Preliminary Evidence for the Complete Digital Esthetic Rehabilitation Treatment: Case Report and 1-Year Follow-up

Abstract

Purpose

To show through computer-aided design and manufacturing technology combined with novel digital acquisition images and the right restorative material that the technology can provide an easier and predictable workflow for general practitioners.

Basic Procedure

This case report presents a fully digital treatment of a 59-year-old patient with tooth-supported crowns and provides a detailed step-by-step digital technique to obtain a successful result.

Conclusion

By avoiding traditional impression and fixed prosthetic techniques, excellent clinical results can be obtained, minimizing the required steps and simplifying the overall procedure. This adds information to the current literature, allowing general practitioners to choose the best treatment option. The function and esthetics remained unaltered over a 1-year follow-up period. No fracture or decementation was observed.

Introduction

With the success of 3-dimensional (3D) technology, the so-called digital dentistry has gained popularity as a diagnosis, treatment planning, and evaluation technique¹ in all the different dental specializations. Digital systems such as computer-aided design and computer-aided manufacturing (CAD/CAM) were introduced in the mid-1980s. Since then, major advances have been made to improve different components of this technology, aiming to make it easier to access, more user-friendly, and widely available.1, 2 Currently, the gold standard technique to obtain replicas of the intraoral preparations for indirect dental restorations is conventional impression with elastic materials.³ So far, elastic impression materials are most widely used in clinical practice, showing excellent results.

It has been reported that marginal and internal fitting accuracy of indirect dental restorations, such as fixed prosthodontics (either by digital workflow or conventional impression), are the crucial factors determining long-term clinical success.³ Dimensional discrepancies ranging from 50 to 150 μm are reported to be acceptable.⁴

Besides the materials' inherent properties, there are some operator-related factors that influence the final outcome. A good manipulative technique is paramount and includes the provision of a uniform bulk material, working at an appropriate time, performing an adequate mixing, and placement in the impression tray.⁵ Some clinical factors, such as margin location, sulcus bleeding, and salivary flow rate, can also influence the final quality of the impression.⁶ An unsuccessful technique can lead to marginal leakage, which can expose the luting material, leading to its dissolution, and end up in prosthetic failure caused by secondary caries or periodontal inflammation.⁶ An inadequate adaptation can result in lack of homogeneous stress distribution under mechanical forces.⁷

Some of the desirable properties of an ideal impression material are reproduction of fine details of 25 μm or less, dimensional stability over time, good flowability to capture grooves, cervical margin detail reproduction,⁵ an acceptable working time to be able to reproduce single or multiple prepared teeth,2, 5, 8 a good shelf life, and economic convenience.5, 9, 10 However, elastic materials still present some problems, such as the need for posterior cast/model fabrication with dental stone, which can eventually present distortion.⁵

Owing to the large number of variables involved, one of the main objectives of dental practitioners is to diminish the required chair time while maintaining the quality of all the procedures.⁹ One of the ways of achieving this is by intraoral scanners, which together with the CAD/CAM technology, provide us a novel approach to everyday procedures. It has been reported that it is possible to improve the patient's acceptance and reduce distortion of conventional materials.⁹ Together with developed restorative materials, clinicians can have a predictable successful outcome.

Every day, patients demand esthetic treatments with excellent results, and full-coverage crowns are among the most common ones.¹¹ For the clinician to be able to achieve highly esthetic and mechanically resistant results, several types of materials, especially ceramic systems, have been studied and developed in the last few years.¹² Ceramic systems are widely available in the market, and the basis for the selection of these restorative materials relies on the requirement of the tooth being restored.¹³

Reformulated lithium disilicate glass ceramic, developed for CAD/CAM systems, has gained an increased popularity over the last few years. Its mechanical properties, as well as clinical performance, are widely reported in the literature. In addition, favorable translucency and high mechanical strength make it an excellent option for the fabrication of anterior and posterior restorations,¹² and thus, a very versatile material. Thus, the aim of the present case report is to provide and report a workflow process for an entire 3D treatment planning and execution, not only for the clinician but also for the technician involved.