Sufficiency of curing in high-viscosity bulk-fill resin composites with enhanced opacity

Ilie, Nicoleta (2019): Sufficiency of curing in high-viscosity bulk-fill resin composites with enhanced opacity. In: Clinical Oral Investigations, Bd. 23, Nr. 2: S. 747-755

Abstract

ObjectivesThe study aims analyzing if improved opacity in modern high-viscosity bulk-fill resin composites (BF-RBC) contradicts with the sufficiency of curing and to assess material's tolerance to less ideal curing conditions.Materials and methodsSimulated large cavities (10x6) mm were filled in one increment with three BF-RBCs (Filtek One, FO;Tetric Evo Ceram Bulk Fill, TEC-BF;SonicFill2, SF2). One central and two peripheral (4mm apart from the center) micromechanical property line-profiles (HV, Vickers hardness;Y-HU, indentation modulus) were measured in 0.2-mm steps at 24h post-polymerization (n=6). Depth of cure (DOC) was calculated from the HV variation in depth. A scratch test (DOCscratch test) estimated the tolerance in polymerization when simulating clinically relevant curing conditions (exposure distance up to 7mm;centered and with a 3-mm offset placement of the LCU). Irradiance and spectral distribution of the used light curing unit (LCU) were assessed at various curing conditions.ResultsDOC varied among 3.6mm (SF2, peripheral) and 5.7mm (FO, central). The BF-RBC influences DOC stronger (p<0.001, P-2=0.616) than the width (p<0.001, P-2=0.398). Significant lower DOC (t test) was measured peripheral compared to center in all materials. Y-HU was more sensitive to the varied parameters as HV. DOCscratch test varied among 2.4mm (SF2, 3-mm offset, exposure distance 7mm) and 3.9mm (FO, center, 0mm).ConclusionsWhether opacity competes with DOC is material dependent. BF-RBCs tolerate small variations in LCU's centricity better than variations in exposure distance.Clinical relevanceThe upper incremental thickness threshold of 4 or 5mm was not reached in all BF-RBCs under simulated clinically relevant curing conditions.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Medizin
• Themengebiete: 600 Technik, Medizin, angewandte Wissenschaften > 610 Medizin und Gesundheit
• ISSN: 1432-6981
• Sprache: Englisch