2CEMENTS IN THIS UNIT Varnish and Liners ( Copalite, Ca OH) Zinc Oxide Eugenol ( ZOE) & IRMZinc PhosphatePolycarboxylateGlass IonomerComposite
3Cement in GeneralMost dental cements are purchased from a dental supply company in the form of powder and liquid or two tubes of paste which are mixed together to form a paste or fluid which hardens in a short period of time. Some cements come in a capsule and are mixed on an amalgamator. The consistency depends upon the intended use. Cements are used alone or in conjunction with other materials in about 50% of all dental restorations.GENERAL USES OF ALL DENTAL CEMENTS1. Capping2. Insulating bases3. Temporary restorations or temporary cementing.4. Permanent cementing (luting) of fixed restorations.Luting agents for orthodontic bands.6. Root canal fillings, surgical cements and periodontal dressings
4Important considerations 1. Cements do not (in most cases) actually adhere to tooth Cements dissolve and disintegrate in the mouth.3. Period of usefulness in oral cavity is likely to be limited.4. Cements are not considered truly permanent when used as arestorative material.5. Chemical and physical properties leave much to be desired.Manipulative techniques are especially important for good results. With some cements, improper mixing can harm the teeth. Poor mixing technique affect the strength of the finished product. Manufacturers change ingredients and instructions. Please read the manufacturer’s instructions each time a new package is opened.
5Dispensing cement rules FLUFF POWDERDispense P before LHold L bottle verticalMany offices mix on pads- area of high contamination?????Autoclave slabs ****
6Luting Crown permanent or provisional(temp) metal(gold) or porcelain
7VarnishA cavity varnish (Copalite) is a liquid used to seal dentinal tubules to protect the tooth from the chemical effects of some cements and restorative materials. It is applied with a microbrush or cotton pellot. DO NOT USE with Composite.
11Uses and Mixing of ZOE USES OF ZOE (not with composite) TEMPORARY / SEDATIVE RESTORATIONS – BALL 1:1Base – Ball 1:1TEMPORARY LUTING – CREAMY 1:2EQUIPMENT NEEDEDPAPER PADFLEX. SPATULAPOWDER AND LIQUID2X2ALCOHOLNORMAL MIXING TIME SEC.SETTING TIME 3-5 MIN. (MOISTURE ACCELERATES)
12Reinforced ZOE= IRM USE LONG TERM TEMP. RESTORATION (not with composite)CAN BE PURCHASED IN P/L FORM or CAPSULEFORM THAT NEEDS TO BE TRITURATED.
13Mixing IRM EQUIPMENT NEEDED PAPER PAD FLEX. SPATULA IRM MATERIAL- POWDER & LIQUID OR CAPSULETRITURATOR IF NEEDEDNEED TO USE A STROPPING MOTION TO MIX IRM.CONSISTENCY for temporary restoration NEEDS TO BE DRY AND ALMOST FLAKEY. (For luting, creamy)RECOMMENDED P/L RATIO IS 1:1 OR 6 TO 1 BY WEIGHT.MIXING TIME IS 1 MINUTE, SET TIME IS ABOUT 5 MIN. AFTER START OF MIX.TO MIX ADD ½ OF POWDER TO LIQUID, THEN 2 SMALLER INCRIMENTS. Clean with alcohol.
14ZINC PHOSPHATE ALSO CALLED CROWN AND BRIDGE CEMENT USED FOR: LUTING Permanent RESTORATIONSINSULATING BASECEMENTING ORTHODONTIC APPLIANCES ( NOT AS POPULAR NOW )TEMPORARY RESTORATIONSLUTING - SHOULD BE LIKE ELMERS GLUE, FOLLOW SPATULA 1 INCH AND BREAK. 1 cap of powder to 6 drops liquidBASE - SHOULD BE THICK, PUTTY, TACKY. 1 cap of powder to 5 drops liquid.ACIDIC IRRITATING TO THE PULP EXOTHERMIC.
15ZPO4 MAIN INGREDIENTS POWDER- ZINC OXIDE LIQUID- ORTHOPHOSPHORIC ACID AND WATERTHE MOST CRITICAL INGREDIENT OF THE LIQUID IS WATERIF WATER CONTENT IS ALTERED IN THE LIQUID IT CHANGES SETTING TIME.WATER EVAPORATES – LIQUID WILL BE CLOUDY OR HAVE CRY-STALS IN IT. IT WILL TAKE LONGER TO SET, INCREASE THE SET-TING TIMEMOISTURE INCORPORATED EITHER FROM GLASS SLAB BEINGTOO COLD OR MOISTURE FROM THE AIR. IT WILL SET FASTERTHUS DECREASed set time
16MIXING IF POWDER IS INCORPORATED TOO FAST CEMENT WILL SET TOO FAST!! WON’T GET AS MUCH POWDER, MAKES A WEAKER, MORE SOLUBLE CEMENT.MORE ACIDIC – POSSIBLY HARMING THE PULP.CAN CAUSE DISCOMFORT FOR THE PATIENT.ZINC PHOSPHATE MATERIAL IS EXOTHERMIC!!!!!!! NEEDS TO BE MIXED OVER A LARGE AREA.IDEAL MIXING TIME IS 1 ½ MIN. - SETS IN 5-9 MIN.CLEAN UP WITH WATER
17Control Set TimesTHE BEST WAY TO CONTROL THE SET IS TO HAVE THE GLASS SLAB AT 68 DEGREES, INCORPORATE THE POWDER SLOWLY OVER A LARGE AREA OF THE SLAB, AND ADD IN SMALL AMOUNTS.IF SETTING TIME IS INCREASED- MATERIAL IS SLOWER TO SET, takes longerIF SETTING TIME IS DECREASED- MATERIAL SETS FASTER, accelerated
19Polycarboxylate Cement Brand name- DURELONUse- Perm LutingADV- ease of mixadheres(enamelst.steel)less acidicLiquid is viscous- syringe not dropper
20MIXING Luting- 1:1 Mix in 30 sec Consistency- glossy Working time 1 ¾ min set 3-4 minClean up ASAP with waterP-zinc oxideL- polyacrylic acid
21Glass IonomerWe have already discussed GI liner. In DMII we will discuss GI as a Perm restoration or core build up. Here, we will discuss GI cement, used for Perm Luting, or as a base.Forms- P&L, capsules, 1 pasteAdv- high strength, low solubility, F,adheres to moist area, bonds to toothIrritating to tissue