2. DH220 Dental Materials Lecture #2 Prof. Lamanna RDH, MS

3. Restorative Dentistry Intermediary Materials: Dental Cements, Temporary Restorations & Periodontal Dressing

4. The tooth is prepared and an intermediary material is placed. What is the purpose of placing intermediary materials? Answer Answer Where are intermediary materials placed? Answer Next AnswerNext A. Which of Black’s Classification is this caries? B. Which of Black’s Classification are these preparations? 12 3 Answer

5. A.Class II - posterior interproximal surface(s) Return

6. B. 1. Class II - posterior interproximal surface(s) 2. Class I - pits & fissures 3. Class I - pits & fissures This is a buccal pit – not Cl V at cervical third. Return

7. Purpose: - pulpal protection = insulating and/or sedative - minimize the occurrence of secondary caries - minimize post-operative sensitivity Return

8. Intermediary materials are placed between the tooth and restorative material. Example 1- #30 base Example 2 - #30 luting agent Return

9. Varnish 1.Composition: resin = natural or synthetic 2. Use: seal dentinal tubules, prevent chemical irritation to the pulp, and migration of metallic ions. 3. Application: 2 thin coats 4. Location: floor & walls in prep. 5. Special characteristics: - Rapid evaporation due to solvent; during use the cap must be replaced immediately. - Easily abraded, negating functional purpose. - Should not be used with composite or resin restoration; inhibits proper curing.

10. Liner 1.Composition: Ca(OH) 2 *, ZOE, GI 2.Use: prevent bacterial invasion; chemical irritation; pulp cap - *Ca(OH) 2 only. 3.Application: thin layer 4.Floor of prep, dentin only

11. 5. Special characteristics: Ca(OH) 2 – 1. bacteriostatic – inhibits bacterial spread 2. ↑ pH (11) – stimulus for 2° dentinal formation 3. ↑ solubility – used only in the deepest portion of the cavity prep. – closest to the pulpal horn 4. compatible with ALL restorative materials Glass Ionomer – 1. releases fluoride for therapeutic advantage (anticariogenic effect) 2. direct (chemical) adhesion to enamel, dentin, and cementum. 3. radiopaque ZOE – 1. non-irritating to pulp – eugenol has a soothing (obtundent) effect on the pulp. 2. not utilized as a direct pulp cap – eugenol in a high concentration can be toxic to the pulp. 3. not used under composite restor. – interferes with polymerization.

12. Base 1.Composition: ZOE, GI, ZOP, Zinc Polycarboxylate 2.Use: thermal/elect. insulator, replacement for missing dentin, mechanical support for restoration 3.Application: Thick layer 4.Location: floor of prep, dentin only. base

13. 5.Special characteristics: ZOP - 1. Acidic cement – chemical irritant to the pulp – used in conjunction with calcium hydroxide liner in deep cavities (< 1mm dentin remaining) 2. very specific mixing technique: mixed by increments (cut into several sections of powder) allows for exothermic reaction (release of heat) Zinc Polycarboxylate – 1. direct (chemical) adhesion to enamel, dentin, and cementum. 2. polyacrylic acid – not as irritating to the pulp as phosphoric acid 3. not as strong as ZOP

14. Varnish, Liner, & Base Application varnish base liner *if pulpal exposure – Ca(OH) 2 only as pulp cap *

15. Cement 1.Composition: ZOE, GI, ZOP, Zinc Polycarboxylate, and Resin cement 2.Use: luting agent 3. Application: runny, loose 4. Location: inside crown, bridge, etc. 5. Special Characteristics: Resin cement: 1. material of choice for luting. 2. requires use of etching agent. 3. mechanical retention to enamel by acid-etch technique p. 94

16. Maryland Bridge 1.Facial view of bridge 2.Lingual view – luted with resin cement 1 2 pontic 1

17. Weakest point of a crown is the margin. Always carefully evaluate the margin for washout when dental charting your patients. Marginal washout

18. Identify the following intermediary materials: liner, base, or luting agent. 1 2 Answer 3

19. 1.Base 2.Luting agent 3.Calcium hydroxide liner on deep dentinal areas. Return

20. Composition: ZOE, ZOP, Zinc Polycarboxylate, GI, and Resin Cement ** Review the typed handout for the composition of these five materials**

21. Differences between these materials?????? 1. Consistency of the mixture – ex: thin, thick 2. Intended use by the clinician – ex: liner, base 3. Powder particle size – ex: small, large

22. Temporary & Interim Restorations I. Temporary Restorations – A. Use: - provisional for short term – days, weeks. - pulpal healing for determination of treatment (ie: endo.) - fabrication of lab work. B. Material: - ZOE – obtundent effect ** not used if composite is placed!!! - GI, ZOP, etc.WHY?? Answer

23. Answer: Eugenol prohibits the polymerization (curing) of composite restorative material. Return

24. II. Interim Restorations – A. Use: - provisional for long term – months, up to a year. B. Material: - preformed crowns – stainless steel or aluminum - crowns & bridges – acrylic (polymer)

25. Periodontal dressing 1.Use: patient comfort from possible injury after surgery, undisturbed healing, reduce possibility of 2º bleeding & infection, and acts as a splint. 2.Composition: zinc oxide & non-eugenol paste - most commonly used material. 3.Handling: Lab 4.Placement: Lab 5.Ingredients: any item listed cause concern?? (p. 7 in typed handout)

26. 1. Before surgery 4. After surgery 2. 3. Placement and removal of dressing

27. Mixing Technique Reference Dental Materials Lab

28. ZOP Glass ionomer -pull test for luting consistency ZOP – mixed for a base consistency Mixing & handling guidelines – see separate handout in your Lab workbook p. 53 - 56. Just a few -

29. ** Review the handout for special characteristics of each material in Lab workbook (p. 53 + 54). It’s show time ……mixing dental cements. Visit www.edpuzzle.com to view 8 very short videos on the mixing technique of intermediary materials, pulp cap and periodontal dressing.www.edpuzzle.com Mixing Glass Ionomer Mixing ZOP