Clinical evaluation of fiber-reinforced composite bridges. One-year report

Objectives: To assess the clinical performance of 3-unit bridges made with glass-fiber reinforced composite frameworks (Vectris) under an experimental microfilled veneering composite (Trend). Presently, Trend is marketed as “SR Adoro”. Methods: A total of 61 bridges randomly divided in two groups were placed. In one group 30 bridges were made with Trend over Vectris. In the other group 31 bridges were made with Trend over gold alloy (Academy Gold-XH). Manufacturer's instructions were followed in all clinical procedures. Trend/Vectris bridges were cemented with ExciteDSC/VariolinkII and Trend/Gold bridges with zinc-phosphate cement. Evaluation criteria, based on the California Dental Association guidelines, were: “shade match”, “surface texture”, “marginal shoulder”, “marginal gap”, “fracture”, “secondary caries”, “retention” and “abutment tooth sensitivity”. The bridges were rated in one of four possible categories, “R” (ideal), “S” (acceptable), “T” or “V” (unacceptable). Results: Comparison between Baseline and 1-Year in the Trend/Gold group showed no change in “color match”. A statistical significant degradation in “surface texture” (p=0.007), “marginal shoulder” (p=0.014), “marginal gap” (p=0.034), and “fracture” (p=0.025) was found. All changes were minor from “R” to “S” except in the criteria “marginal gap” where 1 bridge was rated “T/V”, and “fracture” with 6 “T/V” ratings. In Trend/Vectris group only “surface texture” degradation was statistically significant (p=0.001). Nevertheless, Trend maintained a clinically acceptable surface gloss. Comparing the results for the two groups in each period, the only statistically significant differences found, were on “sensitivity” at Baseline (p<0.001) and on “fracture” at 1-Year (p=0.009). At the 1-Year recall 6 (22.2%) Trend/Gold bridges were considered unacceptable because of “fracture” (n=5) or both “marginal gap” and “fracture” (n=1). Since fractures consisted in loss of small parts of veneering composite, 4 of these bridges remained in service and only 2 were replaced. Conclusion: After 12 months, the overall performance was acceptable. (Study supported by Ivoclar/Vivadent).