Journal of Dentistry Defence Section

CASE REPORT
Year
: 2021  |  Volume : 15  |  Issue : 2  |  Page : 152--155

Digital smile design and Computer-aided design/Computer-aided milling: Pivotal tools in esthetic dentistry


Harmanpreet Atwal, Tanuj Mendiratta, Dinesh Kumar, Amit Khattak 
 Department of Prosthodontics and Crown and Bridge, Army Dental Centre (Research and Referral), New Delhi, India

Correspondence Address:
Harmanpreet Atwal
Department of Prosthodontics and Crown and Bridge, Army Dental Centre (Research and Referral), Subroto Park, New Delhi - 110 010
India

Abstract

In the war of artisan versus automation, it is always the automation that is more efficient. Today's world of the digital revolution has made dental surgeon to go beyond the conventional boundaries to obtain results of perfect form and function. Digital smile design (DSD) plays a pivotal role in esthetic dentistry where problems of midline diastema, generalized spacing, discoloration, and stained teeth can easily be rectified. One can obtain postoperative results even before the patient is operated giving choice to both the patient and operator for correct diagnosis and treatment planning improving communication and predictability of the end result. This case report aims to highlight integrated planning for beautifying the smile of an esthetically conscious patient with a reverse smile line using DSD software which analyzed the facial harmony, dentogingival parameters, and teeth dimensions. The software allowed for correct diagnosis and patient's consent in treatment planning preoperatively and also severed as a guide for designing and fabricating all-ceramic restorations using Computer-aided design/Computer-aided milling.



How to cite this article:
Atwal H, Mendiratta T, Kumar D, Khattak A. Digital smile design and Computer-aided design/Computer-aided milling: Pivotal tools in esthetic dentistry.J Dent Def Sect. 2021;15:152-155


How to cite this URL:
Atwal H, Mendiratta T, Kumar D, Khattak A. Digital smile design and Computer-aided design/Computer-aided milling: Pivotal tools in esthetic dentistry. J Dent Def Sect. [serial online] 2021 [cited 2021 Nov 30 ];15:152-155
Available from: http://www.journaldds.org/text.asp?2021/15/2/152/326216


Full Text



 Introduction



If beauty is power, then a smile is its sword. Modern dentistry is no longer confined to just teeth and gums, it requires clinicians to move a step ahead and integrate the smile with the overall facial framework.[1] The disharmony among the teeth, periodontium, and orofacial structures is one of the main reason for the patient to seek treatment in esthetic dentistry.[2] This requires a Prosthodontist to have deep understanding and knowledge of facial form, facial esthetics, and tooth morphology along with good communication skills.

Digital dentistry has revolutionized the approach in esthetic dentistry with the use of digital smile design (DSD) software. It aids in drawing various reference lines and shapes using extraoral and intraoral high-resolution photographs in a sequential manner to obtain the end result virtually which allows for correct diagnosis and preoperative evaluation of risk factors which can violate the esthetic principles and formulation of multidisciplinary approach treatment plan along with patient consent. There are various softwares available for this purpose nowadays including some of them even available as mobile applications which are integrated with the Computer-aided design/Computer-aided milling (CAD/CAM) machines through the open or close system making the process time-efficient with simpler laboratory procedures in today's digital world. With the evolution of CAD/CAM, the concept of monolithic ceramic materials was introduced increasing the choice of materials available in terms of translucency, brilliance, opacity, and strength to optimize the esthetic results.[3],[4],[5]

This article describes a pragmatic approach using digital workflow for enhancing the smile and overall facial appearance using DSD software and CAD/CAM fabricated indirect restorations for an esthetically conscious patient.

 Case Report



A 45-year-old male patient presented with a chief complaint of unesthetic smile with no display of maxillary central incisors during the smile. The patient had a history of trauma a few years back due to which the maxillary central incisors became nonvital so they were root canal treated and restored with direct composite veneers. With the passage of time, the trauma also led to fibrotic growth of upper lip in the incisor region which further concealed the central incisor display during the smile.

On clinical examination, the patient had midline diastema with mild discoloration of the maxillary central incisors. Mild crowding was observed in the mandibular anterior teeth with normal overjet and overbite. On comparing the size of maxillary central incisors with that of lateral incisors and canine, it was observed that there was a mismatch of proportion because of smaller size of central incisors due to which the patient had an unesthetic reverse smile line. The patient desired for an esthetic smile with display of incisors and emphasized for a minimally invasive treatment approach.

Treatment protocol

In the first visit, for analysis and treatment planning, a complete photograph documentation (extraoral and intraoral) was done which included extraoral frontal view photograph with a) spontaneous smile and b) forced smile [Figure 1] and an intraoral frontal view photograph in occlusion [Figure 2]. It was followed by diagnostic impressions using irreversible hydrocolloid (Cavex Cream Alginate, Holland) for fabricating study models.{Figure 1}{Figure 2}

The captured mobile images were then transferred to Coachman, DSD mobile software for smile designing. The designing was done in a phase-wise manner as guided by the software. First, the patient's photograph was put within the smile frame, and height-to-width ratio was set up to 89% [Figure 3]a. The patient's information of a middle-aged man with an oval facial form was entered and the smile zone was demarcated. It was followed by a smile simulation where various options of the midline, occlusal plane, smile curve, buccal corridor, and the number of teeth to be in the frame were adjusted. As the patient desired an esthetic result with a minimally invasive approach, the designing was kept restricted to four anterior teeth. The smile frame was then finally adjusted to the ideal height-to-width ratio, desired shape, shade of the teeth, and gingiva according to the patient's profile.{Figure 3}

The software then gave the option to obtain the final result which best matched the patient's profile and information entered. The obtained cosmetic result had a before and after option to appreciate the results [Figure 3]b. The procedure was so quick that the patient was shown the end result chairside. The patient was pleased with the result so an informed consent was obtained preoperatively. The software gave a fair idea of the amount of tooth buildup required to obtain the desired result with minimal involvement of teeth as the patient desired.

A decision of CAD/CAM fabricated all-ceramic crowns using monolithic shade gradient Vita Triluxe Forte was made for the maxillary central incisors along with a composite buildup of left lateral incisor as the patient was unwilling for involving lateral incisors by crown fabrication. First, shade selection was done, which was followed by the conventional method of tooth preparation for an all-ceramic full-coverage restoration. An incisal reduction of 2 mm was done using round-end tapered diamond regular grit bur. Facial and palatal reduction of 1 mm was done followed by shoulder margin preparation to obtain adequate bulk of ceramic at tooth ceramic junction in the cervical region. After tooth preparation, gingival retraction was done [Figure 4]a and a final impression was made using two-step putty-wash impression techniques (President, Coltene Whaledent) [Figure 4]b. The models were then poured using die stone. Provisonalization was done chairside using temporary crown and bridge material (Cool Temp NATURAL, Coltene) which was luted using temporary eugenol-free luting agent (Rely × 3M Temp Non Eugenol).{Figure 4}

The obtained models were then scanned using an extraoral scanner (Ceramill map 400, Amann Girrbach) and Ceramill Map software. Designing of the restoration was done based on the guidelines obtained from the DSD software keeping the crown height-to-width ratio of 89% using Ceramill Mind software [Figure 5]a and maintaining adequate overjet and overbite. After finalizing the three-dimensional constructed restorations, material polychromatic VITA Triluxe forte (Feldspathic porcelain) shade A2 was selected for fabrication. Final milling was done using Ceramill Motion software and Ceramill Motion 2 production unit which is 5-axis milling CAD/CAM machine. The milled restorations [Figure 5]b were then checked for fit and accuracy on the cast followed by characterization.{Figure 5}

The finished restorations were then luted intraorally using dual-cure resin luting agent (Variolink-II, Ivoclar) after the trial [Figure 6]. Both the intaglio surface of the restoration and tooth surface were etched with 9% hydrofluoric acid (Ultradent, Germany) for 20s and 37% phosphoric acid (Total etch Ivoclar) for 15s, respectively. The etchant was thoroughly rinsed off from the tooth surface and restoration. The restoration was then silanized with a silane coupling agent (Monobond, Ivoclar). Tooth surface and restoration were coated with bonding agent and cured for 25–30s. Dual-cure resin cement of appropriate shade was then placed into the restoration which was luted on the prepared tooth surface with adequate pressure and light cured for 10s to remove the excess cement with the help of dental floss and probe which was followed by complete curing for 60s. Composite buildup of left lateral incisor was done cervicoincisally with light cure resin in a conventional manner. On completion of the treatment, the overall patient's profile, smile, and self-confidence were boosted which can be evaluated in the pre- [Figure 7]a and postoperative photographs [Figure 7]b.{Figure 6}{Figure 7}

 Discussion



Smile design is known to be driven by both macroesthetics (facial parameters in relation to smile) and microesthetics (smile esthetics in correlation to the lips, teeth, and gingiva).[6] Conventionally, these parameters were evaluated and planned virtually in the operator's mind. This method had its own limitations of a patient being unaware of the treatment outcome, the operator had no visual guide to achieve the desired goal, and communication between the ceramist and the operator was challenging. Thus, there was a lack of planning and communication between the patient, operator, and ceramist by this method. DSD is therefore a boon to esthetic dentistry overcoming all these limitations and enabling the operator to provide predictable results.

CAD/CAM technology has become increasingly popular in dentistry over the past 25 years and has evolved to become an integral part of restorative dentistry.[7],[8] In this case monolithic CAD/CAM, ceramic restorations[9] were fabricated in accordance with the guidelines of DSD software. Vita Triluxe Forte (Feldspathic porcelain) was used in this case, it has a polychromatic shade gradient from cervical to incisal region imparting incisal translucency to the anterior restorations and giving them a lifelike appearance. In addition, this material has a flexural strength of approximately 360 MPa[10] which is adequate for an anterior restoration, fulfilling goals of both form and function. Thus, this material was apt for this clinical situation ensuring lifelike successful restoration and giving a boost to the smile of the patient.

 Conclusion



MM Devan states – “meet the mind of the patient before meeting the mouth of the patient.” In esthetic dentistry, it is of utmost importance that both the operator and the patient are able to visualize the desired outcome before choosing the esthetic treatment option that meets the patient's expectations. With the digital revolution in dentistry, one can evaluate the dynamic display of tooth and perform smile analysis of every patient chairside saving time and improving the predictability of the esthetic treatment. The presented case justified the role of DSD and CAD/CAM as pivotal tools in esthetic dentistry for the esthetic corrections and reshaping of anterior teeth.

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

Nil.

Conflicts of interest

There are no conflicts of interest.

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