Pre-heating effects on extrusion force, stickiness and packability of resin-based composite. Issue 11 (November 2019)

• Record Type: Journal Article
• Authors: Yang, Jiawei; Silikas, Nikolaos; Watts, David C.
• Is Part Of: Dental materials. Volume 35:Issue 11(2019)
• Page Start: 1594
• Page End: 1602
• Publication Date: 2019-11
• Subjects: Resin composite -- Extrusion force -- Handling properties -- Stickiness -- Preheating -- Degree of conversion; Dentistry -- Periodicals; Dental materials -- Periodicals; 617.695
• DOI: 10.1016/j.dental.2019.08.101
• Languages: English
• ISSNs: 0109-5641

Abstract

Abstract: Objectives: To measure temperature effects on stickiness and packability of representative resin-based composites and the effect of pre-heating time on pre-cure properties of Viscalor, including extrusion force. Methods: Five resin-based composites (RBC) and an additional RBC, Viscalor, used with a Caps Warmer (VOCO, Germany) were studied. The extrusion force (N) and extruded mass (g) were measured from Viscalor compules heated in T3 mode for 30 s (T3-30 s) and 3 min (T3-3 min). For stickiness and packability measurements, RBCs were packed into a brass cylindrical cavity controlled at 22 and 37 °C. A flat-ended probe was lowered into the RBC pastes at constant speed. Stickiness: Fmax (N) and Ws (N mm), and packability: Fp (N), were measured. Viscalor was LED photo-cured at 1200 mW/cm 2 for 40 s. The degrees of conversion at 5 min and 24 h post cure (DC5min and DC24h ) of Viscalor (no heat, T3-30 s and T3-3 min) were measured by ATR-FTIR. Data were analysed by one-way ANOVA, independent t -test and Tukey post-hoc tests (p < 0.05). Results: The maximum temperature of the Caps Warmer, in T3 mode, reached 68 °C in 20 min. Viscalor temperatures of 34.5 °C and 60.6 °C were recorded after 30 s and 3 min pre-heating, respectively. Pre-heating significantly reduced extrusion force and increased extruded mass, especially after 3 min. RBCs varied in Fmax, Ws and Fp (p < 0.05). Temperature also affected Fmax (p = 0.000), Ws (p = 0.002) and Fp (p = 0.000). Pre-heating Viscalor for either 30 s or 3 min did not increase the post-cure DC at either 5 min or 24 h, relative to no pre-heating (p > 0.05). Significance: The composites varied to an extent in stickiness and packability but the overall magnitudes remained within a clinically acceptable range. Pre-heating was beneficial in placement of Viscalor and caused no adverse effects through premature polymerization.