Objectives:
This in-vitro study evaluated the microleakage of all-ceramic crowns using 2 different
marginal preparation types and 3 different dual-cure resin cements. Porcelain-fused
to metal (PFM) crowns were cemented with a zinc phosphate cement for the control.
Methods:
Seventy freshly extracted maxillary central incisors were randomly divided into
seven groups (n=10). Thirty teeth were prepared with a 90-degree shoulder with rounded
internal line angle, while the others were prepared with a chamfer finish line.
IPS-Empress 2 crowns (Ivoclar Vivadent; Schaan, Liechtenstein) were manufactured
for all teeth excluding the control group. After the cementation procedure samples
were stored in distilled water for 30 days. All samples were subjected to 5000 thermocycles
(at 5°C to 55°C; 30-second dwell time). After immersion in Indian ink for 48 hours
at 37°C, the samples were sectioned both buccolingually and mesiodistally using
the EXACT cutting and grinding system. Each section was evaluated under stereomicroscope
(Zeiss) at X24 magnification for evaluation of microleakage.
Results:
Kruskal-Wallis test revealed no significant difference (p>.05) among the groups
that dual-cure resin cements were used for the cementation. Mann-Whitney U-test
demonstrated statistically significant difference (p<.05) between group 1,
2, 3, 4 and the control group. Dual-cure resin cements demonstrated the least leakage.
Conclusion:
Dual-cure resin cement showed a better ability to minimize leakage of all-ceramic
crowns
|
Group
|
Marginal preparation
type
|
Luting agent
|
|
1
|
Shoulder
|
Variolink-2 (Ivoclar Vivadent)
|
|
2
|
Shoulder
|
Bifix DC (Voco, Cuxhaven, Germany)
|
|
3
|
Shoulder
|
Calibra (Caulk-Dentsply, Milford, DE)
|
|
4
|
Chamfer
|
Variolink-2
|
|
5
|
Chamfer
|
Bifix DC
|
|
6
|
Chamfer
|
Calibra
|
|
7
|
Chamfer
|
PhosphaCEM PL (Ivoclar Vivadent)
|