429 Too Many Requests

By Daniele Rondoni, RDT

A middle-aged patient sought dental advice because she felt uncomfortable with the aesthetic appearance of her upper front jaw, specifically regions 11, 12, 21 and 22. Additionally, she was not happy about the diastema between her upper central incisors.

Fig. 1: Initial situation.

The oral examination showed four crown regions (12-22) and revealed that all of them have deteriorated. Tooth 21 had undergone an endodontic treatment, while teeth 11 to 22 have been newly built up. Due to the deteriorated conditions, all affected teeth were taken into consideration in the planning and designing of new restorations, including the intention to close the diastema between the width-to-length-ratio for the incisors.

The best suitable material for a natural look in combination with a close gingival attachment to the restoration is, in this case, zirconia, because of its biocompatibility and gentleness to the gingival region. The KATANA^TM Zirconia series from Kuraray Noritake Dental, offers a line-up of high-quality materials combined with true-to-life aesthetics, due to its natural color gradient within the material.

Fig. 2: Preparations, showing discoloration in the cervical area of tooth 21.

Fig. 3: Occlusal view of the preparations.

Fig. 4: The four zirconia crowns after designing followed by milling.

Fig. 5: Result directly after sintering.

To achieve an even more natural-looking and aesthetic restoration, CZR FC Paste Stains were used externally on the zirconia surface.

Fig. 6: Characterization of the restoration.

As often done, Cervical 2 was used to give an orange tint to the cervical area, to accentuate even better the natural tooth gradation. For the incisal areas, Grayish Blue in combination with Value was used to enhance transparency and opalescence. Same procedure applied to the approximal areas. Mamelon Orange 2 was used to reproduce dark orange stain on the mamelons.

Fig. 7: Result after cementation of the four new zirconia crowns. Their shape and chroma blend harmoniously with the arch.

Fig. 8: The vestibular view showing natural-looking characterization.

During a period of five years, annual check-ups showed intact crowns and a healthy gingiva. Additionally, the durability of the restorations, including their mechanical and optical properties revealed no signs of deterioration.

To achieve excellence it is crucial to know the properties of modern materials and their correct clinical procedure. With this premise, surprising clinical results can also be achieved by combining different materials in the same clinical case.

This clinical case follows the aesthetic request of the patient who wanted to solve the pathology concerning the incisors with a direct composite restoration on 2.1 and a KATANA^TM STML crown on 1.1.

Following the mock-up the patient wanted larger incisor shapes with a strong character. The 2.1 was restored only with the MAJESTY^TM ES-2 Classic A2 mass exploiting the extraordinary ability of mimicry that comes from the Kuraray Noritake Dental light diffusion technology - LDT. The restoration on the 2.5 was performed with a CAD/CAM hybrid ceramic block - KATANA^TM AVENCIA^TM.

KATANA^TM AVENCIA^TM Block was characterized with a staining resin before cementation with the new PANAVIA^TM SA Cement Universal. PANAVIA^TM SA Cement Universal includes in its formulation a new type of silane coupling agent – LCSi monomer and this ensures strong and durable chemical bond to glass ceramics and composite resins without pretreatment with silane.

By Japanese Dr. Shigeru Adachi, Cusp Dental Supply Co. Ltd

Initial situation

Checking of the shade (Posterior Crowns: FC Paste Stain, Anterior Crowns: Micro layered CERABIEN™ ZR)

Checking the restoration on the model

Final situation

Ceramist:

MDT Shigeru Adachi, Cusp Dental Supply Co. Ltd

MDT Adachi is a promising ceramist of the new generation, who has been working for Cusp Dental Supply Co. Ltd. since 2013. He received the Award of Excellence 2018 at QDT TECHNICAL CONTEST.

April, 2013 - Present
Working for Cusp Dental Supply Co., Ltd.
March, 2013
Graduated from the Osaka Ceramic Training Center
April, 2009 - March, 2011
Worked for Tsuruga Denatal Laboratory
March, 2009
Graduated from the Aishi Dental Technician College

MDT SHIGERU ADACHI USED KATANA™ ZIRCONIA HTML AND CZR FC PASTE STAIN FOR HIS CASE STUDY

By Irfan Abas
Dental implantologist & restorative dentist

Irfan Abas is a specialist in the field of oral implantology & restorative dentistry and an international speaker on the subject. He has given more than 20 presentations, workshops and live surgery courses throughout the world. TP - a dutch dental magazine, of which he is also editor, has published multiple articles under his name. Another highlight is a publication in the NTvT, in collaboration with Prof. Gert Meijer (Radboud UMC), under whose supervision Abas successfully completed the four-year postdoctoral training Reconstructive Dentistry in 2014. He is also an instructor and lecturer for the AAIE and chair of MINEC Netherlands. Irfan Abas has his own practice in Bussum, the Netherlands (tandartsabas.nl).

A healthy 42 year-old male patient requested reconstruction of his central incisors, which were badly worn.

Pre-Treatment

After producing the mock-up, grooves were prepared through the mock-up.

To fit two lithium disilicate veneers, a preparation of 1 mm was required. After removing the mock-up, the preparation was perfected.

Checking the space using a silicone mold.

Definitive preparation (frontal)

Temporary veneers made from temporary resin based material (Protemp)

Spot-etching before bonding the temporary veneers in place.

A small amount of flowable composite applied to the etched surfaces.

Light curing the entire surface of the temporary veneers.

Finished temporary veneers.

The veneers constructed by the dental technician.

Checking the fit of the veneers

Rubber dam fitted to enable controlled adhesive cementation.

Etching with 35% phosphoric acid K-Etchant Syringe for 10 seconds.

Treatment with selfetching primer PANAVIA™ V5 Tooth Primer (left on for 20 sec.)

Etching of the lithium disilicate veneers with hydrogen fluoride.

Clearfil Ceramic Primer Plus MDP-silane primer applied to the veneers.

Veneers secured to a placement instrument before definitive cementation

PANAVIA V5 Paste applied to the inner surface of the veneer.

PANAVIA V5 Paste spread over the veneer.

Veneer fitted and excess removed.

Light curing (minimum 10 sec.).

Immediately after the adhesive cementation with PANAVIA V5.

Immediately post-op.

Immediately post-op.

Two months post-op.

One year post-op.

One year post-op.

By Paul de Kok, Amsterdam (KVPA) Periodontic Clinic & ACTA

Picture 1

The Patient
Joris reported to the clinic with two discoloured composite two discoloured class IV composite restorations in tooth 11 and 21 11 and 21 (picture 1). These vital teeth were traumatized in his childhood. He was not satisfied with the aesthetics of the restorations neither with the overall shape and colour of the two teeth. It was therefore decided to make porcelain facings for tooth 11 and 21.

Picture 2

The preparation
In order to limit the sacrifice of healthy tooth tissue while still creating sufficient space for the porcelain, a preparation was chosen with an incisal reduction of 1.5mm and a buccal reduction of 0.5mm. A so-called depth cutter – a diamond drill with 0.5mm deep recesses – was used to achieve this (picture 2).

Picture 3

To be able to adjust the shape of the mid-line to the new facings, cutting was carried out centrally through the contact. From the distal aspect the contactpoint was remained. The thin shoulder was positioned equi-gingivally, so that a dry operative field could be achieved without damage to the gingiva.

The preparations were then finished using fine drills and polishing discs. The existing, well bonded diamonds composite restorations were left in situ (picture 3).

Picture 4

Since the transparent facings are very thin, the colour of the cut teeth is significant. The colour of the cores was therefore matched using the Natural Die colour guide (picture 4). Finally, impressions were made. Temporary restorations were placed by means of 4 spot etching points and bonding.

Picture 5

Cementation
To combine superior aesthetics with adequate strength, pressed lithium disilicate restorations were chosen for Joris. Prior to cementing the facings, they were tried for size and checked for marginal integrity, contact points, occlusion/articulation and aesthetics. Then the correct cement colour was established by testing the facings with various try-in colours PANAVIATM V5 Universal (A2); Universal (A2) appeared to be the most appropriate colour in Joris’s case. The teeth were then polished with pumice and the facings were cleaned with alcohol, after which the teeth from 14 up to and including 24 were isolate by a rubber dam.
An incisor clamp was placed on the first teeth to be cemented. The facing was tried for fitting once more to ensure that it was free of contact with the rubber dam or the clamp and that the operative field of the preparation was totally dry (picture 5).

Picture 6

The facing was etched with 9% fluoricacid (picture 6) for 20 seconds to achieve micro-mechanical retention.

Picture 7

It was then rinsed with water for 20 seconds before being neutralised in a solution containing ceramic neutralising powder. CLEARFILTM CERAMIC PRIMER PLUS was then applied to the facing. This ensures chemical bonding between the facing and the composite cement thanks to the incorporated silane and MDP. The adjacent teeth were separated by means of a transparent strip, after which the preparation was etched with 35% phosphoric acid (picture 7). TOOTH PRIMERTM was applied after thorough rinsing with water and drying after it had taken effect for 20 seconds.

Picture 8

A thin layer of PANAVIA V5 cement was then applied to the facing. The facing was placed on the preparation with the application of light finger pressure. A microbrush was used to remove the major excess along the margins. The cement of the buccal and palatal aspect was light cured for 5 seconds. A sharp scaler and floss were used to remove the final excess. Glycerine gel was then applied to the outline to avoid oxygen inhibition during curing. The cement was finally light cured from both sides for 20 seconds, the glycerine gel was rinsed away and the margins were finished by means of a composite polishing stone. After placement of the first facing, the rubber dam clamp was moved to the neighbouring tooth so the cementation of the second facing could proceed. This facing was once more tried for fit, pre-treated and cemented in an identical manner (picture 8).

Picture 9

The result
The facings were checked a few weeks later (picture 9). Joris was very satisfied with the aesthetics of his two central incisors. The transitions from tooth to restoration were invisible and the gingiva was healthy.

Picture 10

The transparency, surface structure and gloss are better adjusted to the neighbouring elements and to Joris’s smile (picture 10).

Dentist:

Paul de Kok, Amsterdam Periodontics Clinic

Paul de Kok studied dentistry at the ACTA and is an authorised restorative dentist at the Amsterdam Periodontic Clinic (KvPA), where he treats referred patients with restoration and aesthetic issues. In addition, Paul teaches indirect restorative dentistry at the Oral Functional Anatomy faculty of ACTA as well as conducting research in the Materials Science department. He also delivers lectures about this discipline at both a national and international level.

Dental technician: Eric van der Winden, Oral Design Center Holland

PAUL DE KOK USED CLEARFIL CERAMIC PRIMER PLUS AND PANAVIA V5 FOR HIS CASE STUDY