Application of near-infrared-to-blue upconversion luminescence for the polymerization of resin cements through zirconia discs.
Dent Mater
; 40(8): 1208-1215, 2024 Aug.
Article
in En
| MEDLINE
| ID: mdl-38851964
ABSTRACT
OBJECTIVES:
To investigate a near-infrared-to-blue luminescence upconversion curing method for polymerizing resin cements under zirconia discs.METHODS:
Lava zirconia discs of different thicknesses (0.5-2.0 mm) were manufactured. First, the transmittances of the NIR and two blue lights (BLs) (LED and halogen lights) through these discs were measured. Second, NaYF4Yb3+/Tm3+ upconversion phosphor (UP) powder was milled into 0.5-µm particle sizes. A light-curable resin cement VariolinkII base was chosen as the control (UP0), and an experimental cement (UP5) was prepared by adding 5 % UPs. These two cements were examined using multiphoton excitation microscopy for particle distribution. UP5 and UP0 were polymerized with or without zirconia shielding then subjected to a microhardness test. A multifold analysis was performed to examine the effects of zirconia thickness, curing protocols (pure BL or combined BL and NIR curing), and cement type.RESULTS:
The transmittance of NIR was superior to that of BL through zirconia discs of all thicknesses. UP particles were homogeneously distributed in UP5 and emitted blue luminescence under 980-nm NIR excitation. UP5 showed higher microhardness values than UP0 under any curing protocol or zirconia shielding condition. The combination of 20-s BL and 40-s NIR curing yielded the highest microhardness in uncovered UP5. However, combining 40-s BL and 20-s NIR curing surpassed the other groups when the zirconia discs were thicker than 0.5 mm.SIGNIFICANCE:
NIR exhibits higher transmission through zirconia than BL. UP particles work as strengthen fillers and photosensitizers in cements. NIR upconversion curing could be a new strategy for polymerizing resin cements under thick zirconia restorations.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Zirconium
/
Materials Testing
/
Resin Cements
/
Polymerization
Language:
En
Journal:
Dent Mater
Journal subject:
ODONTOLOGIA
Year:
2024
Document type:
Article
Affiliation country:
Country of publication: