Fractured root adhesion treatment with 4-methacryloxyethyl trimellitate anhydride/methyl methacrylate-tributylborane (4-META/MMA-TBB) resin cement: Up to 39-year longitudinal study of 369 fractured roots

Since 1982, 4-META/MMA-TBB resin cement (Superbond, Sun Medical, Moriyama, Shiga, Japan; SB) has been applied to preserve root fractures (RFs) in 317 patients (369 roots) treated in our clinic from February 1982 to December 2016, respecting patients' wishes. Follow-up data were collected as of December 31, 2021. The 5- and 10-year survival rates were 92.7% and 65.9%, respectively, with a median survival time of 15.08 years. A multivariate Cox hazard model identified patient age and Masaka's classification (Type M-1: U-shaped RFs treated by intraoral adhesion method) as significant prognostic factors. The hazard ratio for age was 1.022 (95% CI: 1.008-1.037). Type M-1 cases showed a 10-year survival rate of 94.7% with more than half of the treated teeth remaining functional at the time of data collection. These findings suggest that SB can effectively restore and maintain the function of RFs for a decent period.