Functional Esthetic Rehabilitation of Severe Erosive Tooth Wear Using Aligner Therapy and an Additive Digital Workflow

Management of severe tooth wear frequently necessitates an increase in occlusal vertical dimension (OVD) to create adequate restorative space, preserve remaining tooth structure, harmonize esthetics, and/or optimize occlusal relationships. Changes in OVD, however, must be meticulously planned, as excessive increases can negatively affect both function and esthetics. This is particularly true in Angle class I occlusions, where increasing OVD may result in excessive overjet and bulk of anterior restorations that compromises the final outcome. Successful rehabilitation requires a thorough diagnostic workup, functional mockup, patient-specific risk assessment, and a collaborative interdisciplinary approach.

Concerns about potential adverse effects, such as compromised esthetics, altered phonetics, patient discomfort during adaptation, and transient muscular or occlusal symptoms when vertical dimension increases exceed the patient’s adaptive capacity, have made increasing OVD a longstanding source of controversy in restorative dentistry.^1,2

There are, however, several primary indications for changing OVD. One is to gain positive space for the restorative material while preserving tooth structure. Increasing OVD is commonly done in full-mouth rehabilitation of heavily worn dentition.³ Another indication is to harmonize the dentofacial esthetics, which is particularly important in a facially driven treatment plan.^4,5 Increasing OVD can enhance the esthetic tooth display by lengthening the maxillary incisor. A third reason for increasing vertical dimension is to improve the incisal and occlusal relationship, ie, correcting the anterior teeth relationships to improve overjet and overbite. This approach can be particularly useful in deep bite situations and for creation of restorative space for anterior teeth.

Increasing OVD is frequently used in complex full-mouth rehabilitations to preserve enamel and enhance the prosthetic outcome when the aforementioned indications are applicable.^5-9 The treatment, however, is complicated and should be carefully planned and evaluated to avoid excessive increases in OVD.

This case report describes and illustrates the use of aligner therapy as a strategy to enhance full-mouth rehabilitation in an Angle class I patient. By helping to correct anterior relationships and optimize space distribution prior to restorative treatment, aligner therapy contributed to a more predictable and favorable clinical outcome.

Case Overview

A 47-year-old male patient presented in 2024 with severe dental erosion, with the chief complaint that his teeth were “melting.” Intraoral examination revealed advanced erosive tooth wear, predominantly affecting the palatal surfaces of the maxillary anterior teeth and the occlusal surfaces of both maxillary and mandibular posterior teeth, resulting in significant functional and esthetic compromise (Figure 1 and Figure 2).

Review of the patient’s medical and social history revealed long-term, high-frequency cola consumption and a disclosed history of bulimia nervosa, findings that were consistent with the observed erosion pattern. The patient had previously attended the author’s clinic in 2017, at which time moderate erosion was documented. Comparison with the photographic records obtained in 2017 (Figure 3) demonstrated progressive deterioration and substantial loss of tooth structure, particularly on the palatal surfaces of the maxillary canines and premolars, confirming ongoing erosive activity.

Diagnosis, Risk Assessment, and Prognosis

Periodontal: The patient had no evidence of periodontal disease. He had mild attachment loss with 1 mm recession on teeth Nos. 2, 13, 16, and 27 and less than 2 mm of horizontal bone loss (Figure 4). The periodontal diagnosis was American Academy of Periodontology (AAP) stage I, grade A.

Risk: Low

Prognosis: Good

Biomechanical: The patient presented with severe erosion on both the labial and palatal surfaces of the maxillary teeth, further compromised by generalized attrition. If left untreated, the teeth—particularly Nos. 5, 6, 11, and 12—would continue to deteriorate (Figure 5 and Figure 6). In the mandibular arch, erosive changes were confined mainly to the posterior teeth, with a wear pattern consistent with intrinsic acid erosion associated with bulimia nervosa (Figure 7).^10,11

Risk: High

Prognosis: Poor

Functional: Moderate attrition of 1 mm to 2 mm was present in the posterior teeth in both the maxillary and mandibular arches.

Risk: High

Prognosis: Poor

Dentofacial: Among the dentofacial findings at presentation were enlarged incisors restored with composite fillings, a noticeable midline diastema between the central incisors, and a deficient buccal corridor. The tooth proportion of the central to lateral incisors exceeded 2:1, compromising the overall smile esthetics. A yellowish tooth shade throughout much of the dentition was due to erosion and the loss of enamel.

Risk: High

Prognosis: Poor

Treatment Goals

Clinical and photographic evaluation confirmed progressive tooth wear with significant loss of tooth structure. Based on the updated findings, a comprehensive treatment plan was developed to restore the lost tooth volume by increasing the OVD in a stable centric relation.¹²

Aligner-based orthodontic therapy was incorporated to close anterior diastemas, redistribute interdental space, and optimize tooth alignment in preparation for definitive restorative treatment. A minimally invasive, additive restorative approach, guided by digital mockups and virtual prosthetic design, was selected to preserve enamel and enhance adhesive predictability.

The treatment was planned using a multidisciplinary approach, integrating Kois Center diagnostic and occlusal principles^4,12 with digital smile design and aligner-based orthodontics. The aim of the treatment was to achieve a predictable, functional, and esthetic outcome while minimizing biological cost.

Treatment Plan

Phase 1: Deprogramming and Mandibular Position Assessment

The patient completed the Kois Dental Questionnaire (Kois Center, koiscenter.com), a comprehensive patient assessment tool designed to identify a patient’s risk factors, concerns, and treatment needs prior to clinical examination. The survey evaluates such factors as personal history, periodontal health, tooth structure, bite and jaw function, and smile characteristics. The patient then wore a Kois deprogrammer for 2 weeks and was diagnosed with occlusal dysfunction.

To further evaluate mandibular dynamics, a jaw-tracking device (SDI Matrix, sdimatrix.com) was employed to record mandibular movement patterns, including opening–closing cycles, protrusive movements, lateral excursions, and condylar trajectories.

Intraoral scanning was performed using a system (iTero Lumina™, Align Technology, Inc., itero.com) that enables acquisition of multiple digital interocclusal bite records. A dual-bite scanning protocol was implemented to assess mandibular position and occlusal relationships. The first digital bite was recorded in maximum intercuspation (MIP) to document the habitual occlusal position. A second bite record was obtained with the Kois deprogrammer in place, representing the deprogrammed mandibular position. Comparing these two digital bite records allowed evaluation of the positional discrepancy between MIP and the deprogrammed reference position and confirmed the diagnosis of occlusal dysfunction.

Phase 2: Temporization With Indirect Composite Overlays

The Kois deprogrammer was used to establish and evaluate the proposed increase in OVD for the planned full-mouth rehabilitation. A digital design platform for chairside CAD/CAM and in-practice 3D printing workflows (iTero™ Design Suite, Align Technology, Inc.) was subsequently used to perform a digital additive wax-up to enable precise control of occlusal morphology and restorative contours (Figure 8).

Based on the digital design, a 3D-printed model was fabricated, and indirect composite overlays were produced using a vacuum-formed (suck-down) matrix. The provisional restorations were fabricated with a nanofilled composite resin material (3M™ Filtek™ Supreme Ultra, Solventum, solventum.com), which in the author’s experience offers favorable mechanical properties, polishability, and wear resistance (Figure 8 through Figure 10).

These indirect composite overlays served as provisional restorations, enabling the patient to “test drive” the newly established vertical dimension and occlusal scheme. This provisional phase allowed clinical evaluation of temporomandibular joint stability, patient comfort, and functional adaptation.

Phase 3: Aligner Therapy: Redistribute Space, Improve Overjet

Once functional stability at the increased OVD was confirmed, aligner therapy was integrated into the plan. With the use of smile design software (Invisalign® Smile Architect™, Align Technology, Inc.), limited orthodontic movements of the anterior teeth (Nos. 7 through 10) were planned. The primary goals of this phase were to close the median diastema, redistribute space, and bring anterior segments into optimal alignment in harmony with the newly established OVD. The simultaneous planning of orthodontic and restorative goals in the digital workspace enabled predictable control of both function and esthetics, an approach that supported additive veneer placement without the need for extensive tooth reduction (Figure 11 and Figure 12).

Phase 4: Final Mock-up

After aligner therapy was completed (Figure 13), an in-house dental technician developed a new restorative design using the aforementioned digital design platform (iTero Design Suite), which can be used for creating models, restorations, and smile mockups for in-practice 3D printing or milling (Figure 14). A minimally invasive, additive veneer-based approach was planned for maxillary teeth Nos. 4 through 13 and mandibular teeth Nos. 22 through 27. Maxillary anterior teeth Nos. 7 through 10 were digitally lengthened based on smile analysis derived from facial photographs, and the buccal corridor deficiency was addressed through additive contouring of the posterior segments.

The finalized digital design was clinically approved and subsequently 3D-printed in-house. A silicone index was fabricated from the printed model and used to create a same-day intraoral mockup, allowing immediate evaluation of esthetics and occlusal relationships. The trial smile was fabricated using a bis-acryl provisional material (Luxatemp®, DMG America, dmg-america.com) and approved by the patient before proceeding with definitive tooth preparation and restorative treatment (Figure 15).

Phase 5: Final Restorations

Preparations were confined primarily to enamel to maximize long-term adhesive predictability and clinical longevity of the laminate veneers.^13,14 Definitive ceramic veneers were fabricated from hybrid lithium-disilicate ceramic (Amber® Mill, HASSBio America, Inc., hassbioamerica.com), which was selected because of its favorable balance of mechanical durability and esthetic translucency. The veneers on teeth Nos. 6 through 11 and 22 through 27 were bonded using an adhesive cementation protocol with a resin cement (Variolink® II Esthetic Cementation System, Ivoclar, ivoclar.com). The palatal surfaces of maxillary teeth Nos. 6 through 11 were restored with a nanofilled composite resin (3M Filtek Supreme Ultra) to refine anterior guidance and support functional occlusion.

Following a 3-week evaluation period, posterior treatment was initiated. Conservative tooth preparation was performed on maxillary teeth Nos. 4, 5, 12, and 13 and mandibular teeth Nos. 20, 21, 28, and 29, where existing restorations were replaced with additive ceramic veneerlays. Combining features of a veneer and an onlay, these additive veneerlays required no interproximal reduction, thereby preserving proximal contacts and maintaining the structural integrity of the teeth.^15,16 The veneerlays were fabricated by the dental laboratory from the aforementioned lithium-disilicate ceramic (Amber Mill). Close clinician–technician collaboration facilitated precise control of esthetics, contours, and occlusal morphology. The veneerlays were adhesively bonded using the same resin cementation system (Variolink II Esthetic) as the anterior restorations (Figure 16 through Figure 19).

Throughout all phases, tooth preparation remained conservative, avoiding unnecessary removal of sound enamel and preserving interproximal contacts whenever possible to support long-term bonding success. Upon completion of the definitive restorations, a new digital impression was obtained using the intraoral scanning system (iTero Lumina) with a 2-mm leaf gauge bite registration to verify the mandibular position. This scan was used for fabrication of a protective nocturnal occlusal appliance.

Results

The final clinical outcome demonstrated a stable centric relation, balanced occlusal contacts at the increased OVD, smooth anterior guidance, improved lower facial height, and enhanced lip support. Closure of the midline diastema with careful consideration of the dental midline, together with refinement of tooth proportions, provided a more harmonious and natural smile.

The patient reported a high level of satisfaction with regard to comfort and the natural appearance. Comparison with the 2017 records revealed dramatic restoration of both esthetic and functional parameters.

Discussion

When the patient initially presented in 2017 for replacement of a fractured crown on tooth No. 30, clinical examination at the time revealed moderate generalized erosion and attrition, which was documented with photographic records. Although a full-mouth rehabilitation was recommended, the patient elected to proceed with limited treatment and remain under periodic maintenance.

The patient presented again in 2024 with the chief complaint that his teeth were “melting.” His current situation was compared with his 2017 records, and severe non-carious enamel loss was evident. Intraoral scanning, which the author prefers to do on all patients, particularly high-risk ones, to obtain a baseline record, enabled a comparison of the patient’s changes over time and an accurate diagnosis to be made.

Initially, the patient refused orthodontic therapy to close the diastema, saying that its appearance did not bother him. However, after the occlusal stabilization period and the use of treatment outcome simulation, he was able to envision the outcome and committed to the orthodontic aligner treatment.

Veneerlays, which combine features of veneers and onlays, were discussed with the patient as a conservative alternative to full-coverage crowns. Veneerlays may be used to restore both facial and occlusal morphology while preserving enamel whenever possible. In this clinical case, their use contributed to improved esthetics, a broadening of the smile, and reduction in the visual prominence of the buccal corridor, while also supporting the increase in OVD within a minimally invasive restorative approach.

This case highlights the importance of interdisciplinary management—restorative dentistry, orthodontics, prosthodontics/occlusion, esthetic dentistry, periodontics, and dental laboratory technology—and digital integration in the rehabilitation of severe erosive wear. Photographic and digital records were fundamental for progression assessment and patient motivation. Aligner therapy served a crucial preparatory role, improving anterior relationships and space distribution prior to restoration. Predictable results were achieved by uniting functional, orthodontic, and restorative protocols within a single digital workflow. Strict adherence to systematic principles, minimally invasive preparation, and close technician collaboration were essential to long-term success.

Conclusion

In this case of a full-mouth rehabilitation in an Angle class I occlusion patient, the combination of aligner therapy with a functionally guided, digital workflow enabled predictable, minimally invasive comprehensive restoration of a severely worn dentition. Early diagnosis, interdisciplinary planning, and advanced visualization tools helped transform a deteriorated dentition into a healthy and functional one with an esthetic smile, providing durable results and patient satisfaction.

ACKNOWLEDGMENT

The author thanks Apollo Digital Dental Lab (Taichung, Taiwan) for its excellent laboratory support and fabrication of the final ceramic restorations in this case.

ABOUT THE AUTHOR

Ryan Tak On Tse, BDS

Honorary Assistant Professor, Faculty of Dentistry, University of Hong Kong; Private Practice, Hong Kong; Membership, Faculty of General Dental Practitioners (UK); Membership, General Dentistry (MGD)

Figures and Images

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Figure 1

Preoperative full-face smile view demonstrating a median diastema, generalized tooth discoloration, and deficient buccal corridor.

Figure 2

Preoperative intraoral frontal view showing labial erosion, a median diastema, and deteriorated composite restorations.

Figure 3

Clinical photograph taken in 2017, demonstrating moderate labial erosion at the patient’s initial presentation.

Figure 4

Preoperative radiographic examination.

Figure 5

Preoperative maxillary occlusal view revealing severe palatal erosion, particularly affecting teeth Nos. 6, 7, 10, and 11, as well as occlusal erosion of the posterior teeth.

Figure 6

Preoperative maxillary occlusal view from the intraoral scan.

Figure 7

Preoperative mandibular occlusal view from the intraoral scan, showing relative preservation of the mandibular incisors, with erosive changes confined primarily to the posterior teeth.

Figure 8

3D-printed maxillary model following deprogramming, incorporating the overlay design created using the digital smile design and restorative treatment planning software.

Figure 9

Vacuum-formed (suck-down) matrix fabricated on the printed model for provisional overlay fabrication.

Figure 10

Indirect composite overlays fabricated using a freehand technique, guided by the vacuum-formed matrix.

Figure 11

After the increased OVD was established with composite overlays, aligner therapy was designed to correct the overjet and overbite, creating a more favorable occlusal relationship for the planned full-mouth rehabilitation.

Figure 12

Anterior spaces were closed concurrently during aligner therapy, resulting in improved tooth proportions and a more harmonious anterior esthetic outcome.

Figure 13

Post–aligner therapy intraoral scan demonstrating improved smile architecture. The anterior spacing has been closed, and the overjet and overbite have been corrected, establishing a favorable foundation for restorative treatment.

Figure 14

Digital mockup created using the software design suite, illustrating the proposed restorative design for maxillary teeth Nos. 4 through 13 and mandibular teeth Nos. 22 through 27. The maxillary anterior teeth (Nos. 7 through 10) were digitally lengthened based on facial and smile analysis.

Figure 15

Intraoral mockup following digital design transfer. The patient evaluated and approved the proposed final smile design prior to definitive treatment.

Figure 16

Final extraoral portrait photograph after completion of treatment, demonstrating harmonious smile integration with facial features.

Figure 17

Final intraoral view showing the definitive restorations fabricated from hybrid lithium-disilicate ceramic and the esthetic integration of the laboratory work.

Figure 18

Maxillary occlusal view following completion of treatment: hybrid lithium-disilicate restorations on teeth Nos. 4 through 13; composite restorations maintained on teeth Nos. 2, 3, 14, and 15.

Figure 19

Mandibular occlusal view following completion of treatment: hybrid lithium-disilicate veneer and veneerlay restorations on teeth Nos. 18 through 28; full-coverage crown on tooth No. 30; composite resin restorations on teeth Nos. 31 and 32.