Retake 2

Maxillary 1st Premolar

• 2:2 → B & P

• 3 canals = Molarization

• B curve = Lingual

• P curve = straight

• Access shape → Oval/Slot 

• Wider BL

Maxillary 2nd Premolar

• 1:1 ≈ 53% have 1 root. can be 2 canals

• Curve: D, Bayonet, B & straight.

• Pulp horn: B horn larger.

• Access shape → Oval.

• Wide BL.

• If 2 canals = Longer BL access.

Mandibular 1st premolar

• 1:1 → 25% have 2 canals

• Curve: D/L

• Pulp horns: B>L

• Access shape → Oval, wider MD

• Crown tilts lingually, extend linguall access to find lingual canal.

Mandibuar 2nd premolar

• 1:1 → 2-3 canals rare.

• Curve: S/D

• Pulp horns → L>B

• Pulp chamber wider BL

• Access shape → Oval & centered b/w cusp tips. 

• 2L cusps common → Access b/w them. 

Pro-Taper system

• 6 instruments 

• 3 Shaping files → Sx, S1 & S2

• 3-5  finishing files → F1,F2,F3,F4 & F5

Pro-Taper Technique

1. Handfiles 8-15

2. S1, S2 to WL

→ SX only if canal orifice has straight line acces.

1. F1 to WL

2. F2, F3 or bigger to instrument WL to according apical diameter. 

Lateral compaction

• Obturation method

• Length control during compaction. 

• Might not fill canal irregularites as warm vertical compaction. 

• Accomplished w/ any acceptable sealers. 

Lateral condensation protocoll

1. Adapt MC

2. Spreader size

3. Accessory cones (smaller than spreader) 

4. X-RAY w/ MC

5. Mix sealer

6. Dry canal w/ paper points

7. Sealer placement → Paper point, file, sonic activation & small injectors.

Vertical condensation - Easy & hard def

• Easy: Warm softened gutta-percha is vertically packed using pluggers to create dense 3D seal.

• Inserting conical adapted MC to canal, cutting it at apical third & filling free space of canal w/ flowing thermoplastic gutta-percha.

Filling Definition

• Absence of AP b4 treatment

• Dense root canal filling

• Not less than 2mm from x-rat apex. 

Filling functions

• Prevent coronal leakage

• Encapsulate surviivng microorgansims

• Prevent apical leakage

Characteristics of ideal filling

• Easy insert to root canal

• Closes canal apically & laterally

• No shrinkage post filling

• Moist resistant

• Bacteriostatic/reduces bacteral growth

• X-ray contrast

• No discoloration

• Non irritating, toxic & carcinogenic

• Sterile

• East to remove if retreatment

Gutta-Percha

• From trees juice

• Alpha & Beta forms

→ Alpha: Low viscosity. Brittle at room temp. Sticky & fluid when warm. Thermoplastoc filling methods.

→ Beta: Stable, lil flexible, comercial form. Less adhesive & fluid when heated. E.g. MC of lateral condensatin technique. 

• Comercial materials contain 20% gutta pecha. 

Materials & instruments - Lateral condensation

• Choose GP-MC, corresponds to final root canal enlargening

• Compaction instrument - spreader (NiTi for curved canals) 

• Accessory cones - Fill space done by spreader, comp. laterally to master cone. 

• Root canal sealer w/ low setting time - fills gaps b/w cones

• Endo pluggers

Master cone

• Standardised cone that has consistent diameter w/ øargest file used in WL.

• MC should be measured in WL.

• Tug back at 0.5-1mm short of WL

• Cone position checked via x-ray

• Mof - Root canal prepped with rotary instruments , tapered GP-cones (like ProtaperGOLD) can be used. 

Spreader - Finger VS NiTi

• Finger - Tactile sensation

• NiTi - flexible, deeper penetration + better for curved canals. 

Endo pluggers - Heated & Cold

• Removes excess GP w/ heat & coronal mass compacted w/ appropriate plugger. 

• Cold plugger -  GP is condensed. 

• Heated plugger - GP is removed. 

GP removal level

• Posterior - 1mm below canal entrance

• Anterior - 1mm below CEJ level 

Maxillary 1st Molar

• Largest tooth

• 3:3 (or 4canals)

• 3 roots → MB, DB & P

• 4 Pulp horns → MB, MP, DB, DP.

• Pulp chamber cervical outline form = Rhomboid.

• Pulp chamber widest BL, located M from obl. ridge.

• MB root → 2 canals (mb1 & mb2). mb2 is 3.5mm p & 2mm M from mb1. MB root is at an acute angle.

• P root → Longest & largest diameter, 1:1. 2-3 canals have been seen. Curves B at apical 3rd, curves B at apical 3rd.

• DB root → Obtuse angle, conical & 1:1. Goes from oval and becomes rounf at apical third.

Maxillary 2nd Molar

• Conical, smaller & more symmetrical.

• 3:3 (4 canals seen, not as common).

• Distinguishing features: Shorter & fused roots, not as cured.

• Fused roots = 2 canals

• Rare case, 2 canals (B&P), in equal length & diameter. 

• Canals: 1:1 in each root but has exeptions. 

→ MB: 2-3 canals

→ DB: 2 canals

→ P: 2 canals

• Orifice: Flat triangle, straight line. 

• Outline form: 

→ 4 canals = Rhomboid shape

→ 3 canals = Rounded triangle

→ 2 canals = Oval shape

Mandibular 1st Molar

• 2:3 (rare 3 roots)

• 2 roots → M & D. 3 canals → 2M + 1D

• Pulp chamber floor trapezoid/rhomboid. 

• M root & canals: 2 canals MB&ML. If 3 MM. 

→ Wider BL, curved D, thin D wall (perf risk) 

→ MB canal very curved = Strip perforation risk

• Distal root & canals

→ Straight longer & round x-sectio

→ 1 canal D, if 2 DB & DL. 

→ 2 canals = more circular & join apically. 

Mandibular 2nd Molar

• 2 roots, 1-4 canals. 

• 2 roots → M & D (often fused)

• Apices curve distally. 

• Orifices connected in semicircular slit = C shaped canal system. 

• M root: 2 canals (MB & ML), merge at apex, shorter & less curved than Mand 1st Mol.

• D root: 1 canal (D). If 2 = DB & DL. Root short, broad & distally curved.

• 1-4 Canals, 3 common.

→ MB, ML & D. 

→ C shaped canal system = Fusion of M & D canals. 

→ Orifices found centrally, in mesial 2/3 of pulp chamber.

Access outline

• 4 canals = Rectangular/rhomboid

• 3 canals = Triangular

• 2 canals (M+D) = Oval/MD elongated. 

Extra: Apex close to mandibular canal → Paresthesia risk if overfilled/overinstrumented.