Fiber-Reinforced Inlay FPDs: Maximum Preservation of Dental Hard Tissue

Objectives. Restorative dentistry searches for defect-orientated solutions for the esthetic reconstruction of missing teeth. In Zurich, a concept was developed for bonding composite fixed partial dentures (FPDs) to minimal invasive abutment preparations. In in-vitro tests and in a clinical study, conservative fiber-reinforced composite FPDs bonded to inlay abutments, were evaluated. Material and Methods. In in-vitro tests, the marginal adaptation of 18 totally and selectively bonded three- and four-unit fiber-reinforced slot inlay FPDs (IFPDs) was evaluated using a computer controlled masticator. Before and after long-term thermo-mechanical loading, marginal adaptation was analyzed by scanning electron microscopy (SEM). In a clinical study, 60 defect-orientated fiber-reinforced composite IFPDs were inserted in 42 patients using a progressive protocol. The restorations were manufactured using the Targis&Vectris glass-fiber-reinforced composite system (Ivoclar, Schaan, Liechtenstein) and a simplified laboratory technique. The bonded IFPDs were observed over a period of two and a half years and were rated clinically by using the USPHS-criteria. Ten IFPDs were selected at random for SEM analysis. Results. SEM analysis showed well above 90% of perfect margins and a negligible loss of marginal quality of selectively bonded abutment slot inlays after long-term thermo-mechanical loading. Clinically, patient's acceptance and satisfaction of the IFPDs was very high. Up to the present time, no changes in clinical quality have been detected during recall examinations using USPHS-criteria. SEM screening corroborated the clinical findings with an average of about 90% of perfect margins after one and two years. Conclusion. Based on the results of the clinical study and the in-vitro results, bonded glass-fiber-reinforced composite IFPDs were considered clinically successful over the observation period. Keywords: Fiber-reinforced composite, inlay, fixed partial denture, clinical trial, marginal adaptation