New digital dental technologies have and will continue to become available to dentists. To evaluate them properly, we must understand that for technology to be a benefit, it must provide measurable value for the patient. Beyond this, it is critical to realize that most improvement in a process comes from eliminating waste from the process. In full-arch implant treatment, utilizing and coordinating the right digital technologies can eliminate waste from all phases of the treatment process. Selecting the right face-scanning, intraoral scanning, photogrammetry, 3-dimensional printing, milling, and finishing equipment and techniques can dramatically improve the patient experience.
Key points
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For digital technology to be a benefit, it must provide measurable value for the patient.
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Most improvement in a process comes from eliminating waste from the process.
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Utilizing and coordinating digital technologies during pre-procedure planning, surgery, and final prosthetic fabrication can eliminate wastes from full-arch treatment and improve the patient experience.
How can digital technology make full-arch dental implant treatment better?
New digital dental technologies (hardware, software, or technique) typically advertise some “revolutionary” improvement or advance. Our profession, which values scientific rigor and clinical experimentation, knows how to test claims about a new product’s features or benefits, with peer-reviewed publications to disseminate the results. Synthesizing such data, individual doctors estimate the benefit and weigh it against the cost. Perceived benefit greater than cost? Off we go and adopt the new technology. This is the basic flow of evidence-based practice.
Different clinicians, based on how they practice, have different ideas about evaluating benefits of any new technology—about what makes it better . But all such evaluations should start with a preliminary question: Better for whom ? Put differently, who is the customer for whom one is trying to create value? Getting that answer right is critical to growth and survival of any enterprise.
For dental technology companies, the customer is the dentist. But for treatment providers, the customer is the patient. If new technologies do not make treatment better for patients, they are not improvements.
Providing ethical, excellent care requires us as dentists to ensure that value for us aligns with value for the patient. This article explores what value is for full-arch implant patients; what providers should consider in restoring these patients; and how technology can help.
The full-arch dental implant patient
In order to provide value for the full-arch dental implant patient, we must first know who he or she is. In broad strokes: the median full-arch patient is middle aged, often without a dental home, and has been suffering with his/her dental health issues for a long time (think years/decades, not months). In many, though not all cases, some recent negative dental development has created urgency for the patient—spurring him/her to seek treatment that has been long avoided.
This is helpful so clinicians know what to expect treating full-arch patients generally. Much more importantly, every patient has his/her own history, life, and desires. The clinician would do well to take the time to learn these things about each individual patient before attempting to plan treatment.
With regard to dental condition, full-arch implant patients present with wide variability, but within 3 main categories.
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They have no teeth. (edentulous.)
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They need to have no teeth. (hopeless dentition.)
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They have a rational preference to have no teeth. (what might be called borderline full-arch cases. )
The first category is self-explanatory. The second is nearly the same. Patients may present with any one or combination of reasons for a hopeless dentition (generalized gross/non-restorable caries, chronic severe periodontitis with clinical attachment loss, severe dental manifestations of systemic disease, refractory patients with previous failed treatment, traumatic injury, etc.). There will be some variation between clinicians as to when a dentition is fully hopeless, but treatment of these patients with full-arch dental implants is mostly uncontroversial.
The third category is controversial and common. These patients are often partially dentate, and present with something like a questionable prognosis for their dentition. The variations are too many to count, but the theme is the same—the patient could keep some of his/her teeth, and for whatever reason(s) wants to have them removed and replaced with full-arch dental implant treatment. Some teeth can be saved, but is that best for this particular patient? Answering this question touches on subjects of patient-centered care, principles of medical ethics, and value. In a way, it is the first restorative consideration for full-arch dental implant patients.
Borderline full-arch patients and medical ethics
Patient-centered care is practicing dentistry in a way that is respectful of and responsive to individual patient preferences, needs and values, and ensuring that patient values guide all clinical decisions. This dental-care concept dates to at least the year 2000.
Medical ethics dates to circa 400 B.C. with the Hippocratic Oath. Modern readers may be surprised at what the original oath omits—namely, anything about a patient’s right to be informed or involved in treatment planning, much less to make his or her own treatment decisions. This attitude prevailed for 2 millennia. In 1871, Oliver Wendell Holmes told Bellevue Medical College graduating class: Your patient has no more right to all the truth than he has to all the medicine in your saddle-bags. [H]e should get only just so much as is good for him.
Beauchamp and Childress’s Principles of Biomedical Ethics (PBE) presented a modern, thoroughly updated philosophy. Without attempting any in-depth discussion, the 4 principles laid out in PBE are.
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Autonomy (respecting patient values and decisions of the patient)
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Non-maleficence ( do no harm )
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Beneficence (helping patients—sustaining life and treating illness)
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Justice (treat all persons with equal respect)
All good clinicians treat all persons with equal respect. Debates about borderline full-arch cases involve interplay among the other 3 principles.
On autonomy, third-category patients have a rational preference to have remaining teeth removed and get full-arch implant treatment. This does not mean they simply want full-arch treatment. A rational desire requires patients who are both competent to make their own treatment decisions, and informed of treatment options (including risks and benefits). Clinicians need to assess competency and then thoroughly review treatment options.
If a competent, informed patient prefers full-arch replacement, the next questions are beneficence and non-maleficence. Beneficence asks whether properly performed treatment provides benefits (improved dental aesthetics and function). Maleficence asks (a) whether the harm of removing a patient’s teeth exceeds anticipated benefits, and (b) if so, is such harm enough to overwhelm respect for the patient’s right of self-determination? Tension between autonomy and non-maleficence must be resolved on a patient-by-patient basis, informed by the clinician’s clinical judgment and concern to do no harm , while avoiding the condescending, benevolent medical despotism of earlier eras.
Clinicians also must remember that that non-maleficence inquiry is seldom normative or absolute. It does not ask simply “ Is this harmful?” For patients, the pertinent question is “Compared to what? Patients care about the relative value of one treatment versus another treatment versus no treatment, in the context of what is actually possible in their own lives. An example is a patient choosing between (a) full-arch treatment, and (b) a more ideal treatment plan involving caries control, endodontic treatment, periodontal surgery and maintenance, followed by orthodontic treatment, followed then by complex and lengthy restorative/prosthodontic treatment including fixed treatment and implant based restorations. The patient’s decision entails serious cost and time considerations, including overall treatment time and time away from other parts of his or her life.
Our treatment planning goal might be called shared decision-making . As clinicians, we can neither force patients to accept our preferred treatment, nor ignore our ethical responsibilities (as by acquiescing in the patient’s treatment preference if we believe it contrary to the patient’s interests). All this is a part of aligning value for the patient with value for the dentist.
Value for the full-arch dental implant patient
Value for the patient starts by asking, “What does the patient want from the process?” From the patient’s perspective, a process adds value only when it yields something the patient wants. This means a value-added step must move the process closer to completion, and be done right the first time (no rework needed). Whatever their individual treatment goals, full-arch patients share 3 common wants :
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Aesthetics (look good)
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Function (work well and last)
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Time (done as fast as possible while achieving 1 and 2)
On aesthetics, patients typically have specific, subjective desires for how their teeth look, which a clinician should elicit before planning and performing treatment. There are some consistent general factors:
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Midline
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Incisal edge (display at rest and animated smile)
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Papilla/Gingival display
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Occlusal plane (approximately parallel to ala-tragus)
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Buccal Corridors (less than 10% of total smile width) ( Figs. 1–5 )
Fig. 1 Ideal dental midline aligns with facial midline.
Fig. 2 Tooth Show; ( A ) Average tooth show in repose: 1–2 mm for men, 3–4 mm for women (reduced by 1 mm per decade after age 40), ( B ) Average lip movement from repose to animated smile: 6–8 mm.”( From Sabbah A. Smile Analysis: Diagnosis and Treatment Planning. Dent Clin North Am. 2022 Jul;66(3):307-341. doi: 10.1016/j.cden.2022.03.001 . PMID: 35738730.)
Fig. 3 Natural healthy gingival papillae are 40% of the total tooth height. 87% of patients show papillae with an animated smile.( From Levine JB, Finkel S. Smile Design Integrating Esthetics and Function. Vol Volume Two. (Levine JB, ed.). ELSEVIER; 2016.)
Fig. 4 Ideal occlusal plane is approximately parallel to ala-tragus plane.( From Diego Navarro Ortiz, Full Arch Solutions +, Dental Implants GPS, Riverside, CA.)
Fig. 5 Buccal corridors; ( A ) Wide, ( B ) Narrow—<10% dark area vs. total smile width (commissure to commissure).( From Abu Alhaija, E, Al-Shamsi, N, Al-Khateeb, S. Perceptions of Jordanian laypersons and dental professionals to altered smile aesthetics. Eur J Ortho. 2010 33. 450-6. 10.1093/ejo/cjq100 .)
Some patient specific subjective factors:
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Tooth shape/mold
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Anterior anatomy
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Surface Texture ( Fig. 6 )
Fig. 6 Surface Texture; ( A ) Smooth, ( B ) Rough.( Courtesy of Saad Elhallak, Full Arch Solutions+ Dental Implants GPS.) - •
Shade
Functional value for full-arch restorations is a matter of fit, occlusion, and durability.
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Fit
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To multi-unit abutments (MUAs)/implants
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To tissue
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Occlusion
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Horizontal/vertical overlap
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Guidance
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Durability
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Material choices (monolithic zirconia, polymethyl methacrylate [PMMA], metal bar and superstructure)
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Prosthetic thickness/restorative space, span, cantilever length
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There are some patient-specific functional factors to consider:
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Skeletal/dental class
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Class 2-These patients commonly spend most of their time postured slightly forward to create a more pleasing/prognathic facial profile. They may need to be restored to a maximum intercuspal position that reflects their preferred muscular posture, rather than a temporo-mandibular joint (TMJ)-based centric occlusion.
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Class 3-These patients may have so severe a sagittal plane discrepancy that restoring to a class 1 occlusion will require thick prosthetics and difficult to clean gingival adaptations ( Fig. 7 ).
Fig. 7 Skeletal/Dental Profiles; ( A ) Class 2, ( B ) Class 3 Profiles.(With permission from Walnut Grove Orthodontist.)
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Cusp angles/guidance
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Patients who have lost teeth or tooth structure may prefer less vertical overlap of anteriors to create a freer feeling in excursive mandibular movements.
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As to time, all patients want treatment completed as quickly as possible. Dentists may underestimate this factor. Most dental treatments require multiple appointments and often visit to several specialists. This creates selection bias—patients who are referred to and choose to see specialists have life circumstances and attitudes that allow for lengthy treatment. The same is not true for many full-arch patients.
Value versus waste in full-arch treatment
Having defined (broadly) value for full-arch patients, we come to the core concept for improving the process: Everything that does not add value is waste —a term that underscores what is not value for the patient . This idea originated in LEAN thinking, developed in the Toyota Production System and now all-but universally adopted by manufacturers (not just of cars), dramatically increasing quality while reducing cost and production time.
There are 2 types of waste: pure waste and necessary waste. Pure waste is any activity that brings no value and damages efficiency. Necessary waste comprises activities customers have no interest in, but that are required to maximize end-product value. This is illustrated by the milling process for zirconia arches:
Value is added when a bur is in contact with the disk, cutting the zirconia into the shape of the teeth. Time needed to switch between bur sizes is necessary waste . The time lapse from completion of milling to a technician’s removing the disk from the mill to move to the next step is pure waste .
The insight—which is why LEAN thinking revolutionized production worldwide—is that from the customer’s perspective, most improvement comes not from improving value added activities, but from eliminating waste from the process.
This is counterintuitive for highly-trained technical professionals. We spend time in school, in continuing education, and in our practices perfecting techniques—the value added parts of our clinical process. But from the patient’s treatment-experience perspective, the vast majority of time is spent in non -value added steps. Clinical excellence—which patients assume when selecting a provider—is necessary but not sufficient to create a better treatment experience.
Some object that people care about waste and value in this way for commodities, not for medical or dental services. However flattering this may be to dentists, strong evidence shows it is not true. Mayo Clinic, for example, has worked hard to eliminate waste for patients—setting systems so patients see multiple specialists within hours, get test results immediately, and receive necessary procedures within hours or days. When Mayo surveyed patients about what was most important to them, efficiency (speed from initial contact to completed treatment) tied for most important, right alongside a doctor’s skill.
Sources of waste in full-arch treatment
From a customer/patient perspective, there are 8 categories of waste in a treatment process:
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Defects/mistakes
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Waiting
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Transportation
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Motion
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Overproduction
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Inventory
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Overprocessing
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Unused human potential
Full-arch treatment has examples of each:
Defects/mistakes: Any product or process that is done wrong and needs to be redone, (for example, improperly placed implants; an aesthetically or functionally unsatisfactory prosthetics).
Waiting: Any time when a product is not undergoing a value-added process (eg, patients sitting in a waiting room; design orders sitting in an email inbox before being worked on; and zirconia arches waiting on a desk before a ceramist begins adding characterization). For patients, waiting is the main source of waste.
Transportation: Unnecessary or inefficient movement of materials or data (eg, shipping impressions or other materials to/from the laboratory; and emailing files instead of utilizing real-time shared drives).
Motion: Excessive or unnecessary movement within the workplace (eg, going to a storage closet to retrieve surgical instruments instead of having them ready on the table).
Overproduction: Making product for which there is no demand (eg, fabricating back-up sets of temporary/provisional prosthetics).
Inventory: Too much of any raw material, supply, or work-in-progress. Inventory requires labor, processes, and time to track and manage. Work-in-progress leaves us unresponsive to new demand (eg, patients in mid-treatment take chair time that could be used for new patients).
Overprocessing: Adding unnecessary complexity to a product, task, or process (eg, restoring using a thimble bar and multiple individual crowns, when monolithic full-arch restoration would meet the patient’s aesthetic and functional desires).
Unused human potential: Not engaging the minds of people doing valu e -added work to discover and solve problems that arise in any process.
With these waste sources in mind, we can analyze the processes of full-arch implant treatment, discern what does and does not add value for patients, and identify how digital technology can eliminate waste and improve treatment.
Pre-procedure planning
Planning full-arch treatment has 2 essential, co-dependent requirements: Knowing where we want to go, and knowing how to get there. We then plan procedural steps to get therewithout getting lost on the way.
We begin with initial records.
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Frontal and lateral (profile) views of the patient’s face, in repose and with an animated smile.
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Detailed 3-dimensional (3D) records of the patient’s intra-oral condition (either impressions or intraoral scans).
These tell us where the patient is now. We then develop a prosthetic plan (where we want to go) based on the patient’s unique anatomy and desires, which is recorded in a doctor’s prescription.
After implant surgery, we must relate the patient’s new post-operative condition (implant location and tissue anatomy) back to our planned teeth, so the patient can be restored accordingly.
Analog planning traditionally involves:
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Photos with several views of the patient’s face.
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Impressions and stone casts to record the intra-oral condition.
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Interocclusal records to mount/articulate the maxillary and mandibular casts.
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Written laboratory prescriptions describing how to create the prosthetic plan based on the collected data.
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Manufacturing immediate dentures to be used in conversion based on the plan, for which many techniques are available (eg, duplication of casts and manually removing stone teeth, analog setting denture teeth; or techniques that digitize stone casts and manufacture dentures via some manner of 3D manufacturing).
Wastes associated with the analog process include:
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Inventory: impression materials and trays, dental stone and mixing equipment, interocclusal record materials, materials for shipping.
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Motion: moving materials and records around the office.
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Overprocessing: performing steps— e g , impressions, pouring stone, duplicating, manual tooth setting—that digital processes eliminate.
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Transportation—shipping records and casts to/from dental laboratories.
Two other analog process waste categories merit particular attention.
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Mistakes/defects: The analog workflow has many sources of variability and error. Each change of information from one form to another is a state change that carries an associated expectation of error . For instance, information about the patient’s current dentition goes from the actual state inside the mouth, to a negative impression of that state in alginate or polyvinyl siloxane (PVS) impression material, then to a stone model poured into the impression, then to a duplicated model from which the teeth are removed so a planned immediate denture can be set and then fabricated for conversion. There is potential error at every state-change step. The analog workflow also entails built-in estimates that are further sources of defects. Clinicians estimate midline, incisal edge, occlusal plane, and other corrections, recording these on a prescription. Even if the clinician’s estimates are perfect, laboratory technicians must interpret prescription language and try to reflect the changes accurately in stone, wax, and denture teeth,
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Waiting: Impressions setting, stone setting, shipping to a laboratory, waiting in a queue for a laboratory technician to begin the work, shipping back to the clinic … the list goes on. For patients, all these steps are just time lost while waiting for the desired outcome.
Digital pre-procedure planning
Pre-procedure digital records:
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3D face scan(s)
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3D intraoral scans (including interocclusal record)
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CLINIC CARE POINT: Intraoral scans should capture as deep as possible into the vestibule, so one can fabricate a surgical guide that does not interfere with bone/tissue.
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Face and intraoral scans are digitally superimposed or aligned to create a 3D patient avatar.
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CLINIC CARE POINT: Scanner speed and accuracy are critical.
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Face scanning that is too slow makes it difficult/impossible for patients to maintain a true animated smile. This can lead to inaccurate plans and aesthetic failure.
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Many facial scanners produce 3D files (.stl) with point density and accuracy in the 1 to 3 mm range
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This level of error in the placement of a patient’s midline, incisal edge, or gingival margin location is unacceptable.
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Further muddying the clinician’s ability to detect this, the color overlay on a 3D face scan (the .ply data) shows highlights and shadows.
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This gives the illusion that midline, incisal edge, gingival margin, and other details are accurately recorded in the face scan.
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Removing the .ply overlay to reveal the .stl will show true point density and anatomic resolution.
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Facial scanning with accuracy an order of magnitude better (100um or less vs 1–3 mm) is required to plan an aesthetically acceptable outcome.
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A digital smile , designed based on the doctor’s prescription, can be accurately cross-checked with the patient’s digital avatar at every step ( Fig. 8 ).
