Interview: "Denthue removes human errors of shade selection" - Dr. Sachin Chaware

Hearty congratulations Dr. Sachin for launching Denthue app. Can you tell us what Denthue is all about?

The process of shade selection is a critical step in esthetic dentistry. It is the second most common cause for remaking the ceramic crowns or repeating the anterior restorations. A visual shade guide is the most commonly used method, but shade selection has several subjective variations. Shade outcome is further affected by surroundings, weather conditions, and background illumination.

In digital dentistry, we need tools that can provide accurate shade selection by covering maximum tooth surface area and overcoming subjective variations and the risk factors mentioned above.

Denthue is a pocket-friendly and economical app that can provide accurate shade evaluation and help in shade communication with the technician. Its uniqueness lies in recording the shade at nine areas on the tooth surface. 

 

How did the idea come to your mind? When did you feel the need to develop this app?

In one of my prostho cases in the clinic, I finished crown cutting late in the evening. It was my last patient of the day, and I was pretty tired. I finished shade selection and submitted it to the lab. After cementing the final crown inside the patient's mouth, I realized it was not matching the natural shade. Though the patient was ok with it, I was not satisfied with the esthetic outcome as a prosthodontist. My tiredness at the time of shade selection caused the shade selection error.

I felt we needed a digitally automated system that removes subjective errors. 

Then after a few days, I saw on Crime Patrol TV show how police were struggling to find the identity of a victim with the help of fingerprints. It was then that the idea of developing a mobile app for tooth shade selection came to my mind. Luckily I had an excellent PG student with great knowledge of photography.

How many people do you have in your team?

We are a team of three: myself, my PG student who passed his MDS recently, and a software expert.

What were the initial challenges?

Our idea was rejected by several developers, institutional departments, and others. However, we did not lose hope and continued with mobile app development, and with our self-belief and hard work, today we have launched the application on the android platform.

Can you tell us the scientific basis of this app and the technical challenge it overcomes?

Tooth color has more than 700 variants. The tooth is heterogeneous with complex hydroxyapatite crystal at the enamel region and collagenous structure at the dentinal region, making tooth selection tedious.

In addition, the thickness of enamel and dentine at the cervical to the incisal area is a significant factor in color measurement parameters. These intricate structures react with the light more complexly than most other materials.

Moreover, second-generation color properties such as opalescence, fluorescence, translucence effect, surface texture, gloss, and luster are more pronounced on a ceramic or composite makeover of natural teeth.

Our primary objective was to simplify the task of shade selection. So we developed a user-friendly mobile app.

What light conditions are recommended for shade selection through your app?

Light condition requirements are simpler than the visual shade guide. The only requirement is sufficient white light, a single source of light, and no flashlight. 

Similarly, while taking the shade in the evening, the LED light does not create any problem as there is very little difference between natural daylight (5500K) and LED light (5000K). Moreover, artificial light has constant intensity, and natural light shows variation. 

1. While taking the tooth image, there should be sufficient cheek and lip retraction to expose the maximum amount of gingiva. 
2. The mobile camera should be placed 25-35 cm apart and parallel to the tooth surface,
3. Also, care should be taken not to over-dry the tooth surface.

Which reference shade guide/ color system is used in this app?

We cannot disclose this due to a non-disclosure agreement. However, to discover the clinical efficacy of mobile applications, we are using a visual shade guide and VITA Easyshade® Spectrophotometer for comparison.

Why should it be preferred over the 3D master?

Vita 3D master was introduced to overcome the drawbacks of Vita Lumina. It has more ordered color distribution than other commercially available shade guides. However, shade selection is mainly influenced by subjective variations among clinicians and technicians. Moreover, weather conditions, surrounding light conditions, and clinicians facing eye problems such as color blindness, eye fatigue, and aging are significant factors that compromise shade outcome. 

Similarly, the patient's clothing, gray bib, and dark lipstick can partially compromise the shade outcome. Serval past studies have shown that the instrumental method has an objective nature and provides more precise shade selection. 

Moreover, second-generation color properties such as opalescence, fluorescence, translucence effect, surface texture, gloss, and luster have been more pronounced on a ceramic or composite makeover of natural teeth. These color properties explain light reflection, refraction, and scattering from enamel to dentine. 

What are the camera considerations in shade selection and lab communication?

Digital Single Lens Reflex (DSLR) cameras are considered the "golden standard" cameras for taking high-quality dental photographs. The tooth image via DSLR camera provides the technician with a high-quality image. 

Recently, smartphone cameras have developed excellent sensor quality, resolution, and lens sophistication. With dual cameras and increased optical zoom, current smartphones give higher-quality pictures under ultra-angle mode. 

Mobile digital photography is more interesting for dentists due to intelligent features, such as low-light handling capabilities, super-fast-autofocus, and optical image stabilization for a steady picture. The polarized filters (smile lite MDP and Coco lux) are easily attached to a smartphone, which can be used for better documentation of mobile images. In our mobile application, we have adjusted the sensor on nine areas of the tooth surface to identify tooth shade at nine locations. The mobile application and camera are user-friendly because they are easy to carry in a pocket, low cost, and ease of use compared to a DSLR camera.

1. Case 1

2. Case 2

3. Difficult Shade matching due to mixed shade appearance and more variation in repetitive shade matching. Image taken in half closed mouth condition, therefore black shadow absorbed maximum light. Tooth has maximum surface roughness with horizontal and vertical lines, whitish hue appearance. Middle portion of the tooth more suitable for better shade match due to maximum saturation of the color. Hence it is advisable to select middle tooth surface for shade selection. Even the probe of vita spectrophotometer kept at middle portion of the tooth while shade recording.

Is Denthue available on both google play store and IOS?

At present, it is available only on the Google play store. We are developing the iOS application, but it takes more time because of the higher cost and specification sensitivity. Hopefully, by mid- 2022, our iOS application should be available for tooth shade selection.

Which upgrades are expected in the future?

We will soon launch the IOS application and upgrade the app with smile design and gingival esthetic guide capabilities. 

How is the initial feedback from dental practitioners and dental labs? Any technical issues?

The feedback has been positive except for a few problems related to app subscription as the card number has to be added. It is a safe Google transaction where Google will deduct Rs. 2 to confirm your card and initiate a free trial. 

At the end of the free trial, the subscriber will receive a notification to continue or discontinue the app. We are in the process of integrating a third-party payment, such as google pay or phone pay, but it will require some more time. 

We hope that dental practitioners will install our app, use it, and provide relevant feedback.

Any advice to first-time users who are not well versed with this app?

If any practitioner or lab technician faces any issue related to tooth image capturing or cropping of the image, we can provide separate guidelines to help them out. Moreover, step-by-step guidelines are available on our Denthue Facebook page.

How will this app help the dental institutes?

It will encourage Pg students and researchers in the field of esthetic dentistry to evaluate the role of the mobile application and suggest improvements.

Have you been able to create any patentable IPR?

Our mobile application is copyrighted and registered under the "DENTHUE" trademark.

Who are your competitors?

Right now, there are no competitors.

 

About Dr. Sachin Chaware

Dr. Sachin Chaware completed his postgraduation in Prosthodontics from Govt Dental College & Hospital, Mumbai in 2003. He has 17 years of experience as a UG and PG teacher in prosthodontics. Ex-professor and PG teacher at MGV KBH Dental College, Nashik. He has authored a book “Esthetics in Fixed Partial Denture.” He was invited as a data analyst at the University of Lisbon, Portugal.