Katarzyna Knurowska designs smiles that draw the eye without giving away that anything was done.
She is a dental technician who specialises in digital smile design. She works on intraoral scans, photographs and 3D models, and her work ends the moment somebody else places it in a patient’s mouth. Beautiful teeth are the point here, not a side effect. The aim is that they are beautiful the way natural teeth are beautiful, rather than the way a well made restoration looks.
We wrote to her because in her profession perfection has become cheap and naturalness expensive.
Software can design a perfectly symmetrical arch in minutes. Copy one side onto the other, mirror a tooth, align everything to the mathematics. Very often she deliberately does not do it. We wanted to know how she knows when to stop, and what she sees in a patient’s face that the program does not.
What follows are her answers, shortened, but in her own words.
This is not a conversation about technology, although there is a lot of technology in it. It is a conversation about how you can tell that something belongs to someone.
Before the questions, her own description of what this work involves.
The starting point is intraoral scans, supplemented with photographs and further data that make it possible to analyse not only the teeth but their proportions in relation to the face and to the whole smile. From that comes a digital design, individual to that person, to their anatomy, their features and their expectations. The next stage is moving it out of virtual space and into reality: milling the crowns from a carefully chosen material.
And this is where technology meets craft. A milled crown is not the end of the process. Through micro layering, firing the ceramic, individual characterisation and giving the piece the right structure, colour gradation and translucency, the features we observe in natural dentition are rebuilt. As Katarzyna Knurowska puts it, technology gives her precision and repeatability, but it is knowledge, experience and the technician’s hand that give teeth individuality and life. Those details are what let a designed smile be a spectacular change and still look natural.
You design a smile on a screen before anyone sees it in a face. How do you know a design is good before somebody wears it?
Designing a smile is not picking a nice tooth shape from a library and placing it on a model. At the analysis stage we already receive a great deal of information: the midline, the occlusal plane, intraoral scans, photographic documentation. Today we also have a 3D scan of the soft tissues and of the patient’s smile, and that is a huge step forward, because a 2D photograph does not capture the three dimensions of a face.
A lot depends on the collaboration with the dentist. For big transformations I require, among other things, a properly taken close-up photograph of the face, frontal: the patient sitting straight, looking ahead, not resting their head. Any deviation can later distort the reading of proportions.
And how do I know a design is good? When, after some time, I can look at it a second and third time and see nothing I would want to change. And when every further attempt to “improve” it makes it look worse. That is when I know it is the right moment to stop.
The mock-up, an early try-in, matters a great deal too. The design stops being a visualisation on a screen, the patient sees it in their own face and judges how they feel with it. Software can help create a visualisation, but it is experience that tells you whether the design is harmonious, functional and made for this particular person.
People say “I want nice teeth”, but nice for a twenty-year-old and for a sixty-year-old are not the same thing. How do you know what suits a specific person rather than the current fashion?
“I want nice teeth” is definitely not enough for me. There is no single universal smile that works for everyone. What looks natural on a twenty-year-old is not necessarily right for a sixty-year-old, and the other way round.
The choice of tooth shape is not random. In prosthodontics we have classifications and rules that relate tooth form to the shape and proportions of the face, the nose, the general build. There are also classic concepts of a more feminine or more masculine character of teeth. I do not treat this as a rigid scheme, it is a base that I combine with experience and with the analysis of a specific face. We do not design teeth for a classification, we design them for a human being.
Age gives many clues. In a young person the teeth have more pronounced anatomy, preserved cusps, more translucency at the incisal edges. In an older person there is wear, micro-cracks, the edges look different. These elements can be deliberately built into a design if we want a natural result. But that does not mean an older patient automatically gets darker teeth. We can make a very bright smile for a mature person and it will still be natural. The key is that the colour works with the whole face, with the complexion, even with the whites of the eyes. The brighter the whites and the whole face, the more freedom we have with a light shade without it looking artificial.
And one more thing: before we think about aesthetics, we have to create the conditions for it. A patient may come in for beautiful veneers, and the diagnosis shows a malocclusion, crowding, calculus. Then it is hygiene first, treatment, orthodontics, sometimes surgery, and only on a healthy base do we build the restoration. Behind one “before and after” photo there are very often many months of work by several specialists. A trend can be an inspiration, but it should not decide what a person will look like. What matters most to me is that after treatment the first thing you see is not beautiful teeth. I would like us to see a person the smile simply belongs to.
A perfectly even, white smile immediately looks fake. What do you deliberately leave imperfect so the work looks real?
That is true. Perfectly straight, perfectly symmetrical teeth in a very light colour quickly give the effect of a “pasted on” smile, what we jokingly call bathroom ceramics. In our profession we assume that if a patient smiles and the first thing we notice is that they have restorations, then somewhere along the way the naturalness was lost.
Naturalness begins with the material, with how light passes through the restoration. But the most interesting part is symmetry. Today’s software lets you create an almost mathematically perfect smile. I can design one side of the arch and copy it to the other, create one tooth and mirror it exactly. Except that very often I deliberately do not.
A natural smile is not symmetrical. The teeth on the right and the left are not copies of each other, they differ minimally in position, rotation, shape. And it is precisely those small differences that make us read a smile as real. So I position every tooth individually, according to the rules of the profession and the occlusion, but I also leave room for judgement and, to put it simply, for the technician’s hand.
This is not about deliberately doing something wrong. That is a very important distinction. It is about consciously stepping away from mathematical perfection where it would kill the naturalness. A perfect smile can be made today with a single tool in a program. A natural one takes an eye, experience, and the technician’s decision not to use that perfection.
You work on a model, not with a living person across from you. How much do you need to know about that person for the design to fit them?
This work has changed a lot. We used to work on models cast from impressions. Today the dentist scans the mouth and, with one click, while the patient is still in the chair, sends the scan to the lab. I can open it immediately and give feedback, and we often plan the next steps together, live. A technician no longer works “on a model”. We work on a very large amount of digital information about the patient, we just have to be able to read it.
I do not need to know the patient privately. I do not need to know what they do or what their personality is like to design a good smile. I need the right data and the ability to interpret it. The starting point is often the patient’s natural teeth, even when those are exactly what we want to change. They show me where we start and how far I can move away from what this person has had until now.
And this is one of the harder things in this work. There is a very thin line between a smile that is completely different and gives a spectacular transformation, and teeth that start to look foreign. It is not about knowing everything about the patient. It is about extracting what matters from the available data, and designing a smile that is new and yet looks as if it had always belonged to that face.
Software can now propose a finished smile design. What does the hand and the eye still do in this work that the program will not?
Artificial intelligence in design software is a very hot topic among technicians right now. I often hear: “the dentist already clicks through the stages in an AI-assisted program and gets a finished job at the end”. And that is where my most important question comes in: fine, but what kind of job?
An algorithm can analyse data, propose a shape, fit it to the occlusion and produce a design that is technically correct. Except that in our work “correct” does not always mean “good”. Experience lets you judge something more: whether the smile is harmonious, whether it suits this face, whether a small change in position would make it decidedly better. Even within CAD itself there are many parameters that cannot be set once and for all, they depend on the material, the preparation, the clinical situation.
And the design is only the beginning. Then comes manufacturing, the choice of material and technology, finishing, texture, characterisation. That is where a design on a screen starts becoming a real tooth. I am not afraid of artificial intelligence, I treat it as another advanced tool. A program can propose a solution. An experienced technician can judge whether it is the right one for this case, and if not, knows what to change and why.
You do transformations, cases where somebody’s face changes a lot. What changes in a person, apart from the teeth, when they see the result for the first time?
The moment the dentist cements the work and the patient sees their new smile for the first time is probably the most beautiful moment of the whole process. I am lucky to work in a clinic, so I can often be there in person. There have been times when I had tears in my eyes myself.
That is when I see very clearly that a transformation is not only about teeth. We get people who for years did not feel good about their smile, who consciously avoided smiling. When such a patient looks in the mirror for the first time, you can almost watch the change happen in them within a few seconds. First disbelief, then the smile gets wider and wider, and suddenly there is a completely different confidence. The person starts looking at themselves differently.
But for me the most important thing is happiness. The sincere kind, in the eyes, which cannot be mistaken for any other reaction. In those moments I feel that I have helped someone get back something they had been missing for a long time: the freedom to smile, and sometimes simply the joy of their own reflection in the mirror.
You build a piece of somebody’s face and then almost never see how it lives day to day. How do you feel about the work leaving, and coming back to you at most in a photograph?
I do not take it personally and I do not feel any lack. What matters most to me is the feedback from the dentist: how the work looked in the mouth, how the patient reacted. If I hear “it was great, the patient is happy”, that is enough for me.
In fact, I think watching could get in my way. I am very critical of my own work. If I could look at that smile again and again, from different angles, in different light, while the person talks, I would probably wonder every time whether something could have been done differently. You can always find a detail.
That is exactly why work for family and friends is, paradoxically, more stressful than the most difficult cases of strangers. I see the result for years, at every meeting. I have a few such jobs behind me and, surprisingly, I really like looking at them. Although I still inspect them from every side, I cannot switch off the technician in me. I have learned to let my work go. It is not made so that I can look at it. It is made so that someone can live with it normally and, ideally, forget completely that it was ever made.
Which project stayed on your mind longest after you handed it over, and what was it about?
The ones that stay with me longest are not the ones I am proudest of, but the ones that did not come out exactly as I wanted. One such case was a full transformation, an All-on-X bridge. The dentist gave me a clear brief: keep the occlusal plane from the previous restoration, which the patient was used to. I reproduced the arrangement and changed the character of the teeth to something slimmer and more delicate.
And at the try-in it turned out the occlusal plane was slightly “drifting”. The patient noticed it herself. In theory everything followed the brief, and yet the effect in the face was not what we expected. The plan was a small correction. I started it and at some point decided I did not want to keep fixing something I could do better from scratch. I went back to the design and made the whole piece again.
For the lab that meant extra time, material and a cost nobody had planned for. But in situations like this I stop counting hours. I would rather do the work again if it means I can put my name to it. The patient was very happy. And I learned that following the brief exactly does not guarantee the result. What matters then is not who was right, but what to do so that it is right. Sometimes you have to be able to tell yourself: this is correct, but for me it is not yet good enough. And have the courage to start over.
Three things worth taking from this conversation.
First, in this profession perfection has become cheap and naturalness expensive: symmetry is one click, and not using it takes an eye and experience. Second, “correct” and “good” are two different things, and the difference between them is exactly what the algorithm still cannot see. Third, the aim is not an invisible smile but one that draws the eye without revealing where it came from. It should look as though it had always belonged to that face, which is considerably harder than simply looking good.
Katarzyna Knurowska is a dental technician specialising in digital smile design, based in Poland: instagram.com/knurowska_smiledesign