Communication methods and production techniques in fixed prosthesis fabrication: a UK based survey. Part 2: Production techniques

OPEN Communication methods and production techniques in fixed prosthesis fabrication: a UK based survey. Part 2: Production techniques IN BRIEF • Highlights that even though clear RESEARCH guidelines are available, there still seems to be a lack of agreement between dentists and laboratories regarding the disinfection and quality of dental impressions. • Despite the promotion of all-ceramic crowns, this survey indicated that metal-ceramic crowns are still the most frequently prescribed for both anterior and posterior restorations. J. Berry,1 M. Nesbit,2 S. Saberi,2 and H. Petridis*3 Aim The aim of this study was to identify the communication methods and production techniques used by dentists and dental technicians for the fabrication of fixed prostheses within the UK from the dental technicians’ perspective. This second paper reports on the production techniques utilised. Materials and methods Seven hundred and eightytwo online questionnaires were distributed to the Dental Laboratories Association membership and included a broad range of topics, such as demographics, impression disinfection and suitability, and various production techniques. Settings were managed in order to ensure anonymity of respondents. Statistical analysis was undertaken to test the influence of various demographic variables such as the source of information, the location, and the size of the dental laboratory. Results The number of completed responses totalled 248 (32% response rate). Ninety percent of the respondents were based in England and the majority of dental laboratories were categorised as small sized (working with up to 25 dentists). Concerns were raised regarding inadequate disinfection protocols between dentists and dental laboratories and the poor quality of master impressions. Full arch plastic trays were the most popular impression tray used by dentists in the fabrication of crowns (61%) and bridgework (68%). The majority (89%) of jaw registration records were considered inaccurate. Forty-four percent of dental laboratories preferred using semi-adjustable articulators. Axial and occlusal under-preparation of abutment teeth was reported as an issue in about 25% of cases. Base metal alloy was the most (52%) commonly used alloy material. Metalceramic crowns were the most popular choice for anterior (69%) and posterior (70%) cases. The various factors considered did not have any statistically significant effect on the answers provided. The only notable exception was the fact that more methods of communicating the size and shape of crowns were utilised for large laboratories. Conclusion This study suggests that there are continuing issues in the production techniques utilised between dentists and dental laboratories. INTRODUCTION Prosthodontics is a discipline that requires a synergy between the dentist and dental technician, in order to fabricate intraoral prostheses with acceptable fit, function and aesthetics.1–3 The General Dental Council’s (GDC) policy document Principles of dental team working 4 states that ‘members of the dental team should work effectively together in patients’ best interest’. In 1 Clinical Lecturer, Department of Adult Oral Health, Institute of Dentistry, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London; 2Senior Technical Instructor, Prosthodontic Unit, UCL Eastman Dental Institute, London; 3Senior Lecturer, Department of Restorative Dentistry, Prosthodontics Unit, UCL Eastman Dental Institute, London. *Correspondence to: Dr Haralampos (Lambis) Petridis Email: Online article number E13 Refereed Paper - accepted 14 July 2014 DOI: 10.1038/sj.bdj.2014.644 © British Dental Journal 2014; 217: E13 addition, legislation such as the updated European Medical Devices Directive5 must be complied with so that all laboratory made products are constructed of materials considered to be safe and to a standard that will not harm the patient in any way. In order for these recommendations to be implemented, both dentists and dental technicians need to be aware of the processes and protocols used in the fabrication of fixed prostheses. However, a number of studies6–13 from around the world have highlighted the need for improved communication methods and production techniques between dentists and dental technicians during fabrication of fixed restorations. Problems have been identified in various parts of production processes and communication ranging from quality of impressions, to adequate tooth preparation, articulation, and adequate instructions regarding the use of materials.6–13 Und erg rad u at e t raining shoul d theoretically prepare dentists with the required knowledge to provide fixed prostheses in a safe and predictable manner. However, a number of studies12,14 have raised concerns regarding the competency of newly qualified dentists on their understanding of production techniques, possibly due to the reduction in dental technology teaching within the undergraduate curriculum,1,15 as well as the lack of interaction between dental technicians and students during these important formative years. This apparent disparity has led to the conclusion12 that the General Dental Council has failed in its aims published in The first five years: a framework for undergraduate dental education.16 Indeed in Australia this is now being addressed with the introduction of inter-professional teaching schemes.17 The purpose of this cross-sectional study was to identify the communication methods BRITISH DENTAL JOURNAL 1 © 2014 Macmillan Publishers Limited. All rights reserved. RESEARCH and production techniques used by dentists and dental technicians for the fabrication of fixed prostheses within the UK from the dental technicians’ perspective. Part one of this cross-sectional survey reported on the communication issues between dentists and dental laboratories.13 The current publication concentrates on the production techniques used for fixed prosthesis fabrication. MATERIALS AND METHODS The details regarding materials and methods have been published in the first paper.13 A questionnaire was constructed to investigate communication methods and production techniques used between dentists and dental laboratories from the laboratories perspective. The final questionnaire consisted of 30 questions within the following subcategories: general information, communication methods, impression disinfection and suitability, production techniques, shade matching, and time and team management issues. The Dental Laboratories Association (DLA, Nottingham, UK) was approached and approved the use of their database of e‑mail contacts (782 addresses). A web-based survey tool, Opinio (ObjectPlanet Inc. Oslo, Norway), was utilised for the administration of the survey and assimilation of data. Settings were managed in order to ensure anonymity of respondents. The data collected was presented as descriptive statistics and analysed using Fisher’s exact (...truncated)