Endodontics L8: Access cavity preparation incisors, canines, premolars

Question 1

Q1: the removal of the roof of pulp chamber and pulp horn should give you direct vision of the?

Answer 1

Pulpal floor and canal orifices.

Question 2

Q2: if you are not carrying out the root canal treatment in one appointment, why is it important to provide retention between visits?

Answer 2

Providing retention will allow you place temporary restorations between visits.

Question 3

Q3: with incisors most perforations are towards which side?

Answer 3

Labial side

Question 4

Q4: preparation of access cavities requires different types of burs, which bur would you use to cut the initial outline form, and how deep in to the enamel should this be?

Answer 4

Small round diamond bur

Question 5

Q5: preparation of access cavities requires different types of burs, which bur would you use to cut to access the roof of the pulp chamber and to penetrate the roof, whilst avoiding perforation?

Answer 5

A long diamond fissure bur

Question 6

Q6: when using the diamond bur to penetrate the roof of the pulp at which angle must you be at?

Answer 6

When cutting the access cavity with the diamond fissure bur, you must be at 45 degree angle to the palatal surface.

Question 7

Q7: when you have reached the mid point with the diamond fissure bur, what would you next do?

Answer 7

You would change your angulation towards the root canals.

Question 8

Q8: what bur would you use if you had to get access through a metal crown?

Answer 8

Tungsten carbide bur

Question 9

Q9: if a patient has a metal ceramic crown, how would you go abouts selecting which burs to use?

Answer 9

You would use a small round diamond bur to cut through the porcelain and then use the tungsten carbide to access the metal.

Question 10

Q10: once you have accessed the roof of the pulp through the long diamond fissure bur, which bur would you use to completely remove the roof of the pulp. And what speed hand piece would you be using?

Answer 10

You would use a long shank bur for the complete removal of the pulp roof. These hand pieces would be used on slow speed handpiece.

Question 11

Q11: once you have removed the roof of the pulp chamber and established your basic shape, you want finish everything of and we do this by using which bur?

Answer 11

We would use a non-end cutting bur. This allows the floor of the pulp to remain intact allowing you to flare and finish the axial wall.

Question 12

Q12: the access cavity for a maxillary central and lateral incisor should resemble which shape?

Answer 12

Triangular shape

Question 13

Q13: the access cavity for a maxillary/mandibular canine should resemble which shape?

Answer 13

Ovoid shape

Question 14

Q14: there are four principles of access cavity design, the first principle is initial outline. What determines the initial outline?

Answer 14

• Dependant on the tooth type
• Shape – position of canal orifice and pulp horns
• Size
• Depth – 1mm into enamel

Question 15

Q15: there are four principles of access cavity design, the second principle is penetration. What occurs during penetration?

Answer 15

• Use of fissure bur to penetrate through the roof, if the chamber is wide it will feel like falling in to space.

Question 16

Q16: there are four principles of access cavity design, the third principle is enlargement. What occurs during this stage?

Answer 16

• Performed with a long-shanked round bur on a slow-speed handpiece
• The action/cutting is applied on the way out working on the dentinal walls, with a brushing motion to remove all dentine overhangs.

Question 17

Q17: there are four principles of access cavity design, the fourth principle is finishing and flaring. What occurs during this stage?

Answer 17

• A non-end cutting high speed diamond bur to smooth the walls of the access cavity
• Bur is used to slightly flare the cavity