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1.
Clin Oral Investig ; 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-35006294

RESUMO

OBJECTIVES: This study characterized a violet LED light (V-LED; bright max whitening) tooth whitening device and evaluated its efficacy on stained enamel compared to hydrogen peroxide (HP). MATERIALS AND METHODS: Characterization of the V-LED beam profile was performed using a laser beam-profiler. The irradiance was measured throughout an exposure cycle at 0- and 8-mm distances using an integrating sphere and a spectral radiometer. Bovine enamel/dentin blocks stained with black tea (BT), cigarette smoke (CS), or without staining (CONT) were subjected to V-LED or 40% HP (n = 10/group). Color parameters (ΔL, Δa, Δb, and ΔE00) were measured using a digital spectrophotometer. Light transmission was estimated through 1-mm-thick bovine enamel slices (n = 5). ΔL, Δb, ΔE00, and irradiance were analyzed by two-way ANOVAs and Tukey's tests, Δa by Kruskal-Wallis and Mann-Whitney tests, and light transmission by t-test (α = 5%). RESULTS: Heterogeneous beam distribution was observed for the emitting V-LED chips. After 20 sequential exposures, irradiance levels were reduced 25-50%, regardless of the distance from V-LED. Localized irradiance values were statistically different between beam locations and different distances from the target. V-LED produced lower ΔE00, ΔL, Δa, and Δb values than HP for CONT and BT, with no differences for CS. Light transmittance decreased approximately 98% through 1-mm thick enamel. CONCLUSIONS: V-LED irradiance was heterogeneous and decreased throughout the exposure cycles and was also greatly reduced with increasing tip distance. V-LED produced a significantly lower whitening effect on BT and control teeth. CLINICAL RELEVANCE: This study contributes to the knowledge of V-LED and its clinical use.

2.
Braz. j. oral sci ; 20: e213859, jan.-dez. 2021. ilus
Artigo em Inglês | LILACS, BBO - Odontologia | ID: biblio-1253923

RESUMO

Aim: This study evaluated the effect of a desensitizer agent (DES) during bleaching with 10% carbamide peroxide (CP) on enamel microshear bond strength (µSBS). Methods: Sixty bovine incisors were obtained and randomly distributed into groups (n=15): (C) Control: no desensitizing or bleaching, (DES) desensitizing gel application, (CP) bleaching with 10% CP and (CP/DES) bleaching with 10% CP combined with DES. Bleaching was performed for 6 h/day for 14 consecutive days. DES was applied for 8 h only on the 7th and 14th days of therapy. Specimens were stored in artificial saliva among the CP or DES applications and submitted to µSBS testing at three postrestoration times (n=5): 24 h, 7 days, and 14 days after bleaching using a universal testing machine. Failure modes were observed under a stereomicroscope. Data were analyzed by two-way ANOVA and Tukey's test (α=5%). Results: Immediately after bleaching (24 h), CP promoted lower µSBS than the C and DES groups (p<0.05) but with no differences from the CP/DES. µSBS increased in the DES, CP, and CP/DES groups (p<0.05) when bonding was performed for 7 or 14 days elapsed from bleaching. CP/DES exhibited the highest µSBS among the groups 14 days after bleaching (p<0.05). Cohesive failure in enamel was predominant in the CP groups, while adhesive failure was mostly observed for the other groups. Conclusion: The use of a desensitizer during at-home bleaching maintained the enamel immediate bond strength, and its application favored bonding when the restoration was delayed for 14 days


Assuntos
Animais , Bovinos , Clareamento Dental , Esmalte Dentário , Resistência ao Cisalhamento
3.
Clin Oral Investig ; 2021 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-34826031

RESUMO

OBJECTIVES: To evaluate the biaxial flexural strength (BFS), flexural modulus (BFM), and Knoop microhardness (KHN) of incremental and bulk-filled resin-based composites (RBCs) using extended curing exposure times. MATERIALS AND METHODS: Disc specimens (n = 8; 6-mm diameter) were fabricated using three stacked molds (0.5-mm thick for the top and bottom molds, and a 1-mm-thick center mold for the conventional and 3-mm thick for the bulk-fill RBCs). Conventional (Tetric EvoCeram/TCE and Filtek Z250/FIZ) and bulk-fill RBCs (Tetric EvoCeram Bulk Fill/TBF and Filtek One Bulk Fill Restorative/FOB) were evaluated. The stacked RBC-filled molds were light-cured for (1) the manufacturer-recommended exposure (MRE) duration; (2) 50%, and (3) 100% extension of the MRE. The BFS, BFM, and KHN of the top and bottom discs were measured. BFS and BFM were analyzed by three-way ANOVA (material*curing time*depth) and Tukey's post hoc (α = 0.05). KHN was analyzed by two-way ANOVA (curing time*depth) and Tukey's post hoc (α = 0.05). RESULTS: Extending the exposure duration did not change the BFS and BFM on the top of the RBCs, but the BFS and KHN increased at the bottom of bulk-fill RBCs. For the conventional RBCs, TCE showed the highest increase on BFS at the bottom, going from 53.6 MPa at T1 to 69.9 at T3. Among the bulk-fill RBCs, FOB presented the highest increase on the bottom BFS (T1: 101.0 ± 19.9 MPa, T3: 147.6 ± 12.9 MPa). For all RBCs and exposure times, BFS and KHN were lower at the bottom. Only FIZ and FOB reached a bottom-to-top hardness ratio of 80%, at T3 and T2. CONCLUSION: A significant increase on the BFS and KHN on the bottom of bulk-fill RBCs can be observed when the time of exposure to the curing light is double the MRE. However, extended exposure does not eliminate differences on the BFS and KHN between the shallow and deep regions of RBCs. TCE and TBF failed to reach an acceptable B/T hardness ratio at all evaluated exposure times. CLINICAL RELEVANCE: Mechanical properties of RBCs can be affected by insufficient polymerization, specially at deeper regions of the increment. Therefore, clinicians should consider applying twice the MRE to curing-light to polymerize the maximal increment thickness of bulk-fill RBCs.

4.
J Esthet Restor Dent ; 2021 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-34623017

RESUMO

OBJECTIVE: To answer the question: "Does the peroxide gel application regimen (single application vs. renewal) influence the efficacy and the tooth sensitivity outcomes of in-office tooth bleaching?" METHODS: The search was done in Pubmed, Cochrane, LILACS, Scopus, Web of Science, and EMBASE in February 2021 (updated in July 2021). Randomized clinical trials (RCT) comparing the single application vs. the renewal protocols of HP were included. The meta-analyses were performed for the objective (ΔEab ), subjective (ΔSGU) color changes, and absolute risk of tooth sensitivity (TS). Heterogeneity was evaluated using Q test (I2 ). Cochrane Collaboration tool assessed the risk of bias (RoB). The GRADE evaluated the certainty of evidence. RESULTS: Five RCT studies remained. Two studies showed high RoB, and three presented some concerns. No significant differences were observed between the protocols in terms of the ΔEab , ΔSGU, and TS. ΔEab exhibited substantial heterogeneity (I2  = 87%), while ΔSGU (I2  = 60%) and the TS (I2  = 62%) presented a moderate one. The certainty of evidence was considered low or very low, depending on the variable response and the evaluation time. CONCLUSION: The application regimen (single vs. renewal of HP) did not impact color change or the absolute risk of TS. CLINICAL SIGNIFICANCE: The renewal of bleaching gel during the in-office appointment may not be necessary. However, there is at least a low certainty of evidence. Because of this, further randomized clinical trials with appropriate methodology on this topic are encouraged.

5.
Clin Oral Investig ; 2021 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-34269885

RESUMO

OBJECTIVES: To evaluate the long-term outcomes of in-office bleaching with violet LED light (LED) alone or combined with carbamide (CP) or hydrogen (HP) peroxides. METHODS: Volunteers of a previous short-term study were recalled for 6- and 12-month follow-ups, according to the following interventions (n = 18/group): LED, CP, LED/CP, HP, and LED/HP. The objective color (ΔEab, ΔE00) and whiteness index (ΔWID) changes were calculated applying the CIELab coordinates' values obtained using a spectrophotometer. A visual shade guide determined the tooth's subjective color change (ΔSGU). Data were submitted to one-way ANOVA or Welch's ANOVA, following appropriate post hoc tests (α = 5%). RESULTS: The LED and CP groups exhibited the lowest ΔEab, ΔE00, and ΔSGU (p < 0.05), but the LED group displayed a significantly lower ΔWID. After 12 months, the LED/CP group presented a higher ΔEab and ΔE00 than the CP group (p < 0.05). ΔEab, ΔE00, ΔSGU, or ΔWID means did not differ statistically between the LED/CP and HP groups. The LED/HP group presented a higher ΔE00 than the HP group, regardless of the time. CONCLUSIONS: The bleaching efficacy of LED alone was significantly lower compared to the LED/CP and HP-containing protocols. After 12 months, the LED/CP and HP groups did not differ in bleaching efficacy. LED irradiation only increased the objective color change of bleaching gels. CLINICAL RELEVANCE: LED alone promoted a long-term perceptible bleaching, but not compatible with that of high-concentrated HP. The bleaching outcomes of violet irradiation to 37% CP were maintained over time, with LED/CP demonstrating comparable results to HP even after 12 months. NATIONAL CLINICAL TRIALS REGISTRY (REBEC): RBR-5t6bd9.

6.
Eur J Oral Sci ; 129(2): e12773, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33724583

RESUMO

This review compiles the literature on the antioxidants used after tooth bleaching with either low or high-concentrated carbamide and hydrogen peroxide to recover the bond strength. Antioxidants used in bleached teeth are mainly natural and non-enzymatic, except for catalase. Commonly, antioxidants are applied to remove any reactive oxygen species (ROS) residues left from bleaching gels, which adversely affect adhesive procedures, such as restorations or orthodontic brackets bonding. Even though sodium ascorbate, the most thoroughly investigated antioxidant, showed the most efficient bond strength recovery at 10% concentration, its performance depends on the type of solution and the application time. Natural extracts, such as proanthocyanidins and green tea, showed satisfactory results in the reversal of bond strength at 5% and 10% concentrations, respectively. Sodium ascorbyl phosphate, α-tocopherol, and catalase exhibited promising results, but further research is required. The adhesive system type plays an important role in the outcome of enamel bond strength after the antioxidant application. The postponement of either restorations or orthodontic brackets cementation following bleaching procedures seems to be efficiently replaced by antioxidant application prior to bonding procedures. However, the efficacy of using an antioxidant to recover bond strength depends on its type and application time.


Assuntos
Colagem Dentária , Clareamento Dental , Antioxidantes , Cimentos Dentários , Peróxidos , Resistência ao Cisalhamento , Ureia
7.
Photodiagnosis Photodyn Ther ; 34: 102194, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33513440

RESUMO

OBJECTIVES: To evaluate the bleaching efficacy of a violet radiation (VR) combined or not with bleaching gels on the color and mineral content of stained teeth. MATERIAL AND METHODS: Enamel/dentin blocks were obtained and stained (n = 50) with coffee, red wine, tobacco smoke, or were left non-stained. The stained or not-stained blocks (n = 10) were distributed into five bleaching groups (n = 10): VR, CP (37 % carbamide peroxide), VR/CP, HP (35 % hydrogen peroxide), and VR/HP. Color (ΔE00, ΔL, Δa, and Δb) and whiteness index (ΔWID) changes were evaluated after staining and after bleaching using a spectrophotometer. Calcium (Ca), phosphorous (P), and Ca/P contents (in wt%) were measured after bleaching using energy-dispersive X-ray spectroscopy (EDS). Data was statistically analyzed (α = 0.05) using two-way ANOVA and Tukey tests (ΔE00, ΔWID, ΔL, Δb, wt%) or Kruskal-Wallis and Dunn tests (Δa). RESULTS: VR alone caused higher colorimetric changes on coffee, tobacco and red wine-stained groups compared to non-stained enamel (p < 0.05). VR/CP exhibited higher colorimetric changes compared to CP in coffee and non-stained groups. The VR/CP, HP and VR/HP groups exhibited no change differences (p > 0.05). No differences were observed for the wt% of Ca, P and Ca/P between the groups. CONCLUSIONS: The violet radiation was more effective in bleaching stained rather than non-stained teeth. VR combined with 37 % carbamide peroxide was as effective as the HP agent. Besides, no adverse effects could be observed in the enamel mineral content, regardless of the bleaching protocol tested, according to the EDS semi-quantitative analysis.


Assuntos
Fotoquimioterapia , Clareadores Dentários , Clareamento Dental , Animais , Bovinos , Cor , Esmalte Dentário , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes
8.
Rev. Fac. Odontol. Porto Alegre ; 61(2): 50-63, jul-dez. 2020.
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1281698

RESUMO

Objetivo: Este ensaio clínico randomizado avaliou o comportamento de restaurações com resina composta bulk-fill flow em dentes posteriores após três anos do tratamento restaurador. Métodos: Dezessete pacientes (12 mulheres, 5 homens, idade 23-59) foram selecionados para ter pelo menos duas restaurações de amálgama ou de resina composta substituídas, ou receber tratamento restaurador para lesão cariosa. As cavidades foram aleatoriamente alocadas para receberem o compósito bulk-fill flow Suferil SDR Flow, oclusamente coberto por uma resina composta convencional nano-híbrida Esthet-X HD (técnica bulk and body), ou serem preenchidas exclusivamente com Esthet-X HD, inseridas em incrementos de 2mm cada técnica incremental). Um adesivo convencional de dois passos foi aplicado em todas as cavidades. Trinta e quatro restaurações Classes I ou II foram realizados em dentes posteriores (n=17) no início do estudo (baseline). Após 03 anos, os critérios do USPHS modificado e FDI foram utilizados para avaliar as restaurações. Os dados foram submetidos à análise estatística Mann-Whitney (p<0,05). Resultados: No acompanhamento de 3 anos, vinte e quatro restaurações (17 Classes I e 7 Classes II) foram avaliadas. Não foram detectadas diferenças entre as técnicas restauradoras (p>0,05). Não houve falha em nenhuma restauração ao longo do tempo. Conclusão: Após 03 anos de serviço clínico, todas restaurações utilizando um compósito bulk-fill flow em dentes posteriores demonstraram uma performance satisfatória. Significância Clínica: A qualidade geral das restaurações em dentes posteriores realizadas com a técnica bulk and body foi similar ao das restaurações incrementais utilizando um compósito nano-híbrido.


Objective: This randomized clinical trial evaluated the behavior of restorations with flowable bulk-fill resin composite in posterior teeth three years after the restorative treatment. Methods: Seventeen patients (12 women, 5 men, age 23-59) were selected to have at least two failing amalgam or resin restorations replaced and/or to have a carious lesion restored. The cavities were randomly allocated to receive either the flowable bulk-fill composite Surefil SDR Flow occlusally covered with the conventional nano-hybrid composite Esthet-X HD (bulk and body technique) or filled exclusively with Esthet-X HD placed in 2 mm increments (incremental technique). A two-step etch-and-rinse adhesive was applied in all cavities. Thirty-four Class I or II restorations were performed in posterior teeth (n=17) during baseline. After 03 years, modified USPHS and FDI criteria were used to evaluate the restorations. Data were subjected to Mann-Whitney statistical analysis (p<0.05). Results: At the 3-year follow-up, twenty-four restorations (17 Class I and 7 Class II) were evaluated. No diff erences were detected between the bulk and body and the incremental restorations (p>0.05). No restoration failures were observed over time. Conclusion: After 03 years of clinical service, all restorations using a flowable bulk-fill composite in posterior teeth showed an acceptable performance. Clinical Significance: The overall quality of posterior restorations made with the bulk and body technique was similar to that of restorations made with a nano-hybrid composite incrementally placed.

9.
J Esthet Restor Dent ; 32(8): 783-790, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32827227

RESUMO

AIM: To evaluate the effects of activated charcoal powder (COAL) combined with regular (RT) or whitening (WT) toothpastes on enamel color and surface in comparison to carbamide peroxide (CP). METHODS: Dental blocks (n = 10/group) were randomly divided into COAL, COAL/RT, COAL/WT, CP, CP/RT, CP/WT, RT, WT, and CONT (without treatment). Simulated toothbrushing and whitening treatments were followed by colorimetric (ΔE00 , L*, a*, b*), surface roughness (Ra), and enamel topography assays. ΔE00 was submitted to two-way ANOVA and Tukey test. Color coordinates and Ra were tested with three-way repeated measures ANOVA (α = 5%). RESULTS: COAL exhibited greater ΔE00 than CONT (P = .048), but it did not enhance ΔE00 promoted by RT or WT (P > .05). COAL alone increased Ra (P < .001) and altered enamel topography. COAL did not increase Ra caused by RT and WT (P > .05). CP exhibited the highest ΔE00 (P < .05), but it raised Ra and changed enamel topography to a less extent than COAL. CONCLUSION: Even though charcoal powder did not increase enamel Ra when combined with toothpastes, the topography was negatively impacted by COAL. Also, COAL was unable to enhance the color change of RT and WT, or reach the effectiveness of CP. CLINICAL SIGNIFICANCE: The use of activated charcoal-based product, claimed as a natural whitener, before brushing with toothpastes is not only ineffective to change the color of teeth, but also it might result in alterations on the enamel surface. Whitening with CP, instead, was effective during the same period of treatment, which still represents a more appropriate technique to whiten teeth.


Assuntos
Clareamento Dental , Cremes Dentais , Carvão Vegetal , Cor , Esmalte Dentário , Pós , Propriedades de Superfície , Escovação Dentária
10.
Photodiagnosis Photodyn Ther ; 31: 101848, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32492521

RESUMO

AIM: This in vitro study assessed the effects of in-office bleaching with gels (35% hydrogen peroxide [HP] or 37% cabamide peroxide [CP]) and two activation sources (violet radiation [LED] or nonthermal atmospheric plasma [NTAP]) on the mineral content of bovine enamel. MATERIAL AND METHODS: Dental blocks (n = 90) were assessed for initial microhardness before random distribution into nine groups: LED, LED + HP, LED + CP, NTAP, NTAP + HP, NTAP + CP, HP, CP and control (without treatment). Specimens were subjected to bleaching (2 clinical sessions, 7 days apart) using LED [20x/session, 1-min/each, 30 s apart] or NTAP [1x/session, 10 min]. µRaman determined contents of phosphate (PO43) and carbonate (CO32). Micro-energy dispersive X-ray fluorescence (µEDXRF) and spectrophotometry of enamel microbiopsy evaluated the calcium to phosphorous ratios (Ca/P). Two-way ANOVA and Tukey tests analyzed µRAMAN and µEDXRF results. Spectrophotometry results were analyzed using Kruskal-Wallis and Dunn tests. Pearson correlation tested µEDXRF and spectrophotometry results (α = 5%). RESULTS: NTAP and NTAP + HP exhibited greater PO43- content than LED, LED + HP and control (p < 0.05). No statistical differences were detected between CO32- among groups. While µEDXRF evaluation demonstrated that NTAP and LED did not alter Ca/P ratio of enamel (p > 0.05), spectrophotometry showed that Ca/P reduced for LED + HP (p < 0.05). No correlation was found between µEDXRF and enamel microbiopsy spectrophotometry (p > 0.05). CONCLUSIONS: Activation sources did not adversely impact enamel's phosphate and carbonate concentrations after specimens' exposure to bleaching gels (either HP or CP). Visible light radiation emitted by a LED source was shown to adversely impact specimens' Ca/P ratios when treated with HP-containing bleaching gels.


Assuntos
Fotoquimioterapia , Clareadores Dentários , Clareamento Dental , Animais , Bovinos , Esmalte Dentário , Minerais , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes , Clareadores Dentários/farmacologia
11.
J Appl Oral Sci ; 28: e20190720, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32428059

RESUMO

Objective This study evaluated the clinical effect of violet LED light on in-office bleaching used alone or combined with 37% carbamide peroxide (CP) or 35% hydrogen peroxide (HP). Methodology A total of 100 patients were divided into five groups (n=20): LED, LED/CP, CP, LED/HP and HP. Colorimetric evaluation was performed using a spectrophotometer (ΔE, ΔL, Δa, Δb) and a visual shade guide (ΔSGU). Calcium (Ca)/phosphorous (P) ratio was quantified in the enamel microbiopsies. Measurements were performed at baseline (T 0 ), after bleaching (T B ) and in the 14-day follow-up (T 14 ). At each bleaching session, a visual scale determined the absolute risk (AR) and intensity of tooth sensitivity (TS). Data were evaluated by one-way (ΔE, Δa, ΔL, Δb), two-way repeated measures ANOVA (Ca/P ratio), and Tukey post-hoc tests. ΔSGU and TS were evaluated by Kruskal-Wallis and Mann-Whitney, and AR by Chi-Squared tests (a=5%). Results LED produced the lowest ΔE (p<0.05), but LED/HP promoted greater ΔE, ΔSGU and Δb (T 14 ) than HP (p<0.05). No differences were observed in ΔE and ΔSGU for LED/CP and HP groups (p>0.05). ΔL and Δa were not influenced by LED activation. After bleaching, LED/CP exhibited greater Δb than CP (p>0.05), but no differences were found between these groups at T 14 (p>0.05). LED treatment promoted the lowest risk of TS (16%), while HP promoted the highest (94.4%) (p<0.05). No statistical differences of risk of TS were found for CP (44%), LED/CP (61%) and LED/HP (88%) groups (p>0.05). No differences were found in enamel Ca/P ratio among treatments, regardless of evaluation times. Conclusions Violet LED alone produced the lowest bleaching effect, but enhanced HP bleaching results. Patients treated with LED/CP reached the same efficacy of HP, with reduced risk and intensity of tooth sensitivity and none of the bleaching protocols adversely affected enamel mineral content.


Assuntos
Peróxido de Carbamida/administração & dosagem , Peróxido de Hidrogênio/administração & dosagem , Luz , Fototerapia/métodos , Clareadores Dentários/administração & dosagem , Clareamento Dental/métodos , Adolescente , Adulto , Análise de Variância , Colorimetria , Terapia Combinada , Esmalte Dentário/efeitos dos fármacos , Esmalte Dentário/efeitos da radiação , Sensibilidade da Dentina/induzido quimicamente , Feminino , Humanos , Masculino , Valores de Referência , Fatores de Risco , Espectrofotometria , Estatísticas não Paramétricas , Propriedades de Superfície/efeitos dos fármacos , Propriedades de Superfície/efeitos da radiação , Resultado do Tratamento , Adulto Jovem
12.
J Esthet Restor Dent ; 32(1): 102-112, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31845449

RESUMO

OBJECTIVE: The aim is to evaluate the effect of violet light (VL) and nonthermal atmospheric plasma (NTAP) combined with or without 35% hydrogen peroxide (HP) and 37% carbamide peroxide (CP). METHODS: Bovine crowns were divided into (n = 10) VL, VL/HP, VL/CP, NTAP, NTAP/HP, NTAP/CP, HP, CP, and C (control) groups. Color and whiteness change (CIELAB-Δ Eab, CIEDE2000-Δ E00 , whiteness index-ΔWID ), color parameters (ΔL, Δa, and Δb), and intrapulpal concentration (µL/mL) of HP were assessed by spectrophotometry. Scanning electron microscopy evaluated the morphology of enamel surface. Data were analyzed by two-way analysis of variance and Tukey (Δ Eab , ΔE00 , ΔWID , ΔL, and µL/mL) and Kruskal-Wallis and Mann-Whitney tests (Δ a and Δ b, α = 5%). RESULTS: VL increased ΔEab and ΔWID of CP (P < .05). VL and NTAP alone resulted in perceptible color and whiteness change, but lower than those in the gel-treated groups (P < .05). Activation modes increased ΔL compared with that of C, but only VL enhanced Δb when applied alone or combined with CP. VL and NTAP did not increase HP diffusion (P > .05) or cause alterations in enamel morphology. However, HP and CP promoted topographical changes. CONCLUSION: VL and NTAP changed color to a lesser extent than bleaching gels. VL produced supplementary effectiveness only for CP (ΔEab and ΔWID ), without increasing HP diffusion or changing enamel morphology. CLINICAL SIGNIFICANCE: Although violet LED light and nonthermal atmospheric plasma (NTAP) promoted in vitro perceptible bleaching without compromising enamel morphology, bleaching gels (hydrogen peroxide and carbamide peroxide) were more effective than VL or NTAP. VL or NTAP did not increase intrapulpal diffusion of peroxide.


Assuntos
Clareadores Dentários , Clareamento Dental , Animais , Bovinos , Cor , Esmalte Dentário , Peróxido de Hidrogênio , Peróxidos , Ureia
13.
J. appl. oral sci ; 28: e20190720, 2020. tab, graf
Artigo em Inglês | LILACS, BBO - Odontologia | ID: biblio-1134776

RESUMO

Abstract Objective This study evaluated the clinical effect of violet LED light on in-office bleaching used alone or combined with 37% carbamide peroxide (CP) or 35% hydrogen peroxide (HP). Methodology A total of 100 patients were divided into five groups (n=20): LED, LED/CP, CP, LED/HP and HP. Colorimetric evaluation was performed using a spectrophotometer (ΔE, ΔL, Δa, Δb) and a visual shade guide (ΔSGU). Calcium (Ca)/phosphorous (P) ratio was quantified in the enamel microbiopsies. Measurements were performed at baseline (T 0 ), after bleaching (T B ) and in the 14-day follow-up (T 14 ). At each bleaching session, a visual scale determined the absolute risk (AR) and intensity of tooth sensitivity (TS). Data were evaluated by one-way (ΔE, Δa, ΔL, Δb), two-way repeated measures ANOVA (Ca/P ratio), and Tukey post-hoc tests. ΔSGU and TS were evaluated by Kruskal-Wallis and Mann-Whitney, and AR by Chi-Squared tests (a=5%). Results LED produced the lowest ΔE (p<0.05), but LED/HP promoted greater ΔE, ΔSGU and Δb (T 14 ) than HP (p<0.05). No differences were observed in ΔE and ΔSGU for LED/CP and HP groups (p>0.05). ΔL and Δa were not influenced by LED activation. After bleaching, LED/CP exhibited greater Δb than CP (p>0.05), but no differences were found between these groups at T 14 (p>0.05). LED treatment promoted the lowest risk of TS (16%), while HP promoted the highest (94.4%) (p<0.05). No statistical differences of risk of TS were found for CP (44%), LED/CP (61%) and LED/HP (88%) groups (p>0.05). No differences were found in enamel Ca/P ratio among treatments, regardless of evaluation times. Conclusions Violet LED alone produced the lowest bleaching effect, but enhanced HP bleaching results. Patients treated with LED/CP reached the same efficacy of HP, with reduced risk and intensity of tooth sensitivity and none of the bleaching protocols adversely affected enamel mineral content.


Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto , Fototerapia/métodos , Clareamento Dental/métodos , Clareadores Dentários/administração & dosagem , Peróxido de Carbamida/administração & dosagem , Peróxido de Hidrogênio/administração & dosagem , Luz , Valores de Referência , Espectrofotometria , Propriedades de Superfície/efeitos dos fármacos , Propriedades de Superfície/efeitos da radiação , Fatores de Risco , Análise de Variância , Resultado do Tratamento , Colorimetria , Terapia Combinada , Estatísticas não Paramétricas , Esmalte Dentário/efeitos dos fármacos , Esmalte Dentário/efeitos da radiação , Sensibilidade da Dentina/induzido quimicamente
14.
J Appl Oral Sci ; 26: e20170589, 2018 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-30304124

RESUMO

OBJECTIVE: High concentrations of hydrogen peroxide can cause adverse effects on composition and structure of teeth. However, the addition of calcium and fluoride in bleaching agents may reduce enamel demineralization. To evaluate chemical changes of sound and demineralized enamels submitted to high concentrations of hydrogen peroxide containing fluoride (F) or calcium (Ca). MATERIAL AND METHODS: Enamel blocks of bovine incisors with standard dimensions were obtained and half of them were submitted to pH-cycling to promote initial enamel caries lesions. Sound and demineralized enamel samples were divided into (n=10): (C) Control (no whitening treatment); (HP) 35% hydrogen peroxide; and two experimental groups: (HPF) 35% HP+0.2% F and (HPC) 35% HP+0.2% Ca. Experimental groups were submitted to two in-office bleaching sessions and agents were applied 3 times for 15 min to each session. The control group was kept in remineralizing solution at 37°C during the bleaching treatment. The surface mineral content of sound and demineralized enamels was determined through Fourier Transform Raman spectroscopy (FT-Raman), Energy dispersive Micro X-ray fluorescence spectroscopy (µ-EDXRF); and the subsurface, through cross-sectional microhardness (CSMH). In addition, polarized light microscopy (PLM) images of enamel subsurface were observed. RESULTS: According to three-way (FT-Raman and µ-EDXRF analyses) or two-way analysis of variance (ANOVA) (CSMH) and Tukey test (α=5%), the calcium or fluoride added to high-concentrated bleaching agents increased phosphate and carbonate concentrations on sound and demineralized enamels (p<0.05). However, HPC and HPF were unable to completely reverse the subsurface mineral loss promoted by bleaching on sound and demineralized enamels. The calcium/ phosphate (Ca/P) ratio of sound enamel decreased after HP treatment (p<0.001). CONCLUSION: Even though experimental bleaching agents with Ca or F reduced mineral loss for both sound and demineralized enamel surfaces, these agents were unable to reverse the enamel subsurface demineralization.


Assuntos
Cálcio/química , Esmalte Dentário/efeitos dos fármacos , Fluoretos/química , Peróxido de Hidrogênio/química , Clareadores Dentários/química , Desmineralização do Dente/induzido quimicamente , Animais , Carbonatos/química , Bovinos , Esmalte Dentário/química , Testes de Dureza , Teste de Materiais , Microscopia de Polarização , Fosfatos/química , Valores de Referência , Reprodutibilidade dos Testes , Espectrometria por Raios X , Análise Espectral Raman , Propriedades de Superfície/efeitos dos fármacos , Fatores de Tempo , Clareamento Dental/efeitos adversos , Clareamento Dental/métodos , Clareadores Dentários/efeitos adversos
15.
J. appl. oral sci ; 26: e20170589, 2018. tab, graf
Artigo em Inglês | LILACS | ID: biblio-954496

RESUMO

Abstract High concentrations of hydrogen peroxide can cause adverse effects on composition and structure of teeth. However, the addition of calcium and fluoride in bleaching agents may reduce enamel demineralization. Objective: To evaluate chemical changes of sound and demineralized enamels submitted to high concentrations of hydrogen peroxide containing fluoride (F) or calcium (Ca). Material and Methods: Enamel blocks of bovine incisors with standard dimensions were obtained and half of them were submitted to pH-cycling to promote initial enamel caries lesions. Sound and demineralized enamel samples were divided into (n=10): (C) Control (no whitening treatment); (HP) 35% hydrogen peroxide; and two experimental groups: (HPF) 35% HP+0.2% F and (HPC) 35% HP+0.2% Ca. Experimental groups were submitted to two in-office bleaching sessions and agents were applied 3 times for 15 min to each session. The control group was kept in remineralizing solution at 37°C during the bleaching treatment. The surface mineral content of sound and demineralized enamels was determined through Fourier Transform Raman spectroscopy (FT-Raman), Energy dispersive Micro X-ray fluorescence spectroscopy (μ-EDXRF); and the subsurface, through cross-sectional microhardness (CSMH). In addition, polarized light microscopy (PLM) images of enamel subsurface were observed. Results: According to three-way (FT-Raman and μ-EDXRF analyses) or two-way analysis of variance (ANOVA) (CSMH) and Tukey test (α=5%), the calcium or fluoride added to high-concentrated bleaching agents increased phosphate and carbonate concentrations on sound and demineralized enamels (p<0.05). However, HPC and HPF were unable to completely reverse the subsurface mineral loss promoted by bleaching on sound and demineralized enamels. The calcium/ phosphate (Ca/P) ratio of sound enamel decreased after HP treatment (p<0.001). Conclusion: Even though experimental bleaching agents with Ca or F reduced mineral loss for both sound and demineralized enamel surfaces, these agents were unable to reverse the enamel subsurface demineralization.


Assuntos
Animais , Bovinos , Cálcio/química , Desmineralização do Dente/induzido quimicamente , Esmalte Dentário/efeitos dos fármacos , Clareadores Dentários/química , Fluoretos/química , Peróxido de Hidrogênio/química , Fosfatos/química , Valores de Referência , Espectrometria por Raios X , Análise Espectral Raman , Propriedades de Superfície/efeitos dos fármacos , Fatores de Tempo , Clareamento Dental/efeitos adversos , Clareamento Dental/métodos , Teste de Materiais , Carbonatos/química , Reprodutibilidade dos Testes , Esmalte Dentário/química , Clareadores Dentários/efeitos adversos , Testes de Dureza , Microscopia de Polarização
16.
J Mech Behav Biomed Mater ; 55: 264-270, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26600409

RESUMO

Attempts to understand the mechanical behavior of dentin and other mineralized tissues have been primarily focused on the role of their more abundant matrix components, such as collagen and hydroxyapatite. The structural mechanisms endowing these biological materials with outstanding load bearing properties, however, remain elusive to date. Furthermore, while their response to deformation has been extensively studied, mechanisms contributing to their recovery from induced deformation remain poorly described in the literature. Here, we offer novel insights into the participation of proteoglycans (PG) and glycosaminoglycans (GAG) in regulating the nanoindentation creep deformation and recovery of mineralized and demineralized dentin. Accordingly, after the enzymatic digestion of either PGs and associated GAGs or only GAGs, the nanoindentation creep deformation of dentin increased significantly, while the relative recovery of both the mineralized and demineralized dentin dropped by 40-70%. In summary, our results suggest that PGs and GAGs may participate in a nanoscale mechanism that contributes significantly to the outstanding durability of dentin and possibly other mineralized tissues of similar composition.


Assuntos
Dentina/metabolismo , Teste de Materiais , Fenômenos Mecânicos , Nanotecnologia , Proteoglicanas/metabolismo , Fenômenos Biomecânicos , Glicosaminoglicanos/metabolismo , Humanos , Dente Molar/metabolismo
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