A Transitional Full-Mouth Rehabilitation Using Injection-Molded Composite: A 6-Year Clinical Follow-up

New-generation flowable composites designed for injection molding have been used in clinical practice for more than half a decade. These materials, such as G-ænial™ Universal Injectable (GC America Inc., gc.dental/america), Beautifil Injectable X (Shofu, shofu.com), and Clearfil Majesty ES Flow (Kuraray, kuraraydental.com), allow clinicians to manage otherwise rapidly deteriorating dentitions in a minimally invasive, cost-effective, and time-efficient manner. While short-term outcomes have been reported,^1-4 limited data is available regarding the survival of injection-molded composites in load-bearing areas beyond 2 to 3 years. This clinical case review presents a transitional full-mouth rehabilitation performed using an injection-molding technique, with follow-up extending to 6 years. The behavior of the material in both anterior and posterior regions is evaluated, with particular attention given to wear, chipping, occlusal stability, and vertical dimension maintenance.

Case Presentation

A male patient presented with the primary complaint of an uncomfortable bite, a sensation that his teeth could not fully settle, and slightly worn incisors. He reported progressive wear of his anterior teeth and described a feeling that his maxillary incisors were “in the way,” preventing his posterior teeth from contacting comfortably. The patient noted that he habitually postured his mandible forward to achieve comfort and that his wife had commented on this altered facial expression, which she perceived as unnatural (Figure 1 through Figure 3).

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Clinical examination revealed pronounced wear facets on the palatal surfaces of the maxillary anterior teeth (Figure 4). These wear patterns indicated a forced anterior mandibular shift during closure, consistent with the patient’s subjective description of needing to “squeeze” into occlusion to achieve posterior contact.

Diagnostic Work-up

Periodontal Assessment

Periodontal examination revealed mild bleeding on probing without radiographic evidence of bone loss. The patient was diagnosed as American Academy of Periodontology (AAP) stage I, grade B.⁵ Oral hygiene instruction focused on improving interdental cleaning, and a 6-month recall interval for scaling and polishing was recommended.

Biomechanical Assessment

No existing restorations or carious lesions were present. Mild to moderate erosion was observed on the maxillary and mandibular anterior teeth. Some abrasions were noted on the buccal surfaces of the mandibular posterior teeth (Figure 4 and Figure 5).

Functional Assessment

Based on the patient’s symptoms and clinical findings, a diagnosis of constricted chewing pattern (CCP) was made. A Kois deprogrammer (Kois Center, koiscenter.com) was fabricated, and the patient wore it (Figure 6) prior to the recording of centric relation.⁶ The centric registration revealed mandibular positioning nearly identical to the forward position the patient naturally adopted for comfort.

Treatment options for CCP were discussed in detail with the patient and included either of the following: orthodontic repositioning of the anterior teeth, potentially combined with vertical changes; or a purely restorative approach involving alteration of the occlusal vertical dimension (OVD). The patient elected the latter: a restorative solution encompassing modification of the OVD.

Dentofacial Assessment

The patient exhibited low lip mobility, normally colored dentition, and minimal esthetic concern. Functional improvement rather than cosmetic enhancement was the primary motivation for treatment.

Treatment Execution

Following confirmation of complete neuromuscular deprogramming by achieving a repeatable spot on the deprogrammer platform, a definitive maxillomandibular relationship record was obtained. Comprehensive records required for digital smile design (DSD) were collected and evaluated (Figure 7). These included the following photographic views in fixed head position: three frontal views: full face with a wide smile and teeth apart, full face at rest, and retracted view of the full maxillary and mandibular arches with teeth apart; two profile views: side profile at rest and side profile with a full smile; 12 o’clock view with a wide smile and incisal edges of the maxillary teeth visible and resting on the lower lip; and an intraocclusal view of the maxillary arch from second premolar to second premolar.⁷

The maxillary cast was mounted using a Kois dentofacial analyzer, while the mandibular cast was mounted in centric relation based on the recorded jaw position. The articulated casts were subsequently forwarded to the dental laboratory for fabrication of a diagnostic wax-up incorporating the planned occlusal and esthetic modifications.

After clinical approval of the wax-up, the laboratory duplicated both the maxillary and mandibular casts. On the duplicated casts, every other tooth was selectively reduced back to its original anatomy. This approach enabled fabrication of two transparent injection matrices per arch, allowing for an alternating injection sequence (Figure 8 through Figure 10).⁸

In the author’s experience, matrix fabrication typically requires clear bite registration material with a Shore hardness in the 60 to 70 range to provide sufficient rigidity for creation of injection access points while still allowing for accurate intraoral positioning. Polymerization under pressure was employed to enhance adaptation and minimize internal voids. Once fully set, the matrix was separated from the carrier, and injection ports were created. The author has found that these access points are best formed by perforating the matrix from the intaglio surface using a sharp metal tip corresponding to the injectable composite syringe, thus reducing the risk of tearing or distortion.

At the start of the restorative appointment, the matrices were tried in and verified for accuracy of fit. Prior to composite injection, all access ports were inspected and cleared of debris to prevent blockage of composite tips or inadvertent incorporation of silicone remnants into the restorations.⁹

Restorative procedures commenced in the maxillary arch. All teeth were cleaned using air abrasion,¹⁰ followed by thorough interproximal biofilm removal with fine polishing strips. (Figure 11 depicts this being done in the mandibular arch.) Etching and adhesive application were performed on alternating teeth only (Figure 12). To protect adjacent teeth not being treated during this first phase, isolation was achieved using partial matrix bands, polytetrafluoroethylene (PTFE) tape, or Hawe™ strips (Kerr, kerrdental.com) as required.

Composite injection was performed using the first matrix, which maintained every second tooth in its original contour. During material delivery, the injection tip was directed cervically (Figure 13) and gradually withdrawn as composite flowed, with the clinician ensuring that the tip always remained submerged within the material to minimize void formation. While performing light-curing, gentle pressure was applied to the gingival aspect of the matrix to improve marginal adaptation and reduce excess in the cervical region. After matrix removal, interproximal contacts were separated using a Ceri-Saw, and injection sprues were carefully removed.

Teeth restored during the first phase were then isolated with PTFE tape and the second matrix—incorporating all teeth—was seated. The second injection sequence was completed using the same protocol as the first sequence (Figure 14). After polymerization, the matrix and isolation materials were removed. Finishing of the maxillary arch included interproximal refinement with strips, scalpel blade detailing, and preliminary polishing.

The mandibular arch was restored following the same workflow. Occlusion was subsequently refined and equilibrated, and final polishing to a high-gloss finish was completed. Clinical photographs were taken at completion, and the patient was highly satisfied with both the comfort and appearance of the restorations (Figure 15 through Figure 17).

Long-Term Follow-up

The patient was reviewed 2 years after the initial rehabilitation (Figure 18 and Figure 19) and subsequently at 5 years (Figure 20 and Figure 21) and 6 years (Figure 22 and Figure 23). Recall intervals were irregular, as the patient tended to return only when experiencing concerns.

At the follow-up appointments, the injected composite restorations demonstrated excellent performance in the maxillary anterior region, with minimal wear and maintained morphology. In contrast, the mandibular anterior region showed more pronounced wear, which the author attributes to limited material thickness in this area.

In the posterior mandible, composite performance was favorable in the premolar region, while the molar region exhibited chipping and wear that became increasingly noticeable over time. Despite this material degradation, the patient’s OVD remained stable throughout the 6-year observation period, as compensatory eruption maintained OVD despite wear of the material.¹¹

Discussion

This case highlights both the strengths and limitations of injection-molded composite as a transitional full-mouth rehabilitation strategy. The long-term success observed in this case likely was largely attributable to the patient’s low bite-force profile and the fact that all restorations were bonded predominantly to enamel. Where bonding remains confined to enamel, injection-molded composites generally demonstrate good longevity, even in functionally demanding cases. However, in the author’s experience, once significant erosion exposes dentin, and bonding becomes primarily dentin-based, long-term survival is considerably less predictable. Load-bearing areas can also yield less predictability long-term.

Conclusion

Injection molding using flowable composite is an excellent transitional technique for staged full-mouth rehabilitation and can offer reliable performance results over extended periods when case selection is appropriate. While posterior wear and chipping should be anticipated, particularly in molar regions, occlusal stability and vertical dimension can be maintained over many years. Careful patient selection, occlusal force assessment, and an enamel-dominant bonding strategy remain critical determinants of long-term success.

ABOUT THE AUTHOR

Sandra Hulac, DDS
Private Practice, Hong Kong; Fellow, American Academy of Cosmetic Dentistry

Figures and Images

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Figure 1

Pretreatment full smile with habitually forward positioned mandible.

Figure 2

Pretreatment forced maximum intercuspation (MIP).

Figure 3

Pretreatment position of comfort.

Figure 4

Pretreatment maxillary arch, occlusal view: “squeeze” facets were present on palatal surfaces of the anterior teeth; mild erosion was present on incisal edges.

Figure 5

Pretreatment mandibular arch, occlusal view: mild to moderate erosion was present on incisal edges; some buccal abrasions were observed.

Figure 6

The Kois deprogrammer in situ.

Figure 7

Facially generated treatment planning with DSD.

Figure 8

Duplicated cast of maxillary full contour wax-up.

Figure 9

Wax-up with every other tooth reduced back to its original shape.

Figure 10

Injection matrices; two matrices per arch were used.

Figure 11

Interproximal biofilm removal in the anterior of the mandibular arch.

Figure 12

Etching of every other tooth only.

Fig. 13

The composite injection tip must be advanced cervically before injecting is commenced.

Figure 14

The finished second injection sequence.

Figure 15

Postoperative full smile.

Figure 16

Postoperative MIP, retracted view.

Figure 17

Postoperative retracted view, teeth apart.

Figure 18

Two years postoperative full smile.

Figure 19

Two years postoperative mandibular arch, occlusal view: note chipping on the thinner molar composite additions as well as on the anterior additions.

Figure 20

At 5 years postoperative, note continued good performance of injection-molded composite as anterior veneering material.

Figure 21

Five years postoperative mandibular arch, occlusal view: more chipping was observed on the molar and anterior additions; continued good performance was noted in the premolar areas where the material was thicker.

Figure 22

At 6 years postoperative, note the lasting performance of the veneering material.

Figure 23

Six years postoperative mandibular arch, occlusal view: more degradation of material in load-bearing areas was noted, but occlusion continued to be stable and the patient was comfortable.