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35 Cards in this Set
- Front
- Back
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What are the areas of the pulp?
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the pulp chamber: portion within the crown
The root canals: in the confines of the root |
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What is the apical constriction?
What instrument can you use to find it's location? |
the end of tapered root canal opening to the apical foramina.
The apex locator detects the point right after the apex, just entering the apical foramen. |
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How many roots and canals does and upper six have?
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in 60% of people an upper six has 4 canals (2mb on large Mp and one DB)
The other 40% only have one mb |
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What can you see on a pre-op radiograph?
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Number of roots
Curvature of roots Tapering of roots And obstructions like pulpal stones or if the root is occluded. Lateral canals Extimate the length of the root and the distance of the roof of the pulp chamber from the crown. |
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How many roots does a lower 6 have?
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It has 3 roots, one large distal canal and one ML and MB cusp.
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What are the clinical indications for root canal treatment?
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Root canal treatment may be carried out on all patients where other dental procedures may be undertaken, where the following applies:
1. An irreversibly damaged or necrotic pulp with or without clinical and/or radiological findings of apical periodontitis. 2. Elective devitalisation, e.g. to provide post space, prior to construction of an overdenture, doubtful pulp health prior to restorative procedures, likelihood of pulpal exposure when restoring a (misaligned) tooth and prior to root resection or hemisection. |
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Endodontic treatment is far broader than just root canal treatment. What do you understand by this statement?
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When the pulp is diseased/injured, endodontic treatment aims to eliminate infection form the root canal system in order to preserve the normal periradicular tissues or restoring these tissues to health.
The scope of endodontics includes (but not limited to): • The differential diagnosis and treatment of oro-facial pain of pulpal and periradicular origin • Prevention of pulp disease and vital pulp therapy • Pulp extirpation and root canal treatment • Root canal treatment in cases of apical periodontitis • Root canal retreatment in case of post-treatment apical periodontitis • Surgical endodontics • Bleaching of endodontically treated teeth • Treatment procedures related to coronal restoration by means of a core and/or a post involving the root canal space • Endodontically related measures in connection with crown-lengthening and forced eruption procedures and treatment of traumatized teeth. |
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What principles guide access cavity design?
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Access cavity design should involve the following:
• To remove the roof of the pulp chamber so that this chamber can be cleaned and good visibility of the canal orifices can be obtained. • Extension of the opening to include all the root canals. • Entrances of the root canals positioned at the periphery of the access cavity to ensure the instruments can be placed in the root canals easily without undue stress or bending. • Flaring the opening to allow proper visualisation • To conserve as much sound tooth tissue as possible that is compatible with the above |
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What do you understand by the term straight line access?
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Refers to the glide path of the insertion of the instrument into the canal orifice, which should be in a straight vertical line, form the allocated reference point to the canal orifice.
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What information should you glean from a pre-operative radiograph before embarking on root canal treatment?
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Extra canals or branching canals
Canal curvature/degree of curvature Calcifications within the pulp chamber and/or within the root canal Resorbed apex Surrounding bone levels |
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What is the success rate of root canal treatment?
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Pooled probabilities of tooth survival were 86-93% after 2-10 years (Ng et al, 2010)
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How would you ascertain of your root canal treatment was successful?
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Favourable outcomes:
Absence of pain and other symptoms Absence of swelling No sinus tract No loss of function Radiological evidence of normal periodontal ligament space around tooth Uncertain outcome: Radiographic lesion remains the same size or has only diminished NB: Assess the lesion until it has resolved or for at least 4 years. If persistent for this period it is usually considered to be associated with post-treatment disease. |
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What are your goals in preparing the root canal prior to obturation?
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To remove remaining pulp tissue
Eliminate microorganisms Remove debris and shape the root canal(s) so that the root canal system can be cleaned and filled. The apical constriction should be maintained, The canal should end in an apical narrowing and the canal should be tapered from crown to apex. Preparation should be undertaken with copious irrigation. The final length of the preparation should not be reduced by treatment. |
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What is the function of sodium hypochlorite solution?
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To disinfect the root canal system
To dissolve the proteolytic and organic debris Antibacterial properties Provides lubrication Removes debris |
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Sodium hypochlorite solution represents a significant hazard to the patient and the clinicians. What are the potential risks and how can they be minimised?
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Sodium hypochlorite is toxic by all routes:
Acute ingestion may cause burns to the mouth and throat, nausea and vomiting Acute inhalation may cause irritation of eyes and nose, sore throat, cough, chest tightness, headache and confusion Acute eye exposure may cause pain, lacrimation and photophobia Soft tissue damage resulting from inadvertent injection of sodium hypochlorite This risk can be minimised by: Using rubber dam Using the solution in a side-venting syringe To deliver the solution with a pumping action and for the syringe not to remain static or blocked within the canal walls Not to deliver the solution in large volumes at each stage |
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What do you understand by the terms biofilm and smear layer. Can they be removed and how?
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A biofilm is a well-organized community of bacteria that adheres to surfaces and is embedded within a self-produced matrix of extracellular polymeric substance.
Microbial communities grown in biofilms are remarkedly difficult to eracidate with antimicrobial agents. Sodium hypochlorite is an effective antimicrobial. The smear layer is a layer of microcrystalline and organic particle debris that is found spread on root canal walls after root canal instrumentation. The smear layer can be removed by using chelating agents, most common are based on EDTA, which reacts with the calcium ions in dentine, and forms soluble calcium chelates. It has been reported that EDTA decalcified dentine to a depth of 20–30 lm in 5 min. There is no single solution, which has the ability to dissolve organic tissues and to demineralize the smear layer. |
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What causes apical periodontitis and how can it be successfully treated?
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Causes:
Occlusal trauma Egress of bacteria from infected pulps Toxins from necrotic pulps Chemicals irrigants Over instrumentation in root canal treatment As a result of pulpal necrosis in chronic conditions Successfully treated via: root canal treatment, occlusal adjustment or extraction |
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What are the symptoms associated with reversible pulpitis? How does it differ from irreversible pulpitis?
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Symptoms associated with reversible pulpitis:
Pain difficult to localise Pain does not linger after stimulus removed Normal periradicular radiographic appearance No tenderness to percussion unless occlusal trauma Difference from irreversible pulpitis: Pain may occur spontaneously or from stimuli In latter stages cold stimulus may be more significant Response last for minutes or hours When the periodontal ligament is involved the pain can be localised Radiographically may see widening of periodontal ligament |
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How would you manage reversible pulpitis?
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To remove the pulpal irritant, seal and insulate exposed dentine with a restoration.
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What do you understand by indirect and direct pulp protection?
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Indirect pulp capping (stepwise excavation of caries):
Defined as a procedure in which a pulp is covered with a protective dressing or cement placed over a thin partition of remaining dentine or slightly softened dentine which if removed, might expose the pulp. Direct pulp capping: defined as a procedure in which the pulp is covered with a protective dressing or base placed directly over the pulp at the site of exposure. This procedure may be performed when the pulp is exposed through noninfected dentine and the tooth has no recent history of spontaneous pain and a bacteria tight seal can be applied. The tooth should be isolated to prevent contamination. |
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What are the advantages of crown down preparation over step back preparation?
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Advantages:
Enhanced movement of debris coronally minimising pushing debris apically Increased space for irrigant penetration and debridement Better canal shapes facilitating better obturation Rapid removal of bulk of pulp tissue in coronal third Decrease canal blockages Improved access to apical third Less deviation of instruments in curved canals |
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Why are root canals prepared and shaped with a continuous taper?
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So root canal filling material can be introduced into the canals
Prevent the extrusion of materials beyond the apex Removing infected dentine form the canal walls |
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How would you prepare a relatively large and straight root canal using stainless steel hand instruments?
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Using SS files no.55 to 35 to the mid 1/3rd by Watch winding which is the passive rotation of file clockwise to anticlockwise. Stainless steel files can only be used in reciprocating motion up to 90 degrees. The to use files no 15 to 30 using the step back technique.
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How would you prepare a curved root canal using rotary Nickel Titanium instruments?
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Using the step back technique with size 15 to 25 size files in the rotary system to the WL.
Nickel titanium is better able at negiotiating curved root canal sysytems as they have superelasticity and shape memory, making them more flexible that SS and can be used in a 360 rotation. |
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What do you understand by the terms apical patency filing and recapitulation?
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Patency filing:
Maintain patency of the apical foramen by passing a small file no larger than a size 10, 0.5mm through the apical foramen without enlarging it, only to unblock it. This removes the last remnants of debris and allows calcium hydroxide to diffuse into periapical area in order to promote disinfection and healing. Recapitulation: Is the repeat use of a smaller file than the one in use i.e. return to a smaller file used previously. This stirs up debris preventing sedimentation and helps irrigant to wash out debris. |
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What do you understand by the term 2% or 0.02 taper?
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Along the 16mm cutting surface of the SS file, it's diameter increases by 2% every 1mm.
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How would you dress the root canal after completing root canal preparation?
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If pulpal or periodontal inflammation present/pulpal remnants remain/continued bleeding:
Use ledermix paste, which is a cortisone derivative (triamcinolone acetonide) and a broad spectrum antibiotic (demeclocycline calcium) If no symtoms present: A non-setting calcium hydroxide paste, which has an alkaline ph (11) and is bacteriocidal |
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What are the aids for root canal obturation?
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Finger spreaders A to D with matching accessory points.
Master apical points Sealer Paper points |
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Describe how you would laterally condense gutta percha?
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By placing the spreader alongside the master point/ accessory point and to compact it using firm apical finger pressure only. To leave the finger spreader in for 30 seconds, this is so the gutta percha can be deformed along the canal walls to overcome its elasticity.
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What is the role of sealer?
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To fill the spaces in between the gutta percha, lateral canals, voids, cracks and resorptive defects and to cement the GP to the canal walls. It also acts as lubricant, antimicrobial agent.
There are many different types of sealers: ZnO and eugenol based, resin, GIC and calcium silicate |
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What are the advantages of using a warm gutta percha technique such a carrier method?
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Use a verifier to check the length of the hot GP first before you obturate.
Improved lateral and vertical compaction of the softened material Denser obturation result |
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What are the disadvantages of using a carrier method?
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The finger spreaders will not retain heat sufficiently and designed heat carriers should be used.
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What are the ideal properties of a root filling material?
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Biocompatible
Dimensionally stable Capable of sealing the canal laterally and apically, conforming with the various shapes and contours of the individual canal Unaffected by tissue fluids and insoluble Bacteriostatic Radiopaque Easily removed form the canal if necessary |
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Discuss the differences between techniques to restore a root filled anterior tooth compared to a load bearing posterior tooth?
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Restore a root filled anterior tooth:
Ceramo-metal extra coronal restoration All ceramic extra coronal restoration Restoration with composite Posterior tooth (load bearing): Full metal (non-precious) extracoronal restoration Full gold extracoronal restoration |
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How would you diagnose apical periodontitis?
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Acute Apical Periodontitis
Clinically: Pulp sensitivity testing Tenderness to biting Positive percussion testing result Radiographically: Widening of the periodontal ligament Chronic apical periodontitis Clinically: No response to pulp sensitivity tests Mild or no tenderness to biting Tenderness to palpation over root apex Radiographically: Widening of periodontal ligament to apical radiolucency |
