Final Flashcards
What is the definition of a healing tooth?
Teeth with periradicular pathosis that are asymptomatic and functional, or teeth with or without perrardicular pathosis that are symptomatic but for which the intended function is not altered.
What is apexogenesis and what are some options for doing it?
It is vital pulp therapy to encourage continued physiologic development and formation of root end, maintaining pulp vitality. You could do a Cvek pulpotomy, cervical pulpotomy, control bleeding, rinse with NaOCl diluted to 1.25%, MTA or CaOH.
Where does the smear layer accumulate?
Into accessory canals, isthmuses, canal walls, and fins.
What must an instrument do to completely clean the canal space?
a. be deflected at the canal orifice
b. be 2 to 3 mm short of the radiographic apex
c. fit loosely into the canal
d. contact all walls and surfaces
D
Which bug is Chlorhexidine specifically effective against compared to other irrigants?
- Enterococcus faecali. Clorhexidine is mainly just antimicrobial, doesn’t do much else, but it does form an ill-wanted precipitate when combined with bleach.
- Chlorhexidine is similar to NaOCl but unable to dissolve necrotic tissue nor remove smear layer
What are the main inflammatory mediators released when the pulp is irritated?
Histamine, bradykinin, arachidonic acid metabolites, PMN granule products (elastase, cathepsin G, lactoferrin), antitrypsin, calcitonin peptide.
Which of the following is an advantage of gutta- percha?
- adhesiveness to dentin
- slight elasticity and rebound effect
- expansion on cooling of warmed gutta-percha
- adaptation to canal irregularities with compaction
D
What are the names of the two diameters near the apex?
The minor apical diameter and the major apical diameter.
Mandibular Right Second Molar
What percentage of eventual extractions result form an endodontic cause?
Only 10 %. And one study showed that 30% of root-filled teeth (RCT treated) were never restored within two years—11% extracted eventually.
What are Reamers used for?
They are miniature hand-operated twist drills used to enlarge the size of the root canal and to negotiate the canals to their apices.
What is Lortab/Norco made of?
Tylenol and Hydrocodone
The lingual root of the maxillary first molar often has a curvature in the apical third to which of the following?
a. buccal
b. lingual
c. mesial
d. distal
e. none of the above, the root is usually straight
A
What is apexification? And what do you do?
Pulp vitality is not attainable so we introduce a calcific barrier across open apex with pulpal necrosis. You do irrigation with NaOCl 1.25%, get WL short of apex with gentle filing, use CaOH paste to stimulate inflammatory response, use MTA for barrier that is permanent at apex, and you can also do Regendo.
A C-shaped canal is characterized by which of the following?
- has complex internal anatomy
- is most commonly found in Asian populations
- usually occurs in mandibular second molars
- should be referred to an endodontist for treatment
- all of the above
5
What is the main source of microbial irritation to dental pulp and periradicular tissues?
Dental Caries
Which of the following is not associated with acute apical abscess?
- moderate to severe discomfort
- intense and prolonged response to thermal stimulus
- negative response to electric pulp testing
- tenderness to percussion and palpation
2
What is apexogenesis?
a. induction of a calcific barrier across an open apex
b. removal of the necrotic pulp
c. determination of corrected working length
d. continued physiological root formation
D
Which group of microbes dominate intraradicular infections?
- Obligate anaerobes, but are easily removed during conventional RCT
What is the process/technique for placing gutta percha?
The Master Cone Fit (usually same as MAF) is fit to within .05-1mm of WL. Or you can take a little larger size, dip the tip in chlorophorm, dip it in the sealer, and push it the last 1.5mm. Some radiographically firm after this, most don’t. Then for the lateral condensation technique, you place the Master, use the spreader to create space for accessory points, and this is all to within 2-3mm of WL. You have about 6 seconds to place the accessory points to fill space, and you repeat this to coronal 1/3. Then you sear excess with heated plugger (glick). Then you vertically compact with double-ended plugger (5/7) and then you clean the chamber with alcohol-soaked cotton pellet.
Multiple canals in mandibular premolars occur most often in which population?
a. Asians
b. African-Americans
c. Caucasians
d. No difference by ethnicity
B
What are the 4 main cleaning & shaping objectives of root canals?
- Remove infected hard and soft tissue
- Give disinfecting solutions access to the apical canal space
- Create space for the delivery of medicaments and subsequent obturation
- Retain the integrity of radicular structures
Percentages of maxillary 2nd premolars having 2 canals?
2 = 10-20%
Percentages of mandibular incisors having 2 canals?
2 = 30-40%
Removalofthesmearlayeraftercleaningandshaping does which of the following?
- promotes coronal leakage
- decreases dentin permeability
- allows better adaptation of obturating materials to canal walls
- forces bacteria into dentinal tubules
C
What are the 4 main uses of files?
- Canal negotiation 2. Canal debridement 3. Length determination 4. Canal shaping
If a patient has a cold pack on their face to relieve pain, is it most likely reversible, irreversible, or necrosis?
Irreversible, because the cold may cause vasoconstriction, a drop in pulpal pressure, and subsequent pain relief.
What motion is employed with a hand instrument to clean and shape canal walls?
a. pushing
b. broaching
c. reaming
d. vibration
C
What is Percodan made of?
Aspirin and Oxycodone
How do you treat a tooth that has been out of socket for greater than 60 minutes, both closed and open apex?
Closed, Soak in 2% NaF for 20 minutes, and do RCT in NaF soaked guaze in hand. Replant and splint for 4 weeks. It will probably ankylose. Open, May not reimplant due to very high incidence of ankylosis, but do RCT out of mouth as well.
Maxillary Right Central Incisor
Of the following, what is the best transport medium to use for transporting an avulsed tooth?
a. saliva
b. distilled water
c. wrapped in a tissue
d. milk
D
What are the main four vital pulp therapies?
- Indirect pulp therapy
- Hall technique (stainless crown with no caries removal)
- Direct pulp capping (Only with small mechanical or traumatic exposures, but not with caries exposure)
- Pulpotomy (Use formacresol, glutaraldehyde, ferric sulfate, or MTA)
What are barbed broaches used for?
They are used for the removal of pulp tissue and for removing cotton wool dressing pellets.
During Cvek Pulpotomy, what does placing the CaOH after the pulpotomy help with?
Starting the healing process/inflammation response to pulp.
What are the 6 pathways of pulpal disease?
- Dentinal tubules (doesn’t have to be direct)
- Direct pulp exposure
- Caries
- Iatrogenic
- Trauma
What are the common antibiotics used for endodontics?
- Pen VK
- Amoxicillin
- Ampicillin
- Clindamycin
- Augmentin
- Azithromycin
Locan Anesthetic has some antimicrobial activity. True or False?
True
Should bases be used to protect the pulp beneath metallic restorations?
- Yes, a thin cement base should be used.
- Yes, a thick layer of varnish should be used.
- No, a base is only necessary if the tooth is to be crowned.
- No, additional thermal insulation is rarely needed.
4
What is the main essential oil?
Eugenol (oil of cloves), used as an anodyne to inhibit nerve activity, and has potent antimicrobial properties.
What are the three most popular post materials?
- Metal
- Fiber
- Ceramic
How do you perform pulpal therapy on a Non-vital tooth?
Use rubber dam, get WL 2-3 mm short of radiographic length, use NiTi instruments, don’t perforate, and obturate with ZOE, iodoform paste, or CaOH, which are all resorbable, which is the key!!
What are more common with electric pulp testing? False negatives or false positives? And do you wear gloves?
False negatives are more common, and no you don’t wear gloves. If you get a positive response, you know you have a vital tooth.
Why don’t most molars require posts?
- Because pulp chamber and canals provide adequate retention for core buildup
What are the characteristics of the Cell-Free Zone (Weil) of the pulp?
It is 40 nanomicrons long, right next to odontoblastic layer in coronal pulp, free of cells, traversed by blood capillaries and unmyelinated nerve fibers. This are also isn’t found in young or old pulps as much, mainly middle aged.
What is the preferred method to evaluate if a canal has been adequately cleaned?
- The canal is three file sizes larger than the initial master apical file.
- The canal walls are “glassy smooth” when explored with a file.
- Dentin shavings obtained are clean and white.
- Irrigant runs clear with no visible debris.
B
How do you place sealer?
Use the Master Apical File and spin in reverse with hand, then use the gutta percha point to coat the canal walls, then use paper point, or you can use the lentulo spiral which isn’t the best, and the syringe which is the single cone technique.
What are the three elements you need to cut dentin with a file?
- Force 2. Sharp 3. Rake Angle
The degree of canal enlargement during shaping is dictated by which of the following?
a. method of obturation
b. anatomy of the root
c. plan for post placement
d. all of the above
D
Which of the following is not a step as part of the technique for a shallow (partial) pulpotomy?
a. rubber dam isolation
b. pulp tissue removed to about 2 mm below the
exposure
c. use of a large round carbide bur in the slow-speed
handpiece to remove tissue
d. restoration of the cavity with a hard-setting
cement
C
Which of the following describes retentive pins?
- Retentive pins help strengthen the restoration.
- Retentive pins minimize stresses to dentin.
- Retentive pins are the most effective antirotation method for post and cores.
- Retentive pins should not be used because the risks outweigh any potential gain.
D
How do you treat an extrusive tooth?
Reposition on splint for 2-4 weeks, and RCT later if needed.
What is a disadvantage to the cone-image shift?
- Lingual objects become more distorted than buccal objects.
- There is excessive contrast between radiolucent and radiopaque objects.
- It may superimpose normal anatomic structures over the root apices.
- It does not reveal additional canals within a root.
C
How does the Modified Warm Vertical Compaction technique work for obturation?
You have a heat source from an electrical system like System B, and you do the same sort of technique as the warm vertical compaction or you do a softened backfilling technique, so after the apical section is placed, heated, and compacted, the softened gutta percha in an electrical gun-like device is expressed through the syringe tip, then down-packed using the Obtura.
Important characteristics of a Schedule II controlled substance?
Requires written prescription, no time limit to fill, refills are prohibited, multiple prescriptions (90 days) are permitted, fax prescriptions ok for prep only.
What type of drug is a valium?
Benzodiazepine, along with other drugs that end in “am.” The muscle relaxant drugs are Carisoprodol and cyclobenzaprine.
The most accurate radiographs are made by doing which of the following?
a. having the patient hold the film in place with
their index finger
b. using a paralleling device
c. increasing/decreasing the vertical angulation to
move superimposed objects out of the field of
vision
d. having the rubber dam in place for isolation
B
What are characteristics, clinical findings, treatment, and considerations for periodontal lesions only?
Deep pockets, extensive CAL, no pulpal disease. History of disease progression, probing, pulp test positive. Periodontal therapy only. Be cautious of the reliability of pulp testing, especially in multi-rooted teeth with severe periodontitis.
Dens invaginatus (dens in dente) occurs most com- monly in which teeth?
a. maxillary canines
b. maxillary lateral incisors
c. maxillary and mandibular lateral incisors
d. mandibular first premolars
B
What is apical transportation?
Making the canal near the apex way larger than it should be, so essentially taking away tooth structure.
Is a concussed tooth percussion sensitive?
Yes, but no displacement or mobility. No treatment.
When you get pulpal drainage, what comes out first?
- You get purulence first, and then you get hemorrhage. This has to do with the Zones of Fisch. If you take a periapical granuloma there are different zones within that defect. The center of that defect is usually located at the apex of the canal, and in this center is the purulence material, and around that center area is where the battle is, and blood is.
What are the 5 main commonly used irrigants?
- Sodium Hypochlorite 2. EDTA 3. Chlorhexidine 4. Sterile Water 5. Local Anesthetic
Step 5 of Root Canal Preparation:
- Working Length Radiograph Instrument: Use at least a #15 file for this radiograph, place file passively into canal near the estimated W.L. distance, not aggressively. Outcome: From the radiograph, determine the full length of the canal, determine the adjusted or calculated Working Length from the radiograph for each canal, and remember the Working Length is usually 1/2 to 1 mm short of the root length. Observe the canal curvatures and note the possibility of additional canals.
What type of sealer may have a problem with long- term solubility?
a. ZnOE-based sealers
b. plastic sealers
c. glass ionomer sealers
d. calcium hydroxide sealers
D
Theapicalterminationpointforcleaningandshaping the root canal should be which of the following?
a. the radiographic apex
b. at the major diameter of the apical foramen
c. within 0 to 2 mm of the radiographic apex
d. 0.5 mm beyond the radiographic apex
C
What is the difference between the standardized and the conventional sizes for Gutta Percha?
- Standardized is the normal File sizes that range from #15 to #140, with either a .02, .04, .06 taper.
- Conventional is sizes
- extra-fine,
- fine-fine,
- fine,
- fine-medium,
- medium,
- large,
- extra-large.
- The Master Cone Fit is Standardized while the accessory cones are conventional.
What type of immune cells does normal pulp, and even inflamed pulp contain?
T and B cells, macrophages, dendritic cells.
Vital pulp therapies have variable rates of success. What is the most significant determinant of the success of vital pulp therapy?
a. periapical status before the procedure
b. periodontal status before the procedure
c. pulp status before the procedure
d. type of restorative material to be used
C
- The cementodentinal junction (CDJ) is which of the following?
A. the area where cementum contacts dentin inside the canal
B. located at the same level for each tooth type
C. usually located 1.0 to 2.0 mm coronal to the apical
constriction
D. the widest portion of the canal
A
What are characteristics, clinical findings, treatment, and considerations for endo lesions with periodontal disease?
Necrotic pulp, generalized periodontitis with plaque and calculus. Pulp test negative, evidence of inflammation/necrosis, generalized increase in pocket depth, radiographic evidence of pulp and periodontal disease. First, endo treatment, evaluate in 2 months, then periodontal treatment. Avoid extensive root instrumentation during periodontal treatment that might remove cementum.
How do you treat a tooth that has been out of socket for less than 60 minutes, both closed and open apex?
Closed, put in saline, milk, or saliva, irrivate socket, reimplant and splint for 2 weeks, use antibiotics, than do a RCT after one week, and CaOH 2 weeks. Open, saline to clean, doxycycline for 5 minutes, reimplant with flexible splint, use antibiotics, and follow for vitality after 2, 6, and 12 months.
Which type of sensory fibers travel into the dentin? A or C fibers?
A-fibers, which are myelinated, while C are not. The conduction velocity for A fibers (A alpha, beta, gamma, and delta) are a lot faster because of the myelination, they also have a larger diameter. C fibers are strictly for pain and found on the dorsal root and are unmyelinated. The different A fibers have different functions. A delta and C fibers are similar because they both respond to pain. A are found in region of pulp-dentin junction, and react to sharp prickling and have a low threshold, while C fibers are found throughout the pulp and are for burning, aching, less bearable sensations and have a high threshold.
Who are the three stakeholders when it comes to endodontic outcomes?
Patients, insurance companies, and the dentist.
Although you can use with any diagnosis, what are the indications for the placement of Calcium Hydroxide?
Necrotic pulp, and in following the SLA and establishing the master apical file. Probably has little benefit with vital pulps. You mix the powder with glycerin, and can use either a syringe or place it with a lentulo spiral. The research study said lentulo spiral was most effective, syringe next, and #25 K file was least effective.
Step 2 of Root Canal Preparation:
- Find Canal, Explore, Negotiate Instrument: K-Files, #8, #10, and #15. Watch-wind and pull out, up/down, and circumferential filing. Outcome: Identify all canals, determine canal patency, smooth the canal, and agitate irrigation solution to dissolve pulp tissue. You can use the DG16 (explorer) to feel around the orifices.
What is the ideal time and material for a nonsurgical repair of a furcation perforation?
- immediate repair with amalgam
- immediate repair with mineral trioxide aggregate (MTA)
- delayed repair with amalgam
- delayed repair with MTA
B
What is severe swelling in the face usually indicative of?
An acute alveolar abscess, usually from bacteria that has spread from necrotic pulp.
What is the acronym for the colors of the file sizes?
PiGPu, and then Why Your Rain Bow Green Black? Pink, Grey, Purple……White, Yellow, Red, Blue, Green, Black. These all apply to the 0.20 taper.
Which of the following is the most widely used irrig- ant solution?
a. sodium hypochlorite
b. ethylenediaminetetraacetic acid (EDTA)
c. MTAD
d. saline
A
Step 6 of Root Canal Preparation:
- Apical Configuration/Gauging Instrument: Small K files #8-20. Use passively to determine apical gauging and canal size. Use a #10 file to establish apical patency. Outcome: Determine the Patency File size, determine the Initial Apical File size, which is the first file that binds at the WL. Estimate the Master Apical File size, which is the size that will be used to clean the apical canal at the working length. (The MAF is usually 3-4 file sizes larger than the IAF)
What are characteristics, clinical findings, treatment, and considerations for periodontal lesions with endodontic disease?
Deep pockets, extensive CAL, increased pain, evidence of pulpal disease. History of disease progression, probing, pulp test negative, pain, radiographic evidence. First, endo treatment, evaluate in 2 months, then periodontal treatment. Weak evidence for this condition to actually occur.
What pulp and periapical diagnosis may have completed treatment in a single visit?
a. symptomatic (acute) apical periodontitis
b. asymptomatic apical periodontitis (chronic apical
periodontitis)
c. acute apical abscess
d. painful irreversible pulpitis
D
When should you splint a root fracture and when should you not worry about it yet?
Splint if fracture on cervical or middle 1/3, and don’t do anything if apical 1/3.
What is the #1 reason root canal treated teeth fail?
Because of fracture, and usually because of an improper restoration. A vertical root fracture looks like a J on a radiograph.
What causes symptomatic apical periodontitis?
- Eliciting irritants include irreversibe pulpitis, inflammatory mediators from an irreversibly inflamed pulp or egress of bacterial toxins from necrotic pulps, chemicals (such as irrigants or disinfecting agents), restorations in hyperocclusion, overinstrumentation of the root canal, and extrusion of obturating materials. The pulp may be reversibly inflamed, irreversibly inflamed or necrotic.
A major advantage to using a lubricant during clean- ing and shaping is:
- It ensures that canal transportation will not occur.
- It reduces torsional force on the instrument, decreasing the possibility of fracture.
- It minimizes debris production.
- It reduces operator fatigue.
B
What are the minimum difficulty cases for patient considerations in the AAE assessment form?
- ASA class I 2. No history of anesthesia problems 3. Cooperative and Compliant 4. No limitation in ability to open mouth 5. No gag reflex 6. No pain or swelling
What does a modern prescription have on it?
The heading has the name, address, phone #, name and address of patient, and date of prescription. The body has the Rx symbol, name and dosage size or concentration of drug, amount or quantity, and directions to patient.
What is the definition of irrigation?
To wash out a body cavity or wound with water or a medicated fluid.
What are characteristics, clinical findings, treatment, and considerations for combined endo/perio lesions?
Etiologic factors present for both conditions. Generalized periodontal destruction that connects to periapical lesion. Test for root fracture. Pulp test negative. Root canal therapy, periodontal therapy. Classic case is due to a fractured or perforated root.
What is the primary function of the dental pulp?
a. induction
b. formation
c. nutrition
d. defense
B
Percentages of mandibular 1st molar root canals?
Mesial Root 2 canals = 70-80% Distal Root 2 canals = 15-30%
Primary RCT infections are polymicrobial? True or false?
True. And they are dominated by obligatory anaerobic bacteria. The most frequent are gram-neg anaerobic rods, gram-pos anaerobic cocci, gram-pos anaerobic and facultative rods, lactobacillus, and gram-pos facultative streptococus. So mostly everything but gram-neg cocci.
What is Flexeril used for?
Anxiolytic and a muscle relaxant
When does apical closure occur in the developing root?
a. at the time of eruption
b. approximately 1 year after eruption
c. approximately 3 years after eruption
d. approximately 5 years after eruption
C
Step 3 of Root Canal Preparation:
- Pre-Flare and Tissue Debridement Instrument: Hedstrom Files #15, #20. Up/down, circumferential filing motion. Outcome: Canal debridement, enlarge the orifice, and reduce the cervical triangular dentin to improve the SLA to the mid-root canal.
What is condensing osteitis?
- Condensing osteitis, a variant of asymptomatic apical periodontitis, represents an increase in trabecular bone in response to persistent irritation. The irritant diffusing from the root canal into periradicular tissues is the main cause of condensing osteitis. This lesion is usually found around the apices of mandibular posterior teeth, which show a probable cause of pulp inflammation or necrosis. However, condensing osteitis can occur in association with the apex of any tooth.
Which of the following is a disadvantage of gutta- percha?
- poor adaptation to canal irregularities with compaction
- shrinkage if altered by heat or solvents
- not easily managed and manipulated
- difficult to partially remove from a canal
B
What are the 3 main groups of drugs for pain medicine?
- NSAIDS 2. Opioids/Narcotics 3. Steroids
What are the main goals for the general dentist?
- Diagnose pulpal and periapical pathosis 2. Endodontic treatment planning 3. Perform non-surgical conventional RCT on minimum difficulty cases
Which of the following is not an early sign or indication of a perforation?
- pain during access preparation
- sudden appearance of hemorrhage
- burning pain and bad taste during irrigation with NaOCl
- radiographically malpositioned file
A
What are characteristics, clinical findings, treatment, and considerations for endodontic lesions only?
Periapical bone loss, drainage through sulcus, history of extensive restorative treatment, gingival swelling, furcation bone loss. Pulp test negative, periodontal probing has narrow pockets, rapid onset, bad endo before. Endo treatment only. May be a risk factor in patient prone to periodontitis, may spread through cervical tubules into main canal systems.
What are the five main types of endodontic treatments and procedures?
- Conventional RCT 2. Non-surgical Retreatment 3. Surgical Retreatment 4. Traumatic Dental Injuries 5. Dental Implants
Mandibular Right First Premolar
What are the hardest post materials to retrieve?
Ceramic/Zirconium
The post diameter is not to exceed 1/3 of the entire root diameter. True or False?
True
What are the steps of a pulpotomy?
Remove coronal pulp, and then you can do one of three things. 1) place diluted solution of formocresol for 5 minutes which produces partial tissue fixation, and then place ZOE and an intracoronal restoration over pulp stumps. 2. Place 15% ferric sulfate solution for 15 seconds which produces mechanical blockage of open cappilaries, and then place intracoronal restoration. 3. Place MTA over pulp stumps and then a intracoronal restoration.
When mature avulsed teeth are replanted, they cannot be expected to reestablish pulpal blood supply. True or False?
True. Revascularization may occur in immature teeth with wide-open apexes, but it is unpredictable and must be monitored carefully.
What is an acute apical abscess?
• Localized or diffuse liquefaction lesion of pulpal origin
- Destroys periapical tissues
- Disintegrating PMNs
• Necrotic pulp
• Abcess within a granuloma
What is the optimal preparation/obturation length relative to the radiographic apex with pulp necrosis?
a. flush
b. 0.5 to 1.0 mm short
c. slight extrusion of sealer but not gutta-percha
d. 1.0 to 3.0 mm short
B
Maxillary Right Second Premolar
We should never treat until we have a diagnosis. True or False?
True
At what percentage is bleach usually worked with?
2.5-5.25%
Rotary instruments should not be used for gutta percha removal. True or False?
True. Can disrupt apical seal. But later in his slides it says to use rotary if the gutta percha is really old and has lost its thermoplasticity.
Calcifications encountered in the pulp space do which of the following?
a. represent additional dentin formation
b. can always be detected by radiograph
c. are always attached to the chamber or canal walls
d. often prevent instruments from negotiating canals
A
What are the steps in the vicious cycle in response to Trauma and the cause of pulpal pain?
1) Increased blood flow leads to vasodilation and an increased capillary pressure, which leads to 2) increased capillary filtration, which leads to 3) increased tissue pressure, resulting in pulpal pain because it is acting on sensory nerve receptors! Pain also happens because a release of mediators of inflammation by directly lowering the sensory nerve threshold. And it is this increased pressure that compresses the thin-walled venous vessels, which leads to decreased blood flow, strangulating the pulpal vessels, and if this goes on for a while, will lead to pulpal necrosis.
What type of inflammation does both pulpal and periodontal lesions have?
Pulpal, acute. Periodontal, chronic.
What is the outline shape of the access for a maxillary first molar?
a. round
b. triangular
c. trapezoidal
d. square
B
What is the overall outline form of mandibular molars?
Rhomboid
What are the four requirements for an adequte restoration?
- • Preserve Remaining Tooth Structure
- • Protect Remaining Tooth Structure
- • Provide Coronal Seal
- • Satisfy Function and Esthetics
What are the signs and symptoms of a chronic apical abscess?
- • Generally asymptomatic
- • Not sensitive to biting
- • May feel different to percussion
- • No response to pulp vitality tests
- • Apical radiolucency
- • Mucosal or facial sinus tract
- If the abscesses are huge, they are generally in the chronic stage, so Chronic Apical Abscess
What are the minimum difficulty cases for additional considerations in the AAE assessment form?
- Uncomplicated crown fracture of mature or immature tooth 2. No previous endodontic treatment history 3. None or mild periodontal disease
Use of a paralleling technique may not be feasible when which of the following occurs?
a. There is a high palatal vault.
b. There are maxillary tori.
c. A fixed prosthesis is present.
d. There are exceptionally short roots.
B
Maxillary Right Canine
What is the overall prognosis of PDL, root, etc of an avulsed tooth?
-If a tooth has been out of the alveolar socket for more than 1 hour (and not kept moist in a suitable medium), periodontal ligament cells and fibers will not survive, regardless of the stage of root development. Replacement resorption (ankylosis) will probably be the eventual sequela after replantation. Therefore, treatment efforts before replantation include treating the root surface with fluoride to slow the resorptive process. -When mature avulsed teeth are replanted, they cannot be expected to reestablish pulpal blood supply.37 Revas- cularization may occur in immature teeth with wide-open apexes, but it is unpredictable and must be monitored carefully. These teeth must be monitored radiographi- cally over a period of time to watch for evidence of pulp necrosis. In the mature replanted tooth, root canal treatment is definitely indicated and should ideally be started 7 to 10 days after replantation. The splint may remain during treatment for stability. The use of calcium hydroxide as an antimicrobial intracanal interappointment medica- ment may be helpful.43,45 It is particularly beneficial if the root canal is infected, a condition that would be likely to occur when root canal treatment is delayed more than a few weeks after replantation.
What are the 5 objectives of access openings?
- Remove all caries 2. Conserve sound tooth structure 3. Unroof pulp chamber and remove all coronal pulp tissue 4. Locate all canal orifices 5. Establish straight or direct line access
Mandibular Right Canine
Difference between Pulpectomy and RCT?
On slide, they placed ZOE down the canals instead of gutta percha.
If if a tooth is discolored, what does that usually indicate?
Necrosis
What is torsional limit?
- amount of apical pressure that can be applied to a file to the point of breakage
- the beginning of plastic deformation of the instrument
- amount of rotational torque that can be applied to a “locked” instrument to the point of breakage
- amount of force necessary so that a file does not return to its original shape upon unloading of the force
3
Accessory canals are more common in the apical third, and more common in posterior teeth.
a. The entire sentence is true.
b. The first statement is true, the second is false.
c. The first statement is false, the second is true.
d. The entire sentence is false.
A
What are the things that influence retention with posts?
- post length
- diameter
- taper
- luting cement
- passive or active
Which file has a square cross-section?
K-file - filing, circumferential, balanced force, and watch-winding.
Step 7 of Root Canal Preparation:
- Glide Path Preparation Instrument: Starting with IAF, increase the size to at least a #20 K file to be used as the Glide Path file. Work them in sequence in watch-wind, 1/4 turn-pull, circumferential, step-back, balance-force, or crown-down. Outcome: Prepare a path that removes all interferences from the orifice to the apical terminus of the canal, smooth the canal, clear pulp tissue by irrigant agitation, at least a #20 should have a smooth glide to the WL.
What are the signs and symptoms associated with symptomatic apical periodontitis (acute apical periodontitis)?
- normal sensation on mastication
- normal sensation on finger pressure
- marked or excruciating pain on tapping with a mirror handle
- presence of a large periapical lesion
3
What occurs as the cone position moves away from parallel?
- Objects on the film shift toward the direction of the cone.
- The facial or buccal object shifts less than the lingual object.
- The lingual object moves relatively in the same direction as the cone.
- The buccal object moves relatively in the same direction as the cone.
3
What are the 4 main types of core material?
- Gutta Percha
- Silver Cones (oxidizes if exposed to water, and stains tissue)
- Paste Fillers (Calcium Hydroxide for temporary purposes), Sargenti (paraformaldehyde), Russian Red.
- Hot dog on a stick (Thermafil, Gutta-Core)
What is the overall best design for a post to decrease the risk of failure?
- Use the narrowest, longest, smoothest, parallel post that one can fit into the post space
What are the 4 main endodontic access principles?
- Outline form 2. Convenience Form 3. Caries Removal 4. Toilet of Canal (prevent blockage, clean it out)
What are the four main factors that predict the success or failure of an endodontically treated tooth?
- Apical pathosis - the presence of perradicular lesions and larger lesions
- Bacterial status of canal - presence of bacteria in canal prior to obturation (CaOH)
- Extent and quality of obturation - short, long, voids, density
- Quality of restoration - Coronal Seal is Huge
What is the percent chance that an uncomplicated crown fracture will progress to pulpal necrosis? And how do you treat an uncomplicated crown fracture?
This involves enamel and dentin and has a 1-7% chance. You treat it by applying CaOH cement or VitraBond to exposed dentin and then you can restore it if it less than 1/2mm of dentine, and reattach separated tooth fragment with bonding agent.
What are the four main different types of posts?
- • Active—threaded and engage dentinal walls, more retentive, increase stress
- • Passive—retained strictly by luting agent, less retentive, less stress
- • Parallel—more retentive than tapered, less stress
- • Tapered—require less dentin removal, increased wedge effect
When using a prefabricated post system to restore a posterior tooth, the most desirable post design is
- tapered, passively cemented.
- tapered, threaded screw type.
- parallel sided, passively cemented.
- parallel sided, threaded screw type.
C
What are the 5 main types of pulp vitality testing?
- Cold 2. Heat 3. Electric 4. Test Cavity 5. Selective Anesthesia
Step 10 of Root Canal Preparation:
- Final MAF Radiograph & Rinse Instrument: Radiograph with the MAF at working length, final rinse with EDTA - Alcohol - NaOCl - Alcohol. Outcome: Confirm of full WL canal preparation with the MAF, confirmation of a thoroughly clean and rinsed canal.
Which pulp test is most reliable with primary teeth?
Thermal - CO2 testing specifically.
What are the colors of 6, 8, and 10 files, the first three?
- Pink
- Grey
- Purple
PiGPu
What are the main Halides?
- Sodium Hypochlorite (Bleach) 2. Iodine -These are potent bacterial or viral killers.
Of the following, which tooth or root is the most likely to have two canals?
a. Maxillary second premolar
b. Mandibular first molar mesial root
c. Mandibular lateral incisor
d. Maxillary first molar mesiobuccal root
B
What is a good way to differentiate periapical from periodontal inflammation?
- If a painful response is obtained by pressing or by tapping on the crown, this indicates the presence of periapical inflammation. If a painful response is obtained by tapping on the facial surface but not the occlusal/incisal surface, periodontal inflammation is suspected. The pain related to periodontal inflammation is likely to be in the mild-to-moderate range. Periapical inflammation is more often a sharp pain. An additional approach, useful if the patient complains of pain on chewing, is the biting test in which the patient bites down on a cotton swab between each tooth in turn.
Nickel-titanium alloy has increased flexibility over stainless steel. How does the modulus of elasticity for nickel-titanium alloy compare to that of stainless steel?
a. similar to stainless steel
b. one-fourth to one-fifth that of stainless steel
c. half that of stainless steel
d. 2 to 3 times that of stainless steel
B
Diagnostic radiology is helpful in all of the following except:
a. identifying pathosis
b. determining root anatomy
c. determining pulp anatomy
d. determining pulp responsiveness
D
What do mast cells do as part of the inflammatory process of irritated pulp?
They are not normally found in normal healthy pulp, but they can appear and release histamine, leukotrienes, and other platelet-activating factors, and their presence in blood vessel walls indicate their importance in pulpal inflammation.
Does a cold test or a heat test induce pain with pulpal necrosis?
No, but a heat test can sometimes because it exacerbates pain due to expansion of gases or fluids.
What are the diameters at the tip and top of a 006 K file? And at what diameter of the tip does the increments change as you get all the way from a .06 diameter tip to a 1.40 diameter tip?
It starts at a 0.06 and 0.38 (at the D16 level, if you know it is a 0.02 taper, than it should just be .32 above it).
- And it goes 0.06
- 0.08
- 0.10
- 0.15
- 0.20….. etc….. and then starts adding 0.1 between each at 0.60
- 0.60
- 0.70
- 0.80, all the way to
- 1.40
A parallel and serrated post is the post of choice in clinic. True or False?
True
What is a key aspect of the preparation of the coronal tooth structure for a post?
- Remove all internal and external undercuts
What does he say about cotton & cavit and IRM?
- -He does this one the most, and you will either do the cotton and cavit alone, or put in a medicament and then put in cotton and cavit, you always put in cotton and cavit.
- -Intermediate Restorative Material, which is usually mixed with eugenol, helps inhibit nerve activity
What are the 6 main types of mechanical irritants to the tooth/pulp?
- Deep cavity preps 2. Lack of cooling 3. Impact trauma 4. Occlusal trauma 5. Deep perio curettage 6. Orthodontic movement
Percentages of mandibular 2nd molar root canals
Distal Root 2 canals = 5-8%
Why are deeper carious lesions more injurious to the dental pulp?
- increased dentin permeability in deeper areas
- increased length of the dentinal tubule in deeper areas
- decreased density of dentinal tubules in deeper areas
- decreased diameter of dentin tubules in deeper areas
A
What are the signs and symptoms of an acute apical abscess?
• Rapid onset of acute spontaneous pain to percussion and biting and palpation
- Moderate to severe discomfort and swelling—intra and sometimes extraoral
- Purulence (pus), sinus tract sometimes
- Surrounding the abscess is granulomatous tissue (an
abscess within a granuloma)
- Lymphadenophy—submandibular and cervical
- Periapical Radiolucency
- No response to Pulp Vitality Tests
- Varying degree of mobility
- Frequently febrile
If patient has irreversible pulpitis and normal periapex, how do you treat them?
- Treatment—removal of as much pulpal tissue as time allows (pulpectomy/pulpotomy) or clean and shape
- Cotton pellet (as good as anything)
- Relieve occlusion (so not sore between appointments)
- It’s not infected yet, but is just inflamed, but the longer you wait, it will become infected
What are the 5 steps to the correct diagnosis?
- Chief Complaint
- Medical and Dental History (subjective)
- Oral Examination and Tests (objective)
- Correlate findings to reach differential diagnosis
- Formulate definitive diagnosis and treatment plan
What are the main phenols?
- CMCP (Camphorated Monoparachlorophenol) Less toxic
- Cresatin (Metacresylacetate) Even less toxic. Used for vital pulpectomy. -These are antibacterial, and act by binding to cell membrane and lipids
Bone loss in cancellous bone is often detected on radiographs. True or False?
False. It is not. Bone loss must extend to junction of cortical and cancellous bone to be observed usually. The location of root apices in correlation to this junction affects how early a PA lesion can be detected, and most anterior and pre-molar teeth apices are located closer to the cortical/cancellous junction than molar roots.
What are the 5 factors that determine whether pulp tissue becomes necrotic slowly or rapidly after carious pulp exposure and pulpal inflammation?
- Virulence of bacteria
- Ability to release inflammatory fluids to avoid intrapulpal pressure
- Host resistance
- Amount of circulation
- Most importantly, lymph drainage
Is deep or superficial dentin more porous?
Deep dentin
How may selective anesthesia be an aid in diagnosis?
- It can localize a painful tooth to a specific arch.
- It can localize an individual painful tooth in the mandibular arch.
- It can confirm the tooth the patient identifies as the offending tooth.
- It can be used to start posterior and work toward the anterior teeth.
A
How do you treat an intrusive tooth?
-Treatment of intrusive luxation injuries depends on root maturity. If the tooth is incompletely formed with an open apex, it may reposition spontaneously. If it is fully developed, active extrusion will be necessary soon after the injury, either orthodontically or surgically. Root canal treatment is indicated for intruded teeth with the exception of those with immature roots, in which case the pulp may revascularize.
Which of the following has not been demonstrated with MTA when used in apexification?
a. good biocompatibility
b. good sealability
c. high pH value
d. adjacent zone of necrosis
D, that is with CaOH
What are the four characteristics of periapical lesions of endodontic origin?
- Lamina dura is lost apically 2. Lucency remains at the apex in radiographs made at different cone angles 3. Lucency tends to resemble a hanging drop 4. The lesion is usually seen with a necrotic pulp
With the percussion test, what does a painful response from tapping on the crown indicate?
Periapical inflammation. This is more often a sharp pain.
Step 4 of Root Canal Preparation:
- Coronal Canal Preparation Instrument: Gate-Glidden Burs #2-4 (.7 - 1.1) and Orifice Opener Burs (BR 0) Outcome: Enlarge the orifice, enlarge the coronal canal to the mid-root area size of a #70, reduce the cervical triangular dentin, improve the accuracy of the working length measurement by removing any mid-root interferences, improve the depth of irrigation solution penetration.
With orthodontic movement, extrusion reduces pulpal blood flow for a few minutes as the pressure is applied? True or False?
False. It is intrusion that does that.
With the percussion test, what does a painful response from tapping on the facial surface but not the occlusal surface indicate?
Periodontal inflammation
What are we treating when we do a root canal treatment?
Periapical Disease. Specifically, to prevent or treat apical periodontitis.
What is the process for drying the canal?
Use a small-tip aspirator (saliva ejector with large gauge needle tip), then coarse paper point, and then fine paper point (use for final WL check). But do not do direct air spray, that is how you get an air embolism.
What are the 3 requirements for Regendo?
- Stem cells (pulpal mesenchymal stem cells located in cell-rich zone of Hohl. Stem cells of apical papilla SCAP)
- Growth factors/Morphogens
- Scaffold (collagen or glycosaminoglycans)
What is the overall outline form of maxillary molars?
Triangular
What are Hedstrom files used for?
- These are rigid and are used to removed old rootfillings, and sometimes to plane the canal walls.
- The instruments are used only in a filing or rasping mo>on. They should never be rotated or engaged into den>n as they are weak instruments and prone to fracture.
What is Calcific metamorphosis?
- It is long term low grade pulpal irritation, dentin formation obliterates canals, and is usually not pathosis. A yellowish discoloration of the crown is often a manifestation, and the pain threshold to thermal and electrical stimuli usually increases. Does not require treatment.
- Book says = Another type of calcification is the extensive formation of hard tissue on dentin walls, often in response to irritation or death and replacement of odontoblasts. This process is called calcific metamorphosis. As irritation increases, the amount of calcification may also increase, leading to partial or complete radiographic (but not histologic) obliteration of the pulp chamber and root canal. A yellowish discoloration of the crown is often a manifestation of calcific metamorphosis. The pain threshold to thermal and electrical stimuli usually increases; often the teeth are unresponsive.
What is the normal taper for a K file and how do you calculate it?
A normal taper is 0.02
For example, for a 050 file, the D16 is 0.82 and the D0 is 0.50. So we take (0.82-0.50) and divide that by 16mm, to give us = 0.02 taper
What are the characteristics of Calcium Hydroxide?
Antibacterial, non-antigenic, temporary obturant, stimulate apical root end closure. Very powerful. Inactivates biologic ac:vity of bacterial lipopolysaccharides which egress from necrotic’ pulps’into’periapical tissues’and’cause’PA’lesions
What are the minimum difficulty cases for diagnostic and treatment considerations in the AAE assessment form?
- Signs and symptoms consistent with recognized conditions 2. Minimum difficulty in obtaining radiographs 3. Anterior/Premolar teeth with slight inclination 4. routine rubber dam placement 5. normal crown morphology 6. Slight or no curvature (
The shape of the canal in cross-section is variable but is almost always round in the apical third.
- Both parts of the sentence are true.
- The first part of the sentence is false, the second part is true.
- The first part of the sentence is true, the second part is false.
- The entire sentence is false.
C
What are the sizes for the Gates Glidden Drills?
There are 6 of them. The smallest is 0.50 mm and the largest is 1.50 mm. It goes
- 0.50 (#1) -
- 0.70 (#2) -
- 0.90 (#3)..
- 1.10 (#4)
- 1.30 (#5)
- 1.50 (#6)
What are some ideal sealer properties?
Tackiness, air tight seal, radiopaque, fine powder, no shrinkage, no staining, slow setting time, bacteriostatic, insoluble in tissue fluids, non-irritating to periradicular tissue, soluble in common solvent for removal.
How does the “crown-down” technique differ from the “step-back” technique?
- It creates a funnel-shaped preparation.
- It facilitates tissue removal.
- It requires fewer instruments.
- It creates coronal flare early, reducing torsional stress on the instruments.
D
What is palpation testing used to determine?
a. pulpal inflammation
b. periapical inflammation
c. periodontal inflammation
d. periapical histology
B
What is the emergency treatment of choice for pulp necrosis without swelling?
a. trephination for drainage
b. pulpotomy
c. canal débridement to corrected working length
d. single visit root canal treatment
C
What are some of the irrigation techniques with removing the smear layer?
Every 2-3 files you should change, agitate with small file like a #10 or #15, endoactivator, use small side-vented needle, keep chamber wet, alternate NaOCl with 17% Aqueous EDTA.
What solvent has been shown to be the most efficient (fastest) in softening gutta-percha?
a. chloroform
b. halothane
c. methylchloroform
d. xylene
A
What is a disadvantage of finger spreaders as com- pared to standard long-handled spreaders?
a. tactile sensation
b. instrument length control
c. fracture potential in curved canals
d. dentin stress during obturation
C
Percentages of mandibular 1st premolars having 2 canals?
2 = 25%
If patient has irreversible pulpitis and Symptomatic (acute) Apical Periodontitis, how do you treat them?
- They are extremely percussion sensitive
- Treatment—complete pulpectomy or clean and shape (RCT without the obturation)
- Cotton/cavit
- Relieve occlusion
What are the signs and symptoms of symptomatic acute periodontitis (also called acute)?
- Spontaneous pain
- Acute pain to biting or percussion
- Hot, cold, electric sensitivity (pulpitis)
- May or may not respond to Pulp Vitality Tests
- May or may not have PA radiolucency (yet)
- Widened (thickened) PDL
- Histology—PMNs and macrophages
- May have liquefaction necrosis
To prevent extrusion of obturating material, cleaning and shaping procedures must be confined to the radicular space. Canals filled to the radiographic apex would be considered to be the perfect result.
- Both statements are true.
- The first statement is true; the second statement is false.
- The first statement is false; the second statement is true.
- Both statements are false.
B
What is a chronic apical abscess?
- Inflammatory lesion of pulpal origin
- Long standing lesion
- Same histology as AAA
- CAA has a pathogenesis similar to that of AAA. It also results from pulpal necrosis and is usually associated with chronic (asymptomatic) apical periodontitis that has formed an abscess. The abscess has “burrowed” through bone and soft tissue to form a sinus tract stoma on the oral mucosa or sometimes onto the facial dermis. CAA may also drain through the periodontium into the sulcus and may mimic a periodontal abscess or pocket
What additional treatment should be used on the root surface if an avulsed tooth is replanted after more than 1 hour after avulsion?
- thorough scrubbing with antimicrobial soap for disinfection
- scaling of the root surface
- soaking the tooth in 2.4% doxycycline for 5 to 20 minutes
- soaking the tooth in a 2.4% solution of sodium fluoride for 5 to 20 minutes
D
Active posts are more retentive than passive posts. True or False?
True
What kind of pulp vitality testing for cold do we have in the clinic?
We have CO2.
Which of the following is not a hard tissue change that may result from pulpal irritation or inflammation?
a. calcification of pulp tissue spaces
b. resorption of pulp tissue spaces
c. formation of pulp stones
d. thickening of periodontal ligament
D
A patient presents with a chief complaint of pain to cold temperatures. Examination and testing re- veal a maxillary left premolar exhibiting severe lingering pain in response to cold. No caries or frac- tures are noted. Periodontal probings are 6 to 9 mm around that specific tooth and 6 to 7 mm around the other posterior teeth in the quadrant. The patient reports having a “deep cleaning” (root planing) three times per year. What would the diagnosis in this case be?
- primary endodontic disease with secondary peri- odontal involvement
- primary periodontal disease with secondary end- odontic involvement
- separate and unrelated endodontic and periodon- tal disease
- a true combined endodontic-periodontic (endo- perio) disease process
2
What is the best way to clear apical debris?
Use the Master Apical File to working length, and do apical patency with a #10 K file 0.5mm-1mm away one more time.
EDTA is most effective for which of the following uses?
- decalcifying small canals to allow instruments to negotiate to length
- lubricating canals to facilitate instrumentation
- bacterial elimination in canals
- removing smear layer after cleaning and shaping
4
What are the main 4 categories that medications are prescribed for?
- Pain 2. Infection 3. Anxiety 4. Muscle Relaxant
Step 9 of Root Canal Preparation:
- Apical Canal Preparation Instrument: use the #10 to carefully maintain apical patency. Use file sizes from the IAF to the MAF to enlarge the apical canal, and use watch-wind, step-back, or balance-force. Outcome: Maintain canal patency. Maintain working length. Maintain apical position. No canal ledging, zipping, or apical transportation.
Which of the following are true regarding the apical foramen?
- The diameter remains constant throughout life.
- The position of the apical foramen is often visible on radiograph.
- The foramen is most commonly located 0.5 mm to 1.0 mm away from the anatomic root apex.
- None of the above.
3
If a tooth has been out of the alveolar socket for more than 1 hour (and not kept moist in a suitable medium), periodontal ligament cells and fibers will not survive, regardless of the stage of root development. True or False?
True. Replacement resorption (ankylosis) will probably be the eventual sequela after replantation.
What are the characteristics of Nickel Titanium rotary instruments?
It is an exotic metal, superelastic metal. It can accommodate greater stress without increasing the strain, and has the ability to return to its original shape after being deformed. We don’t leave Nickel Titanium rotary instruments in the canal for more than a couple of seconds because it will cause damage, but they are extremely helpful because they can curve and adapt to the shape of the canal.
What is a “pulp cap”?
a. an early stage of tooth development
b. capping the exposed pulp with a thin layer of lining or base material
c. capping exposed necrotic tissue by placing a layer of mineral trioxide aggregate (MTA)
d. a method of isolation used during root canal treatment
B
What does the smear layer mainly consist of?
Organic and inorganic substances as well as fragments of odontoblastic processes, various species of bacteria, and necrotic debris.
What is internal resorption?
- It is inflamed pulp with dentinoclastic activity. The tooth needs to be vital in order for this to happen. Most of these cases are asymptomatic, but you can end up getting pink spots on the crown if it is advanced. You need to do a root canal on these.
- Book says = The pulp is transformed into a vascularized inflammatory tissue with dentinoclastic activity; this condition leads to the resorption of the dentinal walls, advancing from its center to the periphery. Most cases of intracanal resorption are asymptomatic. Advanced internal resorption involving the pulp chamber is often associated with pink spots in the crown. Teeth with intracanal resorptive lesions usually respond within normal limits to pulpal and periapical tests. Radiographs reveal presence of radiolucency with irregular enlargement of the root canal compartment. Immediate removal of the inflamed tissue and completion of root canal treatment are recommended; these lesions tend to be progressive and eventually perforate to the lateral periodontium. When this occurs, pulp necrosis ensues and treatment of the tooth becomes more difficult.
What is the primary purpose of an irrigant such as sodium hypochlorite (NaOCl)?
a. kill bacteria
b. dissolve tissue remnants
c. flush out debris
d. lubricate instruments
C
What is the definition of a prescription?
An order for medication which is dispensed to or for an ultimate user. It is not an order for medication which is dispensed for immediate administration to the ultimate user.
Which of the following steps are used in step-wise evacuation of caries?
- removing all the caries in a single visit
- placing a calcium hydroxide base at the initialvisit
- placing a glass ionomer base at each visit
- removing only a superficial layer of caries at the first visit
C
For the irrigating solution to effectively reach the apical third of the canal, the apical canal should be enlarged to at least a No. _____ file.
a. 25 or 30
b. 20 or 25
c. 35 or 40
d. 45 or 50
C
If a patient has a necrotic pulp and fluctuant swelling (no drainage), how do you treat them?
- • Treatment—Complete pulpectomy or clean and shape (apical penetration)
- • Copious irrigation
- • CaOH after drying
- • Mucosal I & D (It can get dangerous if the swelling is diffuse and is low on the mandible because it can block the airway and they can die in the middle of the night. That is why drainage if super important)
- • Cotton/cavit
- • Antibiotics/Pain Management
Treatment sequencing for primary endodontic disease with secondary periodontal involvement includes
- scaling and root planing followed by endodontic treatment
- endodontic treatment followed by scaling and root planing
- endodontic treatment followed by periodontal surgery
- endodontic treatment followed by reevaluation of periodontal status in 2 to 3 months
4
How do you treat SAP, symptomatic apical periodontitis?
- Do RCT unless it is a hyperocclusion and pulp is vital, reduce occlusion, give it a couple of days, and if not, do RCT
Which of the following describes the filing motion?
- a single-step motion
- used only on the furcation side of a molar root canal
- with a 360-degree rotation motion
- circumferential movement around the canal walls
D
The best description of a difference between nickel- titanium and stainless steel instruments is which of the following?
- Nickel-titanium tends to result in better shaping (less transportation) in curved canals.
- Nickel-titanium usually results in better debridement.
- Nickel-titanium can usually be reused many more times than stainless steel.
- Nickel-titanium has sharper cutting edges.
A
Step 8 of Root Canal Preparation:
- Mid-Root Preparation & Gauging Instrument: Use the MAF and at least two larger files in a passive Balance Force method to enlarge the mid-root portion of the canal. The mid-root preparation will be even more defined with the next step. Outcome: Enlarge the mid-root canal, and continue to agitate the irrigant and disinfect the canal.
What are the characteristics of the Cell-Rich (Hohl)Zone of the pulp?
It has a high proportion of fibroblasts, immune cells like macrophages, dendritic cells, undifferentiated mesenchymal cells. Also known as subodontoblastic area.
What are characteristics about primary teeth morphology?
Smaller in all dimensions, primary crowns are wider M-D relative to crown length. Primary have have narrower and longer roots and are more slender. More constricted at DEJ. Enamel and dentin are thinner.
What is the definition of anachoresis?
It is when microbes are transported in blood to areas of tissue damage. Traumatized teeth become infected thru this pathway, and thru enamel cracks.
What type of files should you establish and finalize the Master Apical File with?
Hand Nickel-Titanium files
Which of the following is not a source of nutrients for bacteria within the root canal system?
- necrotic pulp tissue
- inflamed vital pulp tissue
- proteins and glycoproteins seeping into the root canal system
- components of saliva penetrating into the pulp tissue
2
Tapered posts are more retentive than parallel posts. True or False?
False
How many different sized files are there and what are they?
There are 21, and they are 006, 008, 010, 015, 020, 025, 030, 035, 040, 045, 050, 055, 060, 070, 080, 090, 100, 110, 120, 130, 140.
Root canals can become infected through anachoresis?
a. true
b. false
False
What different types of necrosis are involved with pulpal necrosis?
- Infectious agents cause liquefactive necrosis
- Blood loss causes ischemia or coagulative necrosis
- As stated before, pulp is encased in rigid walls, it has no collateral blood circulation, and its venules and lymphatics collapse under increased tissue pressure. Therefore irreversible pulpitis leads to liquefaction necrosis. If exudate produced during irreversible pulpitis is absorbed or drains through caries or through a pulp exposure into the oral cavity, necrosis is delayed; the radicular pulp may remain vital for long periods of time. In contrast, closure or sealing of an inflamed pulp induces rapid and total pulpal necrosis and periradicular pathosis. In addition to liquefaction necrosis, ischemic necrosis of the pulp occurs as a result of traumatic injury from disruption of the blood supply. Necrotic pulp is a clinical condition associated with subjective and objective findings indicat- ing death of the dental pulp.
Outline form for access is described best by which of the following?
- It mimics the shape of the canal or canals.
- It is toward the distal in the occlusal surface in molars.
- c. It is a projection of the internal tooth anatomy onto the external surface.
- d. It is a constant and unchanging shape regardless of age.
C
What does EDTA do? And what percentage do we use?
- 17%, it is a chelator and it removes the inorganic components of the canal and leaves the organic tissue intact, so we use this right before sodium hypochlorite.
- This effectively removes the smear layer, when used for at least 1 minute.
How can periodontal disease affect the pulp?
It is a two way street and microbes in subgingival biofilms could reach the pulp through canals. Pulpal necrosis only occurs if periodontal disease/pocket reaches the apical foramen due to damage of blood vessels that penetrate the apical foramen.
What is another name for chronic hyperplastic pulpitis and what is it?
- A pulp polyp, and it is when pulp cavity opens and instead of necrosis, pulp tissue proliferates and comes out the top to form a surface epithelium from oral epithelial cell implantation. Usually seen in the younger crowd, and is asymptomatic.
- Treat this with a root canal
How does the Warm Vertical Compaction technique work for obturation?
You do a Master Cone Fit, and then apply heated plugger deep to separate the cone and heat and soften apical section, then you apply apical pressure to produce hydraulic force to softened gutta percha, moving it apically and laterally. And then additional gutta percha sections are added similarly in an incremental fashion to orifice.
What factors should be considered when deciding the timing for obturation?
a. signs and symptoms present
b. pulp and periapical status
c. difficulty of the procedure
d. all of the above
D
How do you treat a laterally displaced tooth?
Reposition with splint for 2-4 weeks, RCT later if needed.
Percentages of maxillary 1st premolars having 2 canals? 3 canals?
2 = 60-80% 3 = 6%
How long should horizontal root fractures be splinted if the coronal section was displaced and repositioned?
a. not indicated
b. 7to10days
c. 4 to 6 weeks
d. 3 months
C
Maxillary Right First Premolar
What is reversible pulpitis?
- severe inflammation of pulp tissue
- yields a negative response to electric pulp testing
- yields a positive response to thermal pulp testing
- requires root canal treatment
3
How far can the smear layer pack into dentinal tubules?
Up to 1 to 5 microns
The most common microorganisms in primary endodontic infections are
a. gram-negative bacteria.
b. gram-positive bacteria.
c. facultative anaerobes.
d. facultative aerobes.
A
What are the smallest and largest dimensions of standardized K-file, H-file, and Gutta-Percha Cones?
006 and 140, and this is measuring the diameter of the very tip.
How long should the post be?
- Make the post about 3/4th the length of the root when treating long-rooted teeth
- With average root length, just stick to the 4 or 5 mm rule of gutta percha
- Should extend at least 4 mm apical to bone crest
- Molar posts shouldn’t extend more than 7 mm down the canal from the pulp chamber
- The post should be as long as the clinical crown is going to be
Which file has a triangular cross-section?
Reamer - Reaming, balanced force, and watch-winding.
Of the following, which is the best technique to determine if a root contains two canals?
a. apex locator
b. viewing access with a microscope
c. searching with an explorer
d. interpreting angled radiographs
D
We know that the number sizes match the diameter of the tip, but what are the diameter numbers at D16?
It starts at 0.38 and ends at 1.72
Maxillary Right Lateral Incisor
Important characteristics of Schedule III-V controlled substances?
These may be oral, written, or faxed. Refills are ok and by call-in.
How many roots do teeth have? Exceptions?
Most teeth have just one. The exceptions are: Maxillary 1st premolar = 2 roots Maxillary 1st molar = 3 roots Mandibular molars = 2 roots
What is the purpose of the flute on the file?
It is the groove that catches debris between the cutting edges.
What is the definition of a negative rake angle? And which files have one?
- If the leading edge of the blade is ahead of the perpendicular, the angle is, by definition, negative.
- Examples of negative rake instruments are reamers, K-files, K-Flex files, diamond burs, most NiTi-files, and burnishing burs or regular burs run backwards.
What paste do you use for electric pulp testing? For heat testing?
Toothpaste for electric and petroleum jelly for heat.
What is the absolute minimum amount of gutta percha left at the apex end for a post placement?
4 mm. Another study says 5 mm, because 95% of accessory canals are within that 5 mm range that go out to the periodontium.
What usually causes reversible pulpitis?
Caries, exposed dentin (most common), recent dental treatment, defective restorations, trauma. RCT’s are not needed. Pain on testing will be sharp.
What is bone resorption and what is its purpose?
- It is a natural host defense mechanism associated with pathological changes in the periapical tissues.
- Resorption provides a separation between the irritants and the bone preventing osteomyelitis
What is irreversible pulpitis?
- a severe inflammatory process
- precedes reversible pulpitis
- resolves when the causative agent is removed
- yields a negative response to thermal pulp testing
1
What are the four case requirements for Regendo?
- Necrotic pulp 2. Immature root apex (young patient) 3. Pulp space not to be utilized by a post or any restorative purposes 4. Coronal seal
What does taper mean?
It means that the file diameter is getting 0.02 mm wider per millimeter increase at D0 towards D16.
Maxillary Right Second Molar
What causes Asymptomatic Apical Periodontitis (chronic)?
- Caused by pulpal necrosis
- Chronic
- Generally asymptomatic
- Sometimes patients don’t respond to SAP and it turns into this which won’t cause pain, they forget about it, and it becomes bad.
- What cell type is primarily related to the immune system in the dental pulp?
a. dendritic
b. macrophages
c. neutrophils
d. all of the above
A
What are the main 4 types of Medicaments?
- Phenolic compounds (essential oils, aldehydes, halogens) 2. Calcium Hydroxide 3. Steroids 4. Antibiotics
The post and core strengthens the tooth prior to restoration with a crown. True or False?
False. It weakens it actually.
What are the different methods of file use for each file?
- Reaming—Rotating clockwise as flutes engage dentin (REAMER, ROTARY)
- Filing—Bind flutes and scrape out along dentinal walls ( KIFILES, HEDSTROM FILES)
- Circumferential Filing—Move file from wall to wall while scraping (ALL but REAMERS)
- Balanced Force—Place, cut w/pressure (force) and remove (KIFILES, REAMERS)
- Watch Winding/Twiddling—Gently and repeatedly rotating instruments apically (ALL)
Diagnosis Image from Book
What are the characteristics of finger spreaders and pluggers compared to handled instruments when used for lateral condensation?
a. They are annealed to give them greater strength.
b. They are best suited for straight canals.
c. They are more rigid to access the canal orifice.
d. They have greater flexibility.
D
What are the negative consequences that root canal treatments, or just pulp death, have on teeth?
- Loss of Moisture—9%
- Irrigation Materials—NaOCl, EDTA, etc interact with dentin and deplete calcium and fragilize dentin
- Aging—reduces fracture resistance
- Aggressive Coronal Access and Instrumentation—results in excessive tooth structure loss
- Loss of Coronal Seal—reinfection leading to additional Endodontic treatment
Radiographs are useful to evaluate the following qualities of an obturation except which of the following?
a. length
b. density
c. sealer thickness
d. canal configuration
C
Which of the following is not a common cause of a perforation during access preparation?
- mandibular molar with a lingual axial inclination of the tooth
- searching for canals through an under-prepared access opening
- directing the bur parallel to the long axis of the tooth
- presence of a misaligned cast restoration
C
What is the evaluation timeframe of a treated tooth?
6 months to 5 years
What happens when you have periodontitis but you treat the endo first?
- By treating the endo first, the toxins and debris from the root canal could be pushed out into the periodontium and exacerbate the periodontal condition.
Why is the smear layer potentially harmful?
It may be contaminated with bacteria and their metabolic by-products, it may prevent sealer contact with the canal wall, permitting leakage, and it may disintegrate then cause obturation leakage.
With infections, which type of bacteria initially dominate for a brief period?
Facultative bacteria initially dominate, and then anaerobes take over as oxygen is depleted from the root canal and pulp necrosis takes place.
A painful response obtained by pressing or by tapping on the crown indicates the presence of which of the following?
a. periapical inflammation.
b. pulpal inflammation.
A
What is Percocet made of?
Tylenol and Oxycodone
What is bone loss wider with both pulpal and periodontal lesions?
Pulpal, wider apically. Periodontal, wider coronally.
What are the five main types of foundatin restorations?
- • Amalgam Core with/without metal post
- • Composite Core without post
- • Composite Core with fiber or ceramic post
- • Composite core with prefabricated metal post
- • Cast Gold post and core
If a lateral root perforation does occur, what is the most favorable location for perforation repair?
- at or above the height of crestal bone
- below the crestal bone in the coronal third of theroot
- on the furcal side of the coronal root surface
- a zipping perforation at the apex of the root
A
Important characteristics of a controlled substance?
Must be dated and signed on day of issue, manually signed, ink, indelible pencil, or typewritten. The physician has to be registered with DEA, but military, public health, FBI are exempt.
Which group of microbes is the most common bacteria in endodontic infections?
Gram negative
What is usually the first symptom of an inflamed pulp in a tooth?
Cold sensitivity
The post length is the least important factor for retentiveness in posts. True or False?
False, it is diameter
What is resistance influenced by with posts?
- remaining tooth structure
- post length and rigidity
- antirotation features
- presence of FERRULE
When is root canal treatment indicated in a mature avulsed, replanted tooth?
- at the time of replantation
- within 7 to 10 days after replantation
- after 3 months if there is no response to pulp testing
- when periapical pathosis is noted
B
What does Alcohol do to a canal?
- Dries Canal, Surfactant (lowers surface tension with NaOCl)
Posts can strengthen roots. True or False?
False, they do not
What is and what is a downside to the Lentulo spiral (low speed latch)?
-A Lentulo spiral is a dental instrument used to properly distribute root canal sealer and cement evenly throughout the root canal system, as when performing endodontic therapy or a post and core cementation. They can cause damage because they catch a lot on the walls.
Step 1 of Root Canal Preparation:
- Access Cavity Preparation Instrument: #330, #557 Outcome: Get straight line access (SLA) to canal orifices, mid-root, or first canal curvature. De-roof the complete pulp chamber, remove pulp chamber tissue, and conserve tooth structure.
What is a disadvantage as a result of the increased flexibility of nickel-titanium instruments?
a. difficulty in negotiating curvatures
b. inability to rotate in the canals
c. cannot precurve the files to bypass ledges
d. tendency to bind in small canals
C
What is another name for the lamina dura?
Alveolar bone proper
What are the two things you can mix CaOH with?
Saline or anesthesia, turns into thick paste.
What is the definition of a positive rake angle? And which files have one?
When the blade is behind the perpendicular. Hedstrom and most dental burs.
What are some characteristics of Sodium Hypochlorite?
- NaOCl—2.5=5.25% (full strength) Bleach
- Best Proteolytic Agent
- Breaks Down Proteins into Amino Acids Through Free Chlorine
- Chelator
- Removes Debris and Wets Canal Walls
- Antimicrobial
- Dissolves Organic and Inorganic Debris
- Opens Dentinal Tubules (Smear Layer Removal)
- Disinfects and Cleans Areas Inaccessible to Instruments
If a patient has a necrotic pulp and Symptomatic (acute) Apical Periodontitis, with no swelling, how do you treat them?
- • They will be extremely percussion sensitive
- • Treatment—complete pulpectomy or clean and
- shape
- • Establish drainage if possible
- • Copious irrigation
- • CaOH medicament if room after drying
- • Cotton/cavit (old school—leave open)
- • Relieve occlusion
- • Antibiotics/Pain Management
Why do we remove the smear layer?
So filling material adapts better to the canal wall, to get better adhesion of sealer to dentin, and to get better tubular penetration of sealer.
How does the smear layer accumulate?
During cleaning and shaping, we push debris against the canal wall.
What are the main Aldehydes?
- Formaldehydes (Formocresol) Used for pulpectomy/pulpotomy to fix remaining pulp tissue. 2. Gluteraldehydes
Premolars require posts more often than molars because they have bulkier and smaller pulp chambers. True or False?
True
What does the cone-image shift do?
- It gives a clear 2-dimensional image.
- It superimposes facial and lingual structures.
- It assists in identifying superimposed canals.
- It moves apical endodontic lesions away from the root apex.
C
What are the 3 reactions that protect the pulp against caries?
- Decrease in dentin permeability
- Tertiary dentin formation
- Inflammatory and immune responses Pulp is the only connective tissue in the body with the ability to protect itself from certain external irritants.
What is the overall outline form of anterior tooth including premolars?
Oval. They start out as triangular and become more oval.
What are the characteristics of irreversible pulpitis?
You can have symptomatic or asymptomatic, and the pain is usually prolonged rather than sharp, but pulp will eventually become necrotic so RCT is needed. The best time to treat is when it is asymptomatic and caries possibly into pulp space.
A post has no benefit in a structurally sound anterior tooth. True or False?
True
In which situation is caries removal necessary to obtain a definitive pulpal diagnosis?
- deep caries with no symptoms and negative pulp testing
- deep caries with no symptoms and positive pulp testing
- shallow caries with mild symptoms and positive pulp testing
- shallow caries with mild symptoms and negative pulp testing
2
What are the main access burs and their categories?
Carbide high speed #330 and #557, Diamound round and round end taper, and specialty burs like the Endo-Z FG and LA Axxess Kit, as well as slow speed round burs.
Which tooth can have the three canals in the shape of a C?
Mandibular 2nd molar. Two towards mesial, one on distal.
How is pulp tested with heat for a vitality test?
- Rubber prophy cup
- Gutta Percha stick (most common)
- Batter powered
Why can pulp testing be inconclusive with immature teeth?
Sensory innervation to pulp does not mature until later stages of root formation. Thermal testing may be more reliable.
What are working length radiographs?
- Radiographs made by removing the rubber dam.
- Radiographs placed using an XCP positioning device.
- Radiographs that help establish an estimated working length.
- Radiographs determine the distance from the radiographic apex to a reference point.
4
Common Variations
Percentages of mandibular canines having 2 canals?
2 = 3-6%
What are K-files used for?
They are like reamers, but have spirals much closer together. They are used to plane and smooth the walls of the root canal.
What are the symptoms of Asymptomatic Apical Periodontitis (chronic)?
- Little or no pain, even with percussion
- No response to Pulp Vitality Tests
- Slightly sensitive to palpation
- Widened PDL to Extensive lesion (starting lesion at least)
- Granuloma—PMNS, Mast Cells, Macrophages (no epithelium)
- Apical Cyst—Stratified squamus epithelium surrounded by CT containing all cellular components found in granuloma (Granuloma that contains a cavity lined with epithelium— Epithelial Cell Rests of Malessev or Hertwigs root sheath)
- 59% granuloma, 22% cysts, 12% scars, 7% ?
- A granuloma is your basica apical abscess
- There may be slight sensitivity to palpation, indicating an alteration of the cortical plate of bone and extension of AAP into the soft tissues. Radiographic features range from interruption of the lamina dura to extensive destruction of periapical and interradicular tissues
What are the 5 main types of sealer?
- Zinc-Oxide and Eugenol (ZOE, Roth’s) (We use Roth’s/Grossman in the clinic)
- Resin-based
- CaOH-base
- Glass Ionomer
- Bioceramic
What are the characteristics of pulp necrosis?
Caused by bacteria and bacterial products or loss of blood supply. If exudate produced during irreversible pulpitis is absorbed or drains through caries into oral cavity, necrosis is delayed.
At an emergency appointment, should teeth be left open to drain?
- Yes, only if there is swelling.
- Yes, only if there is no swelling.
- No, teeth should have an interappointment tem- porary restoration placed.
3
What are the signs and symptoms of condensing osteitis?
- Depending on the cause (pulpitis or pulpal necrosis), condensing osteitis may be either asymptomatic or associated with pain. Pulp tissue of teeth with condensing osteitis may or may not respond to electrical or thermal stimuli. Furthermore, these teeth may or may not be sensitive to palpation or percussion. Radiographically, the presence of a diffuse concentric arrangement of radiopacity around the root of a tooth is pathognomonic. Histologically, there is an increase in irregularly arranged trabecular bone and inflammation.
- Root canal treatment, when indicated, may result in the complete resolution of condensing osteitis.
What is the number one purpose of the post?
- To retain the core
Which file has a teardrop cross-section?
Hedstrom - Filing, circumferential, and watch-winding.
Percentages of mandibular 2nd premolars having 2 canals?
2 = 15%
What is the name of the 3rd root found in Asians on their mandibular 1st molars?
Radix Entomolaris
What is subluxation?
No displacement, but mobile and percussion sensitive with sulcular bleeding, not treatment.
Mandibular Right Second Premolar
What are the 5 main uses for intracanal medicaments?
- Antibacterial
- Enhance anesthesia
- Render canal contents inert
- Control persistent inflammation
- Control post-treatment pain
What is a main purpose of a pulp cap or dressing?
To put on the pulp to create an inflammatory process in order to start the healing process.
Which of the following describes lateral compaction of gutta-percha?
- It is indicated for cases with internal resorption.
- It involves multiple steps and special armamentarium.
- It manages length control well.
- It is difficult to retreat.
C
What are the characteristics of MTA?
- Has high pH
- bacteria tight seal, creates its own seal, works the best
- hardens
- acts as a base for permanent restoration
- needs moisture to cure-two appointments
- grey can’t be used in anterior teeth
- expensive
- It comes in grey and white and white can also discolor while the temporary is on.
Mandibular Right First Molar
What are some ideal core material properties?
Easily manipulated, no shrinkage, seals laterally and apically, non-irrating to PA tissues, unaffected by tissue fluids, bacteriostatic, radiopaque, no staining, steril.
What are the four characteristics of periapical lesions of endodontic origins?
- Lamina Dura lost apically (widened)
- Lucency remains at apex despite angulation
- Lucency resembles hanging drop
- Tooth has necro;c pulp
If a patient has a necrotic pulp and swelling with drainage, how do you treat them?
- This is probably a chronic apical abscess
- • Treatment—complete pulpectomy or clean and shape (apical penetration)
- • Copious irrigation
- • CaOH after drying
- • Cotton/cavit
- • Relieve occlusion
- • Antibiotics/Pain Management
Inflammation increases success for vital pulp therapy. True or False?
False
What is the shape of the access opening of a maxil- lary central incisor in a young patient?
a. round
b. triangular
c. trapezoidal
d. square
B
Maxillary Right First Molar
The pulp chamber follows the anatomy of the crown. True or False?
True
What is Azithromycin made of?
Amoxicillin and Clavulonic Acid
What is osteosclerosis?
- This is idiopathic, no known cause. Tooth is vital, normal, shallow filling, completely asymptomatic. Usually you can elicit pain or you can see that there have been some heavy restorations or something.
Digital radiography has not been proven to do which of the following?
a. provide superior image quality
b. reduce radiation to the patient
c. increase speed of obtaining an image
d. accurately and reliably be transmitted between
computers
A
What is the composition of Gutta Percha?
- 20% gutta percha
- 65% zinc oxide
- 10% radiopacifiers
- 5% plasticizers
What type of bacteria is E. faecalis?
Facultative anaerobic gram positive coccus
Percentages of maxillary 1st molar root canals?
Palatal and Distobuccal root 1 canal = 100% Mesiobuccal Root 2 canals = 40-80%
What are the largest maxillary and mandibular canals in the mouth?
- Palatal of maxillary and distal of mandibular
What is an advantage of caries removal during access?
- It enhances the effectiveness of NaOCl.
- It reduces interappointment pain.
- It strengthens tooth structure.
- It allows assessment of the restorability prior to the endodontic treatment.
4
What does MTAD do?
- (Tetraclycline, Acid, Detergent) Removes smear layer, Antimicrobial
What is the outline shape of the access for a mandibular first molar with four canals?
a. round
b. triangular
c. trapezoidal
d. square
C
What is a post and core?
- • A POST & CORE is a dental restoration used to sufficiently build-up tooth structure for future restoration, i.e. crown when there is not enough tooth structure to properly retain the crown.
- • The POST is placed within the body of the root of a tooth that has already been treated with RCT
- • The CORE is the part of the restoration that shows out in the mouth that helps anchor a cap or crown
What is the preferred treatment for an emergency appointment with a diagnosis of irreversible pulpitis with symptomatic apical periodontitis?
a. caries excavation with provisional restoration
b. trephination through the mucosa and bone
c. partial or total pulpectomy
d. pharmaceutical management of swelling
C
What is zipping?
It is when you completely miss the apex at the bottom and form your own apex.
What are the six common complaints for patients regarding endodontic problems?
- Pain 2. Swelling 3. Broken tooth 4. Loose tooth 5. Tooth discoloration 6. Bad taste/breath
How would you treat a molar with moderate, a molar with severe, a premolar with moderate, and a premolar with severe tooth loss?
- Molar moderate = just a regular core and crown
- Molar severe = post and amalgam core and crown
- Premolar moderate = post and amalgam core and crown
- Premolar severe = custom cast post and core and crown
Serrated posts are active, meaning they engage into the entin wall. True or False?
False, neither is smooth. But threaded will.
What are the main steps of the Regendo Technique?
Anesthetize, isolate, access, debridement of necrotic tissue, WL, irrigate with NaOCl diluted, dry, medicament with CaOH or Triple Antibiotic paste 1:1:1 mixture of cipro, metro, mino (which can stain). Visit in 2-4 weeks, repeat if still infected, anesthetize with 3% Mepivacaine w/o vasoconstrictore, isolate, access, irrigate NaOCL and then 17% EDTA to remove medicament, dry, then use #10 or #15 file out of apex to stimulate bleeding, place collagen matrix (colla-plug) to serve as matrix for white MTA seal, then put on permanent restoration.
What are the teeth with almost always 1 canal only?
Maxillary anteriors, palatal and distobuccal roots of maxillary molars.
What is a complicated crown fracture? What are the factors involved? And how do you treat it?
It involves enamel, dentin, and pulp. The factors are the extent of the fracture, stage of root development, and length of time since fracture, and restorative treatment plan. Immature roots need pulp to develop. You can treat it by pulp capping with CaOH if within 1st 30 hours, otherwise do a partial or pull pulpotomy, or a pulpectomy.
Which type of bacteria are usually eliminated by endodontic treatment? And which type usually persist especially post-instrumentation and post-operation?
- Gram negative are usually eliminated
- Gram positive and facultative bacteria like streptococi, enterococci, lactobacilli, they all usually stay and hang around, specifically Enterococcus faecalis.
What four things in a tooth can bacteria use as nutrients?
- (1) necrotic pulp tissue
- (2) proteins and glycoproteins from tissue fluids and exudate that seep into the root canal system via apical and lateral foramina
- (3) components of saliva that may coronally penetrate the root canal
- (4) products of the metabolism of other bacteria.
