventricle → Pulmonary artery → Lungs → Pulmonary vein → L atrium/L ventricle → Aorta → Common Carotid artery → External Carotid artery → Maxillary artery →
Maxillary Posterior teeth: Pterypopalatine artery → PSA artery
Maxillary Anterior teeth: Pterypopalatine artery → PSA artery → ASA artery
Mandibular Posterior teeth: Mandibular artery → Inferior Alveolar artery
Mandibular Anterior teeth: Mandibular artery → Inferior Alveolar artery → Incisive artery
Veins from the Mandibular teeth → Inferior Alveolar vein →
Veins from the Maxillary anterior teeth→ Infraorbital vein →
Veins from the Maxillary posterior teeth →
Maxillary Vein → Pterygoid venous plexus → retromandibular vein → Internal Jugular vein → Brachiocephalic vein → Superior vena cava → Heart (r. atrium)
What causes periapical pathology?
Bacteria: Kakahashi – lesions developed with exposed pulp in conv. rats & not
Moller – lesions only developed in infected devitalized pulps in monkeys
Sundqvist – bacteria were necessary to cause lesions in human teeth
*Host immune response mediates tissue and bone destruction in response to bacteria (see inflammation section)
What is the general distribution of bacteria within the tooth?
Crown = Aerobes associated with careis: Strep mutans
Mid-root = Facultative species (Gram + rods/cocci): Staph aureus, Actinomyces,
Apex = Anaerobes (Gram – rods/Gram + cocci): Bacteroides, Fusobacterium
What specific bacteria are involved the pathogenesis of a primary root canal infection?
Siqueira – mixed flora (avg. 5 species), predominately gram – anaerobic rods (Porphyromonas endodontalis most common)
Baumgartner – Prevotella nigrescens most common BPB isolated