Endodontics Flashcards
List three reasons for carrying out obturation of the prepared root canal.
- Inhibits bacterial growth - It can be easily removed - It seals the canals apically and laterally
Briefly describe the steps involved in obturating the root canal of an upper central incisor
- apply dental dam and disinfect access area - remove provisional restoration seal using a sterile round bur, remove cotton pledgets from from pulp chamber - irrigate using sodium hypochlorite to remove all traces of calcium hydroxide medicament - Starting with size 10 or 15, introduce files sequentially to confirm access to the working length and to prepare the apical stop - dry the canal using a narrow bore aspirator and size matched paper points in locking tweezers - select master GP which will fit the canal at working length and give tug back. - mix the root canal sealer (AH plus/setting CaOH) - coat the tip of the GP with sealer before reinserting into the canal carefully and gently to length - carry out cold lateral compaction
Describe the steps of cold lateral compaction
- Take a size A finger spreader with a silicone stop set at 1-2 mm short of the CWL and gently place into the canal alongside the master GP point - gently remove the finger spreader, and in the space left, insert a small size A accessory point which has been coated in sealer - repeat this until 3 or 4 points have been used - heat the end of an excavator or plugger in a bunsen flame to cut/melt the GP. - remove excess GP from the pulp chamber
Which part of the root canal filling is most important in ensuring long term success?
a good coronal seal ensures a higher success rate and reduces the risk of reinfection
What is the hydrodynamic theory?
this is the theory used to explain the mechanism by which a tooth perceives pain due to the abrupt movement of fluid within the dentinal tubules due to stimuli. Thermal; hot and cold Osmotic; sugary foods Mechanical; chewing Evaporative; air blasts
what fibres are responsible for sharp pain of short duration?
A-beta and A-delta fibres
what fibres are responsible for dull throbbing pain of longer duration?
C fibres
How many canals are found in the first maxillary premolar?
1 (6%) 2 (95%) 3 (1%)
How many canals are found in the second maxillary premolar?
1 (75%) 2 (24%) 3 (1%)
how many canals are found in the first maxillary molar?
3 (7%) 4 (93%)
how many canals are found in the second maxillary molar?
3 (63%) 4 (37%)
How many canals are found in the first mandibular premolar?
1 (73%) 2 (27%)
How many canals are found in the second mandibular premolar?
1 (85%) 2 (15%)
How many canals are found in the first mandibular molar?
3 (67%) 4 (33%)
How many canals are found in the second mandibular molar?
2 (13%) 3 (79) 4 (8%)
What bacteria is suggested as the prominent isolate in non-healing endodontic cases?
Enterococcus faecalis
What type of bacteria are found in necrotic untreated endodontic cases?
gram negative anaerobic
What type of bacteria are found in failed cases of RCT with persisting infection?
Predominantly gram positive anaerobic
What fibres are responsible for sharp pain of short duration?
A-beta and A-delta
What fibres are responsible for dull throbbing pain of longer duration?
C fibres
Give three reasons for Biofilm resistance to antimicrobials…
* antimicrobials may fail to penetrate beyond the surface layers of the biofilm * antimicrobials may be trapped and destroyed by enzymes * antimicrobials may not be active against non-growing micro-organisms * Expression of biofilm specific resistant genes * stress response to hostile environmental conditions (eg leading to an overexpression of antimicrobial agent destroying enzymes)
What are the four features of apical periodontitis?
- chronic polymicrobial infection of the oral cavity - Predominance of gram negative anaerobic bacteria - stimulation of host response - connective tissue destruction
What are the clinical objectives or RCT?
- removing canal contents - eliminating infection
Give four reasons for the use of dental dam in endodontics…
- prevents contamination - airway protection - allows use of appropriate disinfectants - Improves access and vision - improves patient comfort - improves efficiency
What are the design objectives of RCT?
- create a continuously tapering funnel shape - maintain apical foramen in original position - keep apical opening as small as possible
What is achieved by cleaning and shaping the root canal?
- removing infected soft and hard tissue - give disinfecting irrigants access to apical space - create space for the delivery of medicaments and subsequent obturation - retain the integrity of radicular structures
What is the process of reaching a diagnosis in endodontics?
- why is the patient seeking advice? - history and symptoms prompting visit - objective clinical tests - correlation of objective findings and subjective details to create differential diagnosis - formulation of definitive diagnosis
When a patient attends your surgery with pain, what questions should be asked?
- where is the pain - what does it feel like - how bad is it - how long is it there for? - does anything take the pain away? - what makes it worse - does it keep you awake at night - does the pain come on spontaneously - have you had this before - have you had any dental work recently? - have you suffered any trauma
When taking a pain history, what does SOCRATES stand for?
-Site - Onset -Character -Radiation -Association -Time course -Exacerbating/relieving factors -Severity
If a patient presents with swollen lymph nodes and the origin doesn’t appear to be dental, what could be the cause?
TB lymphoma
If a patient presents with paraesthesia and the origin doesn’t appear to be dental, what could be the cause?
leukaemia anaemia
If a patient presents complaining of bone pain and the origin doesn’t appear to be dental, what could be the cause?
sickle cell anaemia
If a patients presents with tooth mobility and the origin doesn’t appear to be dental, what could be the cause?
multiple myeloma
If a patient presents complaining of pain and it doesn’t appear to be of dental origin, and is otherwise unexplained. What could be the potential causes?
multiple sclerosis acute maxillary sinusitis trigeminal neuralgia
How would you carry out a systematic endodontic exam?
- extra oral - intra oral - STE - intra oral swelling -sinus tract -palpitation -percussion -mobility -perio exam
List what can be used and how cold and heat sensibility testing is carried out
Frozen carbon dioxide (-78degrees), ethyl chloride or refrigerant spray can be used Cold sensibility testing tests the hydrodynamic forces. -dry and isolate the tooth - test close to the pulp horn Heat tests can be carried out using hot GP and vaseline or hot water and dental dam
Describe how an electric pulp test is carried out and how it works
- electric current used to stimulate sensory nerves -primarily A-delta fast conducting fibres -unmyelinated C-fibres may or may not respond -teeth are dried and isolated -probe is placed near the pulp horn -a conducting medium is used such as tooth paste -the circut is complete, current slowly increased until there is a response A negative response is a reliable indicator unreliable in teeth with an open apex
List four special tests that could be carried out to check pulp sensibility
- bite test - test cavity - staining and trans illumination - selective anaesthesia
What radiographs should be taken before carrying out endodontics?
Two pre-op radiographs taken from different angulations
Endodontics Describe a normal pulp
-symptom free and normally responsive to pulp testing -pulp may not be histologically normal -clinically normal pulp results in a mild or transient response to thermal cold testing lasting no more than a few seconds
Describe reversible pulpitis
(pulpal diagnosis)
-inflammation should resolve following appropriate management of the aetiology -discomfort is experiences when a stimulus applied lasting only a few seconds -occurs with exposed dentine, caries or deep restorations -no significant radiographic changes in the periapical region of the suspect tooth -pain is not spontaneous