A Comparison of Artificial Crown Dimensions To Natural Teeth

Abstract

Background: Crown dimensions can have a significant effect on the health of adjacent gingivae and on occlusal harmony. This study aimed to determine crown dimensions on artificial crowns and their contralateral natural teeth.

Materials and methods: Patients attending Dubai dental hospital with an artificial crown on a first or second molar and a sound contralateral tooth were invited to take part in this cross-sectional study. Clinical measures included the Basic Periodontal Examination and a check of inter-occlusal contacts with shimstock. Models were cast from polyvinylsiloxane impressions and scanned using Ortho Insight 3D (Motion View, MicronDental, USA). Mesio-distal (MD) and bucco-lingual (BL) measurements were made using the software and also by use of a Boley gauge (Premium Instruments, USA).

Results: A total of 16 participants (11 males; 5 females) with a mean age of 44 years were recruited to form a convenience sample. There was no difference in mean age by gender. A total of 20 pairs of crowns were included and most were in service for less than 5 years. There were 14 (70%) all-ceramic crowns, 5 (25%) metal-ceramic and 1 metal crown, with the upper left first molar being the most crowned tooth.The mean BL width of artificial crowns was significantly greater than the mean BL width of sound teeth using both methods of measurement (p<0.01). The mean BL widths were 11.57mm/11.17mm using the software and 11.49mm/11.07mm using the Boley gauge. The mean MD dimensions were not significantly different at 10.32mm on artificial crowns and 10.26mm on sound teeth using the software and 10.24mm and 10.16mm with the Boley gauge. Periodontal status was not significantly different between artificial crowns and sound teeth. A cusp tip to fossa relationship was the most prevalent occlusal scheme with a modest correlation between artificial crowns and contralateral sound teeth (Spearman rho=+0.6, p<0.05).

Conclusion: Artificial crowns are wider bucco-lingually than their contralateral sound teeth. The bucco-lingual dimension of sound teeth should be measured, recorded and written in the laboratory prescription so that technicians can replicate this dimension more accurately.