|Year : 2022 | Volume
| Issue : 3 | Page : 322-325
Zirconia monolithic veneers: A durable and cosmetic alternative to regular veneers?
Rajesh Shetty1, Siddharth Shrirang Pinge1, Sanath Shetty1, Parmeet Banga2, Mohammed Zahid1
1 Department of Prosthodontics, Yenepoya Dental College, Mangalore, Karnataka, India
2 Department of Prosthodontics, YMT Dental College, Mumbai, Maharashtra, India
|Date of Submission||21-Jan-2021|
|Date of Acceptance||06-Apr-2021|
|Date of Web Publication||15-Sep-2022|
Dr. Siddharth Shrirang Pinge
Department of Prosthodontics, Yenepoya Dental College, Mangalore -575 018, Karnataka
Source of Support: None, Conflict of Interest: None
Ceramics have greatly evolved since they came into the eye of the dental community. Currently, there is a demand for a highly aesthetic as well as strong restoration and high translucent zirconia fits that criteria pretty well. This has significantly increased the applicability of zirconia as a restorative material in aesthetically demanding cases. Veneers have an innate disadvantage of lack of strength, decreased fracture resistance and chipping. Using these highly translucent zirconia veneers will help overcome these disadvantages. Therefore, the objective of the case series was to test the effectiveness of adhesively bonded highly translucent zirconia veneers using resin cement. This type of veneers provides satisfactory aesthetic outcomes and decreases the risk of fracturing during the trial and clinical use. However, further studies with long-term follow-ups are needed.
Keywords: Aesthetics, diastema, high translucent zirconia, laminates, minimally invasive, smile designing, spacing, veneers
|How to cite this article:|
Shetty R, Pinge SS, Shetty S, Banga P, Zahid M. Zirconia monolithic veneers: A durable and cosmetic alternative to regular veneers?. Adv Hum Biol 2022;12:322-5
|How to cite this URL:|
Shetty R, Pinge SS, Shetty S, Banga P, Zahid M. Zirconia monolithic veneers: A durable and cosmetic alternative to regular veneers?. Adv Hum Biol [serial online] 2022 [cited 2022 Oct 7];12:322-5. Available from: https://www.aihbonline.com/text.asp?2022/12/3/322/356113
| Introduction|| |
Adhesion techniques and strength of restorative materials have progressed by leaps and bounds to help an aesthetic dentist choose the best restorative material as per the requirements of the case. Quite a few aesthetic materials are recommended for veneers: Lithium disilicate, feldspar ceramic, leucite-reinforced feldspar, fluorapatite and zirconia-reinforced lithium silicate. The key drawback of ceramic materials is their brittleness.
In mainstream aesthetic dentistry, zirconia continues to play an important role, with aesthetic potential and high strength. Due to their high fracture resistance and ability to mask the dark substrate, tetragonal zirconia partially stabilised by Yttria-YTZP was originally considered only for the development of frameworks of crowns and fixed prostheses. The use of zirconia in full-contour monolithic designs has become a popular alternative to veneered zirconia to avoid the chipping problem. Monolithic zirconia with high fracture resistance allows as many dental tissues as possible to be retained, thereby minimising required prosthetic space. Zirconia ceramics have undergone many improvements in their microstructure and composition in recent years to improve their translucency without losing their fracture resistance substantially, thus increasing their clinical indication.
The scattering of internal light gives an opaque appearance due to its polycrystalline microstructure, so continuous improvement has been made to get a better translucent appearance. Altering the yttria content up to 5 mol%, cubic-phase zirconia with high translucency that consisted of 50% cubic phase was introduced. This latest category of 5 mol % yttria partially stabilized zirconia 5y psz cubic phase zirconia could give enhanced translucency comparable to or even better as opposed to lithium disilicate ceramic glass.
Adhesion of zirconia, a polycrystalline material which is inert to chemical surface treatment, was considered as a hindrance to using this stronger material as a partial coverage restoration. In order to maximize the adhesion between zirconia and cement, various surface treatments have been proposed: sandblasting with aluminium oxide, tribochemical silica coating followed by silanisation, nanostructured alumina coating, resin cement containing 10-methacryloxydecyl dihydrogen phosphate monomer (MDP), universal primers also containing methacrylate monomers among others. It is achievable to greatly enhance their adhesion to resin cement according to the form of treatment of the zirconia surface.,,,, However, clinical studies with zirconia veneers and ultra-thin zirconia veneers in literature can be counted on our fingers.
Therefore, the aim of this case report was to explain the development of veneers using translucent zirconia through a clinical case based on the favourable results of surface treatments in zirconia and on the aesthetic evolution of this material.
| Case Reports|| |
Case report 1
Presentation of case
A female patient aged 35 years reported to the department of prosthodontics with a chief complaint of an unaesthetic smile with spacing between 12, 11, 21 and 22. Midline diastema of about 2.4 mm was noted between the two central incisors and the gap between the 21 and 22 was about 1.7 mm, and the space between 11 and 12 was around 1 mm [Figure 1].
The patient was explained the various treatment options available and she decided to go ahead with zirconia laminate veneers. At the first appointment, an impression was made, and the study models were mounted using a semi-adjustable articulator to evaluate the occlusal contacts and eccentric movements. Another set of diagnostic impressions was made for making a wax-up of the smile and for purposes of planning the smile digitally.
Once the wax up was done, the occlusal contacts and eccentric contacts were checked again and a mock-up was done for the patient using (Protemp). The patient was asked whether she wanted any further changes in her prosthesis and an agreement was reached about the outcome of the teeth visualised through her temporary mock-up [Figure 2].
The preparations were made using medium grit round end diamond points to remove approximately 0.6 mm of tooth structure buccally and incisal preparation and palatal preparations were done to receive and incisal overlap type of veneer [Figure 3]. An index was built over the wax with additional silicone to direct the preparation at all levels. Finishing and polishing of the preparations were done using fine diamond burs followed by multilaminated burs with the aid of a multiplier contra-angle (NSK). In the same appointment, with additional silicone (zhermack), an impression of the prepared veneers was made and sent to our in-house dental laboratory cad cam dental laboratory. Temporary restorations were fabricated with a direct method using the putty index made from the wax-up.
Scanning of the die stone models was done, and the high translucent zirconia veneers were fabricated with monolithic translucent zirconia (Zolid Fx Multilayer®, Amanngirbach) and milled in a Amanngirbach computer-aided design and computer-aided manufacturing (CAM) system. The veneers were polished with rubber tips followed by which they were stained and characterised along with polishing and glaze. Veneering ceramics were not applied [Figure 4]. The intaglio surface of the veneers was surface treated using Airborne-particle abrasion with Al2O3.
At the cementation appointment, the try-in of the veneers was done and cementation of the veneers was done using RelyX U200 resin cement [Figure 5]. Single bond universal adhesive (3M ESPE), which contains MDP monomer, was used as a bonding agent on the tooth surface [Figure 6], as well as a primer on the intaglio surface of the veneers [Figure 7]. The labial surfaces of the veneers were in harmony with the gingival profile and stable occlusal contacts were provided to ensure smooth anterior guidance. The natural and aesthetic appearance of the prostheses was very satisfactory for the patient.
Case report 2
A 21-year-old patient referred to the prosthodontics department with a chief complaint of an unaesthetic smile [Figure 8]. On examination, it was noted that the patient old crowns were the reason for her unaesthetic smile and the canine in the first quadrant was rotated.
All the diagnostic procedures mentioned above were followed, and the patient was shown the same. It was decided to replace the old crowns and to give a zirconia laminate veneer for the rotated canine.
Preparations were done and impressions were made as described earlier and the prosthesis was fabricated in CAM-CAM [Figure 9] using translucent zirconia (Zolid Fx Multilayer®, Amanngirbach). The crowns were layered using veneering ceramic and veneer was a milled from monolithic translucent zirconia (Zolid Fx Multilayer®, Amanngirbach) [Figure 10].
The cementation protocol was the same as mentioned in case report 1, wherein RelyX U200 was used in addition to single bond universal adhesive (3M ESPE) [Figure 11].
Even and stable occlusal contacts ensuring smooth anterior guidance were provided. The patient was very satisfied with the natural and aesthetic appearance of the prostheses. Informed consent was obtained from both the patients.
| Discussion|| |
In this study, cubic-phase zirconia (5Y-PSZ) with flexural strength of 700 MPa based on the manufacturer's data report was used. The higher translucency is achieved by altering the grain size and sintering temperature and by adding more yttria to reduce the residual pores and reduce the impurities. In aesthetic clinical cases, high-translucent zirconia materials that have increased cubic contents at the expense of mechanical properties can be selectively applied as a monolithic design.
High translucent zirconia laminates not only are comparable in terms of aesthetics to other materials used for fabricating laminate veneers, but they also provide a good resistance to fracture. A large number of failures in laminate veneers cases occur due to fracture of veneering ceramic. These high translucent monolithic zirconia laminate veneers do not need a veneering ceramic due to superior aesthetic properties of this material. Furthermore, when cemented with a resin-based adhesive system, the fracture resistance of monolithic all ceramic is increased restorations when compared with conventional cementation.
Airborne-particle abrasion with Al2O3 is effective for providing mechanical bonds, and an adhesive resin cement or a ceramic primer that consists of monomers, such as 10-methacryloyloxydecyl dihydrogen phosphate (MDP), is recommended for chemical bonding to zirconia. This protocol was followed in the study, using a resin cement and a MDP containing bonding agent.
Long-term follow-up studies are needed to validate this treatment protocol, but in hindsight, high translucent zirconia laminate veneers do seem like a viable option for usage in moderately demanding aesthetic cases.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9], [Figure 10], [Figure 11]