429 Too Many Requests

Case by CDT Daniele Rondoni and MDT Roberto Rossi

Working with high-translucency, multi layered zirconia (KATANA™ Zirconia Multi-Layered series from Kuraray Noritake Dental Inc.) paves the way toward indirect restorations that are closely adapted to our patients’ needs. Reduced wall thicknesses allow for minimally invasive tooth preparations, while polished zirconia in the occlusal contact areas provides for an antagonist-friendly behaviour. All this is possible due to the high aesthetic potential and homogeneous structure of the materials, which work well with a full-contour design or slight vestibular cutback. For individualization or characterization, different options are available. The portfolio of finishing solutions from Kuraray Noritake Dental has just been complemented by Esthetic Colorant for KATANA™ Zirconia, a set of twelve dyeing liquids for the company’s multilayered zirconia. They are applied to the milled restoration surface prior to sintering.

Some readers may wonder why there is a need for effect liquids applied to pre-shaded zirconia with a multi-layered colour structure. Being aware of natural teeth’s unique play of colours stemming from the shape and shade of the dentin core, however, the reason is quite obvious: Esthetic Colorant diffuses into the zirconia structure, hence allowing us to create depth effects even in monolithic restorations. Moreover, it enables the user to pre-treat tissue areas, and even by using the liquids on cutback designs, we are able to reproduce case-specific internal optical characteristics quite easily. Our standard approach for the use of Esthetic Colorant on KATANA™ Zirconia HTML Plus is described by means of the following case example: An implant- and tooth-based twelve-unit bridge with a slight vestibular cutback design, finished with Esthetic Colorant and CERABIEN™ ZR Porcelain.

Fig. 1. Restoration with sintering support removed from the blank.

Fig. 2. Esthetic Colorant for KATANA™ Zirconia: Available shades.

Fig. 3. Frontal view of the milled restoration after the application of Esthetic Colorant. A chromatic map is not needed since the colours of the applied liquids are clearly visible.

Fig. 4. Occlusal view of the milled restoration after the application of Esthetic Colorant. The liquids were applied with the Liquid Brush Pen for Esthetic Colorant.

Fig. 5. Frontal view: Appearance of the restoration after sintering.

Fig. 6. Occlusal view: Appearance of the restoration after sintering.

Fig. 7. Beautiful translucency and mamelon structures in the incisal area.

Fig. 8. Situation after the application of a thin layer of CERABIEN™ ZR Porcelain, which creates an enamellike window effect and reveals the play of colours found underneath.

Fig. 9. Restoration after firing and glazing.

FINAL SITUATION

Fig. 10. Beauty shots…

Fig. 11. … of the final restoration.

Easy handling and application, impressive colour effects: Esthetic Colorant perfectly fits into our micro-layering approach with a cutback design adjusted to the age and needs of every patient. Being applied on the pre-sintered zirconia surface, the liquids do not require any extra heat treatment – the restoration is simply dried and then sintered as usual. Esthetic Colorant may be used instead of or in combination with internal stains, luster porcelains and liquid ceramics – whatever complements a laboratory’s existing approach to highly aesthetic zirconia restorations.

Dentists:

Case by Kokla Thalia, Postgraduate student in Restorative Dentistry program, Faculty of Dentistry, National and Kapodistrian University of Athens, Greece

Restoring Class II cavities can be challenging due to limited access to the posterior area, where the interproximal contact needs to re-established in a proper way. Inadequate contacts tend to result in increased plaque accumulation, food impaction and, as a consequence, the development of caries and irritation of the interproximal gingiva. Therefore, it is essential that the interproximal contact is restored based on the model of nature. A suitable matrix system and a proper clinical protocol can help us succeed in this context. The following clinical case is used to illustrate a possible strategy.

Fig. 1. Initial clinical situation. 23-year-old female patient with caries on the mandibular left second premolar.

Fig. 2. Situation after cavity preparation, isolation of the working field with rubber dam and the placement of a sectional matrix fixed with a ring. It is essential that the matrix imitates the natural shape of the contact area, which is usually rather flat or concave cervically and convex in the middle and occlusal parts.

Fig. 3. Etching of the tooth structure with phosphoric acid etchant. Afterwards, the adhesive needs to be applied (in this case, Universal Bond Quick was used according to the manufacturer’s instructions).

Fig. 4. CLEARFIL MAJESTY™ ES-2 Premium in the shade A3E is applied in the distal box to build up the wall first. In this way, the available space is used to model the most critical part of the restoration before simply filling the cavity in increments with the dentin shade A3D.

FINAL SITUATION

Fig. 5. Final restoration after finishing and polishing. In accordance with the concept behind CLEARFIL MAJESTY™ ES-2 Premium with its pre-defined shade combinations, the final enamel layer was build-up using the shade A3E. However, the use of a single opacity is also possible in the posterior region depending on the aesthetic demands.

CONCLUSION

By elevating deep interproximal margins, it is possible to focus on the critical designing of the contact point when there is still sufficient space available to do so. This simplifies the procedure, while all that is left to do can be managed in a straightforward way like a Class I restoration.

HOW MANY SHADES DO WE NEED?

Case by Gasparatos Spyros, Postgraduate student in Restorative Dentistry program, Faculty of Dentistry, National and Kapodistrian University of Athens, Greece

Restoring anterior teeth with large defects using composite seems to be quite challenging. With high-performance materials at hand and a systematic layering concept in mind, however, it is possible to produce highly aesthetic results in a reproducible way. The clinical case below is used to illustrate a dual-shade layering technique with CLEARFIL MAJESTY™ ES-2 Premium, a composite system with pre-defined colour combinations.

CASE EXAMPLE

The patient, a young male, was unhappy with the appearance of his maxillary anterior teeth. Several years ago, his central incisors had been restored with composite. These existing restorations had defective and heavily discoloured margins, while their shade did not match the adjacent natural tooth structure. The maxillary lateral incisors were peg-shaped (microdontia). Economic considerations and the desire to save as much natural tooth structure as possible made the team decide to restore all four maxillary incisors with composite. CLEARFIL MAJESTY™ ES-2 Premium became the material of choice as it eliminates the need for complicated shade combination formulas and supports predictable outcomes.

Fig. 1. The patient’s initial smile.

Fig. 2. Intraoral image of the initial situation with defective composite restorations and microdonts. Two composite buttons on the right lateral incisor are used to verify the determined shade combination.

RESTORING THE CENTRAL INCISORS

We decided to restore the central incisors first and then focus on the lateral incisors. The tooth shade was determined using the VITA™ classical A1-D4 shade guide, while composite buttons were applied to the teeth to verify the determined shade combination. In order to simplify the restoration procedure, a palatal silicon index was produced before removing the existing restorations. During minimally invasive tooth preparation, bevels were created at the margins to provide for a smooth optical transition from the natural tooth structure to the composite.

An adhesive (CLEARFIL™ Universal Bond Quick) was applied after selective etching of the enamel to achieve a strong bond. With the aid of the silicon index, it was easy to create the palatal shells of the restorations with CLEARFIL MAJESTY™ ES-2 Premium in the shade A3E (enamel), which matches the determined tooth shade A3. The dentin core was built up with the same composite in the recommended shade A3D (dentin), mamelons were modelled and some CLEARFIL MAJESTY™ ES-2 Premium in the shade WD added for the incisal halo, while some individual effects (like enamel cracks) were imitated with brown stain. The build-up was finalized in the interproximal and labial areas with composite in the shade A3E. Between the central incisors, a wedge was used to retract the papilla and facilitate the designing of the interproximal contact area. The finished and pre-polished restorations already had a natural appearance.

Fig. 3. Central incisors after removal of the old restorations and the beveling of the enamel.

Fig. 4. Light-cured palatal shells made of CLEARFIL MAJESTY™ ES-2 Premium in the shade A3E.

Fig. 5. Build-up of the dentin core with mamelons individualized with the shade WD and brown stain.

Fig. 6. Situation after finalization of the central incisor restorations with composite in the enamel opacity.

Fig. 7. Central incisor restorations after finishing and initial polishing.

RESTORING THE LATERAL INCISORS

Tooth preparation was not required on the lateral incisors. Instead, they were merely cleaned after a slight roughening of the enamel surfaces. The build-up procedure was similar to the one used for the central incisors. The adjacent tooth was protected with PTFE tape, and the palatal shell was created with the aid of a finger instead of a silicone index. Afterwards, we focused on the build-up of the interproximal walls before a small amount of dentin was placed and the shape was finalized by applying the labial enamel layer.

Fig. 8. Build-up of the left lateral incisor.

Fig. 9. Situation after finishing and polishing.

FINAL SITUATION

Fig. 10. Final smile of the patient's demands.

CONCLUSION

Two different opacities, a single shade combination and some bleached shade plus stain for special effects – in the present patient case, a simple formula allowed us to create lifelike anterior restorations. With one enamel and one dentin paste used, it is possible to simply rebuild the natural anatomy without the risk of ending up with a bulky core that – once reduced – will lose its special optical structure. It is also easy to control the thickness of the final enamel layer with its huge impact on the light-optical properties of the whole restoration. For most patients and teeth with a simple or medium-to-complex internal colour structure, the selected concept is very well suited and will lead to pleasing outcomes.

Case by Aleksandra Łyżwińska, Warsaw, Poland.

ABSTRACT

Indirect overlays are the contemporary restoration standard for posterior teeth with extensive hard tissue loss. They provide for cuspal coverage, which decreases the likeliness of coronal and/or root fracture. At the same time and in contrast to crowns, overlay preparations minimize the removal of sound tooth structure especially in the cervical region, which is a critical factor.¹ Modern dental resin composites allow for direct cuspal coverage in a single-visit appointment. The results of in-vitro studies suggest that these direct overlays are a suitable alternative to their indirect counterparts in specific situations.^2-6 The following case report is used to describe the direct restoration procedure by means of a maxillary right molar with an extensive, deep MOD lesion.

INTRODUCTION

In the context of treating a tooth with an extensive carious lesion, a biomechanical risk assessment should be performed. The primary method of reducing the likeliness of tooth fracture is treatment with a restoration that provides cuspal coverage. The contemporary gold standard for biomechanically compromised teeth are adhesively cemented overlays as an alternative to crowns.¹ Another option that does not involve labwork is a direct overlay restoration.^2-6 The direct approach is especially suitable for long-term temporization, which may be required during orthodontic treatment, for example.

Case by Dr. Yohei Sato, DMD, PhD, Department of Removable Prosthodontics, Tsurumi University School of Dental Medicine, JAPAN and Dr. Keisuke Ihara, CDT, i- Dental Lab, JAPAN.

Fig. 1. The patient visited us with a chief complaint of a desire for improved esthetics of the maxillary right and left lateral incisors.

Fig. 2. A core fabricated from a diagnostic wax model was applied and the necessary clearances were determined.

Fig. 3. Since the teeth are microdonts, the preparation of each abutment was completed by simply exposing a fresh surface to be covered by the laminate veneers.

Fig. 4. A layer of porcelain was applied on the lithium disilicate glass substrate, to make a complete laminate veneer.

Fig. 5. After a trial fitting, the inner surface of the laminate veneer was cleaned with KATANA™ Cleaner. The inner surface was conditioned according to the prosthesis‘ IFU.

Fig. 6. Milling. CLEARFIL™ CERAMIC PRIMER PLUS was applied and dried to silane couple the restoration.

Fig. 7. After a trial fitting, KATANA™ Cleaner was applied to the abutment, and rubbed for more than 10 seconds. Then, it was washed off sufficiently (until the cleaner color had completely disappeared), and dried with compressed air.

Fig. 8. K-ETCHANT Syringe was applied and left for 10 seconds before water-washing and compressed air-drying.

Fig. 9. PANAVIA™ V5 Tooth Primer was applied and left for 20 seconds before compressed-air drying.

Fig. 10. PANAVIA™ Veneer LC Paste was applied to the inner surface of the laminate veneer.

Fig. 11. The laminate veneer was seated and the fit checked. Then, the excess cement was tack-cured (not more than 1 second at any one point) and removed. Finally, the restoration was light-cured and finished.

FINAL SITUATION

Fig. 12. This photo shows the laminate veneer restorations one month after placement. The morphology and color of the right and left lateral incisors have been improved, providing a good balance to the entire anterior dentition.

Case by Richard Young DDS, San Bernardino, CA

Easy procedure, reliable outcome: that is what most dental practitioners may wish for when placing indirect restorations. The following clinical case example is used to demonstrate an easy, but highly successful clinical protocol for the luting of a lithium disilicate crown.

Fig. 1. Lithium disilicate crown after etching of the intaglio surface with hydrofluoric acid and try-in.

Fig. 2a. Application of KATANA™ Cleaner into the crown for a complete removal of contaminants such as proteins from blood and saliva, which may compromise the performance of any resin cement system.

OR Fig. 2b. Alternatively, KATANA™ Cleaner is applied into a mixing well.

Fig. 3. Application of KATANA™ Cleaner to the restoration.

Fig. 4. KATANA™ Cleaner is applied to the prepared tooth structure in the same way (rubbing for ten seconds followed by rinsing and drying).

Fig. 5. Application of PANAVIA™ SA Cement Universal into the cleaned crown.

Fig. 6. The cement contains a unique silane coupling agent – the LCSi monomer - for a strong and reliable bond to lithium disilicate and other restorative materials like glass ceramics and hybrid ceramics.

   The Silane is activated in the mixing tip by Original MDP.

Fig. 7. Easy clean-up after two to five seconds of tack-curing.

Fig. 8. The excess resin cement is in its gel-state and removed in one piece with an explorer.

FINAL SITUATION

Fig. 9. Treatment outcome immediately after crown placement.

Dentist:

RICHARD YOUNG DDS

Case and images courtesy of Richard Young DDS, San Bernardino, CA

USING THE NEXT-GENERATION SELF-ADHESIVE CEMENTS

by Dr. Tomohiro Takagaki.

INTRODUCTION

In recent years, the use of CAD/CAM systems for the production of indirect restorations has become increasingly popular. The shortage of young, qualified staff in the field of dental technology in Japan¹) is likely to contribute to a further increase of automated production techniques such as CAD/CAM, which require fewer manual production steps compared to traditional manufacturing techniques. Also globally, the number of restorations fabricated using CAD/CAM systems is rapidly increasing. This leads to an even more widespread use of innovative, tooth-coloured restorative materials such as zirconia, silicate ceramics and resins.

Demand for placing restorations using the principle of adhesion by resin cements is more and more increasing in daily clinical settings. However, it is difficult and complicated to condition the tooth and restoration surfaces using many primers correctly. In addition, the combination of many different components is time-consuming, complex and cost-intensive. Self-adhesive resin cements, which do not require conditioning the surface of teeth or some restorations with primers, have been released recently, and have become popular among dental practitioners. However, there are many reports²) on the dislodgement of resin-based CAD/CAM restorations and full-zirconia crowns that have been placed using self-adhesive cements. Hence, demand is high for a resin cement system that is both simple to use and reliable in performance.

In this document, I explain the fundamental technology of resin cement systems and their range of applications. In addition, I will introduce the method of using a next-generation self-adhesive cement, PANAVIA™ SA Cement Universal (Kuraray Noritake Dental Inc., Fig. 1), as an example.

Case by Dr. David Garcia Baeza and DT. Pilar Ballesteros Galan

Shade determination in the planning phase, shade evaluation at try-in: How is it possible to accomplish these highly important tasks in the production of lifelike anterior restorations without meeting the patient in person? A computer-based shade documentation and try-in system is a great solution. Download this clinical case example describing the aesthetic restoration of two maxillary anterior teeth to learn more about one such system and its use!

Case by Dr. Yohei Sato, DMD, PhD, Department of Removable Prosthodontics, Tsurumi University School of Dental Medicine, JAPAN and Dr. Keisuke Ihara, CDT, i-Dental Lab, JAPAN

Fig. 1. The patient was referred to our hospital by an orthodontist. The chief complaints were improper esthetics of the teeth due to black triangles at the edges of the gaps between the teeth and occlusal wear of the teeth.

Fig. 2. On the basis of the pre-treatment diagnosis using a mockup, the abutments were prepared without anesthesia, keeping in mind that the enamel should be preserved to the extent possible.

Fig. 3. Since a fixation retainer was installed on the palate side, it was difficult to take impressions using silicone. Therefore, an intraoral scanner for impression taking was used.

Fig. 4. A layer of porcelain on each of KATANA™ Zirconia STML substrates was applied to complete the laminate veneer resto-rations. The inner surface of each restoration was sandblasted, being careful to prevent chipping.

Fig. 5. After trial fitting, bonding inhibiting substances as blood and saliva were removed using KATANA™ Cleaner.

Fig. 6. Milling. CLEARFIL™ CERAMIC PRIMER PLUS, which contains the phosphoric ester monomer MDP, was applied and dried using compressed air.

Fig. 7. The surface of each tooth was cleaned and treated with K-ETCHANT Syringe for 10 seconds before washing it away with water and compressed air-dried the area.

Fig. 8. PANAVIA™ V5 Tooth Primer was applied and left it for 20 seconds, then compressed air-dried it.

Fig. 9. PANAVIA™ Veneer LC Paste was applied and the laminate veneer was seated. For this case, we treated six teeth during one session.

Fig. 10. The unpolymerized excess paste was removed with a brush. PANAVIA™ Veneer LC Paste is a light-cured type, which was designed to provide sufficient working time.

Fig. 11. This photo shows the results after the final light curing. Since the excess cement was easily removed, there were almost no cement residues.

FINAL SITUATION

Fig. 12. The photo shows the inside of the oral cavity one month after the fitting of the laminate veneer restorations. It can also be noted that the teeth’s marginal gingiva has been improved, thanks to the good fit of the laminate veneer restorations.

Case by Dr. Clarence P. Tam, HBSC, DDS, AAACD, FIADFE

Case background

A stable ASA 2 65 year old female presented to the practice for restorative dentistry with a medical history significant for a non-descript immunoglobulin deficiency, for which she receives regular infusions. She reports no known drug allergies. Clinically, she was diagnosed with an occlusal peripheral rim fracture leaving a food trap on tooth 14 (FDI notation). Tooth 15 featured an extensive amalgam with extreme proximity to the distal marginal ridge, which exhibited distal vertical axial fractures as a result of cyclic expansion-contraction over time. The restorative goal of minimally invasive direct dentistry would be complicated by the undoubtedly dark dentin substrate under the amalgam. A material was sought that featured both an excellent chameleon mechanism as well as physical properties to maximize the prognosis of direct restorations in this area.

Restorative procedure

The patient was subjected to topical anesthetic prior to buccal infiltration using 1 carpule of 2% Lignocaine with 1:100,000 epinephrine. A rubber dam was affixed prior to preparation of tooth 15MO with dissection of the distal vertical marginal ridge fracture. The margins of tooth 14O and 15MOD were refined before bevelling as the ends of enamel rods facilitate better bonding relative to the sides of enamel rods. A 27 micron aluminum oxide micro air abrasion treatment was completed prior to affixing, wedge and matrix to reconstruct the mesial marginal ridge of tooth 15. A matrix-in-matrix solution was used to recreate the proximoaxial contour of 15D. This provided hermetic closure at the proximogingival cavosurface margin as well as an ideal contour for the missing axial wall.

Following a total etch technique, a 2% Chlorhexidine scrub was completed for 30 seconds and the dentin blot dried to a moist state. A 5th generation bond was applied, air thinned and cured as per manufacturer instructions. Microlayers are important during the delicate first 5 minutes of hybrid layer formation, and were completed using 0.25 mm increments of CLEARFIL MAJESTY™ Flow (Kuraray Noritake Dental Inc.). This technique can be expected to increase significantly the shear bond strength to dentin^1,2.

This was completed both in the proximal box floor area as well as mid-occlusally. The marginal ridge was completed using CLEARFIL MAJESTY™ ES-2 Universal (Kuraray Noritake Dental Inc.). Since the dentin base was heavily stained, CLEARFIL MAJESTY™ Flow was used before utilizing CLEARFIL MAJESTY™ ES-2 Universal in a lobe-by-lobe creation of occlusal anatomy. Post-operative occlusal checks verify that the restoration is conformative to occlusion and esthetically excellent with no visible marginal show.

Rationale for material choice

The marginal ridges were micro-layered horizontally as was the floor of the resulting Class I preparation as per a reduced layer thickness-technique modification of Nikolaenko et al³, whereas the highest shear bond strengths were found when a 1mm horizontal layering technique was used.

CLEARFIL MAJESTY™ ES-2 Universal is at the forefront of a simplified restorative armamentarium for the modern practice. It takes cloud-shading one step further by offering a “Universal” shaded composite featuring Light Diffusion Technology (LDT) with simultaneous ideal sculptability, optical metamerism and physical properties for use in any restorative situation in the mouth. Featuring barium glass nano fillers and proprietary pre-polymerized nanoparticle fillers, the latter boasts a high refractive matrix that is able to disperse light and fool the eye with even the thinnest of layers, obviating the need for opaquer composites in cases like the one featured. When paired with CLEARFIL MAJESTY™ Flow in a conservative layered technique, the 81% filled flowable produces a radiographically well-demarcated layer, and the superficial CLEARFIL MAJESTY™ ES-2 Universal boasts an easy-to-polish robust single shade restorative solution that will virtually fulfil all of your restorative needs for non-bleaching patients. Physically, with compressive strength is rated at 348 MPa and flexural strength at 116 MPa, CLEARFIL MAJESTY™ ES-2 Universal is in the range of natural enamel and dentin. The built-in fluorescence is very enamelomimetic, which is excellent for nightclub social situations.

FINAL SITUATION

Dentist:

DR CLARENCE P. TAM, HBSC, DDS, AAACD, FIADFE

Clarence is originally from Toronto, Canada, where she completed her Doctor of Dental Surgery and General Practice Residency at the University of Western Ontario and the University of Toronto, respectively. Clarence’s practice is limited to cosmetic and restorative dentistry and she is well-published to both the local and international dental press, writing articles, reviewing and developing prototype products and techniques in clinical dentistry. She frequently and continually lectures internationally. Clarence is the Immediate Past Chairperson of the New Zealand Academy of Cosmetic Dentistry.

She is currently one of two individuals in Australasia to hold Board-Certified Accredited Member Status with the American Academy of Cosmetic Dentistry. Clarence is an Opinion Leader for multinational dental companies Kuraray Noritake, J Morita Corp, Henry Schein NZ, Ivoclar Vivadent, Dentsply Sirona, 3M, Kerr, GC Australasia, SDI and Coltene and is the only Voco Fellow in Australia and New Zealand. She holds Fellowship status with the International Academy for DentoFacial Esthetics and is a passionate and approachable individual, committed to having an interactive approach with patients in all of her cases to maximize predictability.

References

1. Bertschinger C, Paul SJ, Luthy H, Scharer P. Dual application of dentin bonding agents: effect on bond strength. Am J Dent. 1996;9(3):115-119.
2. Magne P, Kim TH, Cassione D, Donovan TE. Immediate dentin sealing improves bond strengths of indirect restorations. J Prosthet Dent. 2005;94(6):511-519.
3. Nikolaenko SA, Lohbauer U, Roggendorf M, Petschelt A, Dasch W, Franenberberger R. Influence of C-Factor and layering technique on microtensile bond strength to dentin. Dental Mater. 2004;20(6):579-585.