Fracture frequency and longevity of fractured resin composite, polyacid-modified resin composite, and resin-modified glass ionomer cement class IV restorations: an up to 14 years of follow-up.

The aim of this study was to evaluate the fracture frequency and longevity of fractured class IV resin composite (RC), polyacid-modified resin composite (compomer; PMRC), and resin-modified glass ionomer cement (RMGIC) restorations in a longitudinal long-term follow-up. Eighty-five class IV RC (43: Pekafil), PMRC (24: Dyract (D), Hytac (H)), and RMGIC (18: Fuji II LC (F), Photac Fil (P)) restorations were placed in ongoing longitudinal follow-ups in 45 patients (mean age 54.5 years). The restorations were evaluated during 14 years by slightly modified USPHS criteria at yearly recalls especially for their fracture behavior. For all restorations, 36.5% were fractured, with a Kaplan-Meier (KM) estimate of 8.8 years (standard error (SE) 0.5, confidence interval (CI) 7.9-9.8). The number of fractures per material was 11 RC (25.6%; KM 9.9 years, CI 8.7-11.0), 13 PMRC (54.2%; D 66.6%; H 50.0%; KM 7.5 years, CI 5.8-9.2), and seven RMGIC (36.5%; F 22.2%, P 71.4%; KM 6.9 years, CI 7.9-9.8). Significant differences were seen between RC and PMRC (p = 0.043). A significant higher fracture rate was observed in teeth 12 + 22 compared to teeth 11 + 21. No significant differences were observed between male and female patients. Restorations in bruxing patients (45) showed 22 fractures (KM 8 years; CI 6.9-9.3) and in non-bruxing patients (39) nine fractures (KM 9.9 years, CI 8.7-11.1; p = 0.017). With regard to the longevity of the replaced failed restorations, for RC, the mean age was 4.5 years; for PMRC, 4.3 years; and for RMGIC, 3.3 years. It can be concluded that fracture was the main reason for failure of class IV restorations. An improved longevity was observed for class IV restorations compared to those presented in earlier studies. RC restorations showed the lowest failure frequency and the highest longevity.