INTRAORAL REPAIR OF FIBER-REINFORCED COMPOSITE FIXED PARTIAL DENTURES

Statement of the problem. Fractured composite facings may result in re placement of a fixed partial denture unless a reliable intraoral repai r method can be provided. Purpose. This in vitro study tested the qual ity of an intraoral repair method for fractured facings of fixed parti al dentures made of a fiber-reinforced composite system. Material and methods. Shear bond strengths of a light-curing composite to a fiber-r einforced composite material were determined after different mechanica l surface treatments. Aluminum oxide air abrading provided the most re liable bond strength values and therefore was used as a pretreatment f or the facing repair of three-unit posterior fixed partial dentures. F acing repair was performed with the tested light-curing hybrid composi te. Facing fracture strengths of repaired and original fixed partial d entures were determined after thermocycling and mechanical loading. Re sults. Median facing fracture strength of the original fixed partial d entures was 1450 N after a simulated clinical service of 5 years. Faci ng fracture strengths of the repaired fixed partial dentures were sign ificantly lower compared with the control group after an additional si mulated 2-year interval. However, the median fracture force was still 1000 N. Conclusions. The facing repair of a fiber-reinforced tired par tial denture with a hybrid composite in combination with aluminum oxid e air-abrading pretreatment and silanization provided sufficient fract ure strength. Therefore the replacement of the complete restoration ma y be avoided.