Bego (usa) Dental Restoration Model

1. Introduction

As with every part of the human body, the teeth of most people would be vulnerable to breaking down with prolonged use, making the need for dental restoration necessary. There are two forms of dental restoration: direct and indirect tooth restoration (Oral-B, 2016). In the case of direct tooth restoration, there is only one simple step of placing a filling in the tooth cavity in a

single visit to the dentist’s office. However, for the indirect tooth restoration, an individual

customization of crowns, inlays or onlays are required, to suit each specific patient, which would be the focus of this report. Based on research conducted, about 5% of adults within the age range of 20 to 64 years are missing teeth (National Institute of Dental and Craniofacial Research, 2014), where the current Singapore population within that age range amount to 2,610,100 (DEPARTMENT OF STATISTICS SINGAPORE, 2016). Therefore, around 130,500 people in Singapore are missing at least a tooth, which gives the rough scope of the market volume.

The world of manufacturing has improved by leaps and bounds over the past century, due to various advancements in technology. However, these advancements have not had much impact on manufacturing in the dental industry. Since the introduction of dental restoration models, the lost wax technique has been the go-to method for manufacturing dental crowns due to its ability in creating intricate models using a customized mould (e-Manufacturing Solutions, 2016). However, this is a time-intensive process and skilled labour is required so as to produce a good mould. Thus, there is a need to find more cost effective methods to keep up with the rapidly changing economic realities.

With the development of Additive Manufacturing (AM), also known as 3D printing, there is a new breakthrough method that has the potential to reshape the entire dental industry in terms of manufacturing dental crowns, implants and associated parts. This method is called Direct Metal Laser Sintering (DMLS), an AM technique where metal powders are being melted and fused in a layer by layer fashion. This technology allows the manufacturing of dental crowns without the use of moulds. When DMLS is coupled with impression scanning, dentists can model and create a dental crown with lesser production steps and higher flexibility, which would greatly reduce the time and cost of making a dental model.

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In this report, a case study of the dental model manufactured by BEGO USA, a division of 113-year-old German dental giant BEGO GmbH, will be investigated. BEGO USA was founded in 1991, with traditional dental products making up 80 percent of its business (e-Manufacturing Solutions, 2016).

This report analyses and compares the various steps and differences in the two methods to manufacture the dental restoration model: the Lost Wax Casting technique and the DMLS method.

Figure 1: Wirobond C+ three- unit bridge manufactured by BEGO USA

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2. Manufacturing Processes

This chapter discusses the two manufacturing techniques identified for production of dental models. The process time and best estimated cost will also be studied.

2.1. Lost-Wax Casting

Traditionally, metal frameworks used for dental bridges or crowns are manufactured using the ‘Lost-Wax Casting’ technique, also known as Investment Casting. Lost-Wax Casting is an ancient technique which involves a number of processes and highly skilled manual labour. The process steps of how dental parts are produced using this method is illustrated in Figure 2.

Figure 2: Traditional process of tooth making

Modern metal alloys such as Cobalt-Chromium (Co-Cr) alloy are used in Lost-Wax Casting for the production of dental bridges or crowns. Co-Cr alloys have a high resistance to corrosion, high hardness, and allow porcelain to be fused to them for a better aesthetic appearance. While bridges made using Co-Cr alloys do not last as long as those made from gold alloy, they have a much lower material cost, leading to a relatively lower overall cost.

There are many suppliers of Co-Cr alloys used for dental applications, one of which is Dentaurum (DENTAURUM, 2016), who provides Co-Cr alloys of different grades and compositions.

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2.1.1. Process steps

2.1.1.1. Impression

The process begins with the patient biting on an impression material supported by an impression tray. Alginate, an elastic, irreversible hydrocolloid impression material, is usually used. A negative imprint of the patient’s teeth and the surrounding structure of oral cavities will be captured, with the finished impression being sent out to a third party laboratory for the pattern and mould making.

Figure 3: Impression taking (Source: Orthorobot)

Figure 4: Negative imprint of teeth (Source:

Degarmo, Black, Kohser, & Ronald, 2003)

2.1.1.2. Pattern and Mould Making

The impression is then used to create