Endodontics Flashcards
Essay: Detailed steps of performing RCT on a lower first molar in a single visit (14m)
See page 41, long answer
You decided to do an access cavity for endodontic treatment for tooth 36. What are the 4 aims and objectives for an access cavity? (4)
- To remove the entire roof of the pulp chamber so the pulp chamber can be cleaned.
- To enable root canals to be located and instrumented by providing straight-line access to the apical third of the root canals. (The initial cavity may be modified to achieve this objective.)
- To enable a temporary seal to be placed. That is, the cavity provides sufficient retention for the temporary restoration as well as preserving enough bulk of tooth structure to sustain occlusal functional loading during the inter-appointment period.
- To conserve as much sound tooth tissue as possible compatible with the above objectives.
Pre-operative radiographs are very important for a successful endodontic treatment. What 5 things can be obtained from a preoperative radiograph? (5)
Root canal width, length. Any periapical lesion. Any root resorption. Lamina dura – present or not. Curvature of canal.
What are the 3 uses of irrigation during endodontic treatment? (3)
- Flushing - to flush out debris, dentinal shavings, blood, and other materials used/placed in the canal.
- Disinfection - to eliminate as much microorganisms as possible without causing undue irritation to the periapical tissues.
- Lubrication - to lubricate the canal to facilitate cutting and reduce the risk of instrument breakage.
- Dissolution of organic tissues - to dissolve necrotic tissues and organic debris.
Patient presenting with avulsed reimplanted tooth. What are the causes of external inflammatory resorption and replacement root resorption?
- Dental avulsion
- Trauma
- Bacterial infection
- Replacement root resorption: Destruction of PDL cells (so osteogenesis instead)
What are the clinical and radiographic features of the two types of resorption?
External inflammatory resorption: no sign, symptoms of apical periodontitis; Asymmetrical bowl shaped periradicular or periapical radiolucencies
Replacement root resorption: No sign, metallic sound on percussion; Asymmetrical bony replacement of root surface and loss of PDL space
Describe the management of the two types of resorption.
External inflammatory resorption: RCT
Replacement root resorption: no treatment, just monitor
If the avulsed tooth was a primary tooth, what would be the difference in management? What advice would you give the mother?
Don’t need RCT
Extract (don’t want to develop ankylosis permanent tooth cannot erupt..?)
List different kinds of root resorption (5)
Internal inflammatory, internal replacement
External inflammatory, external replacement, external invasive cervical, external surface, external transient apical breakdown
Describe root morphology and pulp canal anatomy of 16
- 3 roots – 2 buccal; 1 palatal
- Usually 4 root canals
- P > MB1 > DB > MB2
- MB – coronal and middle is oval or flat round; apical is round; curves distally
- DB - oval or round cross section; straight root
- P – oval or round cross section; straight root or curves buccally
2 factors whether to do avulsed tooth or not (2)
Any root fracture, dentoalveolar fracture; primary tooth or permanent; time from trauma
3 factors affecting the prognosis of a replanted permanent tooth (3)
- Time of replantation
- Any physiological storage before replantation
- Open or closed apex (closed apex better survival)
- RCT treatment duration
Complications of the replanted tooth and your management (3)
- Ankylosis – if permanent tooth, just monitor; if primary, extract
- Periapical infection – RCT/ need to extract
- Discoloration – poor aesthetics, need crown
List the storage medium for avulsed teeth in the order of favorable treatment outcome. (1)
Milk, Hank’s balanced salt solution, coconut water, (saliva is low)
How can one minimize the complication you mentioned in 6.at the time of avulsion? (4)
- Replant the tooth asap (total extraoral dry time < 60 mins)
- Proper storage medium (Hank’s balanced salt solution / saline, milk, saliva)
- Atraumatic handling of the avlused tooth (grasp by the crown only)
- Ensure tooth surface and socket wall is clean
What is ankylosis? Give a factor that contribute to ankylosis (2)
Ankylosis: pathological fusion between alveolar bone and the cementum of teeth
Factor: after trauma to teeth
How to diagnose ankylosis (4)
- X-ray – lack of PDl
- Percussion – metallic sound
- No mobility
- CBCT
List 2 periodontal complications of avulsed tooth.
External inflammatory root resorption
External replacement root resorption
What are the clinical and radiographic findings of External inflammatory root resorption ?
Clinical
1. Pulpal symptoms
Radiographic
- Bowl shaped radiolucency around the external root surface and corresponding bone
- May be poor defined margin
What are the clinical and radiographic findings of External replacement root resorption?
Clinical
- Loss of mobility (Periotest)
- Percussion with metallic sound
- Tooth may be infraocclusion
- Negative to vitality pulp test
Radiographic
- Loss of PDL space and lamina dura
- Root subsequently replaced by bone completely
In the replantation of avulsed teeth, how should splinting be done to avoid ankylosis? State the reasons (4)
• Flexible splint, allowing slight movement of teeth + replanted permanent teeth should just be splinted up to 2 weeks
o Because this slight movement and short splinting time can promote periodontal and pulpal healing
• Splint should be on buccal surfaces to allow lingual access for endodontic procedures and to avoid occlusal interference
• Splint should not impinge on gum tissues
How many months after RCT should we evaluate? (1)
6 months??
State the conc.and the name of the root canal irrigation that BDS use in polyclinic (1)
Sodium hypochlorite (1.2%)
How likely is it to have a good RCT outcome for these situations? Rank in order. The one with best outcome is 1 as follows (4)
Fresh trauma with exposed bleeding pulp, needing RCT: 1
Irreversible pulpitis, deep leaking restoration, no periapical lesion 2
Traumatized nonvital tooth with no periapical lesion 3
Irreversible pulpitis with periapical lesion 4
Periapical lesion around a tooth that has been endodontically treated 5