3D printing of dental restorations addresses the increasing patients’ needs for more efficient treatment solutions. Thus, this paper presents a step-by-step overview of creating inlay restorations using an indirect CAD/CAM process, achieving an economical solution without compromising the aesthetic results.
By Dr Édouard Lanoiselée in collaboration with Argoat Prothèse Dentaire
Digital dentistry methods and materials have surpassed traditional ones in many ways. Digital tools particularly enhance interconnectedness and communication between patients, doctors, and laboratories. Additionally, the development of new dental materials for restorative dentistry opens up a new world of possibilities, allowing for shorter delivery times and reduced costs while still delivering high-quality restorations.
Today, intraoral scanners and 3D printing systems perform at a high level while maintaining the simplicity of use. The Form 3B printer from Formlabs Dental is an excellent example of this; its plug and play operation puts it within equal reach of printing experts and beginners. Permanent Crown Resin, also from Formlabs, is a restorative material released in 2020 that allows the direct printing of high-quality dental permanent single unit restorations at a reduced price.
The clinical case presented here shows an indirect CAD/CAM step-by-step workflow for the production of inlay restorations. The intraoral impression was taken in the practice with the data then transmitted to the laboratory, where the prosthetic elements with Form 3B and Permanent Crown Resin were designed and 3D printed. The restorations were sent back to the practice, prepared for adhesive cementation, and the treatment was delivered to the patient.
Case presentation and diagnosis
A 58-year-old-female patient with treated hypothyroidism consulted us for sensitivity to cold in the area of her tooth 24. (Fig. 1)
Upon clinical examination, we identified an occlusal-distal fracture of the dental amalgam on tooth 24. The restorations on teeth 25 and 26 were carried out at the same time and appeared to be infiltrated. Following the tests, we diagnosed reversible pulpitis on tooth 24. On the other hand, teeth 25 and 26 did not show pulpal symptoms.
The treatment plan consisted of the removal of amalgam restorations and the transition to direct composite restorations (26) and indirect printed composite resin restorations (inlays on 24 and 25).
The treatment was carried out in two sessions: a preparation session and a cementation session.
Execution of treatment plan
The amalgams were placed under the operating field. In order to conceal the residual discolouration caused by the amalgam and to fill undercuts, the cavities were filled with composite.
Tooth 16 was filled using the direct composite resin technique. The shade of the indirect restorations was determined by the shade selected to fill the cavities of teeth 24, 25 and the filling of tooth 26. The composite filling also protected against the risk of bacterial contamination and prevents possible pulpal sensitivities (Fig. 2).
The teeth were then prepared using calibrated burs for onlays. After polishing, an intraoral impression was taken (TRIOS 4, 3Shape) both statically and dynamically (Fig. 3). The patient’s mandibular movements were recorded to improve the accuracy of the occlusion (Figs. 4-5).
The impression was sent to the prosthetic laboratory (Argoat Prothèse Dentaire) via the secure 3Shape Communicate web portal. The provisional restoration was made using a flexible composite (Luxatemp inlay, DMG), which was selected for easy removal during the assembly session (Figs. 6-11).
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