8/4/2019 Varnish Liners and Bases

http://slidepdf.com/reader/full/varnish-liners-and-bases 1/12

VARNISH, LINERS, and BASES

Stephen C. Bayne  

DENT112Conservative Operative DentistrySchool of DentistryUniversity of North Carolina

Roberson TM. Sturdevant's Art and Science of Operative Dentistry ,

4:170-177.

http:// www.dent.unc.edu/ portfolios/ bayne/ dental-materials/

2006, Bayne and Thompson

8/4/2019 Varnish Liners and Bases

http://slidepdf.com/reader/full/varnish-liners-and-bases 2/12

OVERVIEWOF PULPAL PROTECTION

1. CHEMICAL Protection 2. PULPAL Medication 3. THERMAL / ELECT Protection 4. MECHANICAL Protection 

PROBLEM = No perfect replacement for missing enamel and dentin.

1. SOLUTION LINER = thin film (varnish, bonding system, dentin sealer) 2. Suspension Liner (20-25 mm) 3. CEMENT LINER = medium thickness (100-500 mm)

4. CEMENT BASE = thick (500-1000 mm)

NORMAL

RESTORED

8/4/2019 Varnish Liners and Bases

http://slidepdf.com/reader/full/varnish-liners-and-bases 3/12

PULPALPROBLEMS:

 Fluid Flow Microleakage

FLUID FLOW = J = (P) (r4) / (8) (h) (l)

Occlusion of

tubules

8/4/2019 Varnish Liners and Bases

http://slidepdf.com/reader/full/varnish-liners-and-bases 4/12

CHEMICAL PROTECTION

DEFINITIONS:Varnish = thin film solution liner (hydrophobic)Suspension liner = thin film aqueous liner (hydrophilic)Bonding system = thin film solution liner (hydrophilic)Dentin sealer = thin film solution liner (hydrophilic)

COPALITE = 90% solvent + 10% copal resin

• Hydrophobic and does not wet dentin well.• Requires 2 applications for 85% coverage.• Thin coats work best.

Copalite

Smear Layer on Dentin

8/4/2019 Varnish Liners and Bases

http://slidepdf.com/reader/full/varnish-liners-and-bases 5/12

DENTINFUNCTIONS:

Chemical Protection Thermal / Electrical Protection Biological Protection (Medication) Mechanical Protection

PULPALPROBLEMS:

 Fluid Flow Microleakage

PULPAL MEDICATION(Biological Protection)

RDT

1º Dentin2º Dentin

3º Dentin

8/4/2019 Varnish Liners and Bases

http://slidepdf.com/reader/full/varnish-liners-and-bases 6/12

DENTINFUNCTIONS:

Chemical Protection Thermal / Electrical Protection Biological Protection (Medication) Mechanical Protection

PULPALPROBLEMS:

 Fluid Flow Microleakage

PULPAL MEDICATION(Biological Protection with Eugenol or Calcium Hydroxide)

and ZnO ( Zn++)

• pH = 11.0• Low strength• Ca ion + salicylate 

Ca(OH)2 StimulatingEugenol

Palliative

8/4/2019 Varnish Liners and Bases

http://slidepdf.com/reader/full/varnish-liners-and-bases 7/12

THERMAL PROTECTION

Intraoral HEAT FLOW:Normal thermal transient = 30-60s at 5-60°CHEAT paths = through restoration or via microleakagePulpal temperature = f ( TIME, TEMP, THICKNESS )

T0

Amalgam Dentin PulpT3

T2

T1

T0

+T

+Q

-Q

 

T3

Amalgam Dentin Pulp

T3

T2

T1

T0

+t+Q

Throughrestoration:

Thermal Conductivity Thermal Diffusivity 

Amalgam

Tooth

Aroundrestoration:

Thermal Expansion 

RDT

8/4/2019 Varnish Liners and Bases

http://slidepdf.com/reader/full/varnish-liners-and-bases 8/12

MECHANICAL PROTECTION

PROTECTION = 1-2 mm (1000-2000 mm)

> Chemical Protection (Sealed tubules)> Biological Protection (Pulpal Medication)> Thermal / Electrical Protection (1-2 mm)> Mechanical Protection (BASE = 1-2 mm)

RMGI 

Polycarboxylate 

Zinc Phosphate 

8/4/2019 Varnish Liners and Bases

http://slidepdf.com/reader/full/varnish-liners-and-bases 9/12

BASES

8/4/2019 Varnish Liners and Bases

http://slidepdf.com/reader/full/varnish-liners-and-bases 10/12

COMMERCIAL EXAMPLESof Varnishes, Liners, and Bases

8/4/2019 Varnish Liners and Bases

http://slidepdf.com/reader/full/varnish-liners-and-bases 11/12

PROCEDURE SUMMARYfor Medicament, Liner/Base, Varnish/Sealer/DBS

RDT =

8/4/2019 Varnish Liners and Bases

http://slidepdf.com/reader/full/varnish-liners-and-bases 12/12