RESUMO

This in vitro experimental investigation aimed to evaluate the impact of the combined application of a nanofiber scaffold (NS), a polymeric catalyst primer (PCP) containing 10 mg/mL of heme peroxidase enzyme, and violet LED (LEDv) on the esthetic efficacy (EE), trans-amelodentinal cytotoxicity (TC), and procedural duration of conventional in-office bleaching therapy. To achieve this, 96 standardized enamel/dentin discs were individually placed in artificial pulp chambers. A 35% hydrogen peroxide (H2O2) bleaching gel was administered for 45, 30, or 15 min to the enamel, either previously coated with NS + PCP or left uncoated, followed by irradiation with LEDv for 15 min or no irradiation. The established groups were as follows: G1, negative control (no treatment); G2, 35% H2O2/45 min; G3, NS + PCP + LEDv; G4, NS + PCP + 35%H2O2/45 min + LEDv; G5, NS + PCP + 35%H2O2/30 min + LEDv; and G6, NS + PCP + 35%H2O2/15 min + LEDv. Extracts (culture medium + gel components diffused through the discs) were collected and applied to odontoblast-like MDPC-23 cells. EE (ΔE00 and ΔWI) and TC were assessed using ANOVA/Tukey analysis (p < 0.05). The EE analysis revealed no statistical differences between G6 and G2 (p > 0.05). Cells in G6 exhibited higher viability and lower oxidative stress compared to other bleached groups (p < 0.05). In conclusion, employing NS + PCP + LEDv to catalyze a 35%H2O2 bleaching gel applied for 15 min to the enamel resulted in successful esthetic improvements and reduced the cytotoxicity commonly linked with traditional in-office bleaching procedures.

Assuntos

RESUMO

Background: Failures in glass fiber post (GFP) retention may be associated with low adhesion achieved in root dentin. Material and Methods: 55 single-rooted premolars were endodontically treated and distributed according to different adhesion strategies (n=11): G1: RelyX ARC (3M ESPE; etch-rinse strategy); G2: Relyx Ultimate (3M ESPE; etch-rinse strategy); G3: AllCem (FGM; etch-rinse strategy); G4: Relyx Ultimate (3M ESPE; self-etching strategy); G5: RelyX U200 (3M ESPE; self-adhesive strategy). For Bonding Strength (BS) analysis, the roots were sectioned in slices (1.0mm thickness) corresponding to each root third and submitted to push-out test. The type of failure was assessed by scanning electron microscopy (SEM). Results: The highest BS averages were found in G2 and G3. However, in the middle and apical root thirds, G3 showed statistically similar results to G4 and G5. In the cervical and middle third, G1 was statistically similar to G4 and G5. The mixed type of failure was the most common in all groups. Conclusions: Self-etching (G4) and self-adhesive resin (G5) cements, showed similar BS results of immediate bonding in the cementation of GFP compared to conventional resin cements (G1, G2, G3). Key words:Dental Cements, Dentin-Bonding Agents, Post and Core Technique, Dental Bonding.

RESUMO

OBJECTIVE: Evaluate the influence of a polymeric catalyst primer (PCP) on esthetic efficacy (EE), degradation kinetics of hydrogen peroxide (H2 O2 ), and trans-amelodentinal cytotoxicity (TC) of bleaching gels. MATERIALS AND METHODS: The following groups were established: G1: No treatment (NC, negative control); G2: PCP; G3: 10% H2 O2 ; G4: PCP + 10% H2 O2 ; G5: 20% H2 O2 ; G6: PCP + 20% H2 O2 ; G7: 35% H2 O2 (positive control); G8: PCP + 35% H2 O2 . To determine EE, enamel/dentin discs (E/DDs) were stained and subjected or not to bleaching protocols for 45 min. To assess TC, the E/DDs were adapted to artificial pulp chambers. The extracts (culture medium + gel components diffused through E/DDs) were applied to odontoblast-like MDPC-23 cells. The viability (VB), oxidative stress (OxS), morphology (SEM), amount of H2 O2 diffused and the production of hydroxyl radical (OH• ) were assessed (two-way ANOVA/Tukey/paired Student t-test; p < 0.05). RESULTS: The highest EE was found in G8 (p < 0.05), and G4, G6, and G7 did not differ statistically (p > 0.05). In G4, the limited H2 O2 diffusion reduced OxS and increased cell VB (p < 0.05). CONCLUSIONS: Coating the enamel with PCP containing 10 mg/ml of manganese oxide before applying the 10% H2 O2 bleaching gel maintains the EE of conventional in-office bleaching and minimizes the toxic effects of this esthetic therapy. CLINICAL SIGNIFICANCE: Coating the enamel with a PCP before applying the bleaching gel may potentiate the EE of the conventional in-office tooth bleaching and reduce the toxicity of this professional therapy to the dental pulp.

Assuntos

RESUMO

ABSTRACT The gingival contour, the color of the teeth and the presence of interincisal diastema are seen as unsightly factors, being highly harmful from a social point of view. The present study aimed to report a comprehensive and conservative esthetic treatment executed with a multidisciplinary approach in a 20-year-old female patient that presented darkened teeth with poor spacing and excessive gingival display while smiling, as well as present a brief literature review on multidisciplinary approach in esthetic dentistry. After clinical examination and diagnosis, a treatment plan was elaborated to meet the patient's expectations with a conservative approach. After patient consent, therapy began with supervised home-based tooth whitening with 22% carbamide peroxide applied one hour/daily for 14 days, followed with gingival recontouring surgery and, after a healing period of 30 days, diastemas closure with direct composite resin technique, occlusal adjustment, finishing, and polishing. The multidisciplinary approach was fundamental for the accomplishment of the proposed treatment, achieving satisfactory esthetic and functional results.

RESUMO O contorno gengival, a cor dos dentes e a presença de diastemas interincisivos são vistos como fatores antiestéticos, sendo altamente prejudicial do ponto de vista social. O presente estudo teve como objetivo relatar um tratamento estético conservador executado com abordagem multidisciplinar em uma paciente do sexo feminino de 20 anos que apresentava dentes escurecidos com pouco espaçamento e exposição gengival excessiva ao sorrir, bem como apresentar uma breve revisão de literatura sobre à abordagem multidisciplinar em odontologia estética. Após exame clínico e diagnóstico, foi elaborado um plano de tratamento para atender as expectativas do paciente com abordagem conservadora. Após consentimento do paciente, foi iniciada o clareamento dental supervisionado com peróxido de carbamida 22% aplicado uma hora/dia por 14 dias, seguido de cirurgia de recontorno gengival e, após um período de cicatrização de 30 dias, fechamento de diastemas com técnica de resina composta direta. Neste caso, a abordagem multidisciplinar foi fundamental para a realização do tratamento proposto, alcançando resultados estéticos e funcionais satisfatórios.

RESUMO

Gels with high concentrations of hydrogen peroxide (H2O2) have been associated with cytotoxicity and consequent post-bleaching tooth sensitivity. This study assessed the bleaching efficacy (BE) and cytotoxicity (CT) of bleaching gels with low concentrations of H2O2 containing manganese oxide (MnO2) and photocatalyzed with violet LED (LEDv). The following groups were established: G1: no treatment (negative control, NC); G2: 35% H2O2 (positive control, PC); G3: LEDv; G4: 10% H2O2; G5: 6% H2O2; G6: 10% H2O2 + MnO2 + LEDv; G7: 6% H2O2 + MnO2 + LEDv. To analyze BE, standardized enamel/dentin discs (E/DDs) were subjected to the bleaching procedures for 45 min (1 session). The color change was determined before and after performing the bleaching protocols (ΔE00; ΔWI). To analyze CT, the E/DDs were adapted to artificial pulp chambers, and the extracts (culture medium + diffused gel components) were applied to cultured odontoblast-like MDPC-23 cells. Then, the cells were assessed concerning their viability (VB), oxidative stress (OxS), and Live/Dead. The amount of H2O2 diffused was also determined (ANOVA/Tukey; p < 0.05). Cell viability decreased in all bleached groups compared to G1 (NC; p < 0.05). The cells in G6 and G7 presented higher viability than in G2, G4, and G5 (p < 0.05). The BE in G7 was similar to G2 (PC; p < 0.05). The lowest OxS and H2O2 diffusion values were found in G6 and G7, compared to the other bleached groups (G2, G4, and G5; p < 0.05). The 6% H2O2 bleaching gel (G7) submitted to both methods of catalysis (MnO2 + LEDv) caused only a mild cytotoxicity and maintained the excellent esthetic outcome promoted by in-office conventional tooth bleaching.

Assuntos

RESUMO

Aim This study aimed to analyze the influence of finishing and polishing (F/P) protocols on resin surface through roughness (Ra) values and laser scan microscopy observations. Methods Forty-eight (n=48) resin specimens were sorted into four groups (n=12), according to the type of resin used: Filtek Z250 (Z250), Filtek Z350 (Z350), Filtek One Bulk Fill (BF), Filtek P60 (P60). The specimens were sorted into six groups according to the type of F/P system used (n=2/group): Control group, Diamond bur (KG Sorensen), Soflex Pop-On Discs (3M ESPE), Soflex Spiral (3M ESPE), Dura Gloss (American Burs), and Praxis (TDV). Results The highest roughness values (Ra) were attributed to BF group for all F/P systems, except for the Soft-Lex PopOn discs. The Soft-Lex PopOn, Spiral, and Praxis discs presented a better performance for the surface treatment of the tested composite resins. Regardless of the restorative material, the use of diamond bur or single-step abrasive rubber (Dura Gloss) were associated with the highest Ra values. Conclusion The effect of F/P systems on Ra is material-dependent and instrument or system-dependent.

Assuntos

RESUMO

OBJECTIVE: To assess the influence of coating the enamel with a nanofiber scaffold (NS) and a polymeric catalyst primer (PCP) on the esthetic efficacy, degradation kinetics of hydrogen peroxide (H2O2), and trans-amelodentinal cytotoxicity of bleaching gels subjected or not to violet-LED irradiation. METHODOLOGY: The following groups were established (n = 8): G1- No treatment (negative control); G2- NS+PCP; G3- LED; G4- NS+PCP+LED; G5- 35% H2O2 (positive control); G6- NS+PCP+35% H2O2+LED; G7- 20% H2O2; G8- NS+PCP+20% H2O2+LED; G9- 10% H2O2; G10- NS+PCP+10% H2O2+LED. For esthetic efficacy analysis, enamel/dentin discs were stained and exposed for 45 min to the bleaching protocols. To assess the cytotoxicity, the stained enamel/dentin discs were adapted to artificial pulp chambers, and the extracts (culture medium + components diffused through the discs) were collected and applied to MDPC-23 cells, which had their viability, oxidative stress, and morphology (SEM) evaluated. The amount of H2O2 diffused and hydroxyl radical (OH•) production were also determined (two-way ANOVA/Tukey/paired Student t-test; p < 0.05). RESULTS: G6 had the highest esthetic efficacy compared to the other groups (p < 0.05). Besides the esthetic efficacy similar to conventional in-office bleaching (G5; p > 0.05), G10 also showed the lowest toxic effect and oxidative stress to MDPC-23 cells compared to all bleached groups (p < 0.05). CONCLUSION: Coating the enamel with a nanofiber scaffold and a polymeric catalyst primer, followed by the application of 10%, 20%, or 35% H2O2 bleaching gels irradiated with a violet LED, stimulates H2O2 degradation, increasing esthetic efficacy and reducing the trans-amelodentinal toxicity of the treatment.

Assuntos

RESUMO

Abstract Objective: To analyze the self-reported need of patients compared to professional indications for tooth whitening. Material and Methods: Initially, 58 undergraduate students responded to a form that highlighted the question: "Do you think you need to have your teeth whitened?" Among those who answered positively to the previous question, ten individuals were photographed with their smiles. In addition, they were asked to point out, on the Vita 3D-Master scale, which color they believed their teeth had, a value that was compared to the actual color obtained by a spectrophotometer. Finally, the photographs were presented to dentists, who were asked about the indication or not of the whitening treatment. Results: Most interviewees (63.8%) self-reported the need for whitening, as well as there was a greater incidence of a positive indication among professionals (53.9%). Pearson's Chi-square test revealed a relationship between patient gender and the training course on the desire to have teeth whitened. Among the professionals, the specialty, as well as time since graduation, interfered in the indication for whitening. Conclusion: Professionals and patients share the aesthetic ideal directly related to light teeth; most patients self-perceive the color of their teeth darker than it actually is; the opinion about the color of the teeth has an extremely subjective character and varies greatly from one professional to another (AU).

Assuntos

RESUMO

BACKGROUND: Employing violet LED on tooth bleaching is a recent but promising technique. This study aimed to assess the bleaching effectiveness of violet light-emitting diodes (LEDs) associated or not with bleaching gels containing hydrogen peroxide (HP) or carbamide peroxide (CP). METHODS: seventy bovine incisors were randomly assigned into 7 groups (n = 10) according to the technique and whitening product used. Group C: Artificial saliva (placebo); Group HP L-: three sessions of HP at 35 % without light activation; Group CP L-: three weeks of CP at 16 % for 4 h/day; Group HP CP L-: three sessions of HP at 35 % without light activation + 2 weeks of CP at 16 %, for 4 h/day; Group LED: four sessions with violet LED; Group HP L+: three sessions with HP at 35 % + violet LED; Group CP L+: three weeks with CP at 16 % for 4 h/day + violet LED. Color changes (ΔE and ΔL) were measured with a portable digital spectrophotometer. RESULTS: The results were similar between the groups of bleaching protocols, demonstrating that the use of the violet LED did not influence bleaching effectiveness when using HP 35 % or CP 16 % after 3 sessions. In addition, the use of the violet LED alone obtained ΔE values ​​similar to the protocols with the use of peroxides, however less variation of ΔL was observed for this group. CONCLUSIONS: The use of violet LEDs associated or not with bleaching gels was effective for tooth whitening. In addition, it was also concluded that the physical lightening technique with violet LED used alone produced less variation in dental brightness.

Assuntos