Treatment Planning for Direct-Printed, Graphy, and Thermoformed Aligners

Fabrication method doesn't just change how an aligner is manufactured, it changes how the case should be planned. Staging limits, attachment strategy, batch size, and monitoring cadence all differ between thermoformed aligners and direct-printed (DPA) systems such as Graphy's Tera Harz line. This article outlines the clinical parameters practitioners should account for when planning each type of case, along with what those differences mean for the patient experience.

1. Digital Setup and Staging Software

Both fabrication methods begin with an intraoral scan and a digital virtual setup, but the software ecosystem differs slightly. Thermoformed cases are typically staged in established orthodontic CAD platforms such as 3Shape, Blue Sky Plan, uLab, or Onyxceph. Direct-printed cases can be staged in the same platforms, or in Graphy's own Direct Aligner Designer (DAD), a free treatment-planning and design tool built specifically for the direct-printing workflow, which combines staging with aligner-shell design in a single pipeline.

Clinical movement limits per stage

• Direct-printed aligners: Published protocols commonly stage movement at up to 0.25–0.30 mm of translation and roughly 2–4° of angulation, inclination, or rotation per stage, with undercuts deliberately left unblocked to allow the resin to flow and seat more precisely.
• Thermoformed aligners: Comparable staging limits are used, though established case libraries and years of outcome data give clinicians a larger reference base for predicting tracking accuracy at the margins of these limits.

2. Attachment Strategy

Attachment planning is where the two methods diverge most for the clinician:

• Thermoformed: Attachments are the primary lever for controlling force vectors, since the sheet material itself cannot be locally modified. Attachment shape, position, and engagement are planned conventionally in CAD software.
• Direct-printed: Because the aligner shell itself can be designed with variable wall thickness, surface texture, and built-in pressure points, some tooth movements, for example, controlled labial movement of incisors while managing overbite, can be programmed directly into the shell geometry, which case reports have used to reduce or reposition conventional attachments.

This doesn't eliminate attachments from DPA treatment planning, but it does give the treatment planner an additional design variable that isn't available with a uniform thermoformed sheet.

3. Production Batching and Monitoring Cadence

Direct printing is typically run in small batches, commonly 5 to 8 aligners per print run, taking roughly 30–60 minutes of print time before cleaning and post-curing. Several published protocols intentionally limit batch size to permit closer in-person monitoring and reduce the risk of losing tracking if a stage doesn't fit as planned. This has a direct treatment-planning implication: practices adopting DPA workflows should plan review appointments around smaller aligner batches rather than the larger multi-month batches often dispensed with thermoformed systems.

Customer Consideration: Patients accustomed to receiving 8–10 thermoformed trays at once should be told upfront if their direct-printed plan will be dispensed in smaller batches with more frequent check-ins. Framed correctly, this is a benefit — closer monitoring catches tracking issues early — but it does mean more office visits, which affects scheduling expectations and, for some practices, per-visit fee structures.

4. Force Delivery and What It Means for Case Selection

Treatment planners should factor material behavior into case selection, not just staging mechanics:

• Direct-printed resins have shown better retained force and less stress relaxation than thermoformed materials at higher activation levels (around 0.5 mm), which may support more predictable tracking in cases requiring larger per-stage movements.
• Thermoformed aligners are prone to higher initial peak forces, which some clinicians associate with increased initial discomfort, a relevant chairside talking point when setting patient expectations at delivery.
• Direct-printed aligners maintain their mechanical properties through at least a week of intraoral wear at body temperature without the deformation-related force loss seen in thermoplastic sheets, though surface roughness and porosity increase with wear in both material classes.

Customer Consideration: Because direct-printed aligners tend to deliver a steadier, lower peak force, some patients report a more comfortable transition between stages compared to thermoformed aligners. This is worth mentioning during consultation for patients who cite discomfort as a concern about aligner therapy, without overpromising an outcome that hasn't yet been confirmed in large-scale clinical trials.

5. Turnaround Time and Practice Workflow

Where a lab or in-office setup handles staging and fabrication in a single digital pipeline (as DAD does for DPA cases), the loop between treatment-plan approval and aligner delivery can be shorter than a workflow that requires a separate model print, ship, and thermoform step. For practices working with an outsourced lab, this planning-to-delivery interval should be confirmed with the lab before setting patient-facing timelines, turnaround varies by lab capacity and case complexity regardless of fabrication method.

6. Planning Checklist by Method

Planning Factor	Thermoformed	Direct-Printed (Graphy TC-85/TC-85DAC)
Staging software	3Shape, Blue Sky Plan, uLab, Onyxceph, etc.	Same platforms, or Graphy DAD
Per-stage movement limits	Established, conventional limits	~0.25–0.30 mm translation, ~2–4° rotation/angulation
Attachment role	Primary control mechanism	Primary + shell-geometry design options
Typical batch size	Larger, multi-stage batches common	Smaller batches (often 5–8) for closer monitoring
Review cadence implication	Longer intervals between visits possible	More frequent check-ins may be needed
Force-related patient comfort	Higher initial peak force reported	Lower, more consistent force reported

7. Clinical Takeaway

Treatment planning for direct-printed and Graphy-based aligners is not simply "the same setup, different material." Staging limits, attachment strategy, batch size, and patient monitoring cadence all shift with the fabrication method, and each of those shifts has a corresponding patient-facing conversation, from how many aligners they'll receive at once to how often they'll need to come in. Clinicians and treatment coordinators who plan for both the mechanics and the patient experience will get more consistent tracking and fewer surprises mid-treatment, regardless of which method a given case calls for.

Sources: Journal of Clinical Orthodontics (Ludwig et al., 2024, "Direct-Printed Aligners: A Clinical Status Report"); PMC ("Directly Printed Aligner: Aligning with the Future"); ScienceDirect ("3D Printed Aligners: Material Science, Workflow and Clinical Applications"; "Directly printed aligner therapy: A 12-month evaluation of application and effectiveness").