Biologically Oriented Preparation Technique Through a Digital Workflow, a Case Report Part 1.

Abstract

Introduction: In every prosthetic treatment, the final purpose of the restoration is to restore function and esthetics for the patient, respecting biology and anatomical parameters. Regarding full coverage restorations, there are some factors to take into consideration: like the finish line (chamfer, shoulder, featheredge, etc.), the management of the provisional restoration and tissue healing, the material for the final restoration, and the impression technique. All these aspects will determine the treatment process and its possible results. In recent years, vertical preparation and more specifically biologically oriented preparation technique has generated great interest since its introduction in prosthodontics, changing the periodontal tissues, and providing long-term stability.

Materials and methods: With this technique, the objective is to change the position of the gingival margin, moving it more apically or coronally, depending on the modifications of the provisional. The relining of the provisional is a fundamental step of this technique: the intrasulcular part of the provisional is modified giving a new emergence profile and providing an augmentation of the tissue in the healing process.

Discussion: In vertical preparation, there is no predetermined margin. The dental technician should position the finish line more apically or coronally, depending on the depth of the sulcus and on the esthetic needs. Ceramic restorations should not invade the epithelial attachment, otherwise it may cause biological and mechanical problems, repetition of the impression, and of the crown restoration, which lead to increased clinical and laboratory time usage as well as expenses. One challenge is communicating the shape and contour of the temporary restoration to the dental lab to ensure accurate information for the final restoration.

Conclusion: Finally, the objective of this article is to describe a technique for transferring all necessary information of the provisional and obtaining a predictable result for the final restoration by using an intraoral scanner system and the fabrication of two 3D printed prototypes. One for the final volume of the crowns and the other for the finish line position.

Clinical significance: The fabrication of 3D printed prototypes allows for a more predictable final restoration, reducing possible communication errors between clinician and technician when restoring with biologically oriented preparation technique. In any esthetic treatment where the restoration does not have a predetermined margin, it is possible with this additional clinical step to provide a more esthetic outcome.