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1.
Braz. dent. sci ; 23(2): 1-8, 2020. tab, ilus
Artigo em Inglês | LILACS, BBO - Odontologia | ID: biblio-1096444

RESUMO

Objective: This study's aim was to quantify the hydrogen peroxide (HP) penetration into the pulp chamber of teeth submitted to different protocols of bleaching. Material and Methods: Ninety premolars were randomly divided into nine groups according to the bleaching agent protocol (n = 10): control (no bleaching), carbamide peroxide 10% [10% CP], carbamide peroxide 16% [16% CP], carbamide peroxide 22% [22% CP], hydrogen peroxide 4% [4% HP], hydrogen peroxide 6% [6% HP], hydrogen peroxide 7.5% [7.5% HP], hydrogen peroxide 10% [10% HP] and hydrogen peroxide 35% [35% HP]. The penetration of HP was measured via spectrophotometric analysis of the acetate buffer solution from the pulp chamber. The absorbance of the resulting solution was determined in a spectrophotometer and converted into equivalent concentration of HP (µg/ mL). To analyze the concentration of HP, the titration of bleaching agents with potassium permanganate was used. Data were subjected to ANOVA and Tukey's test for pairwise comparison (α = 0.05). Results: Higher concentration of HP in the pulp chamber was found in the HP 35% group (p < 0.0001). No significant difference between at-home protocols were observed (p = 0.64). Titration values showed that the concentration of the products was similar to that claimed by the manufacturer. Conclusion: It follows that the amount of HP that reaches the pulp chamber is not proportional to the concentration of whitening gels, but depends on the application time recommended by the manufacturers (AU)


Objetivo: o objetivo deste estudo foi quantificar a penetração do peróxido de hidrogênio (PH) na câmara pulpar dos dentes submetidos a diferentes protocolos de clareamento. Material e Métodos: Noventa pré-molares foram divididos aleatoriamente em nove grupos, de acordo com o protocolo do agente clareador (n = 10): controle (sem clareamento), peróxido de carbamida 10% [PC 10%], peróxido de carbamida 16% [PC 16%], peróxido de carbamida 22% [PC 22%], peróxido de hidrogênio 4% [PH 4%], peróxido de hidrogênio 6% [PH 6%], peróxido de hidrogênio 7,5% [PH 7,5%], peróxido de hidrogênio 10% [PH 10%] e peróxido de hidrogênio 35% [PH 35%]. A penetração de PH foi medida por análise espectrofotométrica da solução de tampão de acetato da câmara pulpar. A absorvância da solução resultante foi determinada em um espectrofotômetro e convertida em concentração equivalente de PH (µg / mL). Para analisar a concentração de PH, foi utilizada a titulação de agentes clareadores com permanganato de potássio. Os dados foram submetidos à ANOVA e teste de Tukey para comparação pareada (α = 0,05). Resultados: Foi encontrada maior concentração de PH na câmara pulpar no grupo PH 35% (p < 0,0001). Não foi observada diferença significativa entre os protocolos domiciliares (p = 0,64). Os valores de titulação mostraram que a concentração dos produtos era semelhante à reivindicada pelo fabricante. Conclusão: Conclui-se que a quantidade de PH que atinge a câmara pulpar não é proporcional à concentração de géis clareadores, porém depende do tempo de aplicação recomendado pelos fabricantes.(AU)


Assuntos
Clareamento Dental , Permeabilidade do Esmalte Dentário , Clareadores , Peróxido de Carbamida , Peróxido de Hidrogênio
2.
Oper Dent ; 42(2): E44-E54, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27892835

RESUMO

This study aimed to quantify the concentration of hydrogen peroxide into the pulp chamber in the presence or absence of adhesive enamel restorations and to analyze the resin-dentin interface of bleached groups. Bovine incisors (120) were randomly divided into three groups according to enamel treatment (n=40 each): (1) enamel without restoration (control); (2) enamel cavities (3 mm diameter × 1.5 mm depth) restored with a silorane-based (SB) system; or (3) enamel cavities (3 mm diameter × 1.5 mm depth) restored with a dimethacrylate-based (DB) system. Restorations were thermocycled, and all groups were submitted to one application of 35% hydrogen peroxide (HP) agent for 45 minutes and subjected to four light activation methods (n=10 each): without light, light-emitting diode (LED), LED/diode laser, or halogen light. Acetate buffer solution was placed into the pulp chamber before bleaching, and this solution was collected to spectrophotometrically determine the concentration of HP that reached the pulp chamber after bleaching. Rhodamine B was added to the HP agent and applied on additional enamel samples of each group for 24 hours. Samples were sectioned mesiodistally, and the bleaching agent was traced using confocal microscopy. According to two-way analysis of variance and Tukey test (α=0.05), the HP concentration in the pulp chamber of the control group was significantly lower than that of the SB group (p<0.05), regardless of light activation. No differences were observed between DB and SB groups and between control and DB groups, except for the DB halogen light activated group, which exhibited higher HP intrapulpal concentration (p<0.05). Confocal microscopy exhibited HP diffusion through the interface of the SB and DB restored groups as well as enamel prisms in the control group. The SB restorative system increased the HP diffusion into the pulp chamber, but HP was able to diffuse even in the absence of enamel restorations.


Assuntos
Resinas Compostas/farmacologia , Permeabilidade do Esmalte Dentário , Cavidade Pulpar/efeitos dos fármacos , Peróxido de Hidrogênio/farmacologia , Cimentos de Resina/farmacologia , Resinas de Silorano/farmacologia , Animais , Bovinos , Restauração Dentária Permanente , Técnicas In Vitro , Teste de Materiais , Microscopia Confocal , Rodaminas , Clareamento Dental
3.
J Clin Pediatr Dent ; 40(3): 215-20, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27472569

RESUMO

OBJECTIVE: To compare the permeability of the enamel of primary teeth from individuals free of Early Childhood Caries (ECC) with that from individuals affected with ECC by assessment of dye penetration using Laser Scanning Confocal Microscope (LSCM). STUDY DESIGN: Experimental in vitro study. Exfoliated primary maxillary anterior teeth (n = 44) were collected and divided into two groups (n=22 per group): samples with ECC (Group 1) and without ECC (Group 2). The samples were immersed in Rhodamine B dye solution for 1 day, cut longitudinally into 3 sections, observed using LSCM. Dye penetration depths in the incisal, middle, cervical thirds and on labial, lingual surfaces were recorded. Data were analyzed by the Mann-Whitney test (α = 5%, p < .005). RESULTS: The overall mean penetration depth for group 1 (100.6 µm ± 58.48 µm) was significantly higher than that of group 2 (31.55 µm ± 23.40 µm, p < .000). Mean penetration depth in the incisal, middle, and cervical thirds and on the labial and lingual surfaces of group 1 also presented significantly higher scores than in group 2 (p < .005). CONCLUSION: There was significantly more dye penetration in the ECC group than in the non-ECC group. This could be related to a higher level of enamel permeability in teeth affected with ECC.


Assuntos
Cárie Dentária/metabolismo , Permeabilidade do Esmalte Dentário/fisiologia , Dente Decíduo/metabolismo , Pré-Escolar , Dente Canino/diagnóstico por imagem , Dente Canino/metabolismo , Cárie Dentária/diagnóstico por imagem , Corantes Fluorescentes/farmacocinética , Humanos , Técnicas In Vitro , Incisivo/diagnóstico por imagem , Incisivo/metabolismo , Microscopia Confocal , Rodaminas/farmacocinética , Colo do Dente/diagnóstico por imagem , Colo do Dente/metabolismo , Coroa do Dente/diagnóstico por imagem , Coroa do Dente/metabolismo , Dente Decíduo/diagnóstico por imagem
4.
Braz. j. oral sci ; 14(4): 262-266, Oct.-Dec. 2015. ilus, tab
Artigo em Inglês | LILACS | ID: lil-778241

RESUMO

To evaluate the effect of different in-office bleaching agents on the permeability, roughness and surface microhardness of human enamel. Methods: For evaluation of roughness and microhardness, 40 hemi-faces of 20 premolars were subjected to initial roughness (Ra parameter) and microhardness (VHN) measurements. Thirty-two premolar's crowns were used for permeability test. Then, all specimens were randomly divided into four groups: C - without bleaching (control), HP35 - bleaching with 35% hydrogen peroxide (HP), HPF38 - 38% HP+fluoride, HPC35 - 35% HP+calcium. Final roughness (FR) and microhardness (FM) measurements were evaluated. For permeability, the 32 crowns were immersed in 1% sodium hypochlorite (20 min) and silver nitrate solutions (2 h) and subjected to developing solution under fluorescent light (16 h). Three sections from the crowns were analyzed in light microscope (100x) to evaluate the scores of permeability: Score 0 - no tracer agent penetration; Score 1 - less than half the thickness of enamel penetration; Score 2 - tracer agent reaching half the enamel thickness; Score 3 - entire enamel depth penetration, without reaching dentin and Score 4 - tracer agent reaching dentin. For roughness and microhardness evaluation were used one-way ANOVA and Dunnet post-test for independent samples, and t test for paired samples. For permeability, the data were analyzed by Kruskal Wallis and Dunn tests. Results: A significantly higher permeability and surface roughness were observed in groups HP35, HPF38 and HPC35 compared to the C group, as well as decreased microhardness (p<0.05). Conclusions: All bleaching agents increased permeability and surface roughness, and decreased microhardness of human enamel; thus, the addition of fluoride or calcium was not beneficial...


Assuntos
Humanos , Masculino , Feminino , Clareadores Dentários/efeitos adversos , Esmalte Dentário , Permeabilidade do Esmalte Dentário , Peróxido de Hidrogênio/efeitos adversos , Peróxido de Hidrogênio/uso terapêutico , Propriedades de Superfície , Clareamento Dental
5.
PLoS One ; 10(4): e0124236, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25885796

RESUMO

Dental caries continues to be the most prevalent bacteria-mediated non-contagious disease of humankind. Dental professionals assert the disease can be explained by poor oral hygiene and a diet rich in sugars but this does not account for caries free individuals exposed to the same risk factors. In order to test the hypothesis that amount of amelogenin during enamel development can influence caries susceptibility, we generated multiple strains of mice with varying levels of available amelogenin during dental development. Mechanical tests showed that dental enamel developed with less amelogenin is "weaker" while the dental enamel of animals over-expressing amelogenin appears to be more resistant to acid dissolution.


Assuntos
Amelogênese , Amelogenina/análise , Cárie Dentária/etiologia , Hipoplasia do Esmalte Dentário/complicações , Esmalte Dentário/química , Ácidos/farmacologia , Amelogênese/genética , Amelogênese Imperfeita/complicações , Amelogênese Imperfeita/genética , Amelogenina/biossíntese , Amelogenina/deficiência , Amelogenina/genética , Animais , Esmalte Dentário/efeitos dos fármacos , Hipoplasia do Esmalte Dentário/genética , Permeabilidade do Esmalte Dentário , Solubilidade do Esmalte Dentário , Predisposição Genética para Doença , Genótipo , Dureza , Testes de Dureza , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Desmineralização do Dente/induzido quimicamente
6.
J Dent ; 43(6): 720-5, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25862274

RESUMO

OBJECTIVE: The aims of this in vitro study were to investigate whether optical coherence tomography (OCT) could analyze infiltration of resin infiltrant (RI) into early dental caries (EC), and to confirm the correlation between the results of OCT and confocal laser scanning microscopy (CLSM) for evaluation of RI infiltration into EC. METHODS: Sound bovine permanent teeth were used to produce sixty specimens by making two windows on the teeth. Each 20 specimens were demineralized for 20, 30, and 40 days, and the RI was treated on one of the windows. As a result, the images of the fifty-two specimens were taken by OCT and CLSM. The demineralized lesion depth (LDOCT and LDCLSM) and the infiltrated depth of RI into lesion (IDOCT and IDCLSM) obtained from the OCT and the CLSM were analyzed. The correlations between the LDOCT and the LDCLSM, and between the IDOCT and the IDCLSM, were analyzed by Pearson correlation and intra-class correlation. Also, Bland-Altman plot was constructed to assess the agreement between the IDOCT and the IDCLSM, and the IDOCT divided by refractive index of RI and the IDCLSM. RESULTS: The Pearson correlation coefficient and intra-class correlation of 0.75 and 0.83 (95% CI: 0.71-0.91) respectively were confirmed between the LDOCT and the LDCLSM (p<0.001), and 0.59 and 0.71 (95% CI: 0.50-0.84) respectively were observed between the IDOCT and the IDCLSM (p<0.001). The lower bias was confirmed in Bland-Altman plot between adjusted IDOCT and the IDCLSM than between the IDOCT and the IDCLSM. CONCLUSION: The OCT was the promising quantitative evaluation method for RI penetrated into EC. CLINICAL SIGNIFICANCE: The OCT would be used as a nondestructive and real-time evaluation method for RI penetrated into EC on clinical procedure.


Assuntos
Cárie Dentária/diagnóstico por imagem , Cimentos de Resina/química , Tomografia de Coerência Óptica/métodos , Animais , Bovinos , Cárie Dentária/metabolismo , Esmalte Dentário/diagnóstico por imagem , Esmalte Dentário/metabolismo , Permeabilidade do Esmalte Dentário , Microscopia Confocal/métodos , Refratometria , Cimentos de Resina/farmacocinética
7.
Caries Res ; 49(3): 209-15, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25677114

RESUMO

BACKGROUND: Over the years, certain primary teeth have been shown to be highly sensitive to dental caries, while others have remained caries-free. It has been hypothesized that this may be attributed to differences in the permeability of the enamel surface. AIM: The aim of the study was to evaluate the hypothesized differences in the permeability of primary tooth enamel in children with and those without Severe Early Childhood Caries (S-ECC) using scanning electron microscopy. MATERIALS AND METHODS: Sixteen children between 3 and 6 years of age were randomly selected and divided into two groups: Group 1, children without S-ECC (n = 8), and Group 2, children with S-ECC (n = 8). In each child, 4 teeth (the maxillary right and left central and lateral incisors) were subjected to evaluation. An impression was made with polyvinylsiloxane impression material, and scanning electron microscopy was used to inspect the negative replicas for droplets. RESULTS: The results indicated higher significance when individual regions (cervical, middle, and incisal thirds) in the two groups were evaluated and compared. Similarly, the overall results showed high statistical significance between S-ECC and non-S-ECC teeth. CONCLUSION: There could be a positive relationship between the permeability of tooth enamel and the development of caries, which needs further research.


Assuntos
Cárie Dentária/metabolismo , Permeabilidade do Esmalte Dentário/fisiologia , Dente Decíduo/metabolismo , Criança , Pré-Escolar , Cárie Dentária/patologia , Esmalte Dentário/ultraestrutura , Humanos , Incisivo/metabolismo , Incisivo/ultraestrutura , Microscopia Intravital/métodos , Microscopia Eletrônica de Varredura/métodos , Técnicas de Réplica , Colo do Dente/metabolismo , Colo do Dente/ultraestrutura , Coroa do Dente/metabolismo , Coroa do Dente/ultraestrutura , Dente Decíduo/ultraestrutura
8.
Eur J Prosthodont Restor Dent ; 23(4): 164-72, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26767237

RESUMO

Almost 60% of operative dentistry is devoted to replacing restorations. When practitioners have to replace an amalgam restoration, they tend to opt for an adhesive restoration, as it is conservative of tooth tissues and mimics the natural appearance of teeth. Based on a literature review, the aim of this article is to determine the best tissue approach when replacing an old amalgam by a new adhesive restoration. After analyzing and understanding tissue alterations due to the amalgam corrosion process, the authors propose an analytical approach to managing the situation. Both tissue orientated and specific mechanical approaches are developed and should be implemented to carry out the optimal clinical procedure and achieve the most conservative and durable treatment.


Assuntos
Protocolos Clínicos , Amálgama Dentário , Esmalte Dentário/anatomia & histologia , Restauração Dentária Permanente/métodos , Dentina/anatomia & histologia , Força de Mordida , Fenômenos Químicos , Resinas Compostas/química , Corrosão , Amálgama Dentário/química , Colagem Dentária , Preparo da Cavidade Dentária/métodos , Permeabilidade do Esmalte Dentário/fisiologia , Materiais Dentários/química , Falha de Restauração Dentária , Permeabilidade da Dentina/fisiologia , Humanos , Oxirredução , Retratamento , Desmineralização do Dente/etiologia
9.
Artigo em Inglês | LILACS | ID: lil-724854

RESUMO

OBJECTIVE: Resin infiltration is an innovative microinvasive measure, whereby hard tissues are preserved, that has been used to treat medium stages of caries. The aim of this study is to evaluate with Confocal laser scanning microscopy the indirect staining technique of resin infiltration in teeth with different degrees of fluorosis. METHODS: Twenty-four fluorosed human molars and premolars were infiltrated and light cured. Specimens were prepared and lesions, as well as penetration depth were analyzed using dual fluorescence method in confocal laser microscopy. RESULTS: Percentage penetration, was significantly higher in teeth with mild and very mild fluorotic lesions, unlike moderate and control group which was significantly lower (p < 0.05, Bonferroni test). However, there are no statistically significant differences between control and moderate groups neither between very mild and mild groups (p > 0.05, Bonferroni test). CONCLUSION: It can be concluded that resin penetration in mild and very mild fluorotic lesions is higher than in moderate lesions


OBJETIVO: La infiltración con resina es una innovadora técnica microinvasiva, donde los tejidos duros son preservados, que ha sido usada para tratar estadios medios de caries. El objetivo de este estudio es evaluar con microscopio laser confocal la técnica indirecta de tinción en dientes con diferentes grados de fluorosis. MÉTODOS: Veinticuatro molares y premolares humanos con fluorosis fueron infiltrados y fotocurados. Los especímenes fueron preparados y las lesiones (FDmax), así como la profundidad de penetración fueron analizadas usando el método de fluorescencia dual en el microscopio láser confocal. RESULTADOS: El porcentaje de penetración fue significativamente mayor en dientes con fluorosis leve y muy leve, a diferencia de los especímenes con fluorosis moderada y grupo control en los que el porcentaje de penetración fue significativamente menor (p < 0,05, test de Bonferroni). Sin embargo, no hubo diferencias significativas entre el grupo mode-rado y control, ni entre los grupos leve y muy leve (p > 0,05, test de Bonferroni). CONCLUSIÓN: Se puede concluir que la penetración de la resina en dientes con fluorosis leve y muy leve es mayor que en los dientes con lesiones moderadas


Assuntos
Humanos , Resinas Sintéticas , Resinas Sintéticas/uso terapêutico , Dente Pré-Molar , Microscopia Confocal , Permeabilidade do Esmalte Dentário , Ácido Clorídrico , Dente Molar , Fluorose Dentária
10.
J Clin Dent ; 25(3): 61-4, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-26054180

RESUMO

OBJECTIVE: The purpose of this in vitro study was to determine if a novel 970 ppm F ion SnF2OTC gel (Enamelon Preventive Treatment Gel) and a 1150 ppm F- ion SnF2OTC Enamelon Toothpaste, each delivering amorphous calcium phosphate (ACP), can significantly reduce the effect of an acid challenge to enamel as compared to two prescription (Rx) strength 5000 ppm F- ion (NaF) dentifrices containing tri-calcium phosphate (TCP), and an Rx 900 ppm F- ion (NaF) paste with casein phosphopeptide-amorphous calcium phosphate (CPP-ACP). The effect will be determined by measuring the resistance of enamel specimens to an acid challenge before and after treatment with the test dentifrices. METHODS: The procedure used in this study was the FDA Test Method #33 for the determination of the effect of different test dentifrices on enamel solubility reduction. Twelve sets of three extracted human teeth were unprotected and etched prior to treatment with 0.1 M lactic acid buffer solution. The amount of phosphate dissolved from the teeth was quantified via measuring the phosphate in the retained lactate buffer solution with phosphorous analysis (pre-treatment phosphorous levels). The teeth sets were then exposed to the following treatments (diluted 1:3 parts in preheated [37 degrees C] distilled water): 5000 ppm F- ion, sodium fluoride (NaF) Rx dentifrice containing TCP; 5000 ppm F- ion, NaF Rx dentifrice; 900 ppm F- ion, NaF Rx paste with CPP-ACP; 1150 ppm F- ion, stannous fluoride (SnF2) OTC toothpaste delivering ACP Enamelon Toothpaste; and 970 ppm F- ion, SnF2 OTC gel delivering ACP (Enamelon Preventive Treatment Gel). The teeth sets were rinsed with distilled water and then exposed to 0.1 M buffered lactic acid solution. The amount of phosphate in the lactic acid buffer was determined for a second time (post-treatment phosphorous levels). The percent of enamel solubility reduction was then computed as the difference between the amount of phosphorous in the pre- and post-treatment lactic acid solutions divided by the amount of phosphorous in the pre-treatment solution, and multiplied by 100. RESULTS: The percent reduction in enamel solubility recorded in this study was as follows: 60.14 ± 0.79 for the Enamelon Toothpaste; 56.91 ± 1.05 for the Enamelon Preventive Treatment Gel; 18.78 ± 3.20 for the 5000 ppm F- ion, NaF prescription dentifrice "A' with TCP; 6.84 ± 1.20 for the 900 ppm F- ion, NaF paste with CPP-ACP; 5.82 ± 3.10 for the 5000 ppm F- ion, NaF prescription dentifrice "B" with TCP; and -5.45 ± 1.86 for the negative control. The differences between all the products tested were statistically significant (p < 0.05), except for the Enamelon products that were not statistically different. The 900 ppm F- ion, NaF paste with CPP-ACP and the 5000 ppm F- ion, NaF toothpaste results were also not statistically different. CONCLUSION: The Enamelon products (970 ppm and 1150 ppm F- ion, SnF2 OTC dentifrices) delivering ACP were statistically significantly more effective in reducing enamel solubility than two Rx strength 5000 ppm F- ion NaF toothpastes containing TCP and the Rx 900 ppm F- ion NaF paste containing CPP-ACP.


Assuntos
Fosfatos de Cálcio/farmacocinética , Solubilidade do Esmalte Dentário/efeitos dos fármacos , Esmalte Dentário/metabolismo , Fluoretos/farmacocinética , Géis/química , Fluoreto de Sódio/farmacocinética , Cremes Dentais/química , Permeabilidade do Esmalte Dentário , Humanos , Técnicas In Vitro , Dente Molar , Fluoreto de Sódio/química , Remineralização Dentária
11.
Oper Dent ; 39(2): 166-73, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-23802644

RESUMO

The present study evaluated transenamel and transdentinal penetration of hydrogen peroxide during tooth whitening recognized in altered enamel by the presence of cracks or microabrasion. We used 72 experimental units (n=20) obtained from bovine incisors: GI-sound enamel; GII-teeth showing visible enamel cracks (4 mm to 5.7 mm in length); and GIII-microabrasioned enamel. The 12 remaining specimens were used to analyze the enamel surface morphology using scanning electron microscopy. The specimens were cylindrical and 5.7 mm in diameter and 3.5 mm thick. A product based on 35% hydrogen peroxide was used for bleaching, following the manufacturer's recommendations for use. To quantify the H2O2 penetration, the specimens were placed in artificial pulp chambers containing an acetate buffer solution. After bleaching, the solution was collected and adequately proportioned with leucocrystal violet, peroxidase enzyme, and deionized water. The resulting solution was evaluated using ultraviolet visible reflectance spectrophotometer equipment. The data were analyzed by analysis of variance (ANOVA) and Fisher's PLSD at a significance level of 0.05, and significant differences in the penetration of peroxide in different substrate conditions were observed (p<0.0001). The penetration of hydrogen peroxide was more intense in cracked teeth. The group in which the enamel was microabraded showed intermediate values when compared to the control group. Microabrasion and the presence of cracks in the enamel make this substrate more susceptible to penetration of hydrogen peroxide during in-office whitening.


Assuntos
Esmalte Dentário/metabolismo , Peróxido de Hidrogênio/farmacocinética , Abrasão Dentária/metabolismo , Clareadores Dentários/farmacocinética , Animais , Bovinos , Permeabilidade do Esmalte Dentário , Permeabilidade da Dentina , Espectrofotometria Ultravioleta , Clareamento Dental/efeitos adversos
12.
Gen Dent ; 61(3): e21-5, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23649584

RESUMO

This study sought to quantify the concentration of hydrogen peroxide (HP) in the pulp chamber and evaluate changes on dental permeability after bleaching with 3 HP concentrations (10%, 35%, and 50%). This study was divided into 2 experiments and the bleaching treatments consisted of 3 applications of HP for 30 minutes during a single session. The first experiment tested HP penetration into the pulp chamber of 4 experimental groups (n = 10) of bovine crowns, which were divided by HP concentration: an unbleached control group (0% HP), 10% HP, 35% HP, and 50% HP. Acetate buffer solution was placed into the pulp chamber and after each application of HP. This solution was collected to determine spectrophotometrically the concentration of HP that reached the pulp chamber. The second experiment evaluated dental permeability. Bovine crowns were divided into 3 groups (n = 10). The crowns were connected to a permeability device and the initial permeability was measured at 10 psi. Three different concentrations of HP gels (10%, 35% and 50%) were applied to the buccal enamel surfaces and the dental permeability was measured after the first, second, and third applications of HP. The data were analyzed by 2-way ANOVA and Tukey test (P ≤ 0.05). All concentrations of HP reached the pulp chamber, although no significant differences were noted between the 3 concentrations tested (P > 0.05). However, the increase of dental permeability in the group that received 50% HP was significantly higher than the 10% HP group (P < 0.05). The results indicate that the HP bleaching treatments increased dental permeability.


Assuntos
Cavidade Pulpar/metabolismo , Peróxido de Hidrogênio/farmacocinética , Clareadores Dentários/farmacocinética , Permeabilidade Dentária/efeitos dos fármacos , Animais , Bovinos , Esmalte Dentário/efeitos dos fármacos , Esmalte Dentário/metabolismo , Permeabilidade do Esmalte Dentário/efeitos dos fármacos , Cavidade Pulpar/efeitos dos fármacos , Dentina/efeitos dos fármacos , Dentina/metabolismo , Permeabilidade da Dentina/efeitos dos fármacos , Corantes Fluorescentes , Violeta Genciana , Peróxido de Hidrogênio/administração & dosagem , Peróxido de Hidrogênio/farmacologia , Distribuição Aleatória , Espectrofotometria/métodos , Fatores de Tempo , Clareadores Dentários/administração & dosagem , Clareadores Dentários/farmacologia , Coroa do Dente/efeitos dos fármacos , Coroa do Dente/metabolismo
13.
Eur J Esthet Dent ; 8(2): 180-90, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23712339

RESUMO

Enamel white spot lesions are frequent and can impact patients' quality of life. The most conservative treatment in such cases is microabrasion, a technique that presents some drawbacks. The proposed strategy is not based on the elimination of dysplastic enamel, but on masking the lesion by infiltrating the porous subsurface enamel with a hydrophobic resin that has a refraction index closer to that of sound enamel, after permeating the non-porous surface enamel through hydrochloric acid erosion. Erosion-infiltration approaches have been proposed to treat initial caries, but this report suggests extending it to two novel indications: fluorosis and traumatic hypo-mineralization lesions. Four cases were treated by erosion infiltration following the original protocol. They were followed up clinically at several intervals during a period of 19 months of clinical service. The clinical results, although not perfect, satisfied the patients entirely. Erosion infiltration could be a promising alternative for minimally invasive treatment in similar situations.


Assuntos
Hipoplasia do Esmalte Dentário/terapia , Fluorose Dentária/terapia , Resinas Sintéticas/uso terapêutico , Descoloração de Dente/terapia , Adulto , Permeabilidade do Esmalte Dentário , Feminino , Seguimentos , Humanos , Masculino , Adulto Jovem
14.
Photomed Laser Surg ; 31(2): 82-9, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23336742

RESUMO

OBJECTIVE: The aim of this in situ study was to analyze the influence of the Er:YAG, Nd:YAG, and CO(2) lasers on the enamel acid resistance of pits and fissures. BACKGROUND DATA: The laser tissue interaction has been studied as a method of preventing occlusal caries. METHODS: Thirteen volunteers wore palatal acrylic appliances containing human occlusal enamel blocks that were divided into four groups (G1, control; G2, Er:YAG; G3, Nd:YAG; G4, CO(2)). Each palatal acrylic appliance was used in the four studied groups and was used for 14 consecutive days. A sucrose solution was applied to the specimens six times per day. The specimens were then sectioned in half, and a microhardness test was applied. The other halves were analyzed using polarized light microscopy to measure the caries-like lesion areas, and a morphological analysis was conducted using a scanning electron microscope (SEM). RESULTS: For the statistical analysis of the data obtained from the microhardness test (Knoop hardness number. [KHN]) (α=5%), Fisher's exact test was performed, and the group means were as follows: G1, 247±71; G2, 258±70; G3, 272±73; and G4, 298±56. The results demonstrated that the control group was significantly different from G3 and G4, which presented higher microhardness values. The Wilcoxon signed-rank test was used to analyze the data obtained from the caries-lesion area measurements (mm(2)) (α=5%) (G1, 0.01±1.08; G2, 0.13±0.18; G3, 0.05±0.17; and G4, 0.09±0.22). The results no showed significant differences among the groups in this analysis. CONCLUSIONS: Based on the results from the present study, it may be concluded that the CO(2) and Nd:YAG lasers increased the enamel acid resistance in pits and fissures.


Assuntos
Esmalte Dentário/efeitos da radiação , Fissuras Dentárias/radioterapia , Lasers de Estado Sólido , Adulto , Cárie Dentária/radioterapia , Permeabilidade do Esmalte Dentário/efeitos da radiação , Feminino , Humanos , Masculino , Microscopia Eletrônica de Varredura , Adulto Jovem
15.
Caries Res ; 47(3): 183-92, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23222001

RESUMO

This study aimed to test the hypothesis that organic volume is the main variable for explaining the optical properties and predictive degree of diffusion of enamel histological points at zones of natural enamel caries (NEC; surface layer, SL, n = 30, and body of the lesion, BL, n = 58) and normal enamel (NE, n = 131). Molars with either NEC or NE were quantitatively analyzed regarding the mineral, organic and water volumes (considered as effective pore volume), opacity (predicted in 94% of cases by water volume in NEC), and water volume more easily available for diffusion, αd (squared water volume divided by the nonmineral volume; related to permeability). NEC presented lower mineral volumes and higher organic volumes, effective pore volume and opacity than NE. External origin of organic volume in NEC was evidenced by an organic gradient decreasing from the surface inward (R2 = -0.7), which was not detected in teeth with NE only; αd values of the SL and NE were similar and both were lower (p < 0.0001) than that of the BL. Comparing the SL from both NEC and artificial enamel caries (AEC; published data; n = 71), with similar mineral volumes, against developing enamel (published data), AEC showed more effective pore volume (3 times higher), higher αd and opacity than NEC mainly due to differences in organic volumes. Our results reasonably matched widely known features of NEC histological zones, and confirmed the organic volume as the main variable for explaining optical properties and αd (related to permeability).


Assuntos
Cárie Dentária/patologia , Esmalte Dentário/química , Esmalte Dentário/patologia , Birrefringência , Cárie Dentária/diagnóstico por imagem , Esmalte Dentário/diagnóstico por imagem , Permeabilidade do Esmalte Dentário , Humanos , Processamento de Imagem Assistida por Computador , Microrradiografia , Minerais/análise , Compostos Orgânicos/análise , Fotografia Dentária , Porosidade , Estatísticas não Paramétricas , Água/análise
16.
Am J Dent ; 26(5): 283-5, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24479281

RESUMO

PURPOSE: To assess the trans-enamel and trans-dentin toxicity of a 10% hydrogen peroxide (HP) whitening strip to odontoblast-like cells (MDPC-23). METHODS: Enamel surfaces of enamel/dentin discs adapted to artificial pulp chambers were subjected to two 30-minute whitening strip applications to obtain indirect extracts (DMEM + bleaching components that diffused across enamel and dentin). The extracts were applied for 1 hour to the cells for 1 or 5 days. A bleaching gel with 35% HP was used as the positive control. Cell viability (MTT assay) and morphology (SEM) as well as the quantity of HP in the extracts were assessed. RESULTS: Discrete cell viability reduction (21.9%) associated with slight alterations in cell morphology occurred after application of the extracts for 5 days to the MDPC-23 cells (Tukey's test; P < 0.05). Lower enamel/dentin diffusion of HP was observed after the use of the whitening strip compared with the bleaching gel (Mann-Whitney; P < 0.05).


Assuntos
Polpa Dentária/efeitos dos fármacos , Peróxido de Hidrogênio/toxicidade , Odontoblastos/efeitos dos fármacos , Clareadores Dentários/toxicidade , Animais , Bovinos , Técnicas de Cultura de Células , Forma Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Corantes , Permeabilidade do Esmalte Dentário/efeitos dos fármacos , Polpa Dentária/citologia , Permeabilidade da Dentina/efeitos dos fármacos , Difusão , Peróxido de Hidrogênio/farmacocinética , Microscopia Eletrônica de Varredura , Saliva Artificial/administração & dosagem , Sais de Tetrazólio , Tiazóis , Fatores de Tempo , Técnicas de Cultura de Tecidos , Clareamento Dental/instrumentação , Clareadores Dentários/farmacocinética
17.
Caries Res ; 47(3): 203-10, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23235388

RESUMO

This study aimed at testing how active and inactive enamel caries lesions differ by their degree of resin infiltration, and whether the choice of acid pretreatment plays a crucial role. Four examiners assessed 104 human molars and premolars with noncavitated enamel lesions and classified them as 'active' or 'inactive' using the Nyvad criteria. Forty-five teeth were included in this study after independent unanimous lesion activity assessment. Lesions were cut perpendicularly into 2 halves. Each half lesion was pretreated with either 15% hydrochloric acid or 35% phosphoric acid. The lesions were infiltrated after staining with rhodamine isothiocyanate. Thin sections of 100 µm were prepared and the specimens were bleached with 30% hydrogen peroxide. The specimens were then counterstained with sodium fluorescein, subjected to confocal laser scanning microscopy and analyzed quantitatively. Outcome parameters were maximum and average infiltration depths as well as relative penetration depths and areas. In active lesions no significant difference of percentage maximum penetration depth and percentage average penetration depth between lesions pretreated with hydrochloric or phosphoric acid could be observed. In inactive lesions, however, phosphoric acid pretreatment resulted in significantly lower penetration compared to hydrochloric acid pretreatment. Surface conditioning with hydrochloric acid led to similar infiltration results in active and inactive lesions. Moreover, inactive lesions showed greater variability in all assessed infiltration parameters than did active lesions. In conclusion, caries lesion activity and acid pretreatment both influenced the infiltration. The use of phosphoric acid to increase permeability of the surface layer of active lesions should be further explored.


Assuntos
Condicionamento Ácido do Dente , Cárie Dentária/patologia , Permeabilidade do Esmalte Dentário , Análise de Variância , Permeabilidade do Esmalte Dentário/efeitos dos fármacos , Humanos , Ácido Clorídrico/farmacologia , Microscopia Confocal , Ácidos Fosfóricos/farmacologia , Cimentos de Resina/química , Estatísticas não Paramétricas
18.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 30(5): 483-6, 2012 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-23173311

RESUMO

OBJECTIVE: To compare the penetration abilities of resin infiltration into natural initial caries lesions with those of adhesive in vitro. METHODS: Thirty-six extracted human molars and premolars showing proximal white spot lesions were selected. Teeth roots were removed, and the crowns were cut across the caries lesions perpendicular to the surface. Corresponding lesion halves were etched for 2 min with 15% hydrochloric acid gel and were subsequently treated with either adhesive or resin infiltration. Specimens were observed with confocal laser scanning microscopy (CLSM) in dual fluorescence mode. In confocal microscopic images, penetration depth (PD) and lesion depth (LD) were defined as the distance from the surface to the deepest point of red and green fluorescence, respectively. The penetration percentages (PP) were calculated. RESULTS: At the same level of caries, mean maximum lesion LD were comparable for both lesion halves (P > 0.05). But mean maximum PD and PP of the resin infiltration were significantly higher than those of the adhesive (P < 0.01). CONCLUSION: Penetration of enamel caries lesions is observed in the adhesive and the resin infiltration. But the resin infiltration is capable of penetrating almost completely into enamel parts of natural caries lesions.


Assuntos
Permeabilidade do Esmalte Dentário , Esmalte Dentário , Dente Pré-Molar , Cárie Dentária , Humanos , Ácido Clorídrico , Microscopia Confocal , Dente Molar
19.
Eur J Paediatr Dent ; 13(3): 231-5, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22971262

RESUMO

AIM: The aim of this study was to evaluate in vivo the occurrence of outward fluid flow on primary tooth sound enamel surface. MATERIALS AND METHODS: Sixty primary upper canines from preadolescent patients (mean age 8.0±1.9) and 24 retained primary upper canines from adult subjects (mean age 35.0±1.8) were analysed. The enamel surface was gently polished and air dried for 10 s. An impression was immediately obtained by vinyl polyxiloxane. Replicas were then obtained by polyether impression material, gold coated and inspected under SEM. The hydrophobic vinyl polyxiloxane material enabled to obtain in situ a morphological image of the presence of droplets, most likely resulting from outward fluids flow through outer enamel. For each sample three different representative areas of 5µ² in the cervical, medium and incisal third were examined and droplets presence values was recorded. All data were analysed by by Fisher's exact test. RESULTS: Primary enamel showed a substantial permeability expressed as droplets discharge on its surface. Droplets distribution covered, without any specific localisation, the entire enamel surface in all the samples. No signs of post-eruptive maturation with changes in droplets distribution were observed in samples from adult subjects. No statistically significant differences (P = 0.955) were noted in the percentage distribution of enamel area covered with droplets among the two group studied. CONCLUSION: SEM evaluation of droplets distribution on enamel surface indicated a substantial enamel permeability in primary teeth, accordingly with histological features, without changes during aging. A relationship between enamel permeability, caries susceptibility and bonding procedures effectiveness could be hypothesised.


Assuntos
Permeabilidade do Esmalte Dentário , Dente Decíduo/ultraestrutura , Adulto , Criança , Colagem Dentária , Suscetibilidade à Cárie Dentária , Método Duplo-Cego , Humanos , Técnicas Analíticas Microfluídicas , Microscopia Eletrônica de Varredura , Técnicas de Réplica , Molhabilidade
20.
J Adhes Dent ; 14(6): 569-74, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22724105

RESUMO

PURPOSE: To investigate the influence of caries infiltrant application on the shear bond strength of different adhesives on sound and demineralized enamel. MATERIALS AND METHODS: Sound and artificially demineralized (14 days, acidic buffer, pH 5.0) bovine enamel specimens were treated with a caries infiltrant (Icon, DMG), three different commercial adhesives (unfilled etch and- rinse adhesive: Heliobond, Ivoclar Vivadent; filled etch-and-rinse adhesive: Optibond FL, Kerr; or self-etching adhesive: iBOND Self Etch, Heraeus Kulzer) or a combination of caries infiltrant and adhesive. The shear bond strength of a nanohybrid composite was analyzed after thermocycling (5000x, 5° to 55°C) at a crosshead speed of 1 mm/min. Failure mode was inspected under a stereomicroscope at 25X magnification. RESULTS: In both sound and demineralized enamel, the shear bond strength of the caries infiltrant was not significantly different from the etch-and-rinse adhesives, while the self-etching adhesive showed significantly lower values compared to all other groups. Pretreatment with the caries infiltrant significantly increased the bond strength of the self-etching adhesive in both substrates and of the filled etch-and-rinse adhesive in demineralized enamel. While shear bond strength was not significantly different between the two substrates, cohesive failures were more likely to occur in demineralized than sound specimens. CONCLUSION: The shear bond strength of the caries infiltrant was similar to the etch-and-rinse adhesives. The caries infiltrant did not impair bonding to sound or demineralized enamel, and even increased adhesion of the selfetching agent.


Assuntos
Colagem Dentária , Cárie Dentária/tratamento farmacológico , Permeabilidade do Esmalte Dentário , Esmalte Dentário , Cimentos de Resina , Resinas Sintéticas , Animais , Bovinos , Esmalte Dentário/efeitos dos fármacos , Esmalte Dentário/patologia , Corrosão Dentária , Falha de Restauração Dentária , Análise do Estresse Dentário , Nanocompostos , Resinas Sintéticas/uso terapêutico , Resistência ao Cisalhamento
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