Curing Effectiveness of Single-Peak and Multi-Peak Led Light Curing Units on Tpo-Containing Resin Composites With Different Chromatic Characteristics

Abstract

SUMMARYThis study evaluated the surface microhardness of Lucirin-TPO (TPO) containing resin based composite (RBC) cured with three light-emitting diode (LED) light curing units (LCUs) (two single-peak LED and one multi-peak LED), and two different energy density (ED) (8 J/cm 2 and 16 J/cm 2 ). Ninety specimens (8 mm wide and 2 mm thick) (n=5), were prepared with three different shades: translucent (T), A2 dentin (A2d), and A4 dentin (A4d). Specimens were subjected to micro-hardness Vickers measurements (Vickers Hardness Number, VHN) on both top and bottom surfaces. Hardness ratio (rHV) was also calculated. Data were analyzed using multifactorial ANOVA and Bonferroni tests (<=0.05). Results indicated that higher ED performed better than lower ED. Multi-peak LED achieved higher VHNs and rHV than single-peak LED when curing a TPO-containing RBC. A4d invariably achieved lower rHV and VHN than T and A2d. Single-peak LED achieved comparable VHNs and rHVs with multi-peak LED only curing A2d and T shades with 16J/cm 2 .

Evaluation of Surface Roughness of Composite, Compomer and Carbomer After Curing Through Mylar Strip and Glycerin: A Comparative Study

“…The degree of polymerization is influenced by parameters such as filler content, color, initiator, light intensity, and curing time. [12][13][14] In the present study 3 different restorative materials, namely a hybrid composite, a polyacid modified composite resin, and a nanofiller integrated glass ionomer carbomer, were examined to see the effect of different curing conditions on surface roughness. The intensity of the LED and curing time was kept the same as in the aforementioned factors affecting the polymerization capacity.…”

The Photoinitiators Used in Resin Based Dental Composite—A Review and Future Perspectives

“…Single-peak light-curing unit has narrow range of light: 450–470 nm and the absorption of Lucirin TPO is out of this matter. However, polywave light-curing units are provided with extra light range: 400 to 415 nm and the exposure of resin containing TPO to the light is sufficient [ 46 ]. Additionally, Ilie et al in their analysis proved that TPO can replace CQ, when the dual-wavelength LED units would initiate polymerization process [ 45 ].…”

“…Because of the CQ is the most common photoinitiator in resin-based composites every property is compared to CQ’s feature in most analysis. The composites including TPO have higher degree of conversion than the composites containing CQ [ 18 , 36 , 46 , 47 ] The TPO-composites display an average 10% conversion increase. Miletic et al [ 44 ] in their analysis proved that TPO is more efficient than CQ, because 0.86 wt% resulted in 74% degree of conversion and the lower concentration 0.22 wt% led to 68% DC.…”

“…The temperature increase of TPO resin-based composites is lower than CQ controls. The polymerization efficiency in dental resin is higher when TPO is used in dental resin, compared to CQ, PPD and BAPO’s efficiency, when the halogen light curing unit initiates the polymerization [ 46 ]. Lucirin TPO is more effective than CQ, because it produces two free radicals by α-cleavage, when CQ delivers only one.…”

Ocular hazards of curing light units used in dental practice – A systematic review

“…Initially, the dental light curing unit (LCU) delivered ultraviolet (UV) light for photopolymerization (Mahn et al, 2013, Conte et al, 2017) later the LCU transitioned into blue light emitting units because of the health concerns with the use of UV light. Currently, three main types of LCUs are used in the dental setting – halogen, plasma arc and light emitting diodes (LEDs).…”