Conservative circular preparation, minimum wall thickness 0.4 mm Minimum occlusal wall thickness: 0.5 mm, including a 0.1 mm reserve for occlusal adjustment Marginal region, minimum wall thickness 0.2 mm Zirconia ht Cercon ® ht and Cercon ® ht Shaded Zirconia Directions For Use
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Cercon ht and Cercon ht Shaded Zirconia Directions For Use · Cercon® ht Shaded Zirconia Directions For Use ... • Conical and telescope crowns • Crowns • Multi-unit bridges
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Conservative circular preparation, minimum wall
thickness 0.4 mm
Minimum occlusal wall thickness: 0.5 mm, including a 0.1 mm reserve for occlusal adjustment
PRODUCT DESCRIPTIONCercon® ht blanks are made of yttria-stabilized zirconia (Y-TZP). They are used infabricating frameworks for fixed prostheticrestorations. They are made of a ceramicoxide material characterized by particularlyhigh-strength.
Depending on the framework design,Cercon® ht frameworks can be veneeredwith ceramics or inserted as fullyanatomical restorations. Which blank isselected will depend on the tooth shade tobe reproduced and the space available forthe veneer.
With fully anatomic restorations, no space isrequired for the ceramic veneer, which mayallow the dentist to preserve more of thetooth structure.
Objects are individually fabricated to yourdigital design specifications such asanatomic contour, framework and wallthickness, connector diameter andcementing gap.
TECHNICAL SPECIFICATIONS:• Type II, class 6 (pursuant to DIN EN ISO
6872:2008)• CTE; 10.5 µm/m · K (25–500°C)• Modulus of elasticity: 210 GPa• Flexural strength: approx. 1,200 MPa
INDICATIONS IN THE ANTERIORAND POSTERIOR SEGMENTS:• Conical and telescope crowns• Crowns• Multi-unit bridges (up to 16 units, with no
more than two pontics between abutmentcrowns)*
• Bridges with cantilevered pontics, withmin. 2 abutment teeth
*For Canada: Restricted to 6 units or less
Cercon® ht can be used as a substructure(framework) which is then veneered with adental veneering ceramic or can be used forfull-contour application (without veneering)as well. In the case of Telescopic primarycrowns the substructure is not veneered.
CONTRAINDICATIONS• This medical product may not be used in
patient hypersensitivity to zirconia (Y-TZP)or one of the other ingredients
• Bruxism or recalcitrant parafunctionalhabits (for ceramically veneeredframeworks)
• Insufficient available space• Endodontic posts• Endosseous implants• Inlay bridges
WARNINGSKnown cross-reactions or interactions of thismedical product with other medicalproducts or material already present in theoral environment must be taken intoconsideration by the dentist in charge whenselecting this medical product.
PRECAUTIONS Please note: • Keep product dust away from eyes • Avoid any contact with mucosa • After use, wash your hands and apply a
hand cream • When using, do not eat or drink, do not
ingest, do not inhale dust particles • Use local suction and suitable
Processing the material will result in therelease of dust that may cause irritation ofthe eyes, skin or respiratory passages. Thesafety and warning notes listed heredescribe how to use our system componentsin a safe and risk-free manner. Notify thedentist in charge of all factors describedabove if you use this medical product for acustom design and make sure to complywith the Instructions for Use and thepertinent Safety Data Sheet (SDS).
ADVERSE REACTIONSWe are not aware of any risks or adversereactions related to Cercon® ht. If properlyprocessed, adverse reactions of this medicalproduct are highly unlikely. However,reactions of the immune system (such asallergies) or localized paraesthesia (such asan irritating taste or irritation of the oralmucosa) cannot be completely ruled out asa matter of principle. Should you hear or beinformed of any adverse effects – even whendoubtful – we would like to requestnotification.
SPECIAL NOTES ON FRAMEWORKDESIGN
Framework design for fully contouredrestorations:Indicated especially where limited occlusalspace is available, for frameworks that arenot to be veneered or for frameworks withbody stains. The surface of fully contouredframeworks can carefully be optimized withrotary tools such as fine cutters prior tosintering.
Make sure that the occlusal surface is notchanged by subsequent deepening offissures, as notching action maycompromise the strength of the material.Figure 3. Please note that flat occlusal reliefscan extend the life expectancy of fullycontoured restorations. When makingmanual adjustments, make sure never toseparate the interdental spaces of theframeworks with cutting discs or other rotaryinstruments, Doing so might damage theframework and compromise the strength ofthe material! Figure 4.
Important note:Please ensure that the minimum wallthickness of the framework in the area of theocclusal surface is respected even afterocclusal adjustments.
Framework design for veneeredrestorations:Frameworks to be ceramically veneered aredesigned with reduced anatomical contourto provide maximum support for the veneer.The frameworks can be veneered using thebuild-up technique.
Framework dimensions for the anteriorand posterior regions
Wall and border thickness:
Additional dimensional requirements for theanterior region:
Additional dimensional requirements for theposterior region:
Wall thickness, singlecrowns
0.4 mm
Margin thickness, singlecrowns
0.2 mm
Wall thickness, bridges 0.5 mm
Margin thickness, bridges 0.2 mm
Number of pontics 2
Connector cross-section 6 mm2
Number of pontics 2
Connector cross-section 9 mm2
Cantilever pontic at toothposition (only one pontic,up to one premolar width)
Special nesting notes for large-spanbridges (9 units or more)For distortion-free sintering of long-spanbridges (9 units or more) when nesting theobject in a Cercon ht 98mm disk, make sureto keep zirconia material in the lingualaspect of a long span arch, to reinforce theform during the sintering process andprevent distortion of the framework.
Always place objects (single copings, three-unit frameworks) within the sinteringreinforcement lingual aspect in order toachieve a homogeneous shrinkage of large-span objects during sintering.
Entering the shrinkage factor for themilling unit:In CAM software allowing the entry of 3dimensions, enter X, Y and Z values.In CAM software allowing the entry of 2dimensions, enter X, Y or Z values.In CAM software allowing the entry of 1dimension, enter the X value.
MILLING
Special notes on milling:Please read the respective Instructions forUse for your device regarding furtherprocessing. We recommend the followingmilling strategies for secure processing(Table 1).
Notes on separating the objects:Separate the objects from the disk bysandblasting with aluminium oxide (50 µm,max. 1.5 bar) with a fine blasting tip (Figure1). The sandblasting aid facilitates theremoval of objects from the blank. It helpsprevent framework fracture or other damageto the objects. For large-span bridges (9units or more), separate only the labial andbuccal sprues of the objects and keep thelingual connector intact, because theobjects must be sintered together with thatlingual portion to prevent from distorting(Figure 2). Any protruding ridges at thebottom of the lingual must be removed inorder to assure that the objects will stayfirmly put on the sintering tray. The smallerobjects nested inside the lingual aredetached completely and sinteredseparately.
General notes on framework design:
Make sure the occlusal surfaces are notmodified by severely deepening existingfissures, as this might compromise thestability of the material. (Figure 3) Note thata shallow occlusal relief will increase the life
expectancy of fully anatomic restorations.When manually finishing the frameworks,never deepen the interproximals(connectors) with cutting wheels, disks, orother rotary instruments, as this may causefracturing. (Figure 4)
SINTERING
Sintering in the Cercon heat plus P8:
• 1,500°C in the Cercon heat plus– Program #4 for bridges up to 8 units,
Tmax = 1,500°C– Program #5 for bridges of 9 units or
more, Tmax = 1,500°C
Special sintering notes for large-spanbridges (9 units or more) Two wide-span bridges (9 or more units) canbe sintered in the Cercon heat plus P8 atone time. Place the objects on the sinteringblock with due regard to the internal verticalclearance of the Cercon heat plus (130 mm)and the need to facilitate contractionwithout any mechanical constraints. Theobjects must not touch the sintering blockduring the sintering.
Sintering in the heat DUO/Multimat2Sinter:– Program #6: Speed program for bridges up
to 6 units, Tmax = 1,540°C– Program #7: Standard sintering for bridge
frameworks up to 8 units, Tmax = 1,520°C– Program #8: Sintering program for bridges
of 9 units or more, Tmax = 1,520°C
Special sintering notes for large-spanbridges (9 units or more) Two wide-span bridges (9 or more units) canbe sintered in the heat DUO or Multimat2Sinter at one time. Place the objects on thespecial sintering bar for large-span bridgesand keep in mind that the objects must nottouch the sintering block during thesintering (Figure 5, 6, 7). The maximum dimensions for milling: Height: 65 mmWidth: 90 mm
Sintering in third-party furnaces:
Sintering results may be adversely affectedby e.g.: • Incorrect sintering temperatures • Insufficient heating power• Incorrect temperature curves • Incorrect object placement • Insufficient heat-storing capacity of the
furnace over the time of the sintering cycle • Manufacturer-related or age-related
variations in heating performance • Object contamination by oxidation
products emitted by non-enclosed heatingelements
Any of these factors by itself or incombination may reduce the maximumstrength of our above-mentioned zirconiumdioxide materials and compromise the lifeexpectancy of the frameworks.
For these reasons, we cannot grant generalapproval for the use of third-party furnacesfor sintering two-piece abutments(mesostructures) and crown and bridgeframeworks made of Cercon ht. We will,however, open the system technically for theuse of furnaces of third-party furnaces onlyon condition that the following requirementare met:
IMPORTANT!The sintering of Cercon ht in third-partysintering furnaces is done at the user’s ownresponsibility and risk. Dentsply can acceptno responsibility for any kind of damagecaused by the sintering of zirconia materialsin third-party furnaces, including but notlimited to damage to or damage caused bythe sintered objects such as abutments,crowns or bridge frameworks.
Additional notes:The programming you use for your sinteringfurnace should be analogous to the Dentsplysintering programs.
Figure 5Placement ofbridges withsintering bar(more than 9
PROGRAMMING SUGGESTION #1(STANDARD SINTERING OF BRIDGEFRAMEWORKS UP TO 8 UNITS)Heat from room temperature to 900°C in 40minutes, to 1,500°C in another 55 minutes,hold for 2:25 hours, then allow to cool slowlyin the closed furnace; the total sinteringcycle takes about 7:35 hours.
Examples of different representations of thesame sintering curve:• RT³ > in 40 min > 900°C in 55 min >
1,500°C/2:25 h > allow to cool to 200°C,firing chamber closed
• RT³ > 22°C/min > 900°C > 11°C/min >1,500°C/2:25 h > allow to cool to 200°C,firing chamber closed
• RT³ > 1,320°C/h > 900°C > 660°C/h >1,500°C/2:25 h > allow to cool to 200°C,firing chamber closed
PROGRAMMING SUGGESTION #2(SINTERING OF BRIDGE FRAMEWORKSWITH 9 OR MORE UNITS) Heat from room temperature to 860°C in 120minutes, to 1,500°C in another 320 minutes,hold for 2 hours, then allow to cool slowly inthe closed furnace; the total sintering cycletakes about 13 hours.
Examples of different representations of thesame sintering curve:• RT³ > in 120 min > to 860°C in 320 min >
1,500°C/2 h > allow to cool to 200°C, firingchamber closed
• RT³ > 7°C/min > 860°C > 2 °C/min >1,500°C/2 h > allow to cool to 200°C, firingchamber closed
• RT³ > 420°C/h > 860°C > 120 °C/h >1,500°C/2 h > allow to cool to 200°C, firingchamber closed
PROGRAMMING SUGGESTION #3(SPEED SINTERING OF BRIDGEFRAMEWORKS UP TO 6 UNITS)Heat from room temperature to 1,540°C in 90min, hold for 35 min, then and thensuccessively open up to 1,150°C, thensuccessively open up to 750°C. The objects can then be taken off thesintering tray at 200°C. (Total cooling time
about 2 hours.) Total sintering time is about4 hours.
Examples of different representations of thesame sintering curve:• RT³ > 17°C/min > 1,540°C/35 min >
successively open up to 1,150°C >successively open up to 750°C > removeobjects from the sintering tray at 200°C.
• RT³ > 90 min > 1,540°C/35 min >successively open up to 1,150°C >successively open up to 750°C > removeobjects from the sintering tray at 200°C.
Sintering temperatures are recommenda-tions. If necessary, carry out a trial sinteringcycle and adapt the sintering temperaturesor times as needed.
Separating the sintering reinforcement inthe case of large-span bridges: Objects are separated from the “tongue”after sintering using irrigated rotary diamondcutters.
Manual finishing after sintering:• Sandblast the inside and outside of the
framework with aluminium oxide (110–125µm, max. 2–3 bar, 45° angle).
• Eliminate premature contacts one by oneuntil the framework has reached its finalposition on the die(s).
• During the try-on and fitting of theframework, keep the dies on the cast andtry on the framework as a whole.
• Once the try-on and fitting has beencompleted, do not perform any additionaladjustments such as finishing the entireframework.
Note: Zirconia crown or bridge abutmentsshould fit passively, without friction. Therationale for requiring a passive fit if zirconiaframeworks lies in the physical properties ofthe material itself: Ceramics will toleratecompressive stress but not tensile stress. Incrowns that exhibit a friction fit, this frictionis generated by certain “bearing” parts ofthe framework, as the crown itself neverrests completely on the die due toprocessing-related surface roughness (thesame actually holds for cast-metalframeworks). So it is only the peaks of thesurface roughness (the named “bearing”parts) that are in contact with the diesurface. This converts the compressiveforces generated by masticatory pressureinto tensile forces, which may damage thecrown.
Adapt the framework margins exactly to thepreparation margins.
Note: Sintered zirconia should be finishedusing diamond instruments under properirrigation only. Keep the pressure on theframework material to a minimum and workonly in one direction.
• Sandblast the finished areas once againwith aluminium oxide (110–125 µm, max. 2-3 bar, 45° angle).
• Finally, clean the framework using a steamcleaner.
Veneering/staining:Adjust your build-up technique to therespective Cercon ht shade. Note that the light transmission of Cercon htis very high due to its translucency.
GeneralThe reproduction of the individual patient'stooth color can be significantly influencedby:• Shade of the die• Shade of the material used for temporary
or definitive cementing• Framework wall thickness• Liner, if applied
Staining techniqueFor tooth-colored staining of fully contouredCercon ht restorations we recommendCercon® ceram body stains.
Build-up techniqueWe recommend Ceramco PFZ porcelainmaterials for veneering zirconia frameworks.Make sure to follow the applicableDirections for Use. (Figure 8, 9, 10)
ANNEALING:Based on the results of our scientific testingof zirconia frameworks, we consider aseparate annealing (“healing”) step bothunnecessary and inappropriate.
POLISHING IN THE LABORATORY:Unveneered Cercon ht frameworks should behighly polished or glazed with a high-glossceramic glaze. This also makes therestoration more amenable to proper oralhygiene procedures.
Polishing in the dental office:Extensive studies have shown that theabrasive action of Cercon ht on antagonistsis less than that of conventional ceramicveneers and not more than standard lithiumdisilicate ceramics even after finishing andpolishing.
Important: After making minor final occlusaladjustments at chairside, we recommendprophylactic polishing of the adjusted sitesto a high lustre or adding glaze with asmooth surface prior to temporary ordefinitive cementing to protect theantagonists from possible abrasion. Thisalso makes the restoration more amenableto proper oral hygiene procedures.Tooth surfaces whose shade was obtainedby staining may present brighter spotswhere occlusal adjustments were made.
Transport and storage:No particular requirements.
STAINING GUIDE FOR DIPPEDCERCON HT UNITS:
For tooth-colored staining of fully anatomicCercon® ht restorations, we recommend theCercon® ht Zirconia Stain and Glaze kit (partnumber 67390113). However, other stainsdesigned to be used with zirconia may alsobe used, including Ceramco PFZ and CerconCeram Kiss. Firing schedules may be foundin Table 4.
Mix the Cercon glaze with the Ducera® LiquidSTAIN, to a thin consistency. Apply a thinmixture to the crown. It is not necessary todo a separate firing. Use the following chartto complete the shade. (Figure 11, 12)
Fire according to Table 4. • If the final crown has too high of a sheen,
lower the High Temp in 5°C (41˚F)increments to achieve the desired sheen.
• If the final crown has too low of a sheen,increase the High Temp in 5°C (41˚F)increments to achieve the desired sheen.
TABLE 3. 6 TO 16 STAINING TECHNIQUE FOR PRE-SHADED CERCON HT:1. Sandblast the frameworks with 110 µm Al2O3 / 3 bar2. Clean with steam cleaner3. Apply a very thin layer with Celtra glaze4. Start with Celtra stains according to the Celtra stain recipe mentioned below5. The Celtra stains should be put on the framework in thin layers. For dark colors you need
more firing cycles. If you put on thick layers the stain form puddles
Vita Shade Disk ShadeCeltra StainBody 1. Glaze firing