Research abstract
British Dental Journal 197, 261 - 264 (2004)
Published online: 11 September 2004 | doi:10.1038/sj.bdj.4811621
The quality of dental casts used in crown and bridgework
N Alhouri1, J F McCord2 & P W Smith3
- There is a need to focus attention not only on prepared teeth but also the remaining teeth in the same arch when making impressions for indirect restorations.
- When using dual phase impressions, clinicians need to be careful when seating the loaded impression tray so as to avoid subsequent inaccuracies in dental casts.
- On the whole clinicians are better at making impressions for study and opposing casts than working crown and bridge impressions.
Abstract
Objective To assess the quality of dental casts used in crown and bridge construction.
Design Observational cross-sectional study of dental casts.
Setting Commercial dental laboratories and a university dental hospital laboratory in the UK.
Materials and methods A sample (n = 150) of working and opposing casts used for crown and bridgework prescribed by general dental practices and a dental hospital were sampled from two commercial dental laboratories and an 'on-site' university dental hospital laboratory respectively. A simple '3 point' assessment scale of quality (good, fair and poor) was used to categorise the casts depending on the clarity of reproduction of soft and hard tissues.
Results The quality of opposing casts used for articulation purposes was significantly better (P<0.001) than that of the working casts. In addition it was found that for working casts the quality in the preparation area(s) was significantly better (p<0.001) than that in areas remote from preparation(s) in the same arch. In general, the quality of casts in the incisal or occlusal surfaces was better than the buccal and lingual surfaces.
Conclusions This study has demonstrated that variation exists in the quality of casts used in crown and bridgework, specifically those used in the construction of indirect restorations and also those used for articulation purposes. This study highlights the need for clinicians to exercise continued vigilance with crown and bridge impressions, and casts, particularly in areas away from the prepared teeth.
- Lecturer, Damascus University, Syria
- Professor/ Hon. Consultant in Restorative Dentistry, University Dental Hospital of Manchester, Manchester
- Lecturer/ Hon. Consultant in Restorative Dentistry, Unit of Prosthodontics, University Dental Hospital of Manchester, Manchester
Correspondence to: P W Smith3
Unit of Prosthodontics, University Dental Hospital of Manchester, Manchester M15 6FH
e-mail: psmith@man.ac.uk