We are using cookies to implement functions like login, shopping cart or language selection for this website. Furthermore we use Google Analytics to create anonymized statistical reports of the usage which creates Cookies too. You will find more information in our privacy policy.
OK, I agree I do not want Google Analytics-Cookies
The Journal of Adhesive Dentistry



Forgotten password?


J Adhes Dent 21 (2019), No. 6     6. Dec. 2019
J Adhes Dent 21 (2019), No. 6  (06.12.2019)

Page 545-550, doi:10.3290/j.jad.a43651, PubMed:31802070

Effect of Molar Preparation Axial Height on Retention of Adhesively-luted CAD-CAM Ceramic Crowns
Wake, Robert / Buck, Richard / DuVall, Nicholas / Roberts, Howard
Purpose: To evaluate the effect of axial wall height (AWH) on failure resistance of CAD-CAM adhesively-bonded, all-ceramic crowns on molar preparations with a conservative total occlusal convergence (TOC).
Materials and Methods: 60 newly extracted maxillary third molars were divided into 5 groups (n = 12) and prepared for all-ceramic crowns with occlusal cervical AWH of 0, 1, 2, 3, and 4 mm, all containing a conservative 10-degree TOC. Scanned preparations were fitted with lithium-disilicate glass-ceramic crowns using a self-adhesive resin-composite luting agent after intaglio surface preparation with hydrofluoric acid and silane. Specimens were stored at 37°C/98% humidity for 24 h and tested to failure at a 45-degree angle applied to the palatal cusp on a universal testing machine. Mean results were analyzed using ANOVA and Tukey's test (p = 0.05).
Results: Preparations containing 2, 3, and 4 mm AWH demonstrated similar and higher failure resistance than the 0- and 1-mm axial wall height groups.
Conclusions: Under the conditions of this study, evidence is presented that under certain conditions CAD-CAM adhesive technology may compensate for less than optimal AWH. Based on both failure load results and failure mode analysis, adhesively-luted maxillary molar CAD-CAM crowns based on a preparation containing 10-degree TOC require at least 2 mm AWH for adequate resistance and retention. However, adoption of these findings is cautioned until both fatigue analysis and appropriate clinical evidence has been provided.

Keywords: CAD-CAM, adhesion, lithium disilicate, failure load, axial wall height, total occlusal convergence