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Copyright © 2005 by Elsevier Inc. All rights reserved. Dental Cements Chapter 45.

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Presentation on theme: "Copyright © 2005 by Elsevier Inc. All rights reserved. Dental Cements Chapter 45."— Presentation transcript:

1 Copyright © 2005 by Elsevier Inc. All rights reserved. Dental Cements Chapter 45

2 Copyright © 2005 by Elsevier Inc. All rights reserved. Introduction Dental cements are a classification of dental materials that are routinely used when working with indirect restorations.

3 Copyright © 2005 by Elsevier Inc. All rights reserved. Classification of Cements Type I –Luting agents which include permanent and temporary cements Type II –Restorative materials such as glass ionomers Type III –Liner or bases placed with the cavity preparation

4 Copyright © 2005 by Elsevier Inc. All rights reserved. Luting Agent Type I dental cements that act as an adhesive to hold together the casting to the tooth structure –Luting agents are designed to be either permanent or temporary.

5 Copyright © 2005 by Elsevier Inc. All rights reserved. Fig Casting ready to be cemented

6 Copyright © 2005 by Elsevier Inc. All rights reserved. Permanent Cement For the long ‑ term cementation of gold and ceramic restorations such as inlays/onlays, crowns, bridges, veneers, and orthodontic fixed appliances.

7 Copyright © 2005 by Elsevier Inc. All rights reserved. Temporary Cement Temporary cements are used if the restoration would have to be removed due to sensitivity or other symptoms, and for the temporary cementation of provisional coverage.

8 Copyright © 2005 by Elsevier Inc. All rights reserved. Variables Affecting Cements Mixing Time Before mixing, follow the manufacturer's directions Measure the powder and liquid according to the intended use Separate powder and the liquid to allow space for mixing Divide the powder into increments. When increment sizes vary, the smaller increments are incorporated first Incorporate each powder increment into the liquid and then mix thoroughly

9 Copyright © 2005 by Elsevier Inc. All rights reserved. Variables Affecting Cements-cont’d Humidity –If warm or humid, premature exposure to these environments can create a loss of water from the liquid or addition of moisture to the powder. Powder to Liquid Ratio –Incorporating too much or too little powder will alter the consistency. Temperature –Some cements will have an exothermic reaction.

10 Copyright © 2005 by Elsevier Inc. All rights reserved. Types of Cements Zinc-Oxide Eugenol Zinc Phosphate Polycarboxylate Glass Ionomer Composite Resin

11 Copyright © 2005 by Elsevier Inc. All rights reserved. Zinc Oxide Eugenol Chemical Makeup –Liquid: Eugenol, H 2 O, acetic acid, zinc acetate, and calcium chloride. –Powder: Zinc oxide, magnesium oxide, and silica.

12 Copyright © 2005 by Elsevier Inc. All rights reserved. Types of Zinc-Oxide Eugenol Type I –Lacks strength and long ‑ term durability and is used for temporary cementation of provisional coverage Type II –Has reinforcing agents added for the permanent cementation of cast restorations or appliances

13 Copyright © 2005 by Elsevier Inc. All rights reserved. Fig Type I ZOE cement

14 Copyright © 2005 by Elsevier Inc. All rights reserved. Fig Type II ZOE cement

15 Copyright © 2005 by Elsevier Inc. All rights reserved. Supply of Zinc-Oxide Eugenol Type I (Paste) –Supplied as a two ‑ paste system as temporary cement. –Pastes are dispensed in equal lengths on a paper pad and mixed. Type II (Liquid/Powder) –Mixed on an oil ‑ resistant paper pad. –Mixing time ranges from 30 to 60 seconds. –Setting time in the mouth ranges from 3 to 5 minutes.

16 Copyright © 2005 by Elsevier Inc. All rights reserved. Zinc Phosphate Chemical Makeup –Liquid: Phosphoric acid, aluminum phosphate, and water –Powder: Zinc oxide, magnesium oxide, and silica

17 Copyright © 2005 by Elsevier Inc. All rights reserved. Types of Zinc Phosphate Type I (fine grain) –Used for the permanent cementation of cast restorations such as crowns, inlays, onlays, and bridges. This material creates the very thin film layer necessary for accurate seating of castings. Type II (medium grain) –Recommended for use as an insulating base for deep cavity preparations.

18 Copyright © 2005 by Elsevier Inc. All rights reserved. Supply of Zinc Phosphate Type I (Powder/Liquid) 1.Powder is divided into increments varying in size. 2.It is critical that the powder be added to the liquid in very small increments. 3.Cement must be spatulated slowly over a wide area of a cool, dry, thick glass slab to dissipate the heat.

19 Copyright © 2005 by Elsevier Inc. All rights reserved. Fig Zinc phosphate cement

20 Copyright © 2005 by Elsevier Inc. All rights reserved. Polycarboxylate Cements Chemical Makeup –Liquid: Polyacrylic acid, itaconic acid, maleic acid, tartaric acid, and water –Powder: Zinc oxide

21 Copyright © 2005 by Elsevier Inc. All rights reserved. Use of Polycarboxylate Permanent cement for cast restorations, stainless steel crowns, and orthodontic bands As a nonirritating base under both composite or amalgam restorations As an intermediate restoration

22 Copyright © 2005 by Elsevier Inc. All rights reserved. Supply of Polycarboxylate Powder/Liquid –Liquid may be measured by using either the plastic squeeze bottle or the calibrated syringe ‑ type liquid dispenser. –Liquid has a limited shelf life because it thickens as its water evaporates. –Mixed on a nonabsorbent paper pad.

23 Copyright © 2005 by Elsevier Inc. All rights reserved. Fig Polycarboxylate cement

24 Copyright © 2005 by Elsevier Inc. All rights reserved. Glass Ionomer Chemical Makeup –Liquid: Itaconic acid, tartaric acid, maleic acid, and water –Powder: Zinc oxide, aluminum oxide, and calcium

25 Copyright © 2005 by Elsevier Inc. All rights reserved. Types of Glass Ionomer Type I –For the cementation of metal restorations and direct ‑ bonded orthodontic brackets Type II –Designed for restoring areas of erosion near the gingiva Type III –Used as liners and dentin bonding agents

26 Copyright © 2005 by Elsevier Inc. All rights reserved. Benefits of Glass Ionomer Powder is an acid ‑ soluble calcium. The slow release of fluoride from this powder aids in inhibiting recurrent decay. Causes less trauma or shock to the pulp than many other types of cements. Low solubility in the mouth. Adheres to a slightly moist tooth surface. Has a very thin film thickness, which is excellent for seating ease.

27 Copyright © 2005 by Elsevier Inc. All rights reserved. Supply of Glass Ionomer Type I (Powder/liquid) –Mixed manually on a paper pad or a cool, dry glass slab. –Glass slab increases the working time of the cement. Type I (Premeasured capsules) –Triturated and expressed through a dispenser.

28 Copyright © 2005 by Elsevier Inc. All rights reserved. Fig Premeasured capsules of glass ionomer cement

29 Copyright © 2005 by Elsevier Inc. All rights reserved. Composite Resin Chemical Makeup –Physical properties comparable to composite resins –Low film thickness (thinner in consistency compared to composite resins) –Insoluble in the mouth

30 Copyright © 2005 by Elsevier Inc. All rights reserved. Uses of Composite Resin Cementation of ceramic or resin inlays and onlays Cementation of ceramic veneers Cementation of orthodontic bands Direct bonding of orthodontic brackets Cementation of all metal castings

31 Copyright © 2005 by Elsevier Inc. All rights reserved. Supply of Composite Resin Powder and liquid mix Syringe-type applicator Base and catalyst Light cure/dual cure system –Recommended portions of either application are dispensed onto a paper pad and mixed rapidly with a spatula

32 Copyright © 2005 by Elsevier Inc. All rights reserved. Fig Examples of composite resin

33 Copyright © 2005 by Elsevier Inc. All rights reserved. Cement Removal Operator Preparedness and Knowledge –Instruments selected for the procedure: Explorer, mouth mirror, excavator –Use a fulcrum. –Use dental floss in and around the embrasure areas.

34 Copyright © 2005 by Elsevier Inc. All rights reserved. Fig Excess cement to be removed


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