IADR Abstract Archives
Bio-tribocorrosion Wear Resistance of Posterior Composites at Macro- and Micro-scale
Objectives: The objective of the study was to parallel a macromorphological and microwear analysis of nano-hybrid (Tetric Evo Ceram/Vivadent-Ivoclar), conventional fine-hybrid (Tetric Ceram/Vivadent-Ivoclar) and micro-fine hybrid (Gradia Direct Posterior/GC company) posterior composite restorations versus human enamel in an RCT, to compare their bio-tribo corrosive wear resistance.
Methods: 16 Tetric Evo Ceram (TEC), 16 Tetric Ceram and 16 Gradia Direct Posterior restorations were placed in upper or lower molars. BA: AdheSe - Tetric Ceram and TEC restorations, UniFil Bond - Gradia Direct Posterior restorations. Influence of bio-tribo corrosive wear on the macromorphology of restorations was evaluated at baseline, 6-, 12-, 24- and 36-months, using modified USPHS criteria. For the microwear analysis, replicas were made in gypsum for 3D-Pro laser scanning (Willytec, Munich) to quantify wear and in araldite epoxy resin for SEM analysis (Philips, XL20) to investigate the microstructure of worn restoration surfaces.
Results: The Sign test exhibited for Gradia Direct Posterior, a significantly better polishability than for TEC (p=0.002) and Tetric Ceram (p=0.006) restorations after 36 months. TEC restorations showed significantly better colour match compared with Tetric Ceram (p=0.021) and Gradia Direct Posterior (p= 0.035) restorations. No statistically significant higher bio-tribo corrosive wear (increased vertical and volume loss mean) was observed either between the evaluated materials or materials versus enamel (p>0.05). SEM images of TEC exhibited surface delamination compared with pull-out of fillers in Tetric Ceram and microcracks at filler-matrix interface in Gradia Direct Posterior.
Mean occlusal contact area (OCA) wear of composites versus enamel in µm
|
Materials/Time |
6M |
12M |
24M |
36M |
|
Enamel (Heavy OCA) |
-36 (SD=16) |
-54 (SD=20) |
-76 (SD=22) |
-107 (SD=25) |
|
Enamel (Light OCA) |
-17 (SD=4) |
-21 (SD=4) |
-38 (SD=10) |
-56 (SD=12) |
|
Tetric Evo Ceram |
-43 (SD=14) |
-54 (SD=17) |
-67 (SD=22) |
-81 (SD=23) |
|
Tetric Ceram |
-46 (SD=13) |
-61 (SD=17) |
-81 (SD=21) |
-99 (SD=28) |
|
Gradia Direct Posterior |
-49 (SD=16) |
-72 (SD=28) |
-98 (SD=38) |
-125 (SD=45) |
Mean occlusal volume loss in mm3
|
Materials/Time |
6M |
12M |
24M |
36M |
|
Tetric Evo Ceram |
-0.2 (SD=0.3) |
-0.3 (SD=0.3) |
-0.5 (SD=0.3) |
-0.9 (SD=0.4) |
|
Tetric Ceram |
-0.4 (SD=0.4) |
-0.6 (SD=0.5) |
-0.8 (SD=0.6) |
-1.2 (SD=0.9) |
|
Gradia Direct Posterior |
-0.1 (SD=0.2) |
-0.1 (SD=0.3) |
-0.3 (SD=0.7) |
-0.8 (SD=0.7) |
Quantified range of material loss in µm along the margins
|
Materials |
Tetric Evo Ceram |
Tetric Ceram |
Gradia Direct |
|||||||||
|
Time |
6M |
12M |
24M |
36M |
6M |
12M |
24M |
36M |
6M |
12M |
24M |
36M |
|
Min |
-30 |
-31 |
-36 |
-54 |
-30 |
-35 |
-50 |
-53 |
-30 |
-36 |
-50 |
-50 |
|
Max |
-307 |
-393 |
-397 |
-471 |
-231 |
-309 |
-312 |
-325 |
-286 |
-310 |
-310 |
-324 |
Conclusions: After three years of clinical service, bio-tribo corrosive wear resistance of all composites was acceptable versus human enamel, clinically at macro-level. At micro-level, although composites exhibited adequate wear resistance as enamel, SEM analysis revealed material-specific surface delamination pattern.