The Future of Crack Detection in Dentistry.

Dentistry has gotten much better at seeing structural damage after it happens, but the tooth that hasn’t declared itself yet has always been harder to diagnose. InnerView, a newly FDA-cleared device from Perimetrics, measures how a tooth or implant responds mechanically to a controlled tap, and that changes the kind of evidence a dentist can bring to a difficult diagnostic decision, without replacing the judgment that decision still requires.

Cracked teeth have frustrated dentists for as long as I’ve been practicing.

A patient points to one side of the mouth but can’t identify the tooth. Nothing obvious appears on the radiograph. The restoration looks intact. Percussion is inconclusive. A bite test produces a response on one cusp but not another. The patient knows something isn’t right, and the dentist knows the symptoms matter, but the evidence is incomplete. That uncertainty is part of what makes cracked teeth difficult.

We’ve become much better at seeing anatomy. Digital radiography, CBCT, magnification, transillumination, and modern restorative diagnostics give us information earlier generations of dentists didn’t have. Even with those tools, a structural defect can exist before it becomes easy to see.

InnerView is interesting because it approaches that problem from a different direction. Instead of trying to create another image, the system measures how a tooth or implant responds mechanically to a controlled percussion. The FDA cleared the current InnerView System in September 2025 to measure external mobility and what the clearance describes as internal mobility within tooth or implant structures. The device itself is not cleared to diagnose a crack. Clinical interpretation still belongs to the dentist.

That distinction matters. InnerView doesn’t eliminate clinical judgment. It gives the clinician another kind of information to judge.

Why Do Cracked Teeth Remain Difficult to Diagnose?

The clinical challenge usually isn’t recognizing an obvious fracture. It is the tooth that isn’t obvious yet.

Cracks can create vague or intermittent symptoms. Some patients feel discomfort only on release from biting. Others report cold sensitivity or a sensation they can’t describe clearly. The crack may be difficult to visualize, and conventional imaging may not reveal it at the stage when the patient first becomes symptomatic.

That limitation is well documented. Research on quantitative percussion diagnostics has described cracks and fractures as difficult to detect clinically and radiographically, particularly when the structural defect is small.

The consequence is not that dentists are missing something they should obviously see. The problem is that much of traditional diagnosis depends on either visual evidence, patient symptoms, or a clinician applying and interpreting a mechanical test manually.

Those methods remain important, but they also leave room for uncertainty. The question InnerView raises is whether structural behavior itself can become another objective data point.

What Does InnerView Actually Measure?

The science behind InnerView is called Quantitative Percussion Diagnostics, or QPD.

The handpiece applies a series of brief, controlled taps to a tooth or implant. Sensors record the mechanical response, and the system analyzes the resulting energy-response pattern.

The FDA-cleared InnerView System produces two measurements. One quantifies external mobility. The other, called NFE, quantifies internal mobility within the tooth or implant structure. FDA documentation is careful about what that means: the system measures mobility. It is not itself intended to diagnose a medical condition.

That wording is more important than the marketing language surrounding the product.

A dentist should not look at a number and say, “The machine diagnosed a crack.” The better interpretation is that the device has measured structural behavior that may add information to the rest of the examination. That is a more disciplined way to use new technology.

Did the Research Behind InnerView Begin With This Device?

InnerView is new as a commercial system, but the underlying QPD work is not.

Dr. Cherilyn Sheets, Dr. James Earthman, and other investigators have studied quantitative percussion for years in natural teeth, restorations, and implants, going back to early laboratory and clinical research comparing QPD readings against reference methods such as microscopy, transillumination, and dye penetration. Subsequent clinical research examined whether QPD measurements corresponded with structural pathology identified when teeth were disassembled under magnification. Other studies looked at structural changes before and after restorative treatment and followed sites over time.

A later prospective, multicenter clinical study evaluated whether QPD could estimate the probability of a structural microgap defect in restored and unrestored teeth. That body of work is why I think this technology deserves more than a quick product review. It represents a different diagnostic question. Instead of asking only, “Can I see a fracture?” the dentist can also ask, “How is this structure behaving mechanically?”

Hypothetical Example: The Tooth That Never Quite Declares Itself

Imagine a patient comes in with discomfort on the lower right side.

The radiograph is unremarkable. The restoration on the first molar looks serviceable. There is no obvious fracture under magnification. The patient occasionally feels a sharp sensation when chewing something firm, but the symptoms aren’t consistent enough to reproduce every time.

The dentist has choices: watch it, replace the restoration to investigate underneath, adjust the occlusion, refer, or gather more information. Now add an objective structural measurement showing abnormal internal mobility compared with the surrounding teeth.

That number still does not tell the dentist exactly what treatment to perform, but it changes the conversation. The clinician has another reason to look carefully, another baseline to follow, and another piece of information to combine with history, imaging, magnification, occlusion, pulpal testing, and the rest of the examination.

That is where I see the practical value. Not as an answer machine, but as another layer of evidence.

Can Objective Data Also Improve the Decision Not to Treat?

There is another side to this.

New diagnostic technology can create overtreatment if clinicians assume that every abnormal measurement demands intervention. That would be a mistake.

The value of measurement is not simply finding more things to treat. It is improving the quality of the decision.

A borderline tooth may be monitored. A measurement may be repeated. The trend may remain stable. A patient with mild symptoms and no progression may be managed differently from someone whose structural measurements change over time while the clinical symptoms increase.

Longitudinal tracking may turn out to be one of the more useful aspects of this category of diagnostics. InnerView’s current system is designed to store measurements so clinicians can compare mobility over time rather than relying entirely on one examination. Dentistry is already familiar with this idea. We monitor periodontal measurements, compare radiographs, watch wear, follow lesions, and look for change. Structural mobility may become another variable that is more useful as a trend than as a single isolated number.

The Objection: Do We Really Need Another Diagnostic Device?

That is a fair question.

Dental practices are full of technology that looked essential during a demonstration and became expensive furniture six months later. A diagnostic tool deserves a higher standard.

Does it answer a question the practice cannot answer reliably now? Does it change clinical decisions? Is the information reproducible? Can the team collect it without turning a recall appointment into a technology demonstration? Does the dentist understand what the measurement means and, equally important, what it does not mean? InnerView should be judged by those questions.

FDA clearance is important, but clearance does not mean the device replaces radiographs, CBCT, transillumination, microscopy, pulp testing, occlusal evaluation, or the clinician’s examination. The FDA documentation says the device measures mobility and is not intended to provide diagnosis. That should shape how dentists think about adoption.

The best new diagnostic tool does not compete with judgment. It makes judgment better informed.

Where Might the Hygiene Team Fit?

A device only becomes clinically useful when it fits the practice.

InnerView’s current materials position the measurement as brief enough to incorporate into routine examinations and ongoing monitoring. The QPD literature also describes the technique as noninvasive and suitable for repeated measurements. That raises an interesting workflow possibility.

Hygienists already collect longitudinal information. Periodontal measurements, radiographs, recession, wear, mobility, tissue changes, and patient-reported symptoms often emerge first in hygiene. Structural measurements could become part of that larger record when clinically indicated.

I would still be cautious about turning every hygiene appointment into a full-mouth screening protocol simply because the technology makes it possible. The clinical question should come first. Technology should support an examination, not create an examination simply to justify the technology.

Is Patient Communication One of the Quieter Benefits?

Dentists live with diagnostic uncertainty more comfortably than patients do.

A patient who says, “Something hurts when I bite, but you can’t see anything,” may hear uncertainty as doubt. The dentist may be thinking exactly the opposite. The symptoms are credible. The problem simply has not declared itself clearly.

Objective measurement can help explain that distinction. A dentist might say that the imaging does not show an obvious fracture, but the tooth is behaving differently from the neighboring teeth and deserves closer observation or additional evaluation. That is a better conversation than pretending certainty where none exists.

It can also support restraint. If the measurements are stable and the rest of the examination does not justify treatment, the patient can understand why monitoring is a deliberate clinical decision rather than inaction. Better data should improve both treatment and non-treatment conversations.

Does the Implant Application Deserve Separate Attention?

The same handpiece also measures mobility in dental implants.

That is not a minor feature, although I would keep it separate conceptually from crack detection. Teeth and implants are different biological systems, and the clinical meaning of mobility is different.

The underlying measurement principle, however, is related. QPD research has been used to study implant stability and the implant-bone interface, and the FDA-cleared InnerView indication includes both teeth and implants. That could make longitudinal implant monitoring an important use case, particularly when the dentist wants an objective mechanical measurement to compare over time. Again, the measurement is information. It is not the treatment plan.

What Would I Want to Know Before Putting InnerView Into a Practice?

I would start with the clinical questions rather than the sales presentation.

How repeatable are the measurements in normal practice? How should a clinician interpret changes over time? What thresholds should change management? How does the information affect a decision that would otherwise have been made differently? Where is the strongest evidence, and where is the evidence still developing? How much calibration does the team need? What is the consumable cost per measurement? Which patients benefit enough to justify using it?

Those questions are not skepticism for the sake of skepticism. They are how good technology becomes good dentistry.

There is also a difference between evidence supporting the underlying measurement science and evidence supporting every future clinical use that may eventually be marketed around it. Perimetrics currently maintains a research library describing its studies, but its own clinical-studies materials also note that some published claims relate to technologies or uses that were under evaluation and were not necessarily included in FDA clearance. Dentists should keep those boundaries clear.

The Future Is Probably Additive, Not Replacement

I do not think cracked-tooth diagnosis is about to become simple. Biology rarely gives us that gift.

Patients will still describe symptoms poorly. Imaging will still matter. Magnification will still matter. Occlusion will still matter. Pulpal status will still matter. Sometimes the only way to understand a tooth completely will be to see what is underneath an existing restoration.

What may change is the amount of objective structural information we have before making that decision, and that is meaningful.

InnerView introduces a measurable variable into an area where dentists have often had to combine symptoms, visual evidence, mechanical testing, and experience without an objective measurement of internal mobility. The product will need to prove its place in everyday dentistry over time, which is exactly how it should be.

A technology this interesting does not need exaggerated claims. The clinical question is strong enough on its own.

If we can measure structural behavior earlier and use that information responsibly, we may be able to make some difficult diagnostic decisions with more evidence and less guesswork. For a dentist, that is worth paying attention to.

Frequently Asked Questions

What is the InnerView System?

InnerView is a dental device from Perimetrics that uses Quantitative Percussion Diagnostics to measure external mobility and internal mobility within teeth and implants. The current InnerView System received FDA 510(k) clearance in September 2025.

Does InnerView diagnose cracked teeth?

No. The FDA-cleared indication is for measuring mobility characteristics of teeth and implants. The FDA documentation specifically states that the device is not intended to provide diagnosis. The clinician must interpret the measurement alongside the rest of the examination.

What is Quantitative Percussion Diagnostics?

QPD is a noninvasive method that applies brief controlled percussion to a tooth or implant and analyzes the mechanical response. Research has evaluated the method for structural defects in teeth and for implant stability.

Can InnerView replace radiographs or CBCT?

No. InnerView provides a different type of information. Radiographs and CBCT provide imaging data, while InnerView measures mechanical mobility. These tools may complement one another, but the FDA clearance does not position InnerView as a replacement for established diagnostic methods.

Why might longitudinal measurements matter?

A single measurement shows structural behavior at one point in time. Repeated measurements may help the clinician identify whether mobility remains stable or changes across visits. InnerView’s current system is designed to store data for comparison over time.

About the Author

Dr. Jim Arnold, DDS is the Founder and CEO of Foundation Dental Alliance, a leadership and practice development organization serving dentists from graduation through retirement. He has 30 years of experience as a multi-practice owner and has been involved in more than 60 dental practice transitions. He leads the Foundation Dental Mastermind, Luxury Dental Retreats, co-founded Foundation Dental Transitions, and hosts the Foundation Dental Podcast. He also publishes the Foundation Dental Newsletter and Blog weekly, focused on leadership, practice design, and long-term sustainability in dentistry.

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