Chairside Emax Crown with Cerec Workflow: A Case Report

INTRODUCTION

Digital work flow in dentistry has increased in recent years due to headway made in technologies such as intraoral scanners and software programs, which have contributed to improve communication between clinician and dental technician. Digital Smile Design (DSD) is digital tool which provides, from facial perspective, rehabilitative aesthetic planning, better communication between specialists and an improvement in expected outcome of treatments.¹

A dynamic documentation of smile is an important step in 2D/3D digital smile design process that can be performed in entire digital flow and will help in re-habilitative procedures. Advantages of using video documentation are that it facilitates and simplifies the documentation process, improves smile design, facial analysis, treatment planning, team communication and patient education.² The DSD could be converted in to conventional or virtual diagnostic model to facilitate subsequent clinical treatments, i.e. CAD-CAM restorations.^3-7

The preparations for minimally invasive treatments have become easily achievable in restorative dentistry because of combination of adhesive technique with restorative materials featuring translucent properties. Materials like lithium disilicate ceramic^8-11 have properties like those existing in natural teeth so they have presented positive outcomes.^12,13

Another important tool that integrates the digital workflow are intraoral scanners. These are powerful devices that allow an immediate determination of quality of the impression and have the capacity to easily send models to laboratory using e-mail, thus reducing expense and time.¹⁴

This report is a presentation of a clinical case that follows a full digital workflow. After a minimal invasive preparation approach, the digital smile protocol, CAD-CAM monolithic lithium disilicate crowns was used to solve a loss of vertical dimension and subsequent aesthetics.

CASE REPORT

A 20-year-old male patient reported to the clinic with aesthetic complains of pain in upper anterior and smile make-over demand. Patient has lost his incisal edge due to trauma 2 days back. Oral hygiene was good and soft tissues were healthy. The patient did not have any other symptoms. [Figure 1]

Patient has to travel abroad for further studies so we have to perform all treatment in single day. Considering all the examinations and the data collected, Single sitting root canal treatment with chairside smile make-over with direct aesthetic composite crown was planned. Single sitting root canal treatment was planned on maxillary incisors w.r.t 11,21. Here we opted for CEREC workflow using eMax CAD block to make it convenient and effective for the patient and save time. [Figure 2]

Chairside single visit root canal treatment was done on 11 and 21 followed by digital impression using Dentsply Sirona. Single-visit of less than one hour was the time consumed to get the output through the CEREC CAD/CAM chairside system. The system allows scanning, digitally designing, making occlusal adjustments, and calibrating the proximal contacts. [Figure 3]

Upper central incisors tooth preparation was done based on the thickness of the prosthetic material. Minimum thickness helps in achieving structural durability and aesthetics. Round angles were made to improve load distribution through the material. Tooth preparation was avoided from any irregular surfaces. We then read the Morphology of dentition on software, and the data is observed by optical impression once the virtual model was developed to select insertion axis. Designing was done in 5 minutes followed. The obtained data had to be sent to the milling machine. Wet milling was done in the primemill which took around 11minutes. An intraoral digital impression was achieved which was converted to a stereolithography (STL) file using special software. The STL files were introduced into additional software systems for design and fabrication of a digital wax-up [Figure 4 a,b,c,d,e].

After milling the sprue detachment was done from the block followed by sintering and glazing. Sintering was done for strength which took around 12-15 minutes. Both sintering and glazing were simultaneously done in speed fire. Glazing was done to provide aesthetic and gloss in speed fire which took around 8-10 minutes.

Both crowns were made from a single block and treatment was done with eMax CAD block. Later final adhesive luting of veneer was done. The patient was very pleased with the final result. [Figure 5]

DISCUSSION

Due to the introduction of a whole range of devices, machines and software, the digital revolution is completely changing the dental profession. Thanks to the virtual world, we can plan in detail from surgical to restorative procedures, with the help of 3D modelling and software like CAD-CAM. Intraoral scanners are digital devices used not only to obtain study models but also for the detection of impressions necessary for the modelling of a whole series of restorations. Digital impressions are also a procedure that contribute to a more precise register of the bite, and they can eliminate several analogue procedures that can generate distortions.¹⁵

In recent years, the variety of applications, together with the advantages of these machines, have made intraoral scanners highly interesting devices. Nowadays, there are several intraoral scanners in the market, but the most important element to be considered should be the accuracy, i.e. the quality of the data derived from scanning, a combination of trueness and precision. There are already reports in specialized literature that have studied the accuracy of the different intraoral scanners available.¹⁶

In modern digital dentistry, the fundamental steps of the therapeutic flow can be summarized into 3 fundamental phases: acquisition of the images and patient data, processing of the information and production of parts, and clinical application onto patients. Digital instruments and the CAD-CAM enable development of more predictable and reliable prosthetic workflows. All these principle work on AI [Artificial intelligence]. Furthermore, the immediate control of the operational procedures guarantees the transmission of accurate information to the dental laboratory and to all the team involved in the therapy.¹⁷

The aesthetic demands and expectations of the patients also increase: The digital aesthetic preview thus becomes an expression of everything that the clinician in theory is able to do, legitimizing the patient's demands.In the described clinical case, the accuracy of the Digital Smile System software was assessed by making customized composite veneers from a totally digital workflow and checking the consistency with the initial project, as described experimentally by other authors.¹⁸

CONCULSION

Smile is person’s most important ability to express wide range of emotions and determines how well person can function in society. Dentist can provide better aesthetic rehabilitation with minimal tooth preparation by preserving enamel layer for bonding of ceramic with tooth structure. In this case series, anterior aesthetic rehabilitation of patients by zirconia crown placement.

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