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Published on: October 27, 2023
Technique for Darkening of Extracted Teeth Simulating Pulpal Necrosis Discoloration
Thais R D Paini1, Joana Y T Uchimura1, Francielle Sato2
1Department of Dentistry, State University of Maringa, Maringá, PR, Brazil.
Background:
The use of discolored teeth is required to test whitening products, and it is difficult to obtain them, given their scarcity.
Objective:
To present a technique for in vitro darkening of extracted teeth simulating pulpal necrosis discoloration.
Materials And Methods:
Hemolysates I and II from human blood were subjected or not to laser irradiation (442 nm) for 1 h. The concentration of oxyhemoglobin (O2Hb) was analyzed by ultraviolet/visible spectroscopy, and the conversion of O2Hb to methemoglobin (MetHb) by transmission spectroscopy was assessed immediately and after 3 and 40 days. For darkening evaluation, bovine incisors were divided into two groups (n = 25), and their pulp chambers were filled with hemolysate solution II (HSII) and hemolysate II solution + laser (HSII+L). After storage in artificial saliva for 40 days at 37°C, color changes were measured by a colorimeter and ΔE was compared with the NBS parameters. Data were analyzed using a mixed linear model (α=5%).
Results:
HSII+L presented the lowest O2Hb and higher MetHb. The conversion of O2Hb to MetHb in HSII+L was 42% higher than in HSII. Both groups were effective in darkening the teeth, according to the NBS. Darkening stabilized from day 35. HSII promoted a marked color difference.
Conclusion:
The proposed technique was effective in darkening the extracted teeth simulating necrosis discoloration for in vitro models.
