Objectives: The purpose of this in vitro study was to determine the influence of preparation type on marginal integrity of Cerec 3 Vita Mk II partial ceramic crowns (PCC).

Methods: 18 extracted human molars were prepared: A. retentive PCC (mod-cavity, coverage of functional cusp, chamfer); B. adhesive onlay (mod-cavity, horizontal reduction of functional cusp); C. adhesive PCC (mod-cavity, complete reduction of functional cusp, chamfer). All proximal margins were placed within dentin. After insertion (Variolink II, Vivadent) and 1d storage (0.9% saline solution), samples (n=6/group) were thermocycled (TC:5000x, 8-55°C) and mechanically loaded (ML:500000x72.5N). Marginal quality was assessed by quantitative SEM analysis. Gap formation (GF) and marginal expansion (ME) were determined along cervical (Cv), occlusal (O) and vestibular (V), ceramic/luting material (Cer), and luting material/tooth (En=Enamel/De=Dentin) interfaces separately, before (I) and after TCML (II). Marginal quality (MQ) was defined as sum of GF and ME and used as test parameter. The data were statistically evaluated with the Mann Whitney U test, Wilcoxon Rank Sum test and error rates method.

Results: MQ: 25%percentile-Median- 75%percentile:

Prep/Loc	Cv-En	Cv-De	Cv-Cer	O-En	O-Cer	V-En	V-Cer
A-I	0-0-0	33-47-76	0-1-3	0-0-1	0-0-0	0-0-0	0-1-7
A-II	0-0-1	25-31-56	0-0-4	0-2-5	0-1-6	0-0-11	0-0-13
B-I	0-0-0	48-61-88	0-1-2	0-0-4	0-0-4	0-0-2	0-0-2
B-II	0-0-1	49-67-77	1-3-5	0-0-6	0-0-27	0-0-4	0-1-6
C-I	0-0-0	61-84-98	0-0-2	0-0-0	0-0-0	0-0-0	0-0-0
C-II	0-0-0	71-91-96	0-0-1	0-2-5	0-4-7	0-0-14	0-0-0

No statistically significant influence of the preparation types before and after TCML was observed.

Conclusion: Cerec 3 PCC revealed statistically significant reduced marginal integrity at the dentinal margin independent of preparation method.

Back to the Dental Materials: III - Ceramics and Cements Program
Back to the IADR/AADR/CADR 80th General Session (March 6-9, 2002)

Top Level Search