Presentation on theme: "DENT 1200 Materials I CEMENTS CEMENTS IN THIS UNIT Varnish and Liners ( Copalite, Ca OH) Zinc Oxide Eugenol ( ZOE) & IRM Zinc Phosphate Polycarboxylate."— Presentation transcript:
DENT 1200 Materials I CEMENTS
CEMENTS IN THIS UNIT Varnish and Liners ( Copalite, Ca OH) Zinc Oxide Eugenol ( ZOE) & IRM Zinc Phosphate Polycarboxylate Glass Ionomer Composite
Cement in General Most 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 CEMENTS 1.Capping 2.Insulating bases 3.Temporary restorations or temporary cementing. 4.Permanent cementing (luting) of fixed restorations. 5. Luting agents for orthodontic bands. 6.Root canal fillings, surgical cements and periodontal dressings
Important considerations 1.Cements do not (in most cases) actually adhere to tooth 2.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 a restorative 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.
Dispensing cement rules FLUFF POWDER Dispense P before L Hold L bottle vertical Many offices mix on pads- area of high contamination????? Autoclave slabs ****
Luting Crown permanent or provisional(temp) metal(gold) or porcelain
Varnish A 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.
Zinc Oxide Eugenol ZOE IS THE LEAST IRRITATING OF THE DENTAL CEMENTS SOOTHING BASIC INGREDIENTS POWDER- ZINC OXIDE, FILLERS LIQUID- EUGENOL, OIL OF CLOVES
FORMS P/L2 PASTE
Uses and Mixing of ZOE USES OF ZOE (not with composite) TEMPORARY / SEDATIVE RESTORATIONS – BALL 1:1 Base – Ball 1:1 TEMPORARY LUTING – CREAMY 1:2 EQUIPMENT NEEDED PAPER PAD FLEX. SPATULA POWDER AND LIQUID 2X2 ALCOHOL NORMAL MIXING TIME SEC. SETTING TIME 3-5 MIN. (MOISTURE ACCELERATES)
Reinforced ZOE= IRM USE LONG TERM TEMP. RESTORATION (not with composite) CAN BE PURCHASED IN P/L FORM or CAPSULE FORM THAT NEEDS TO BE TRITURATED.
Mixing IRM EQUIPMENT NEEDED PAPER PAD FLEX. SPATULA IRM MATERIAL- POWDER & LIQUID OR CAPSULE TRITURATOR IF NEEDED NEED 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.
ZINC PHOSPHATE ALSO CALLED CROWN AND BRIDGE CEMENT USED FOR: LUTING Permanent RESTORATIONS INSULATING BASE CEMENTING ORTHODONTIC APPLIANCES ( NOT AS POPULAR NOW ) TEMPORARY RESTORATIONS LUTING - SHOULD BE LIKE ELMERS GLUE, FOLLOW SPATULA 1 INCH AND BREAK. 1 cap of powder to 6 drops liquid BASE - SHOULD BE THICK, PUTTY, TACKY. 1 cap of powder to 5 drops liquid. ACIDIC IRRITATING TO THE PULP EXOTHERMIC.
ZPO4 MAIN INGREDIENTS POWDER- ZINC OXIDE LIQUID- ORTHOPHOSPHORIC ACID AND WATER THE MOST CRITICAL INGREDIENT OF THE LIQUID IS WATER IF 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 TIME MOISTURE INCORPORATED EITHER FROM GLASS SLAB BEING TOO COLD OR MOISTURE FROM THE AIR. IT WILL SET FASTER THUS DECREASed set time
MIXING 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
Control Set Times THE 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 longer IF SETTING TIME IS DECREASED- MATERIAL SETS FASTER, accelerated
ZPO4 P&LMix on slab, divide P
Polycarboxylate Cement Brand name- DURELON Use- Perm Luting ADV- ease of mix adheres(enamel st.steel) less acidic Liquid is viscous- syringe not dropper
MIXING Luting- 1:1 Mix in 30 sec Consistency- glossy Working time 1 ¾ min set 3-4 min Clean up ASAP with water P-zinc oxide L- polyacrylic acid
Glass Ionomer We 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 paste Adv- high strength, low solubility, F, adheres to moist area, bonds to tooth Irritating to tissue
Capsules, Paste, P&L
Comp of Cements Varnish- copal Liner- calcium hydroxide or GI ZOE zinc oxide eugenol ZPO4 zinc oxide orthophosphoricA Carbox zinc oxide polyacrylic Acid GI FAlosilicate glass polyacrylic Acid