1. Anatomy Appreciation & Access Cavity Flashcards
What are the main objectives of endodontic treatment?
- Maintain health of the pulp
- Remove disease of the root canal
- Maintain health of the periapical tissues
What is the canal configuration of UPPER central and lateral incisors? What are the special features that we should take note of?
- Both are always single-canalled
- Both have the presence of a lingual shoulder overhanging the lingual portion of the canal orifice… this portion must be removed by filling with an endodontic file or with the Gates-Glidden drill
- The upper lateral incisor often presents with an apical curvature in the distopalatal direction (should take note to ensure adequate and careful C&S)
What is the canal configuration of LOWER central and lateral incisors? What are the special features that we should take note of?
- Lower incisors can be single or 2-canalled. There can be a 1-2 configuration (1 canal orifice leading to 2 canals), or a 2-1 canal configuration
- Long slender lower incisors usually have a single uncomplicated root canal while short blunted roots are more likely to have divided root canals
What is the canal configuration of LOWER and UPPER canines? What are the special features that we should take note of?
- Both lower and upper canines are single canalled
* They have the longest canals
What is the canal configuration of UPPER 1st premolars? What are the special features that we should take note of?
- The upper 1st premolar can present with two distinct roots, each with a single root canal in each root, or one broad root with two root canals
- The diameter of the apical third tends to be small and should be carefully instrumented
What is the canal configuration of UPPER 2nd premolars? What are the special features that we should take note of?
• They are usually single rooted with 1 canal
What is the canal configuration of LOWER premolars? What are the special features that we should take note of?
- They are usually single-rooted with single canals
- The first lower premolar tends to have a lingual tilt of the crown so caution should be taken when making the access cavity
What is the canal configuration of UPPER 1st molars? What are the special features that we should take note of?
- Upper 1st molars are 3-rooted: Mesiobuccal, Distobuccal and Palatal roots
- There are 3 canals, sometimes 4 (usuallly 2 canals found in the mesiobuccal root)
What is the canal configuration of LOWER molars? What are the special features that we should take note of?
- Lower molars are 2-rooted: mesial and distal root
- There are usually 3 canals (the mesial root has two canals that can be merged or entirely separate canals)
- The distal root usually has 1 canal, but a broader distal root can have 2 canals
- Sometimes, there is a separate distolingual root which is acutely curved
What is the purpose of an access cavity?
- To gain direct access to all root canal orifices
- To facilitate root canal instrumentation and disinfection
- To debride the pulp chamber
- To remove all caries and defective restorations
Why must an access cavity be properly widened?
- It acts like a funnel for irrigants to stream into the chamber and canals
- It allows the evacuation of infected pulp and debris
- It facilitates cleaning and shaping of the canals as well as obturation, by allowing better visual access and easier maneuvering of instruments
Note: Certain critical areas has to be preserved, such as the load-bearing areas
What are the outline forms of all the different teeth?
Upper incisors: Triangular, tip near cingulum, base near incisor edge
Lower incisors: Ovoid, tip near cingulum, base near incisor edge
Upper & Lower canines: Ovoid, between cingulum and 2mm short of cusp
Upper premolars: Elongated ovoid, 1-2mm short of cusp tips
Lower premolars: Ovoid but less elongated than upper PMs
Upper 1st molar: Triangular, within mesial ridge, oblique ridge and mesio-palatal cusp tip
Lower 1st molar: Rounded trapezoidal or rectangular (if 2 distal canals). Within distal marginal ridge, mesiobuccal and mesiolingual cusp tips
