Introduction

Three European directives - Council Directive 90/385/EEC of 20 June 1990 on the approximation of the laws of the Member States relating to active implantable medical devices (Active Implantable Medical Devices Directive [AIMDD]),1 Council Directive 93/42/EEC of 14 June 1993 concerning medical devices (Medical Device Directive [MDD])2 and Directive 98/79/EC of the European Parliament and of the Council of 27 October 1998 on in vitro diagnostic medical devices (In Vitro Diagnostic Medical Devices Directive [IVDMDD])3 - were introduced in the 1990s with the aim of harmonising medical device legislation within the European Union (EU).

These Directives, and the later amendment Directive 2007/47/EC,4 were given effect in the UK by The Medical Devices Regulations 2002 (Statutory Instrument 2002/618)5 and its amendments, The Medical Devices (Amendment) Regulations 2003 (SI 2003/1697)6 and The Medical Devices (Amendment) Regulations 2008 (SI 2008/2936).7

Dental professionals who prescribe and/or manufacture custom-made devices were required to do so in accordance with the relevant requirements of the MDD. The MDD was replaced by Regulation (EU) 2017/745 (Medical Device Regulation [EU MDR]),8 which was due to be fully implemented on 26 May 2020. However, in April 2020, Regulation (EU) 2020/561 was adopted, which deferred this for one year until 26 May 2021, so that efforts could be concentrated on the response to the coronavirus disease 2019 (COVID-19) pandemic.9

The UK left the EU on 31 January 2020 and entered an 11-month implementation period (IP), during which EU law continued to apply. In preparation for the UK's withdrawal from the EU, Regulation (EU) 2017/745 was largely transposed into The Medical Devices (Amendment etc) (EU Exit) Regulations 2019,10 (Statutory Instrument 2019/791 [UK MDR 2019], an amendment of the UK MDR 20024) and was expected to be fully implemented on exit day. However, the UK MDR was further amended by The Medical Devices (Amendment etc) (EU Exit) Regulations 2020 (Statutory Instrument 2020/1478 [UK MDR 2020]), which essentially removed the provisions of the EU MDR and substituted 'exit day' for 'IP completion day'.11

In Great Britain, from 1 January 2021, medical devices must conform to The Medical Devices Regulations 2002 (in the form in which they exist on 1 January 2021) or the EU MDR (until 30 June 2023). Northern Ireland remains in line with the EU legislation and implementation timeline12 under the terms of the protocol on Ireland/Northern Ireland.13

1. From a dental perspective, what is a custom-made device?

Under medical device legislation, a custom-made device is a medical device intended for the sole use of a particular patient. While its definition has been revised under the new legislation, the essential meaning of what defines a custom-made device remains the same (Table 1). In a dental context, custom-made devices cover a wide variety of appliances and prostheses; Figure 1 provides examples of commonly prescribed custom-made devices in a dental setting.

Table 1 Definitions given in medical device legislation that are pertinent to this paper
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Fig. 1
figure 1

Typical custom-made devices provided in a dental setting

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2. In terms of UK dental professionals, who prescribes custom-made devices?

Custom-made devices are usually prescribed by a dentist, although clinical dental technicians can prescribe and provide complete dentures direct to patients.14

3. In terms of UK dental professionals, who is the manufacturer of custom-made devices?

In a typical dental scenario, the role of manufacturer will be shared by the prescriber and the dental professional who constructs the device (Table 1): the prescriber 'has a device designed, manufactured or fully refurbished' while the constructor 'manufactures or fully refurbishes a device'. Custom-made devices in a dental context can be constructed by dental technicians, clinical dental technicians and dentists. Other dental professionals are permitted to construct certain custom-made devices, provided they are trained, competent and indemnified to do so.14 The medical device legislation that applies to devices fabricated by dental technicians in dental laboratories applies equally to devices constructed by other dental professionals in dental practices.

Table 2 summarises the aspects of the General Dental Council Scope of practice that can pertain to custom-made devices and indicates which registrants may undertake which procedures, if trained, competent and indemnified. A device repair will not fit within the definition of manufacturing unless the device has been fully refurbished. Procedures performed in order to fit a custom-made device such as preparation, impression taking, prescribing, final fitting and any adaptation are not considered to fall within the scope of the UK MDR.20

Table 2 Aspects of the General Dental Council Scope of practice that can pertain to custom-made devices, indicating which of its registrants may undertake which procedures, if trained, competent and indemnified14
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4. Which requirements remain the same for providers of custom-made dental devices?

The following requirements remain as they were under the MDD (see Table 3 for second point):

Table 3 Custom-made dental device classification under EU and UK medical device legislation
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  • Medical device manufacturers will continue to be required to inform the Medicines and Healthcare products Regulatory Agency (MHRA) before placing devices on the market

  • Under the EU MDR, there are now 22 classification rules instead of 18, but those for custom-made dental devices remain unchanged. Devices are classified according to risk level, which is based on factors including intended duration of use, intended purpose and invasiveness. Custom-made dental devices are categorised under Rule 5 (invasive devices intended to be used in the oral cavity as far as the pharynx) and Rule 8 (implantable devices and long-term surgically invasive devices)

  • Under the MDD, manufacturers of custom-made devices were required to prepare documentation regarding the design, manufacture and performance of the devices they produce, which must be kept available for the MHRA (Annex VIII[3-3.1]). This obligation is unchanged under the EU MDR (Annex XIII[2-3]

  • As before, custom-made device manufacturers must review and document experience gained in the post-production phase, and report serious incidents and field safety corrective actions. These obligations are given in EU MDR Annex XIII(5).

5. Which new requirements relate to providers of custom-made dental devices?

The EU MDR introduces numerous changes, some of which apply to custom-made dental devices (* = see Table 1, ** = see Table 4):

Table 4 Exemption conditions for health institutions
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  • Under the MDD, devices manufactured within a health institution (defined here*) were not considered to have been placed on the market (also defined here*) so were exempt from these requirements.15 This remains the case for health institutions in Great Britain but those in the EU and Northern Ireland that wish to maintain an exemption will now need to satisfy the conditions given in EU MDR Article 5(5)**

  • Under the EU MDR, medical device manufacturers are now required to have a 'person responsible for regulatory compliance' in place (EU MDR Article 15), which is similar to the 'qualified person' in pharmaceuticals, who is responsible for the quality assurance of medicinal products

  • Quality management obligations are much more explicitly defined in the EU MDR and are given in Article 10(9). The requirements correspond with parts of International Organisation for Standardisation (ISO) standard 13485 'Medical devices - quality management systems - requirements for regulatory purposes'16

  • Risk management requirements are also better defined. The General Safety and Performance Requirements provided in EU MDR Annex I, which replace the MDD Annex I Essential Requirements, include the requirement to establish, implement, document and maintain a risk management system. These obligations correlate with parts of ISO 14971 'Medical devices - application of risk management to medical devices'17

  • The requisite information that must be included on the statement that accompanies custom-made dental devices is broadly as it was under the MDD, but there are additional requirements. In addition to the name and address of the manufacturer, the name and address of any additional manufacturing sites now need to be incorporated and, where applicable, the name and address of the authorised representative now need to be included (EU MDR Annex XIII[1])

  • Custom-made device manufacturers were mandated to keep a copy of the statement that accompanies such devices for at least five years under the MDD. This has changed to at least ten years (EU MDR Annex XIII[4])

  • The requirement for manufacturers outside the EU placing medical devices on the EU market to appoint an authorised representative remains the same, but with additional obligations (EU MDR Article 11). This also applies to manufacturers outside Northern Ireland who place medical devices on the Northern Ireland market. Manufacturers outside Great Britain who place devices on the Great Britain market are required to appoint a UK responsible person (UK MDR 2002 regulation 60 [as amended by the UK MDR 2019]).

As stated previously, in a typical dental setting, the role of manufacturer will be shared by the prescriber and constructor of the device. Table 5 provides a summary of the legislative obligations that relate to manufacturers of custom-made devices.

Table 5 UK and EU legislative obligations pertinent to manufacturers of custom-made devices
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6. What are the differences between the EU MDR and the UK MDR 2019?

The EU MDR was essentially transposed into the UK MDR 2019, but with some minor changes:

  • The word 'shall' was largely replaced with the word 'must'

  • The main divisions in the UK MDR are called regulations while those in the EU MDR are named articles

  • In UK legislation, any consequential or supplementary provisions that appear after the main divisions are set out in schedules. The EU legislative equivalent to schedules are known as annexes

  • The subdivisions of the schedules in the UK MDR are named paragraphs but those in the EU MDR Annexes are called sections.

7. Will custom-made devices need to be registered with the new unique device identification system for medical devices?

One of the most significant changes is the introduction of a unique device identification system for medical devices based on a Unique Device Identifier (UDI) (definition given in Table 1). The identification system aims to improve the traceability and post-market safety-related activities of medical devices, but does not apply to custom-made devices (Table 6).

Table 6 Unique Device Identification (UDI) system exemption for custom-made devices
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8. Do custom-made devices need to bear the CE marking of conformity?

The CE marking (defined in Table 1) is a certification mark that is used to indicate conformity with health, safety and environmental standards for products sold within the European Economic Area. The letters 'CE' stand for 'Conformité Européenne' (French for 'European Conformity'). Custom-made devices were not required to carry the CE marking under the MDD and this remains the same under the EU MDR (Table 7). In Great Britain, the CE marking is being replaced by the UKCA marking.18

Table 7 CE marking of conformity exemption for custom-made devices
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9. Do custom-made devices require the intervention of a notified body?

A notified body (also referred to as a UK-approved body in the UK) (defined in Table 1) assesses whether medical devices meet the legal requirements.19 Under the new legislation, notified bodies have extended obligations and face greater supervision. However, custom-made devices do not require the intervention of a notified body.20

10. Do tooth-whitening trays fall under the jurisdiction of the MDR?

Tooth-whitening trays do not fall under the definition of a medical device (Table 1). Unlike the MDD, the EU MDR regulates medical devices that are similar to medical devices in terms of their function and risk level, but do not have an intended medical purpose. EU MDR Annex XVI lists the products without an intended medical purpose (Table 8), but tooth-whitening trays do not fall under this category either so they continue to be outside the jurisdiction of the MDR.

Table 8 Products without an intended medical purpose
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Conclusion

The regulations that govern medical devices in the UK and the EU have recently undergone a period of transition, which became more complex due to the UK's departure from the EU and the COVID-19 pandemic. This paper answers some important questions for dental professionals who provide custom-made devices but is not a substitute for reading the legislation itself.