Operative Dentistry Viva ques

Dr. Muaaz Amjad AwanDr. Almas M Arshad

UCD, UOL (PAKISTAN)

• Pulp capping agent

• Intracanal medicament

• Canal sealer • Antimicrobial properties

• Ph 12.5 strongly alkaline• Types:

• Setting

• Non - Setting (Intra-canal)

Composition: 1- Tricalcium Silicate2- Tricalcium Aluminate BOSA3- Tricalcium Oxide4- Bismuth oxide 5- Tetracalcium Silicate (Grey MTA)USES:

1-Pulp capping Agent2- Root end filling after apicectomy3- In Internal and external root resorption4- Lateral perforation sealing5- Root canal sealer

• In the crown: o Temporary enamel restorationo Permanent dentin restorationo Deep or large carious lesionso Deep cervical or radicular lesionso Pulp cappingo Pulpotomy…..

• In the root: o root and furcation perforationso internal/external resorptionso Apexificationo Retrograde surgical filling.

ZnO 75%

Gutta percha 25%

Types:• Standardized type: follows same ISO

classification as endodontic files• Non-standardized: have a greater taper than

the standard ISO type

Use:Root canal IrrigantRoot canal Medicament

Advantages:broad spectrum antimicrobial properties 2% equals to 5% NAOCL in sense of antibacterial actionsynergic affect when used with NAOCL

Disadvantage: can’t dissolve orgainc and inorganic components of pulp

• Chlorohexidine

• Sodium hypochloride

• EDTA (also decalcifying agent)

• Sodium Hypocholorite (5 – 35%)

• Sodium Perborate – Walking bleach

• Carbamide peroxide

• Components :

• Bacteria: • Streptococcus mutans

• Peptostreptococcus

• P gingivalus

• Fusobacterium

• P denticola

• P Forshytia

• Prevents Hypocholorite accident

• K FILE:• triangular or square cross section

•Advantages:• More flexible and don’t fracture

•Disadvantages:1- Less cutting efficiency

2- Extrusion of debris periapically

• H FILE:

• has flutes that resemble successive triangles..

• Advantage: They have superior cutting efficiency

• Disadvantage is they are not flexible and fracture easily

• Used to extirpate PULP

• Removal of cotton and paper points

• Small flame shaped

• Used in conventional hand piece

• Used for :

1- enlarging canal orifice (/coronal 3rd)

2- to remove lingual shoulder in Anteriors

• To remove GP during post preparation

• Small flame-shaped cutting instrument

• used in the conventional handpiece

• Small flexible instrument

• Placement of material into the canal

• Fits into the conventional slow handpiece

• Loss of working length

• Ledging and stripping

• Perforations

• ZIP: Apical portion transportation of a canal

• ELBOW: Rotating the instrument in curved canal can produce a biomechanical defect.

How to avoid these

1- never rotate instrument in curved canal

2- Always pre curve the small size instruments

Requirements:Good adhessivnessBiocompaitabilitySlow setting timeEasy manipulationLess solubility Types:

1- zinc oxide eugenol bases 2- Plastics: epoxy based 3- Calcium hydroxide 4- glass Inomers

Returning to smaller num file time to time before advancing

to a larger file.

• Tofflemire Universal

• Ivory Bands

• Pilodent – for composites

• Automatrix – difficuilt to contour

• When the tooth structure is prepared with a bur or instruments, residual organic and inorganic components form a smear layer that is composed of hydroxyapatite and denatured collagen.

• When primer and bonding agent are applied on the etched dentin they form resin-dentin interdiffusion zone called hybrid layer.

• Etching with 35% Phosphoric acid

• EDTA

1. Cold Lateral

2. Warm vertical

3. Thermoplastisized GP inj

4. Chemically Plasticized GP

5. McSpadden thermomechanical GP

6. Continuous wave compaction

7. Carrier based GP

8. Custom cone

• Maxillary 1st Molar

• MB (MB1 MB2), DB, Palatal

• Mandibular 1st Molar

• MB (MB1 MB2), DB

• Should have a continuous tapering, conical shape, with the narrowest cross-sectional diameter apically and the widest diameter coronally.• The walls should taper evenly towards the apex and should be confluent with the access cavity.• To give the prepared root canal the "quality of flow;' i.e, a shape that permits plasticized gutta-percha to flow against the walls without impedance.• Should keep the apical foramen as small as practical.• Should clean and shape the canal without transporting the apical foramen.

• Iodoform paste – (zinc oxide and iodoform mixture)

– bactericidal and nonirritant

• ZnO Eugenol paste (without catalyst)why catalyst not used… > to increase working

time……..

• Material should be resorbable, nonirritant and radioopaque.

• Why GP not used? – Not degraded

• Abutment for space maintainer

• Bruxism

• Caries involving 3 or more surfaces

• Developmental defects like Dentinogenesis imperfecta and enamel hypoplasia

• Extensive caries in class 2 involving cusps

• Following pulp therapy to avoid fracture of weekend tooth

• Handicapped children

• Stain less steel crowns

• Nickel based crowns (ni-chromium 3M)

• The process of inducing the development of root and apex closure in an immature permanent tooth with open apex.

• Calcific Root-End closure.

• Types:

1. Multiple Step(CaOH)

2. Single Step (MTA)

• Physiological process

• Formation of apex in vital young permanent tooth with appropriate vital pulp therapy

• MAINTAIN PULP VITALITY

• Includes :

1- Direct pulp capping

2- Indirect pulp capping

3- Pulpotomy/Partial Pulpotomy

• Since gallium amalgam expands after trituration, it provides better marginal seal than silver amalgam….

• Setting time is less than silver mercury amalgam, therefore can be finished and polished after one hour..

• Most of the physical and mechanical properties of gallium alloy are similar to high copper mercury amalgam.

So better marginal seal, less setting time and same mechanical properties………

• A ferrule, is defined as a circumferential area of axial dentin superior to preparation bevel should have a height of 1.5mm to 2.5mm

• Vertical → Extraction

• Horizontal:

• Coronal 3rd Immobilization + Splinting

(4weeks)

• Middle 3rd RCT of coronal segment +/-

removal of apical segment

• Apical 3rd Reposition Radiograph

Splint (4-6weeks)

• Leave the tooth in place• Clean with saline and chlorohexidiene • Suture the lacerated gingiva• Determine position of the tooth both clinically and

radiographically.• Apply a flexible splint for 2 weeks• Antibiotics adminstration for 7 days • Initiate root canal in transplanted tooth after 10 days with

closed apex• Open apex in growing children can be waited for pulp

revasculrization and in adult cases open apex closed with MTA

• Apply local anesthesia

• Rinse the area with saline or chlorohexidine

• Reposition the tooth using digital pressure or forcep.

• Reposition the displaced bone both facially and lingually

• Suture the gingiva if lacerated

• Splint with wire or acrylic for 4 months.

• BV Rupture → Blood into Dentin → Breakdown of blood (Hemin, Hematin, Hemosiderin) → Pinkish brown discoloration

• Concentration: 5% NaF• When to apply?

• Radiographic Apex : Apex of tooth determined radiographically

• Anatomic Apex: apex of tooth determinedmorphologically. At the CDJ.

• Difference can be 1.5 – 3 mm because ofcementum deposition with age.

• From a Coronal refrence point to the point where cleaning and shaping or obturation ends

• Refrence point:– Anteriors → Incisal Edge

– Anteriors with broken edges → Smoothen the edge

– Posteriors → Cusp Tip

Pulp sensibility Test

MOA:

Ionic shift in the dentinal tubules Local depolariztion in

Delta A fibers

Tells if the tooth is Vital or Non-Vital

• False Positive

➢ Gangrenous necrotic pulp

➢ Partially necortic pulp in multi-rooted

• False Negative➢ Recent Trauma

➢ Extensive pulpal calcification

➢ Fibrotic pulp

➢ Extensive restorations with base

➢ Pt on sedatives

1. Zinc phosphate

2. GIC

3. RMGIC

4. Dual cured resin cement

5. Light cured composite cement

6. Polycarboxylate

7. Conventional cement

Based on Shape (Parallel, Tapered, Parallel and

Tapered)

Based on surface characteristic ( Active, Passive)Based on Method of fabrication:

• Custom

• PreFabricated (Metal, Zirconia, Fiber-post)

Which one causes most internal stresses..+ Fracture :

Metal, Active, Tapered

Tooth has incompletely cracked but no part of

the tooth has yet broken off.

Diagnosed with:

Bite Test

Biting on Tooth Sloth

(Pain on releasing of biting force)

Pain on biting Symptomatic apical periodontitis

Conventional tooth prep: • Specific walls, floor, angulation.

• Amalgum

Modified: • Does not require specific wall forms, angulation, Walls and floor

• Composite

Shape and form of cavity is such that it prevents the

displacement or removal of restoration by tipping and

lifting forces

Occlusal covergence

Adhesive systems

Beveling/flaring cavity margin for composite

“Shape and placement of preparation walls and cavity is

such that it enables to tooth structure AND THE

RESTORATION to withstand the forces of mastication

without getting fractured” Box like cavity

Flat floor

Rounded line angles

Adequate thickness of material

Preservation of cusps and marginal ridges

Reduction of cusp for capping

• Macrofill (filler size upto 8um)

• Microfill (0.01-0.04 micrometer)

• Nanofill 0.007um

• Hybrid type (0.4-1um)

• Flowable (having lower filler content and hight matrix)………….

Resin : BISGMA/UDMA

Filler: Silica

Coupling agent: Silane

Initiator : Camphorquinone

Powder: Flouroaluminosilicate

Liquid : Polyacrylic acid

• Silver

• Tin

• Mercury

• +/- Copper

• Zinc - Setting Expansion

• Pallidium etc

PrimaryOcclusal Convergence

SecondaryPins

Slots

Retention Grooves (0.5mm into the dentin,

axiolingual and axiobuccal walls)

Coves

Amalgum Bond

Hydrodyanamic Theory

Stimulus (Hot/Cold/Sweet) → Movement of fluid in dentinal

tubules → stimulation of Delta A fibers → PAIN

PRECIEVED!!

Sharp pain → Delta A fibers (Fast Conducting/Myelinated)

Dull, Continuous Pain → C - fibers

Treatment: RCT + Follow up

Sinus Tract will heal on its own

1.Bisecting Angle - Used in Endoa.Xray beam is at right angle to long axis of tooth

2.Parallexa.For curved roots in upper anteriors

b.Not recomended for Endo though

c.Superimposition of zygomatic process

• Right angle to the dentin surface

• Vertical in the cuspal region

• Deciduous Horizontal cervically

• Permenant Oblique cervically