The Benefit of Low-Fusing Veneer - GC America

1 The Benefit of Low-Fusing VeneerLuke S. Kahng, CDT1 Franz Weyandt, DMD, PC2 QDT 20061oday, dental professions are conflicted asto which materials achieve the best es-thetic results for cosmetic selecting a material, each case should belooked at individually. There are many factors toconsider, including underlying tooth color afterpreparation (stump shade), preparation design,and the patient s medical history (eg, any allergiesor a history of bruxism). After preparation, if the underlying tooth coloris dark, between shades A5 and C10, the sub-structure should be built up with a highly opaquematerial, such as zirconium or opaque pressablematerials. These mask underlying color. If the un-derlying tooth color falls between the Vita Classicshades of A1 and D4, alumina or porcelain ve-neers can be used successfully. However, an ad-vanced technician can still mask underlying toothcolor by utilizing porcelain veneers in combinationwith detailed color-masking design factors also influence mate-rial choice, particularly when trying to achieve theright amount of reduction.

2 For the margin prepa-ration, a shoulder or deep chamfer is recom-mended for the best esthetics. The preparationdesign for anterior dentition should have a labialreduction between 1 and mm, an incisal re-duction between and 2 mm, and a lingual re-duction of 1 mm to achieve esthetic results. In addressing the patient s concern over esthet-ics, biggest issue for the clinician and dental tech-nician can be choosing PRESENTATIONA 36-year-old male patient presented with two ex-isting porcelain -fused-to-metal (PFM) crowns on themaxillary central incisors, a composite buildup onthe maxillary left lateral incisor, and a chipped maxil-lary right lateral incisor (Fig 1). The patient was un-happy with his anterior dentition and wanted to re-place these teeth with esthetic restorations. Thepatient s gum line also needed to be addressed,raising the tissue height of both central incisors (Figs2 to 4). The patient had options for different restora-tions.

3 The PFM crowns could be replaced with all-ceramic restorations. porcelain veneers were choseninstead of crowning the lateral incisors. 1 Dental Technician, LSK Division, Capital Dental TechnologyLaboratory, Naperville, Illinois, practice, Naperville, Illinois, USA. [Au: Please verify.]Correspondence to:Mr Luke S. Kahng, LSK Division, CapitalDental Technology Laboratory, Inc, 952 McDowell Rd, Suite303, Naperville, IL 60563, USA. Fax: 630-355-6833. 20062 Each restorative system or product has its limita-tions in esthetics, function, and long-term success,which can make a combination case difficult. Somemanufacturers recommend using only one porce-lain, but today dental professionals also have ac-cess to products designed for different applica-tions. Using specialized porcelains are for specificapplications can achieve the maximum or highestesthetics. The GC Initial porcelain system that waschosen for this case has five different porcelainpowder systems and a pressed ceramic ingot sys-tem.

4 Choosing between the five different powdersdepends on the framework or substructure that isin place. Initial MC is for PFM restorations and ve-neers. Initial LF is Low-Fusing porcelain , which canbe used for PFM restorations, on pressed ceramicingots, and for porcelain veneers. The other threepowders are Initial ZR for zirconium restorations,Initial AL for alumina restorations and Initial Ti forporcelain- titanium restorations. As pressed ceramic crowns were chosen in com-bination with the cut-back technique and porcelainveneers, the Initial LF porcelain would be LSK treatment-plan waxup (Capital DentalTechnology Laboratory) was prepared. The clini-cian reviewed the treatment plan and anticipatedresults with the patient, using the natural-lookingwaxup as a visual aid. A waxup can be a powerfulvisual tool that can help a patient understand andaccept a treatment plan. In most cases, the LSKtreatment-plan waxup is delivered with a prepara-tion guide model and/or a vacuum stent.

5 Thestent can be used as an in-mouth preparationguide and to produce provisional restorations (Fig5). Provisionals produced using the stent allow pa-tients to test drive restorations to evaluate theshape and function in their mouths and clinicianscan photograph their smile with the provisional inplace. If needed, adjustments can be made to theprovisional restorations (Fig 6). CASE PRESENTATION324 Fig 1 Wax coping ready for 2 Mesial concavity on right lateral incisor. Veneermust be contoured normally for tissue 3 Recommended crown 4 Postoperative view of gum Benefit of Low-Fusing Veneer3 QDT 2006 The central incisors were waxed to full contourand cut back for the incisal edge (Fig 7). To com-pensate for extra facial room of the central in-cisors and to ensure alignment with the lateral in-cisors, the waxup was built up more facially (Fig8). The waxup was then sprued and prepared topress (Fig 9).Ceramic ingot selection was also very impor-tant (Fig 10); using different manufacturer s ce-ramic ingots provides a wider assortment of col-ors.

6 In choosing a ceramic ingot, a clinician musttake into consideration whether it is for a singlerestoration or a combination case, how muchtooth reduction is required, and the stump shadeor internal colors of the preparation. Also, thegreater the tooth reduction, the thicker thepressed crown will have to be. Knowing, however,that the translucence of pressed ceramic ingots atdifferent thicknesses will affect the crown color theGC Initial PC was chosen. This system offers awide variety of pellet colors in 16 dentin shades, 4bleached shades, 3 Veneer shades, 4 occlusalenamel light shades, 4 occlusal enamel milkyshades, 4 translucent shades, and 5 opaque ce-ramic ingots. The opaque ceramic ingots are valu-able when dealing with discolored preparations,as the opacity is at 85%. The colors are light yel-low, pale yellow, red yellow, olive, and white. Aspressed ceramics can sometimes get too translu-cent, a wide range of choice is preferred.

7 Theopacity level of the Initial PC ingots ranges from30% to 85%.78910 Fig 7 Full contour waxup for pressable crownsFig 8 Facial buildup of the full contour waxup to compensate for extrafacial room of the central incisors and to ensure alignment with the lat-eral incisors. Fig 9 Wax coping ready for 10 Numerous ceramic ingots, ranging from opaque to transparent. Fig 5 Intraoral view of 6 Provisional restoration need-ing adjustment of incisal 20064 KAHNG/WEYANDTA fter pressing (Fig 11), it was important not toapply too much heat while cutting off the spruesor performing other modifications. Once the cut-back framework was ready for porcelain applica-tion, the thickness and available room for layeringporcelain were checked (Fig 12). The shade of theframework was also checked to see if any modifi-cations with internal stains were needed (Fig 13).GC Initial has INvivo, INsitu, and INover stains forapplication on the pressed ceramic material, bothinternally on the porcelain buildup and dentin porcelain was built up over the en-tire pressed coping to give the crown optimalchroma (Fig 14).

8 The dentin porcelain was cutback to give room for the desired mamelon effect(Fig 15). The enamel porcelain and enamel opalporcelain were applied. The enamel porcelain (Fig16) provides a shade gradation to the incisal edgesimilar to that of natural tooth. The enamel opalporcelain (Fig 17) has a higher level of opales-cence as well as a high translucence. Fluo Dentin,a newly developed high-fluorescence porcelainavailable in dentin colors, creates an underlyingbackground of mamelon effect (Fig 18).A thin layer of Clear Fluorescence powder(CLF) was applied between the dentin layer and1718 Fig 17 Application of Enamel 18 Application of fluorescentopacious dentin to create underly-ing background of mamelon 11 Pressable ceramic crownafter 12 Occlusal view showing fa-cial room and alignment for fabri-cating color restorations betweenporcelain veneers on the lateral in-cisors and pressable crowns on thecentral 13 First application of internalstaining for greater color saturationof pressable 14 Buildup of Natural Dentin.

9 Fig 15 Trimming of Natural Dentinfor mamelon 16 Application of Enamel Oc-clusion porcelain . overlaying enamels (Fig 19). This so-called scle-rose dentin brings true-to-nature depth into thetooth color. Translucence modifiers were applied(Fig 20) over the CLF; they can be used individu-ally or mixed with the Neutral or Opal create the whitish line of natural tooth denti-tion, a Fluo Dentin was used (Fig 21). Enamel Ef-fect powders were used at the area of the incisaledge and helped give the natural appearance thatcannot always be re-created with just one enamelshade (Fig 22) and an application of Translucent(Fig 23), the neutral color. The application of theenamel powder gave full color saturation (Figs 24and 25). A white craze line was re-created (Fig 26),the enamel retouched up (Fig 27), and the enamelapplication completed (Fig 28).QDT 20065 The Benefit of Low-Fusing Veneer1920 Fig 19 Application of CLF for natu-ral depth in tooth color.

10 [Au: Editretain meaning?]Fig 20 Application of 24 Enamel application. Fig 25 Full color 26 Creation of white craze 27 Touch-up of enamel 28 Completed enamel applica-tion. Fig 21 Application of white flores-cent transparent color to create whit-ish line of natural tooth 22 Application of Enamel Ef-fective 23 Application of TranslucentNeutral. 262728 QDT 20066 KAHNG/WEYANDTFig 34 Postoperative smile. Fig 36 Postoperative 37 Postoperative facial 35 Postoperative smile showing left lateral 29 Lingual buildup of 30 Occlusal buildup of 31 Buildup complete andready to 32 Completed restorations onsolid 33 Lingual view of completedrestorations. Dentin was applied to the lingual surface of thecrown (Fig 29) and incisal enamel and occlusionwas built up (Fig 30). The crown was taken off themodel, and the buildup was completed on thecontact areas (Fig 31). After the crowns were fired,any adjustments to complete the restoration weremade on the solid cast (Fig 32).