647514154-CEMENTATION protocolIN-FPD.pptx

Cementation protocol

1. CEMENTATION IN FPD 7/9/2025 1

2. INTRODUCTION How do we keep our restorations stuck to the teeth for as long as possible? How do we choose materials that last for many years without sensitivity, leakage, fracture or failure? 7/9/2025 2

3. LUTING AGENTS Ensure the stability of fixed prostheses throughout their serviceable lifespan. Luting Agents Interim Luting Agents Definitive Luting Agents Water Based Polymer Based 7/9/2025 3

4. General Requirements Long working time Adheres well to both tooth structure and restorative materials Marginal seal Biocompatibility Mechanical properties Low film thickness Low viscosity and solubility Ease of use Radiopacity Esthetics 7/9/2025 4

5. Commonly Used Luting Agents Zinc phosphate cement Zinc polycarboxylate cement Glass Ionomer cement Zinc oxide eugenol with and without ethoxybenzoic acid Resin-modified glass ionomer luting agents Resin luting agents 7/9/2025 5

6. Advantages DV, Sita Ramaraju , et al. "A Review of Conventional and Contemporary Luting Agents Used in Dentistry."  American Journal of Materials Science and Engineering  2.3 (2014): 28-35 7/9/2025 6

7. Disadvantages DV, Sita Ramaraju , et al. "A Review of Conventional and Contemporary Luting Agents Used in Dentistry."  American Journal of Materials Science and Engineering  2.3 (2014): 28-35 7/9/2025 7

8. Indications/Contra-indications DV, Sita Ramaraju , et al. "A Review of Conventional and Contemporary Luting Agents Used in Dentistry."  American Journal of Materials Science and Engineering  2.3 (2014): 28-35 7/9/2025 8

9. STEPS IN CEMENTATION Type of restoration – metal or ceramic Resistance and retentive form of the prepared tooth History of patient’s experience 1. SELECTION OF LUTING AGENT 7/9/2025 9

10. Metal alloys can be classified into non-precious (for example, nickel chromium and cobalt chromium) and precious (for example, type IV gold and palladium rich). 2. SURFACE TREATMENT METAL ALLOYS 7/9/2025 10

11. NON PRECIOUS ALLOYS Readily form an oxide surface layer that chemically bonds to the phosphate ester groups of MDP. Predictable adhesive bonding can be achieved APA (air particle abrasion) is used to roughen the metal surface and promote micromechanical retention of the resin cement. ultrasonic bath cleaning to remove loosely retained alumina particles that could reduce resin bond strength to the alloy PRECIOUS ALLOYS Do not provide a convenient oxide layer compatible with MDP bonding. The following methods have been tested and shown to produce a clinically acceptable bond strength to resin: Heat treating the metal in the laboratory (to force a copper oxide layer to form) followed by MDP. Tribochemical coating followed by silane coupling agent . APA followed by a primer containing specific sulphate monomers that chemically adhere to the precious metal surface 7/9/2025 11

12. CERAMICS ACID SENSITIVE CERAMICS ACID RESISTANT CERAMICS Glass infiltrated ceramics (In- Ceram Spinell , Alumina and Zirconia systems), densely sintered aluminized ceramics ( Procera AllCeram ), and ceramics based on zirconia partially stabilized by yttrium oxide. Feldspathic ceramics, leucite enhanced feldspathic ceramics (IPS Empress), and lithium disilicate (IPS Empress II) ceramics . 7/9/2025 12

13. The chemical process of conditioning with hydrofluoric acid causes a reaction with the glassy phase of leucite -reinforced ceramics, resulting in hexafluorsilicate . These silicates are removed by the jet of water forming a honeycomb surface that is ideal for the cement micromechanical retention. This is the surface treatment of choice for ceramics with feldspar or vitreous silica in a 2.5-10 percent of hydrofluoric acid for 20 seconds to 3 minutes , and subsequent application of silane . GLASS CERAMICS 7/9/2025 13

14. Lithium or feldspathic disilicate ceramics are frequently used with 10% hydrofluoric acid and silane application. The 10% hydrofluoric acid conditioning is designed for two minutes. However, it may vary according to the composition of the ceramic used. 7/9/2025 14

15. SILANIZATION As the silane will react with the hydroxyl group of the porcelain surface, it allows for the chemical adhesion by making it more reactive to the composite . STEPS: This bonding agent must be used in the ceramic with a disposable brush for one minute . Air-dried using a triple syringe for five seconds before applying the adhesive system. In order to stimulate the reaction between the silane coupling agent and the inorganic surfaces of the ceramic, the reaction can be catalyzed by heating the silane agent . 7/9/2025 15

16. Chemical Surface Treatments HYDROFLUORIC ACID ETCHING HF removes the glassy matrix of glass ceramics creating a high surface energy substrate with microporosities for the penetration and polymerization of resin composites, that is, enabling a micromechanical interlocking . Does not produce any change in arithmetic roughness (Ra) of ZrO2. 7/9/2025 16

17. 2. FUNCTIONAL MONOMERS 10-methacryloyloxyidecyl-dihyidrogenphosphate (MDP) BIS-GMA based resin cement 6-methacryloyloxyhexyl phosphonoacetate (6-MHPA) MEPS ( thiophosphoric methacrylate ) 6-[4-vinylbenzyln-propyl]amino-1,3,5-triazine-2,4-dithione (VBATDT) 6- methacryloyloxyhexyl-2-thiouracil-5-carboxylate (MTU-6) 4-methacryloxyethyl trimellitic anhydride (4-META) Since results are not always significant, the combination of primers and air-abrasion methods tend to produce better bond strength , especially in longterm . The surface treatment with primers containing functional monomers such as MDP (e.g., Alloy Primer and Clearfil Ceramic Primer, Kuraray Medical Inc., Japan) or other phosphoric acid acrylate monomer (e.g., Metal/ Zirconia Primer, Ivoclar-Vivadent ) are often recommended to improve the bonding to ZrO2. 7/9/2025 17

18. 3. SILANE COUPLING AGENTS Also called trialkoxy silanes Hybrid inorganic-organic bifunctional molecules that are able to create a siloxane network with the hydroxyl (OH) of the Si in the ceramic surface and copolymerize with the resin matrix of composites. Lower the surface tension of a substrate, wet it, and make its surface energy higher . 7/9/2025 18

19. Mechanical Surface Treatments AIR ABRASION WITH ALUMINIUM OXIDE PARTICLES When it comes to abrasion with Al2O3, a wide range of particle size, pressure, distance from ceramic surface, working time, and impact angle have been studied. On a yttrium stabilized tetragonal zirconia (Y-TZP) material, the use of greater particle size (from 50 𝜇m to 150 𝜇m) results in a rougher surface but no significant alteration in bond strength. 7/9/2025 19

20. Try-In Procedure for Crowns CHECKING THE CROWN ON THE DIE  Marginal fit, aesthetics and articulation can be anticipated prior to try in.  Always check the fit surface of the crown for defects and the die for damage, preferably with a good light and under magnification. 7/9/2025 20

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22. 2. SEATING THE CROWN Any temporary restoration is removed and the preparation is carefully cleaned of all residues of temporary cement , especially in retention grooves.  The crown should be tried in without forcing it onto its preparation; if it fails to seat there are a range of reasons why this may have happened. It pays to use a systematic approach to localise problems: First, ensure there is no retained temporary cement or trapped gingival tissue 2. Then check and adjust tight proximal contacts as these often prevent seating. Also check the original cast for damage to the stone in these contact areas. 7/9/2025 22

23. 3. Then re-check the crown for the most obvious laboratory errors , including casting blebs, damaged or chipped dies or grossly overextended margins. Casting blebs can be removed with a bur. Over-extended margins should be adjusted from the axial surface, not from underneath. To avoid the abrasive dragging metal over the margin, run the disc so that the abrasive travels in the direction of the occlusal surface, not towards the margin. 7/9/2025 23

24. 3. ASSESSMENT OF THE SEATED CROWN Proximal contacts The tightness of proximal contacts can be tested with dental floss and should offer some resistance but not make its passage too difficult. Assessment of marginal fit Poor fit can present as a gap or an overhanging margin (positive ledge) or deficient margin (negative ledge). Overextended margins and positive ledges may be corrected by adjusting the crown from its axial surface until it is possible to pass a probe from tooth to crown without it catching.  7/9/2025 24

25. Aesthetics Grinding with diamond burs can alter crown contours and porcelain additions can be made to metal ceramic crowns if necessary.  Shades that are slightly too light may be darkened by the addition of stain and re-firing while all ceramic crowns with no cores may have their shade modified slightly by the luting composite in the same way as veneers. Assessment of the occlusion  It is best to remove the seated crown and identify a pair of adjacent occluding teeth, termed index teeth , which, after re-seating, can be used to assess visually, and with shim stock, how much adjustment is needed. 7/9/2025 25

26. ISOLATION AND CEMENTATION The following equipment is needed • Mirror • Explorer • Dental floss • Cotton rolls • Prophylaxis cup • Flour of pumice • Cement • White stones • Cuttle disks • Local anesthetic (if needed) • Saliva evacuator • Forceps • Thick glass slab (chilled) • Cement spatula • Gauze squares • Adhesive foil • Plastic instrument 7/9/2025 26

27. Clean the preparation and crown with water spray Air dry but do not desiccate preparation Mix cement according to manufacturer's instructions Coat the fit surface with cement – do not overfill Only apply cement to preparation if cementing a post 7/9/2025 27

28. The crown should be seated quickly with firm finger pressure until all excess cement has been expressed from the margins. Depending on the angulation of the tooth, pressure may then continue to be exerted onto the crown by the dentist or by the patient biting onto a cotton roll. Pressure should be maintained for about one minute . Maintaining pressure beyond this time has no appreciable additional effect. Adequate moisture control should be maintained until the cement has set. 7/9/2025 28

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30. 7/9/2025 30 Youngblood A. A safe and convenient technique for the cementation of fixed partial dentures. JADA 2002; 133(10): 1381-1382.

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32. Post Cementation Instructions FIRST APPOINTMENT Crown preparation - Following the first appointment you will receive a temporary crown that is placed and cemented to the prepared tooth. Because temporary cement washes out rapidly , you may experience some sensitivity to cold and hot. Try to brush the area gently and when you floss , pull the floss out from the side rather than upward . The rapid upward motion may dislodge the temporary crown. If a temporary crown becomes loose or falls out, clean the temporary cement from the inside the crown, then apply vaseline inside the crown and place it back on the tooth. Immediately call and come back to the office to get the crown either re-cemented or re-fabricated. 7/9/2025 32

33. SECOND APPOINTMENT Final cementation- Please do not eat or drink for 30 minutes after your new crown is cemented. Do not eat hard or sticky foods for 24 hours while the cement completely sets. Your new crown may feel tight or as if it is pushing against the teeth next to it for several hours. This discomfort will go away within a day or two. Sensitivity , especially to hot and cold is common after a crown is cemented. This may be the results of chemical reaction between the final cement and the tooth. The sensitivity usually subsides within a week or ten days. Usually the deeper the cavity, the more sensitive the tooth will be. You should make an adjustment appointment if the sensitivity persists or increases. apexdentalnm.com/PDF/Crown%20And%20Bridge%20Instructions.pdf 7/9/2025 33

34. The finished restoration may be contoured slightly different and have a different texture than the original tooth. Your tongue usually magnifies this small difference, but you will become accustomed to this in a few days. Please follow prescribed oral hygiene instructions -45 degree angle brushing twice a day and flossing once a day to avoid getting a cavity or gum disease around your new crown. Flossing is especially important in preserving the health of your crown or bridge. 7/9/2025 34

35. SUMMARY 7/9/2025 35