Objectives. The purpose of this clinical trial was to evaluate the influence of in-office dental bleaching on the pulp oxygen saturation (SpO2p) reading. Material and Methods. SpO2p was measured using a pulse oximeter in 112 upper and lower anterior teeth (canines and incisors) of patients submitted to bleaching. Whitegold Office 35% (WGO) (upper and lower left hemiarch) and Whiteness HP Auto Mixx 35% (WHP) (upper and lower right hemiarch) bleaching agents were used. SpO2 measurements (teeth and index finger) were taken before and after each of the three application sessions of the agents. In the 4th session, in which no bleaching gel was used, only SpO2 was measured. Before and after the bleaching sessions, a colorimetric device performed the teeth color reading. The waiting time between sessions was 7 days. Data were analyzed by the Friedman, Kruskal–Wallis, and Mann–Whitney U tests (α = 0.05). Color change (ΔE) data were correlated (Spearman’s Rho test) with the SpO2p levels. Results. Neither of the two bleaching agents showed significant differences between the readings when evaluated individually (WGO, P = 0.780 , and WHP, P = 0.494 ). When taken together, the results showed significant difference between the readings performed, with higher median values after bleaching sessions: before (97.3) and after (98.6) 1st session; before (98.3) and after (98.3) 2nd session; before (98.3) and after (99.0) 3rd session; and after 1 week (98.3). The dental groups formed by maxillary lateral incisors ( P = 0.012 ) and mandibular incisors ( P < 0.001 ) showed a significant difference. Spearman’s Rho test showed a nonsignificant and weak correlation between ΔE and SpO2p in most comparisons. Conclusions. The in-office dental bleaching influenced the SpO2p reading, regardless of the dental group evaluated or the bleaching agent used. Clinical Relevance. This study provides information about the influence of in-office tooth whitening on the pulp SpO2p levels. The observation of pulp vitality during and after the use of bleaching agents is important for the follow-up of patients undergoing tooth whitening. The use of a pulse oximeter may be a viable and painless alternative to perform this monitoring. The clinical trial was registered with the Brazilian Registry of Clinical Trials (ReBEC; registration number: https://clinicaltrials.gov/ct2/show/RBR-68xbth).

This study aimed to evaluate the influence of different dental tissue thickness on the measurement of oxygen saturation (SpO2) levels in high (HP) and low (LP) blood perfusion by comparing the values obtained from two different pulse oximeters (POs) - BCI and Sense 10. Thirty freshly extracted human teeth had their crowns interposed between the POs and an optical simulator, which emulated the SpO2 and heart beats per minute (bpm) at HP (100% SpO2/75 bpm) and LP (86% SpO2/75 bpm) modes. Afterwards, the palatine/lingual surfaces of the dental crowns were worn with diamond drills. The reading of SpO2 was performed again using the POs alternately through the buccal surface of each dental crown. Data were analyzed by the Wilcoxon, Mann-Whitney and Kendall Tau-b tests (α=5%). The results showed significant difference at the HP and LP modes in the SpO2 readouts through the different dental thicknesses with the use of BCI, and at the LP mode with the use of Sense 10, which had a significant linear correlation (p<0.0001) and lower SpO2 readout values in relation to the increase of the dental thickness. Irrespective of tooth thickness, Sense 10 had significantly higher readout values (p<0.0001) than BCI at both perfusion modes. The interposition of different thicknesses of enamel and dentin influenced the POs measurement of SpO2, specially at the low perfusion mode. The POs were more accurate in SpO2 measurement when simulated perfusion levels were higher.

In this study, we evaluated the effectiveness of 1 and 5.25% NaOCl solutions, with or without surfactant, in disinfecting gutta‐percha cones. Surface changes of the gutta‐percha cones after disinfection were also assessed under scanning electron microscopy (SEM). One‐hundred and eight gutta‐percha cones previously contaminated with Enterococcus faecalis were left in contact for 30 s or 1 min with the following solutions (n = 12): 1% NaOCl; 1% NaOCl + 2% cetrimide; 5.25% NaOCl; 5.25% NaOCl + 2% cetrimide. Positive control group was composed by the remaining contaminated cones (n = 12), and the negative control group by noncontaminated cones (n = 12). The cones were kept in Eppendorf tubes containing Trypticase Soy Broth at 37°C for 24 hr, and then, the presence of turbidity was analyzed. Ten additional cones (n = 2) were observed under SEM to evaluate surface changes after 1 min of disinfection. The data analysis (Kruskal–Wallis test, α = 5%) demonstrated that regardless the presence of surfactant, the NaOCl solutions used were effective in the disinfection when cones were immersed for 1 min. However, at the 30‐s period, only the 5.25% NaOCl solution was effective. SEM analysis demonstrated that NaOCl solutions promoted the formation of sodium chloride crystals on cones surface, less visible when the 1% NaOCl associated to surfactant was used. The addition of surfactant did not affect the disinfection capacity of NaOCl solutions. However, the surfactant has apparently inhibited the sodium chloride crystals deposition on the cones surface when associated to 1% NaOCl solution.