Tooth color change caused by photosensitizers after photodynamic therapy: An in vitro study

Abstract

This study aimed to perform an in vitro evaluation of the effect of photosensitizers used in photodynamic therapy (PDT) on tooth color change when used in combination with conventional endodontic treatment. Forty extracted human mandibular premolars were accessed and underwent root canal therapy and PDT. Photosensitizers were used in accordance with the experimental groups: MB (n=10) - PDT with Methylene Blue at 0.01%; TB (n=10) - PDT with Toluidine Blue at 0.01%; MG (n=10) - PDT with Malachite Green at 0.01%, at the concentration of 0.1mg/mL; and PC (n=10) - positive control, PDT with Endo-PTC cream stained with Methylene Blue at 25%. The samples were irradiated with 660-nm diode laser by means of a 330-μm-diameter optical fiber cable at a power density of 40mW for 120s. After light curing, the photosensitizers were removed from the specimens with 10mL sodium hypochlorite at 1%. A reflectance spectrometer was used for evaluation of color prior to and 60days after the experimental procedure based on the CIE L*a*b* system. According to ANOVA test, there were statistically significant differences between the experimental groups (p=0.003). Tukey's test showed a significant difference between PC and TB (p=0.008), as well as between MG and TB (p=0.009). However, there was no statistically significant difference between PC, MG (p=0.957) and MB (p=0.103). It was concluded that the use of PDT as an adjuvant to root canal therapy, using different photosensitizers, led to color change in tooth structure.

Effects of dyes used in photodynamic therapy on color stability of composite resins

“…A disadvantage of PDT-a method for cleaning and disinfecting the root canal system-is that the dyes used stain tooth structures and result in an undesirable aesthetic appearance. A few studies investigated dental tissue discoloration induced by photosensitizers after PDT [5,19]. The present study evaluated color change in RBCs with different compositions by simulating PDT application during endodontic treatment for anterior teeth with previous RBC restorations, and investigated the effectiveness of NaOCl in preventing such discoloration.…”

Antimicrobial Photodynamic Effect of Cross-Kingdom Microorganisms with Toluidine Blue O and Potassium Iodide

“…However, it cannot be ignored that higher TBO concentration after photoactivation was reported to induce cytotoxicity to normal host cells [ 34 ]. Likewise, high concentration of photosensitizer after incubation may stain the tooth dentin and affect the aesthetics of anterior teeth in dental treatment [ 35 ]. Thus, a lower concentration of TBO was used in this study.…”

Antibacterial Effect of Red Laser Therapy on Enterococcus faecalis Using Different Photosensitizers: An In Vitro Study

“…In contrast to our study, Silva et al used a higher concentration of the photosensitizers used (0.1%), which resulted in greater bacterial reduction as opposed to the present study where the concentration used was lower (0.005%). However, this concentration of 0.1% can stain the teeth, making it unsuitable for clinical application [ 18 ].…”