Objective: Long-term (>3y) clinical analyses for composite color-match (restoration-versus-tooth) are rare. The objective was to examine long-term color-match trends for a wide range of composites in varying circumstances from clinical trials.
Methods: Information from 8,828 observations involving 21 clinical trials (UNC, similar procedures, 8 operators, 1970-2010), spanning 0-to-17y, and involving 37 composite brands (b) was pooled. Various classes (I+II, III, IV, V) and types (SC=self-cure, UV=ultraviolet-light-cure, VL=visible-light-cure) were rated using USPHS “color-matching” criteria (A=ideal; B=acceptable; C=unacceptable). Pooled results (%A) across all trials were analyzed for trends (Class/Type-versus-time) by regression analysis (r2).
Composite: | Color-Match (%A) | |||||
Class: | I+II | III | IV | V | ||
Type: | SC | UV | VL | VL | VL | VL |
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0y=baseline | 89 (b=8) | 100 (b=4) | 87 (b=8) | 95 (b=2) | 100 (b=2) | 99 (b=19) |
0.5y | 76 (b=10) |
| 82 (b=11) | 80 (b=2) |
| 95 (b=18) |
1-year | 72 (b=10) | 91 (b=4) | 78 (b=11) | 100 (b=2) | 95 (b=2) | 94 (b=18) |
2-year | 62 (b=10) | 91 (b=4) | 78 (b=10) | 98 (b=2) | 99 (b=2) | 92 (b=17) |
3-year | 61 (b=8) | 89 (b=4) | 70 (b=8) | 100 (b=2) | 100 (b=2) | 93 (b=16) |
4-year | 57 (b=2) | 96 (b=4) | 86 (b=4) |
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5-year | 51 (b=7) | 83 (b=4) | 86 (b=8) |
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8-year |
| 98 (b=4) |
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10-year |
| 94 (b=4) | 93 (b=4) |
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17-year |
| 91 (b=4) |
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r2 (0-3y) | 0.85 | 0.90 | 0.75 | 0.26 | 0.05 | 0.37 |
r2 (3-10y) | 0.98 | 0.02 | 0.62 |
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Results: Color-match changes for 0-3y were minor for Class-III-IV-V but pronounced for Class-I+II (emphasized by r2 for %A-vs-t). Subsequent changes for 3-17y for Class I+II SC restorations continued decreasing, but UV and VL types actually improved. C-ratings were extremely rare. Restorations and teeth probably changed color at different rates explaining this reversion. Wide-ranging factors influence both tooth and restoration color. Yet, there was “no evidence” beyond the SC-type that future color-match changes might produce regular clinical failures by ~20y.
Conclusion: No evidence existed from color-match trends for contemporary materials (VL) that clinical failures would occur.