Managing Vital and Nonvital Tooth Bleaching Among Endodontists and General Dental Practitioners: A Knowledge, Attitude, and Practice Study.

Tooth bleaching has become increasingly popular in recent times. It is the preferred conservative approach for lightening discolored teeth. The primary objective of tooth bleaching is to whiten teeth using oxidizing chemicals that work on both enamel and dentin. The noninvasive nature of modern bleaching systems allow for effective treatment options that meet the high expectations of patients. The objective of this study was to investigate the knowledge, attitude, and practices of dental practitioners in South India for managing discolored upper front teeth. We created and distributed a structured, validated questionnaire about bleaching discolored anterior teeth to South Indian dental practitioners and analyzed the data. We found a statistically significant relationship between endodontists and general dentists in their preferences for isolation techniques, choice of materials for vital bleaching, management of intact nonvital teeth, and management of postbleaching sensitivity. Women exhibit a greater preference for teeth-whitening procedures than men, with 74% opting for whitening treatments. The predominant method for addressing tooth discoloration is bleaching, which makes up approximately 63.8% of the whitening procedures. In-office bleaching is the preferred method for both vital and nonvital bleaching procedures, demonstrating its widespread acceptance and preference among practitioners.

Assessment of tooth discoloration induced by root canal filling materials in pediatric dentistry.

This study investigated the potential for tooth discoloration of root canal filling pastes used in pediatric dentistry. Sixty bovine incisors were sectioned 2 mm apical to the cementoenamel junction and allocated into 6 groups (n = 10) according to the type of filling material used: G1- Zinc oxide-eugenol sealer; G2- Zinc oxide-eugenol and iodoform paste; G3- Calcium hydroxide (CH) and zinc oxide paste; G4- CH, zinc oxide, and iodoform paste; G5- CH and iodoform paste; and G6- Control. Polyethylene glycol 400 was used as a vehicle for CH-containing pastes. Color measurements were taken at specific intervals: preceding endodontic treatment (T0) and at successive points of 1 month (T1), 2 months (T2), 3 months (T3), and 1 year (T4) after the placement of the filling material. The color change (∆E) was calculated using the CIELab formula. Statistical analysis was performed using ANOVA, followed by Tukey's post hoc test (α = 5%). Significant differences were observed among the filling materials and time intervals (p <0.001). All groups exhibited color changes over time, except G1 and G5, which showed color changes only after 1 year. G1 and G2 demonstrated the highest ∆E values, with a statistically significant difference observed only at T2 when compared to G3 (p = 0.008). Root canal filling materials used in primary teeth have the potential to induce tooth discoloration.

The color stability of artificial white spot lesions treated with resin infiltration after exposure to staining beverages.

BACKGROUND: To evaluate the effect of staining beverages on the color-changing of resin-infiltrated artificial white spot lesions (WSLs). METHODS: Thirty-five artificial WSLs were created by pH cycling on flat bovine teeth specimens. The WSLs were treated with resin infiltration and were divided into five groups based on staining beverages: artificial saliva, coffee, wine, green tea, and Coca-Cola. These specimens were subjected to a 28-day exposure to the respective beverages. Color stability was assessed using a spectrophotometer at different time points: baseline, after 7, 14, 21, and 28 days of exposure, and repolishing. The color difference (∆E) between each time point and the baseline was calculated. Statistical analysis was performed using two-way measures ANOVA with a significance level of p = 0.05. RESULTS: All resin-infiltrated specimens exposed to staining beverages for 7 days exhibited more significant color changes than those exposed to artificial saliva. The color change patterns varied based on the type of beverage. The color alterations intensified with extended immersion in the wine and Coca-Cola groups, while there were no significant differences in the color of specimens after 28 days of immersion in the coffee and green tea groups. However, after cleaning with pumice powder, all specimens showed significantly reduced color changes compared to those observed after 28 days of immersion, except those immersed in coffee. CONCLUSIONS: Exposure of resin-infiltrated bovine tooth specimens to staining beverages resulted in a significant color alteration as the immersion time increased. However, the staining effect could be minimized by cleaning with pumice powder, except for the coffee group. CLINICAL RELEVANCE: After resin infiltration treatment, patients should be advised to minimize the consumption of colored beverages to prevent staining that could impact esthetic appearance.

Long-term complications and management of dental trauma in the adult patient - Part 2: discoloured, displaced and missing teeth.

The second paper in this two-part review series aims to outline the long-term complications of dental trauma in the adult patient in relation to discoloured, displaced or missing teeth. A brief overview of the cause of discolouration is outlined, followed by assessment and management options. These can include bleaching, veneers, or crown restorations to mask the discolouration. Displacement of teeth from the socket can occur due to luxation injuries. Management can include simple digital manipulation, surgical repositioning, or orthodontic extrusion based on the severity of extrusion and the time from injury. Teeth can be lost early or in the long-term following dental trauma and associated hard and soft tissues deficiencies may also ensue. Replacement options can include a removable partial prosthesis, resin-retained bridge or dental implants. Often, hard and soft tissue augmentation procedures may be required to address any defects and rebuild lost anatomical contours. A thorough assessment followed by the development of a sound management plan which takes patients' general and local factors into account can ensure a predictable and successful treatment outcome. This would end in an aesthetically pleasing and a functionally stable result for the patient.

Effectiveness of Three Bleaching Techniques for Endodontically Treated Teeth: A Randomized Clinical Trial.

BACKGROUND: Various techniques, products, and protocols are used for the bleaching of non-vital teeth. The walking bleach technique involves sealing the bleaching agent in the pulp chamber. In the inside/outside technique, a low-concentration bleaching agent is applied at home using a custom tray. In the in-office technique, a high-concentration bleaching agent is applied by a dental professional. Limited research has compared the effectiveness of these techniques. OBJECTIVE: This clinical trial aimed to evaluate the effectiveness of the walking bleach, the inside/outside, and the in-office bleaching techniques. METHODS AND MATERIALS: Fifty-four discolored teeth were selected according to eligibility criteria, randomized, and assigned to three treatment groups (n=18): walking bleach (sodium perborate - SP), inside/outside bleaching (7.5% hydrogen peroxide -HP7.5), and in-office bleaching (35% hydrogen peroxide - HP35). A cervical seal was placed in all the teeth, and nonvital bleaching was performed according to each technique. The CIELab color coordinates were measured using a clinical spectrophotometer at baseline, weekly, and at the 1-week follow-up. ΔE00 and ΔWID were calculated between the baseline and each evaluation time point. The ANOVA, Fisher exact, and Kruskal-Wallis tests were used to compare the quantitative variables, and the Fisher exact test, to determine the association among categorical variables. Bleaching effectiveness was interpreted by 50:50% perceptibility and acceptability thresholds. RESULTS: As the treatment progressed, all techniques presented a significant increase in L* and WID (p<0.001), and a significant decrease in a* and b* (p<0.001). HP7.5 and HP35 presented greater increases in WID mean values, in comparison with SP (p=0.006). No significant differences were observed among the techniques for ΔE00 after treatment completion (p=0.383). There were no statistical differences in bleaching effectiveness among the techniques after treatment completion (p=0.098). CONCLUSION: All techniques presented excellent effectiveness after treatment completion. However, HP7.5 and HP35 techniques provided a more rapid whitening response.

Normal Saline or Sodium Hypochlorite Irrigation for Vital Pulp Therapy? A Non-Inferiority Randomized Controlled Trial.

criteria were randomized to each irrigant, 65 in the NaOCl and 60 in the NSS groups. ProRoot® MTA was used as a pulp dressing material in both groups and teeth were followed for 12 months. The primary outcome was the success of VPT; requiring both clinical and radiographic success to be considered as success. The hypothesis was that the absolute difference of VPT success in the NSS group was not worse than that in the NaOCl group, by a margin of 5%. The secondary outcome was discoloration; percentages of discolorations between both groups were compared. Results: Using a per protocol analysis, the absolute difference of VPT success between the NSS and NaOCl groups was 2.08% (95% CI: -1.95, 6.1). Perceptible gray discolorations were 80% and 63% in NaOCl and NSS groups (difference -17%; 95% CI: -40.0, 6.2; p=0.15). Conclusions: For MTA-VPT procedure, irrigation with NSS was not worse than that with NaOCl. However, both irrigants caused discoloration. (EEJ-2023-05-065).

Black stain and dental caries in primary dentition of preschool children in Qingdao, China.

Black stain (BS) and caries are common oral issues in children worldwide. This study aimed to reveal the prevalence of BS and caries in primary dentition of children in Qingdao, China and evaluate the potential association between them. A total of 672 preschool children aged 3-5 years old from 12 kindergartens in Qingdao, northern China were enrolled in the study. The prevalences of BS and caries were counted, and their distributions across different ages and genders were analyzed. The potential protective role of BS (independent variable) on caries (dependent variable) was analyzed via binary logistic regression analysis. BS was observed in 103 children (15.33%), including 3 severe- (0.45%), 28 moderate- (4.17%), and 72 mild (10.71%) forms. Caries was observed in 374 children (55.65%) and it was positively associated with age. Notably, the prevalence of caries was lower in children with BS than in those without BS (42.72% vs. 58.00%, respectively). Children with BS were less likely to suffer from caries than those without BS. BS in mild or moderate/severe forms was associated with a low risk of caries. In summary, the prevalence of BS in primary dentition in Qingdao, China is at a relatively high level worldwide. BS is a protective factor for caries in primary dentition.

Influence of coffee characteristics on tooth discoloration.

PURPOSE: To evaluate the impact of coffee attributes on tooth discoloration, emphasizing the importance of potential factors such as serving temperature, bean variety, and chlorogenic acid (CGA) content. METHODS: Coffee preparation involved the extraction of espresso from four types of roasted beans (Vietnam Robusta, Uganda Robusta, Ethiopia Yirgacheffe Arabica, and Colombia Supremo Arabica), followed by chlorogenic content analysis using high-performance liquid chromatography. Bovine tooth enamel specimens were carefully prepared and stained with coffee (hot and iced), with a color assessment conducted at different time intervals (3, 9, 24, 48, and 72 hours). The Vickers hardness tester was employed to ensure specimen quality, while spectrophotometry aided in color analysis using the CIEDE2000 formula. RESULTS: The results revealed varying effects of serving temperature, bean type, and CGA content on tooth discoloration. It was demonstrated that perceptible color differences occur after a 3-hour immersion in coffee, with hot coffee showing higher staining potential compared to iced variations. Furthermore, chlorogenic acid content and bean type significantly affected tooth discoloration, with higher chlorogenic acid levels associated with increased staining. Notably, Robusta coffee showed less discoloration compared to Arabica, potentially due to differences in pH levels. CLINICAL SIGNIFICANCE: The findings provide valuable insights for both dental practitioners and coffee consumers, assisting in making informed decisions regarding coffee intake and oral hygiene.

Reduced staining from a chlorhexidine mouthwash: A randomized clinical trial.

PURPOSE: To investigate the stain preventing ability of a new chlorhexidine mouthwash while maintaining efficacy using a randomized clinical trial design. METHODS: 98 subjects were enrolled and completed a 4-week clinical study that evaluated the effectiveness of the new mouthwash on plaque, gingivitis, and staining as compared to a commercially available chlorhexidine mouthwash. A subset of 62 subjects was evaluated for the effectiveness of the mouthwashes against plaque bacteria. RESULTS: After 4 weeks of use, the new chlorhexidine mouthwash reduced staining by 42.6% (P< 0.05) as compared to the commercially available mouthwash. The two mouthwashes were equivalent with regards to their effect on gingivitis, plaque, and plaque bacteria. CLINICAL SIGNIFICANCE: A new mouthwash, containing 0.12% chlorhexidine gluconate, has been developed that delivers stain reduction while maintaining equivalent efficacy to a commercially available chlorhexidine mouthwash with regards to gingivitis, plaque, and plaque bacteria. These findings should be considered by dental practitioners when making recommendations to patients whose teeth stain easily and need an anti-gingivitis and anti-plaque mouthwash.

Current perspectives on calcium silicate-based intracanal medicaments: A scoping review of clinical and laboratory evidence.

OBJECTIVE: Intracanal medicaments, primarily calcium hydroxide, play a significant role in optimizing root canal disinfection. Recently, calcium silicate-based intracanal medicaments have emerged as potential alternatives. This scoping review sought to map the available evidence concerning the clinical and laboratory properties of these bioceramic medicaments. DATA: The study protocol was registered a priori (https://osf.io/rnyuv/) and a systematic search strategy using relevant MeSH terms was employed. SOURCES: The search was conducted across databases including the Cochrane Library, EMBASE, PubMed/MEDLINE, SciVerse Scopus, and Web of Science. STUDY SELECTION: Studies that investigated the clinical and laboratory properties of calcium silicate-based intracanal medicaments were included. CONCLUSIONS: Out of 1008 potentially relevant articles, 15 met the inclusion criteria. The majority of the studies came from Brazil, primarily focusing on Bio-C Temp (Angelus). The studies revealed acceptable biocompatibility, alkaline pH, and high calcium ion release. However, they showed reduced antibacterial activity compared to conventional calcium hydroxide formulations. Tooth discoloration beyond clinically acceptable thresholds was also a significant concern. A single clinical case report exhibited potential for periapical healing and root development, though this evidence is very limited. While current evidence is preliminary, high-quality clinical trials are essential to determine their clinical efficacy and safety in endodontic treatments. CLINICAL RELEVANCE: Calcium silicate-based intracanal medicaments have lower antibacterial activity and potential for tooth discoloration compared to conventional calcium hydroxide-based medicaments. Given the available evidence, they cannot be recommended for routine clinical practice.

Evaluation of Staining Propensity of Silver Diamine Fluoride With and Without Potassium Iodide in Children (Project Healthy Smiles): Protocol for a Randomized Controlled Trial.

BACKGROUND: Silver diamine fluoride (SDF) is becoming more widely recognized as a simple, cost-effective approach to minimize sensitivity and arrest caries. However, SDF results in caries that are stained black. Potassium iodide (KI) treatment with SDF may minimize or lessen the staining. However, the effectiveness of KI on staining has not been investigated. Studies demonstrating that potassium iodide reduces the black staining are still insufficient. This paper presents the study protocol for Healthy Smiles, a randomized controlled trial implemented to compare the staining propensity of SDF and SDF+KI. OBJECTIVE: This study, Healthy Smiles, aims to evaluate the staining propensity of SDF and SDF+KI using a Nix Mini color sensor among children aged 4 to 6 years. Another objective of the study is to evaluate the caries-arresting effect of SDF and SDF+KI in the treatment of carious primary teeth. METHODS: This study is a randomized controlled trial. A total of 60 children with caries that meet the criteria of the International Caries Detection and Assessment System (code 1 or above) will be randomly assigned to treatment groups, where group 1 will be treated with SDF and group 2 will be treated with SDF+KI. Discoloration of treated lesions will be assessed digitally using a Nix Mini color sensor. Participants will be followed up at 1, 3, and 6 months after treatment to digitally record the ∆L and ∆E values using the Nix Mini color sensor. Data will be analyzed using SPSS (version 28; IBM Corp). Independent sample t tests and the Mann-Whitney U test will be used to compare the 2 groups. RESULTS: Enrollment started in October 2023. It is estimated that the enrollment period will be 12 months. Data collection is planned to be completed in 2024. CONCLUSIONS: The presented paper describes Happy Smiles, a project that provides an opportunity to address the aesthetic inconvenience of patients without compromising the effectiveness of the SDF treatment. The trial findings will contribute to the limited evidence base related to discoloration after SDF intervention to improve aesthetic appearances in child oral health. If the results from the trial are promising, it will lead to the development of a model for child oral health and pave the way for further research in child oral health. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/51087.

Potential Crown Discoloration Induced by the Combination of Various Intracanal Medicaments and Scaffolds Applied in Regenerative Endodontic Therapy.

BACKGROUND: Regenerative endodontics involves the use of various root canal medicaments and scaffolds, which may cause crown discoloration. AIM: This study aimed to investigate the combined crown discoloration of scaffolds [platelet-rich fibrin (PRF) and blood clot] applied after administration of different medicaments [modified triple antibiotic paste including doxycycline (mTAPd), modified double antibiotic paste (mDAP), calcium hydroxide (CH), and propolis]. METHODS: In total, 100 human mandibular premolar teeth were selected and prepared. The teeth were apically resected to simulate immature teeth. The positive and negative control groups (n = 10) consisted solely of blood-only and serum-only samples. The remaining 80 teeth were used for the experimental groups with four different medicaments. Three weeks later, either blood or PRF was applied as a scaffold after removing the medicaments (n = 10). Color changes were assessed before medication placement and at the end of the first, second, and third weeks, as well as on days 0, 1, 30, 60, and 90 after scaffold application. Analysis was carried out using repeated measures of variance, Friedman, one-way ANOVA, Kruskal-Wallis, the dependent paired t-test, and Wilcoxon test. RESULTS: Statistical significance was determined at P = 0.05. All groups including blood and the group including propolis and PRF combination, resulted in a significant increase in discoloration (P < 0.05) and discoloration exceeding clinically acceptable thresholds. CONCLUSIONS: CH and the modified versions of TAP (mTAPd) and DAP (mDAP) demonstrated an acceptable level of discoloration when used with a combination of PRF at day 90.

[The efficacy of iRoot BP plus in the treatment of adult carious pulp exposure and its impact on pulp blood flow].

PURPOSE: To explore the efficacy of iRoot BP plus in the treatment of adult carious pulp exposure and its impact on pulp blood flow. METHODS: A total of 126 cases of 156 permanent teeth from adult patients with carious pulp exposure who were treated from January 2020 to January 2022 were selected, the patients were divided into experimental group(63 cases with 79 permanent teeth) and control group(63 cases with 77 permanent teeth) by the envelope method. The experimental group was treated with iRoot BP plus, while the control group was treated with mineral trioxide polymer. The differences in treatment effectiveness, operation time, and tooth discoloration between the two groups were observed. Statistical analysis was performed with SPSS 22.0 software package. RESULTS: There was no significant difference in treatment success rates between the experimental group and the control group at 3, 6, and 12 months after surgery(P＞0.05). The operating time for each capsule in the experimental group was (2.53±0.41) min, which was significantly shorter than that in the control group(P＜0.05). The incidence of tooth discoloration in the experimental group at 12 months after surgery was 3.80%, which was significantly lower than that in the control group (P＜0.05). The bite force quotient and masticatory efficiency of the experimental group 12 months after operation were (16.65±1.14) Ibs and (94.45±5.65)%, which were significantly higher than those of the control group(P＜0.05). CONCLUSIONS: IRoot BP plus has good efficacy in the treatment of adult carious pulp exposure, with advantages such as convenient operation, less tooth discoloration, less inflammatory reactions and stable pulp blood flow after decline.

The effect of silver diammine fluoride on In Vitro Enamel caries lesion remineralization and staining as a function of lesion baseline mineral distribution.

OBJECTIVES: to investigate whether baseline mineral distribution modulates the ability of silver diammine fluoride (SDF) to remineralize and stain enamel caries lesions. METHODS: This laboratory study followed a 3 [treatment: SDF/fluoride varnish (FV)/deionized water (DIW)] ×3 [lesion protocol: methylcellulose (MeC)/hydroxyethylcellulose (HEC)/Carbopol 907 (C907)] factorial design. Lesions were created in bovine enamel specimens (n = 20). Treatments were applied and lesions remineralized in artificial saliva. Digital transverse microradiography (TMR-D) was used to analyze lesions. Lesion color was monitored spectrophotometrically. The effects of lesion protocol and treatment on changes in lesion depth (ΔLD), mineral loss (ΔΔZ), maximum mineral density at the surface zone (ΔSZmax), and color changes related to remineralization (ΔL*remin) were analyzed using two-way ANOVA. RESULTS: The treatment×lesion protocol interaction was significant for ΔΔZ (p < 0.01) and ΔL*remin (p < 0.01), however not for ΔLD (p = 0.23) or ΔSZmax (p = 0.91). There were no differences in ΔΔZ between treatments in HEC and C907 lesions. However, DIW resulted in more remineralization than both SDF (p < 0.01) and FV (p = 0.01) in MeC lesions. Considering changes from lesion baseline after remineralization in MeC lesions, SDF treatment resulted in the highest mineral gain in the surface zone. However, DIW revealed the highest mineral gain after remineralization in the lesion body. SDF stained lesions with the intensity increasing after remineralization in C907 lesions, whereas staining decreased in MeC and HEC lesions. CONCLUSION: High fluoride treatments can interfere with continuous remineralization of caries lesions due to partial arrest. Baseline lesion mineral distribution affects SDF's ability to enhance remineralization and the staining caused by SDF. CLINICAL SIGNIFICANCE: SDF is being used to arrest active caries lesions extending into dentin and to treat dentin hypersensitivity. This study shed light on SDF's effect on an isolated process in dental caries only, remineralization. It achieved this by examining enamel caries lesions with differing mineral distributions and assessing their staining properties.

Evaluation of staining potential of Silver Diamine Fluoride, Potassium Iodide, Nanosilver Fluoride: an in vitro study.

BACKGROUND: The black staining effect of silver-containing solutions for use to arrest caries can have a negative aesthetic impact on children and parents. This study aims to assess the staining effects of Silver Diamine Fluoride/Potassium Iodide (SDF/KI), SDF and Nanosilver Fluoride (NSF). MATERIALS AND METHODS: Forty-four extracted carious primary molars were collected and randomly divided into four groups (n = 11). The carious tissue in all teeth was removed using a chemo-mechanical caries removal agent with an excavator. After caries removal in all groups, SDF, SDF/KI, and NSF were applied to the different groups, while no solution was applied to the control group. Subsequently, the teeth in all groups were restored with compomer. Color values L*, a* and b* were measured using a spectrophotometer at three time points: immediately after compomer restoration (T0), one week later (T1), and four week later (T2). Changes in brightness (ΔL) and color (ΔE) over time were calculated and comparisons among groups were made. RESULTS: The SDF solution induced statistically significant black staining (p = 0.013) and a decrease in L* value (p < 0.001) on the compomer material compared to the other groups over time. CONCLUSIONS: It was observed that SDF/KI has the potential to reduce the black staining effect of SDF, though not entirely. Novel experimental solutions like NSF may offer an alternative to counteract the staining effect of SDF.

Distinguishing discolored caries lesions using biofluorescence and dental bleaching: An in vitro simulation model study.

BACKGROUND: Distinguishing between discoloration caused by caries and organic stains is challenging for dentists in clinical settings. Biofluorescence (BF)-bleaching assesses caries lesions by evaluating BF changes after removing organic stains through dental bleaching, leaving cariogenic discoloration. This study aimed to apply BF-bleaching to a simulation model mimicking cariogenic discoloration and compare the BF color changes between organic staining and cariogenic discoloration. METHODS: Thirty artificial caries lesions in bovine incisors were equally divided into three groups: non-stained (NS), organic-stained (OS), and cariogenic-stained (CS) groups. The specimens were treated with bleaching agent, then BF color of each specimen was evaluated using red BF intensity (ΔR), BF hue angle (h°), and hyperspectral BF spectrum. RESULTS: The ΔR of CS was approximately 2.74 and 1.73 times higher than that of OS, at baseline and after bleaching for 20 min, respectively. After 20 min of bleaching, the h° of CS increased by approximately 8.1° compared to the baseline, while maintaining the red BF hue range (345‒15°). In contrast, the BF hue of OS shifted from orange (15‒45°) to yellow (45‒75°) simultaneously, and the h° change was approximately 21.9°. Both CS and OS exhibited first emission peaks near 515 nm, and CS showed second peaks in the red range (620‒780 nm). After bleaching, the first peaks were restored to the sound enamel direction (peak at 486 nm), whereas the second peaks of red BF in CS were maintained. CONCLUSION: Applying BF-bleaching to discolored caries lesions allowed differentiation between cariogenic discoloration and organic staining based on BF color changes.

Effect of fluoride or chitosan toothpaste and at-home bleaching in enamel roughness, tooth color, and staining susceptibility.

PURPOSE: To evaluate how fluoride- or chitosan-based toothpaste used during at-home bleaching affects enamel roughness, tooth color, and staining susceptibility. METHODS: Bovine enamel blocks were submitted to a 14-day cycling regime considering a factorial design (bleaching agent x toothpaste, 2 x 3), with n=10: (1) bleaching with 16% carbamide peroxide (CP) or 6% hydrogen peroxide (HP), and (2) daily exposure of a fluoride (1,450 ppm F-NaF) toothpaste (FT), chitosan-based toothpaste (CBT), or distilled water (control). Then, 24 hours after the last day of bleaching procedure the samples were exposed to a coffee solution. Color (ΔEab, ΔE00, L*, a*, b*) and roughness (Ra, µm) analyses were performed to compare the samples initially (baseline), after bleaching, and after coffee staining. The results were evaluated by linear models for repeated measures (L*, a*, b*, and Ra), 2-way ANOVA (ΔEab, ΔE00) and Tukey's test (α= 0.05). RESULTS: After the at-home bleaching procedure (toothpaste vs. time, P< 0.0001), the toothpaste groups presented a statistically lower Ra than the control (CBT 0.05). After coffee exposure, CBT presented lower ΔEab and ΔE00 values in the HP groups (toothpaste, P< 0.0001), and lower b* and a* values in the CP groups (toothpaste vs. time, P= 0.004). CLINICAL SIGNIFICANCE: Fluoride or chitosan delivered by toothpaste can reduce surface alterations of the enamel during at-home bleaching, without affecting bleaching efficacy.

Evaluation of the effects of different photosensitizers used in antimicrobial photodynamic therapy on tooth discoloration: spectrophotometric analysis.

BACKGROUND: Tooth discoloration is a common concern in antimicrobial photodynamic therapy (aPDT) using various photosensitizers (PS). Toluidine Blue (TB), Methylene Blue (MB), Phthalocyanine (Pc), and 2-mercaptopyridine-substituted zinc phthalocyanine (TM-ZnPc) are among those studied, but their relative impacts on tooth discoloration remain unclear. AIM: This study aimed to compare the effects of TB, MB, Pc, and TM-ZnPc in aPDT on tooth discoloration, utilizing a controlled experimental setup. MATERIALS AND METHODS: The study comprised seventy-five single-rooted incisors with root canals. Following meticulous preparation, a standardized area on the crown surface was designated for examination, and precise measurements of the initial tooth colors were recorded. Samples were randomly divided into five groups: Negative control, MB, TM, Pc, and TM-ZnPc. Photoactivation was performed using LED light, and color measurements were taken at multiple time points up to 90 days. Data were converted to Lab* color values of the CIE Lab* color system (International Commission on Illumination, Vienna, Austria), and ΔE values were calculated. Statistical analysis was performed using Two-way ANOVA and Post-Hoc Tukey tests (p < 0.05). RESULTS: At day 7 and 30, TM-ZnPc and Pc caused less discoloration compared to MB and TB. TM-ZnPc caused more tooth discoloration compared to Pc (p < 0.05). Compared to baseline, MB and TM-ZnPc caused more tooth discoloration at 30 days and TB caused more tooth discoloration at 90 days (p < 0.05). No significant difference was observed in terms of tooth discoloration at all periods evaluated after Pc application (p > 0.05). All photosensitizers tested in the study caused tooth coloration. CONCLUSION: All PS induced clinically detectable tooth discoloration, with TB and MB causing more significant discoloration compared to Pc and TM-ZnPc at certain time points. TM-ZnPc and Pc demonstrated more stable coloration levels over time, suggesting their potential reliability in aPDT applications. This study highlights the importance of selecting appropriate PS to minimize tooth discoloration in aPDT, with Pc showing promise in this regard.