Influence of different phosphoric acids before application of universal adhesive on the dental enamel.

BACKGROUND: There are different etching gels available, which have different composition, different pH, and different viscosity, and there is little information in the literature comparing all these products. OBJECTIVE: To evaluate the mean microshear bond strength and morphological characteristics of tooth enamel by evaluating different phosphoric acids combined with a universal adhesive system. MATERIALS AND METHODS: Eighty-four enamel samples were used, which were divided according to the acid conditioning: G1: Scotchbond Etchant (3M Oral Care), G2: Ultra-Etch (Ultradent), G3: Eco-Etch (IvoclarVivadent), G4: ETCH-37 with BAC (Bisco), G5: Etching gel (Densell), G6: Condac 37 (FGM), and G7: Scotchbond Universal Adhesive (3M Oral Care) in self-etch mode. For the adhesive procedure, Scotchbond Universal Adhesive was the one used as indicated the manufacturer's instructions, 0.9-mm-diameter resin cylinders were placed. The microshear bond strength test was performed after being stored for 24 hours in water. The morphological characteristics of tooth enamel were analyzed using the Raman confocal microscope alpha300RA. The analysis of variance (ANOVA) test and Tukey post-test were used to analyze the differences between the groups. RESULTS: The mean microshear bond strength values obtained for groups 1, 4, 5 were significantly greater than groups 2, 3, 6 and 7 (p < .05). All groups presented demineralization after the application of the etching acid, and few signs of demineralization were evident in group 7. CONCLUSIONS: Acid-etching with ETCH-37 with BAC, Etching gel, and Scotchbond Etchant improved the adhesive strength in the enamel using an universal adhesive, and acid-etching with Condac 37, Ultra-Etch, and Eco-Etch provides similar adhesive strength values to self-etch mode of universal adhesive. CLINICAL SIGNIFICANCE: All acid etchants should be considered as different. The test confirms that enamel etching prior to the application of a universal adhesive system depends on the selected acid etchand product.

Effect of the addition of silver nanoparticles on the mechanical properties of an orthodontic adhesive.

Objectives: This study evaluated the effects of adding silver nanoparticles on the shear bond strength, microhardness, and surface roughness of orthodontic adhesives. Material and Methods: Fifty upper premolars were randomly allocated to five groups (n = 10). Orthodontic brackets were bonded with silver nanoparticle (AgNP)-modified adhesives (1 %, 0.5 %, 0.1 %, 0.05 %), and conventional adhesive was used as a control. The shear bond strength was recorded using a universal testing machine, and the adhesive remnant index was evaluated using a stereomicroscope. Ten discs of each adhesive were subjected to the microhardness and surface roughness tests. The Vickers microhardness values were measured under a constant load of 100 g for 30 s using a microhardness tester. The samples were analyzed using a surface profilometer, and the arithmetic average roughness was used as the measurement parameter. Data were analyzed using one-way analysis of variance and chi-square tests. A significance level of 5 % was considered significant. Results: AgNP concentration > 0.1 % significantly reduced the shear bond strength (p < 0.05). At higher AgNP concentration, the bonding failure pattern occurred mainly at the bracket-resin interface. The Vickers microhardness increased with increasing concentration, and significant differences were observed between the group with 1 % AgNP and the other groups (p < 0.05). The average roughness values were similar between the groups with AgNP concentrations > 0.1 % (p > 0.05). Conclusion: The incorporation of AgNP into an orthodontic adhesive has the potential to decrease the shear bond strength while increasing the microhardness and surface roughness.

Effectiveness of a novel experimental herbal toothpaste against bacterial consortium associated with dental caries.

Background: To evaluate the effectiveness of an experimental toothpaste based on Hypericum laricifolium Juss. essential oil against a bacterial consortium associated with dental caries. Material and Methods: The antibacterial activity of the essential oil was evaluated by the disk diffusion and microdilution tests against Streptococcus mutans, Streptococcus sanguinis and Streptococcus salivarius. Petri dishes were incubated at 37°C for 24 h. An experimental toothpaste was prepared at a concentration of 201.76 mg/mL. The antibacterial activity of the experimental and six commercial toothpastes were evaluated by agar well-diffusion method. Petri dishes were inoculated with a bacterial consortium prepared with the three strains. 80 mg of the toothpastes were placed in the wells and the Petri dishes were incubated at 37°C for 24 h. The inhibition zones were measured with a digital compass. The differences between the pastas were evaluated with the one-way ANOVA test, with a 5% level of significance. Results: The essential oil was more effective than 0.12% chlorhexidine in inhibiting the growth of S. mutans (29.02±1.74 mm) and S. sanguinis (21.92±3.43 mm), being more moderate for S. salivarius (17.66±1.11 mm) . In MBC tests, the EO showed complete inhibition of the growth of S. mutans at a concentration of 5% (50.44 mg/mL), 10% (100.88 mg/mL) for S. sanguinis and 2.5% (25.22 mg/mL) for S. salivarius. The experimental toothpaste was effective in inhibiting the growth of the bacterial consortium (31.88±66 mm), having a similar performance to Total Dent, Colgate Total 12, Kolynos® Herbal and Colgate® Herbal (p> 0.05). Conclusions: The development of an experimental paste based on H. laricifolium Juss. essential oil (0.28% v/v) showed an important antibacterial activity similar to commercial toothpastes against a bacterial consortium of S. mutans, S. sanguinis and S. salivarius. Key words:Antibacterial agents, toothpastes, medicinal plants, Streptococcus mutans, Streptococcus sanguinis, Streptococcus salivarius.

A new universal simplified adhesive: 6-month clinical evaluation.

STATEMENT OF THE PROBLEM: Multimode adhesives, which can be used as etch-and-rinse or as self-etch adhesives, have been recently introduced without clinical data to back their use. PURPOSE OF THE STUDY: To evaluate the 6-month clinical performance of Scotchbond Universal Adhesive (SU; 3M ESPE, St. Paul, MN, USA) in noncarious cervical lesions (NCCLs) using two evaluation criteria. METHODS/MATERIALS: Thirty-nine patients participated in this study. Two hundred restorations were assigned to four groups: SU-TEm: etch-and-rinse + moist dentin; SU-TEd: etch-and-rinse + dry dentin; SU-SEet: selective enamel etching; and SU-SE: self-etch. The composite resin Filtek Supreme Ultra (3M ESPE) was placed incrementally. The restorations were evaluated at baseline and after 6 months using both the World Dental Federation (FDI) and the United States Public Health Service (USPHS) criteria. Statistical analyses were performed with Friedman repeated measures analysis of variance by rank and McNemar test for significance in each pair (α = 0.05). RESULTS: Only four restorations (SU-SE: 3 and SU-TEm: 1) were lost after 6 months (p > 0.05 for either criteria). Marginal discoloration occurred in one restoration in the SU-SE group (p > 0.05 for either criteria). Only 2/200 restorations were scored as bravo for marginal adaptation using the USPHS criteria (one for SU-SE and one for SU-SEet, p > 0.05). However, when using the FDI criteria, the percentage of bravo scores for marginal adaptation at 6 months were 32%, 36%, 42%, and 46% for groups SU-TEm, SU-TEd, SU-SEet, and SU-SE, respectively (p > 0.05). CONCLUSIONS: The clinical behavior of the multimode adhesive does not depend on the bonding strategy at 6 months. The FDI evaluation criteria are more sensitive than the USPHS criteria. CLINICAL SIGNIFICANCE: At 6 months, the clinical behavior of the new multimode adhesive Scotchbond Universal was found to be reliable when used in noncarious cervical lesions and may not depend on the bonding strategy employed.

Raman microscopy evaluation of the preventive effect of a modified orthodontic adhesive with silver nanoparticles on the formation of white spot lesions.

Background: Silver nanoparticles (AgNPs) are an effective antibacterial agent, and their inclusion in orthodontic adhesives has been proposed to prevent white spot lesions (WSLs). The objective of this study was to evaluate by Raman microscopy the preventive effect of an orthodontic adhesive modified with AgNPs on the formation of WSLs. Material and Methods: AgNPs were added in four concentrations (0.05%, 0.1%, 0.5%, and 1%) to an orthodontic adhesive. Metal brackets were bonded with the experimental adhesives, and the specimens were subjected to a microbial model for caries induction. The preventive effect on the formation of WSLs was evaluated by Raman microscopy, considering the intensity peak of the phosphate ion at 960 cm-1. The acquisition mode was linear scanning in the most representative lesion area, with a length of 136µm. Intensity values expressed the relative amount of phosphate ions remaining in the lesion. Microphotographs were analyzed in the Image J program to assess the depth of the lesions. Results: Significant differences were observed between all groups (P <0.05). The addition of 1% AgNPs effectively maintained the relative amount of phosphate ions close to sound enamel values. Furthermore, as the concentration of AgNPs increased, the depth of the lesions decreased. Conclusions: AgNPs were effective in decreasing the formation of WSLs. At a higher concentration of AgNPs, a more significant preventive effect on the formation of WSLs results in a relative amount of phosphate ion close to sound enamel values. Key words:White spot lesions, antibacterial, orthodontics, Raman microscopy, adhesive, Silver-nanoparticles.

Long-term efficacy of in-office and at-home bleaching: a 2-year double-blind randomized clinical trial.

PURPOSE: This parallel, double-blind randomized clinical trial evaluated the 2-year bleaching efficacy and sensitivity produced by at-home (AH) and in-office (IO) bleaching therapies. METHODS: 60 participants with tooth color darker than C2, without restorations in the anterior dentition and older than 18 years old, were randomly allocated into two groups to receive either IO with 35% hydrogen peroxide or AH with 16% carbamide peroxide. Color was recorded at baseline (BA); 1-week (1W); end of the treatment (ET); and 2 years (2Y) after bleaching, using the Vita Classical shade guide. The perception of TS was recorded on a 0-4 scale during and 2Y after bleaching. The variation in shade guide units (deltaSGU) from BA vs. 1W was compared to deltaSGU from BA vs. 2Y using paired t-test. The percentage of subjects who reported TS was evaluated by Fisher's exact test. The intensity of TS was evaluated by a Mann-Whitney test (alpha=0.05). RESULTS: Both bleaching techniques demonstrated equivalent and significant tooth color shade lightening. No significant color rebound occurred after 2Y for both techniques (P= 0.77 and 0.87, for AH and IO respectively). The absolute risk of TS was similar for IO and AH (P= 0.12), however the intensity of TS was significantly higher for IO (P= 0.001). No subjects reported sensitivity after 2Y.

Effect of water storage and heat treatment on the cytotoxicity of soft liners.

OBJECTIVE: To evaluate the effect of water storage time on the cytotoxicity of soft liners. METHODS: Sample discs of soft liners Dentusoft, Dentuflex, Trusoft, Ufi-Gel-P and denture base acrylic resin Lucitone-550 were prepared and divided into four groups: GN: No treatment, G24: Stored in water at 37°C for 24 h; G48: Stored in water at 37°C for 48 h, GHW: Immersed in water at 55°C for 10 min. To analyse the cytotoxic effect, three samples of each group were placed in tubes with Dubelcco's Modified Eagle Mediums and incubated at 37°C for 24 h. During this period, the toxic substances were leached to the culture medium. The cytotoxicity was analysed quantitatively by the incorporation of radioactivity (3)H-thymidine checking the number of viable cells (synthesis of DNA). The data were statistically analysed using two-way anova and Tukey's honestly significant difference tests (α = 0.05). RESULTS: Treatments did not reduce the cytotoxicity effect of the soft liners (p > 0.05). It was found that Ufi-Gel-P had a non-cytotoxic effect, Trusoft had a slightly cytotoxic effect, Dentuflex had a moderated cytotoxic effect, Dentusoft alternated between slightly and non-cytotoxic effect, and Lucitone-550 had non-cytotoxic effect when stored in water for 48 h. CONCLUSION: The effect of water storage and the heat treatment did not reduce the cytotoxicity of the soft liners.

Effect of an orthodontic resin modified with silver-nanoparticles on enamel color change.

Background: To evaluate the effect of an orthodontic resin modified with various concentrations of silver-nanoparticles (AgNPs) on enamel color. Material and Methods: Twenty lower premolars were collected and divided into four groups (n = 5) according to the concentration of AgNPs (0.05%, 0.1%, 0.5%, and 1% wt/wt). Additionally, a group bonded with a conventional resin was used as control (n=5). Previous to the bracket bonding, enamel color was measuring with a spectrophotometer. Specimens were stored for 6 months in deionized water. Brackets were debonded and color changes of enamel were calculated with the CIEDE 2000 formula (∆E00). One-way ANOVA and Tukey test were used to assess the color change (α = .05). Results: The control group showed the lowest ∆E00 values, and no significant difference was observed when compared to the group with 0.05% of AgNPs (P > .05). The highest color change was observed in the group with 1% of AgNPs (∆E00 = 8.04±1.48), however no significant difference was observed between groups with 0.1% and 0.5% AgNPs. Conclusions: The incorporation of AgNPs into orthodontic resin result in tooth color alteration. Lower concentrations of AgNPs should be considered to minimize negative changes in enamel color. Key words:White spot lesions, antibacterial, orthodontics, adhesive, Silver-nanoparticles.

Antibacterial and white spot lesions preventive effect of an orthodontic resin modified with silver-nanoparticles.

BACKGROUND: To evaluate the antibacterial property of a modified orthodontic resin with different concentrations of silver-nanoparticles (AgNPs), and quantify its preventive effect on the formation of white spot lesions (WSLs). MATERIAL AND METHODS: An orthodontic resin (Transbond XT) was modified with four concentrations of AgNPs (1%, 0.5%, 0.1%, and 0.05%), the orthodontic resin without AgNPs was used as control. Polymerized resin discs (n=80) were submitted to Agar diffusion test on Petri dishes inoculated with Streptococcus mutans and Lactobacillus acidophilus. In addition, resin discs of each group (n=40) were placed in 96-well plates with bacterial suspensions to evaluate the colony-forming-units (CFU). For the WSLs prevention test, brackets were bonded with the experimental orthodontic resins on 45 premolars (n=5), and were subjected to a microbiological caries induction method for 9 days. Photographs were taken before and after the test, and the images were evaluated with the Image J software to calculate the area of WSLs. The data were analyzed using ANOVA and Tukey-HSD test, Student´s t-test and Kruskal-Wallis test (α=0.05). RESULTS: The 0.5% and 1% AgNPs modified resin inhibit the growth of S. mutans and L. acidophilus. All the modified resins showed significantly less CFU, when compared to the control (p<0.05). 1% AgNPs resin promote the higher prevention of WSLs formation. There was no significant difference between the control group and the 0.1% and 0.05% groups. CONCLUSIONS: 0.5% and 1% of AgNPs modified orthodontic resin exhibit an important antibacterial activity against S. mutans and L. acidophilus, and prevent the formation of WSLs. Key words:White spot lesions, antibacterial, orthodontics, adhesive, Silver-nanoparticles.

Evaluation of the palatal bone in different facial patterns for orthodontic mini-implants insertion: A cone-beam computed tomography study.

OBJECTIVE: Evaluate the height, thickness and cortical density of the palatal bone of adults with different vertical facial patterns using Cone-Beam Computed Tomography (CBCT). METHODS: This study analyzed 75 CBCTs of patients between 18 and 35 years old (45 men and 30 women). The CBCTs were classified into three groups based on their facial pattern: normodivergent, hypodivergent and hyperdivergent as determined from lateral cephalograms synthesized from the CBCTs. The height, cortical thickness and cortical density of the palatal bone were measured at 4, 8, 12, 16 and 20mm posterior to the incisive foramen, and at 3, 6 and 9mm lateral to the midpalatal suture. ANOVA with Tukey post-hoc tests were used for analysis of the data, at significance level of p< 0.05. RESULTS: The hypodivergent pattern had a significant difference and the greatest height and cortical thickness of the palatal bone, followed by the hyperdivergent and the normodivergent patterns. No significant differences were found in minimum and maximum values of cortical density. CONCLUSION: The palatal bone is a favorable anatomical area to install different orthodontic temporary anchorage devices (TADs), where individuals with the hypodivergent vertical facial pattern have a higher height and cortical thickness of the palatal bone, followed by the hyperdivergent pattern and finally the normodivergent pattern. No significant differences in the cortical density of the palatal bone in the three facial patterns were found.

Effect of the Purple Corn Beverage "Chicha Morada" in Composite Resin during Dental Bleaching.

During dental bleaching the staining potential of the surface would increase. This study aims to evaluate the staining susceptibility of one bleached composite resin after the exposure to three different beverages: Peruvian purple corn based beverage (chicha morada), green tea, and distilled water. Thirty disk-shaped specimens of one nanofill composite resin were prepared. The specimens were then divided into six groups (n = 5): purple corn (P), purple corn + bleaching (PB), green tea (T), green tea + bleaching (TB), distilled water (W), and distilled water + bleaching (WB). In groups that received bleaching, two sessions of bleaching with 35% hydrogen peroxide were done. Following bleaching, specimens were exposed to each liquid thirty minutes daily. Color was measured with a digital spectrophotometer. For statistical analysis, color measurement differences between the obtained results were used: during bleaching, after bleaching, and during + after bleaching. Two-way ANOVA was used to compare the color changes in the resins of all groups (p < 0.05). We conclude that all the evaluated beverages produced changes of color in the composite resin regardless of the bleaching procedure. However, purple corn was the only beverage that caused a perceptible color change (ΔE > 3.3).

Evaluation of the palatal bone in different facial patterns for orthodontic mini-implants insertion: A cone-beam computed tomography study

ABSTRACT Objective: Evaluate the height, thickness and cortical density of the palatal bone of adults with different vertical facial patterns using Cone-Beam Computed Tomography (CBCT). Methods: This study analyzed 75 CBCTs of patients between 18 and 35 years old (45 men and 30 women). The CBCTs were classified into three groups based on their facial pattern: normodivergent, hypodivergent and hyperdivergent as determined from lateral cephalograms synthesized from the CBCTs. The height, cortical thickness and cortical density of the palatal bone were measured at 4, 8, 12, 16 and 20mm posterior to the incisive foramen, and at 3, 6 and 9mm lateral to the midpalatal suture. ANOVA with Tukey post-hoc tests were used for analysis of the data, at significance level of p< 0.05. Results: The hypodivergent pattern had a significant difference and the greatest height and cortical thickness of the palatal bone, followed by the hyperdivergent and the normodivergent patterns. No significant differences were found in minimum and maximum values of cortical density. Conclusion: The palatal bone is a favorable anatomical area to install different orthodontic temporary anchorage devices (TADs), where individuals with the hypodivergent vertical facial pattern have a higher height and cortical thickness of the palatal bone, followed by the hyperdivergent pattern and finally the normodivergent pattern. No significant differences in the cortical density of the palatal bone in the three facial patterns were found.

RESUMO Objetivo: Avaliar a altura, a espessura e a densidade cortical do osso palatino em adultos com diferentes padrões faciais verticais, utilizando a tomografia computadorizada de feixe cônico (TCFC). Métodos: O presente estudo analisou 75 TCFCs de pacientes com idades entre 18 e 35 anos (45 homens e 30 mulheres). As TCFCs foram classificadas em três grupos, de acordo com seus padrões faciais: normodivergentes, hipodivergentes e hiperdivergentes, conforme determinado na radiografia cefalométrica lateral reconstruída das TCFCs. Altura, espessura e densidade cortical do osso palatino foram aferidas a 4, 8, 12, 16 e 20 mm para posterior do forame incisivo e a 3, 6 e 9 mm lateralmente à sutura transpalatina. Os testes ANOVA e post-hoc de Tukey foram utilizados para análise dos dados, com nível de significância de p< 0,05. Resultados: O padrão hipodivergente apresentou uma diferença significativa e a maior altura e espessura cortical do osso palatino, seguido pelos padrões hiperdivergente e normodivergente. Nenhuma diferença estatisticamente significativa foi encontrada nos valores mínimos e máximos da densidade cortical. Conclusão: O osso palatino é uma área anatomicamente favorável para instalar diferentes dispositivos de ancoragem temporária. Indivíduos com padrão facial vertical hipodivergente apresentam maior altura e espessura cortical do osso palatino, seguido do padrão hiperdivergente e finalmente do padrão normodivergente. Não foi encontrada qualquer diferença significativa na densidade cortical do osso palatino entre os três padrões faciais.

Effectiveness of nano-calcium phosphate paste on sensitivity during and after bleaching: a randomized clinical trial.

The study aimed to evaluate the effectiveness of in-office bleaching and associated tooth sensitivity on application of nano-calcium phosphate paste as desensitizing agent. Bleaching was performed with 35% hydrogen peroxide gel in 40 patients who were randomly divided into placebo and nano-calcium phosphate paste groups. Bleaching efficacy (BE) was evaluated using a value-oriented Vita shade guide. Tooth sensitivity was recorded using a numeric rating scale (0-4) during bleaching and up to 48 h after each session. The primary outcome of absolute risk of tooth sensitivity was compared using the Fisher's exact test (α = 0.05). The intensity of tooth sensitivity and the efficacy of in-office bleaching were also statistically evaluated. No significant differences in absolute risk and intensity of tooth sensitivity were detected between the groups (p = 1.0 and p = 0.53, respectively). BE was also found to be similar between the groups (p = 0.67). Although the use of a nano-calcium phosphate paste associated with fluoride and potassium nitrate did not influence the whitening outcome, but it also did not reduce bleaching-induced tooth sensitivity.

Randomized clinical trial of four adhesion strategies in cervical lesions: 12-month results.

The aim of this study was to evaluate the 6- and 12-month clinical performance of four adhesion strategies from the same manufacturer (Kerr) in non-carious cervical lesions (NCCLs) using two evaluation criteria. Thirty-five patients, with at least four NCCLs each, participated in this study. After samplesize calculation, 180 restorations were assigned to one of the following groups: OFL (Optibond FL), OSP (Optibond Solo Plus), XTR (Optibond XTR), and AIO (Optibond All-In-One). The composite resin Filtek Supreme Ultra (3M ESPE) was placed incrementally. The restorations were evaluated at baseline, after 6 months, and after 12 months, using both the FDI and the USPHS-modified criteria. Statistical analyses were performed with Friedman repeated measures, ANOVA by rank, and the McNemar test for significance in each pair (α=0.05). Six restorations (2 for OFL, 1 for OSP, 2 for XTR, and 1 for AIO) were lost at 12 months (P>0.05 for both evaluation criteria). Marginal staining was observed in seven restorations using the FDI criteria (P>0.05) and three restorations using the USPHSmodified criteria (P>0.05). Eight restorations (2 for OSP, 3 for XTR, and 3 for AIO) were classified as Bravo for marginal adaptation using the USPHSmodified criteria (P>0.05). However, 62 restorations (14 for OFL, 12 for OSP, 15 for XTR, and 21 for AIO) were classified as Bravo using the FDI criteria (P>0.05). The four adhesion strategies showed similar clinical retention at 6 and 12 months. The FDI evaluation criteria tend to be more sensitive than the USPHS-modified criteria.

Effect of the manual manipulation of composite resin with latex gloves / Efecto de la manipulación manual de resina compuesta con guantes de látex

Purpose: This in vitro study aimed to evaluate the influence of the manual manipulation of two composite resins: Filtek™ Z350XT (3M ESPE) and Herculite Précis® (Kerr), with latex gloves contaminated with powder, human saliva and alcohol, on the microhardness values. Material and Methods: Manual manipulation was evaluated using latex gloves with powder, latex gloves without powder, latex gloves without powder with saliva, latex gloves without powder with alcohol, and without hand manipulation or contaminants (control). Each resin was manually manipulated for 10 seconds and photoactivated for 20 seconds with a light intensity of 1000mW/cm2 using a VALO ­Ultradent LED light­ cured unit, and then each sample was evaluated on the microhardness Vickers tester Leitz (Wetzlar). The collected data were analyzed using Kruskal ­Wallis and Mann ­ Whitney post-test (p<0.05). Results. Microhardness values showed a significant difference between the evaluated and control groups, showing lower microhardness values in the group of latex glove with powder for Filtek™ Z350XT and the group of latex glove without powder with saliva for Herculite Précis®. Conclusion. The manual manipulation of composite resins decreases their surface microhardness.

Propósito: Este estudio in vitrotuvo como objetivo evaluar la influencia de la manipulación manual de dos resinas compuestas: Filtek ™ Z350XT (3M ESPE) y Herculite Précis® (Kerr), con guantes de látex contaminados con polvo, saliva humana y alcohol, sobre los valores de microdureza. Material y Métodos: La manipulación manual se evaluó utilizando guantes de látex con polvo, guantes de látex sin polvo, guantes de látex sin polvo con saliva, guantes de látex sin polvo con alcohol, y sin manipulación manual o contaminantes (control). Cada resina fue manipulada manualmente durante 10 segundos y fotoactivada durante 20 segundos con unaintensidad de luz de 1000mW/cm2 usando una unidad de fotocuración LED VALO - Ultradent, y luego cada muestra fue evaluada en el tester de microdureza Vickers Leitz (Wetzlar). Los datos recopilados se analizaron utilizando Kruska ­Wallis y post-test Mann­ Whitney (p<0.05). Resultados: Se observó una diferencia significativa en los valores de microdureza entre los grupos evaluados y el grupo control, con valores más bajos de microdureza en el grupo de guantes de látex con polvo para Filtek™ Z350XT y el grupo de guantes de látex sin polvo con saliva para Herculite Précis®. Conclusión. La manipulación manual de resinas compuestas disminuye su microdureza superficial.

Evaluation of different treatment methods against denture stomatitis: a randomized clinical study.

OBJECTIVE: The aim of this clinical study was to determine the efficacy of Uncaria tomentosa (cat's claw) against denture stomatitis (DS). STUDY DESIGN: Fifty patients with DS were randomly assigned into 3 groups to receive 2% miconazole, placebo, or 2% U tomentosa gel. DS level was recorded immediately, after 1 week of treatment, and 1 week after treatment. The clinical effectiveness of each treatment was measured using Newton's criteria. Mycologic samples from palatal mucosa and prosthesis were obtained to determinate colony forming units per milliliter (CFU/mL) and fungal identification at each evaluation period. RESULTS: Candida species were identified with HiCrome Candida and API 20C AUX biochemical test. DS severity decreased in all groups (P < .05). A significant reduction in number of CFU/mL after 1 week (P < .05) was observed for all groups and remained after 14 days (P > .05). C albicans was the most prevalent microorganism before treatment, followed by C tropicalis, C glabrata, and C krusei, regardless of the group and time evaluated. U tomentosa gel had the same effect as 2% miconazole gel. CONCLUSIONS: U tomentosa gel is an effective topical adjuvant treatment for denture stomatitis.

Efecto del Extracto de Maíz Morado "Chicha Morada" durante el blanqueamiento Dental. In vitro / Effect of Purple Corn Beverage "Chicha Morada" During Dental Bleaching. In vitro

RESUMEN: El resultado del tratamiento de blanqueamiento dental puede verse afectado en pacientes que consumen bebidas pigmentantes durante el tratamiento. El objetivo de este trabajo consistió en valuar el efecto in vitro de la exposición al extracto de maíz morado (chicha morada) sobre el color del esmalte humano, durante y después del tratamiento del blanqueamiento dental con peróxido de hidrógeno al 35 %. Se utilizaron 48 dientes humanos, divididos en grupos según la bebida a la que se expuso: Extracto de maíz morado peruano (MM), té verde (T) y agua destilada (A); la mitad de los especímenes expuestos a cada bebida fueron sometidos a blanqueamiento dental con peróxido de hidrógeno al 35 % durante los primeros días de exposición a la pigmentación, resultando en los siguientes grupos: Grupo A: Sin blanqueamiento + maíz morado, Grupo B: Sin blanqueamiento + té verde, Grupo C: Sin blanqueamiento + agua destilada, Grupo D: Con blanqueamiento + maíz morado, Grupo E: Con blanqueamiento + té verde, Grupo F: Con blanqueamiento + agua destilada. Los cambios de color se midieron con un espectrofotómetro digital (VITA Easyshade Advance 4.0, VITA, Alemania) antes del blanqueamiento, durante el blanqueamiento, finalizado el blanqueamiento y al final de los 36 días de exposición a los pigmentos. Según el ∆E, el extracto de maíz morado difiere significativamente con el agua destilada (p < 0,05). Con respecto al grado de luminosidad, el extracto de maíz morado con blanqueamiento presentó los menores valores de luminosidad (p < 0,05). En cuanto al croma, no hubo diferencias entre los grupos (p > 0,05). La exposición al extracto de maíz morado pigmenta los dientes, durante el blanqueamiento el extracto de maíz morado no afecta el tratamiento, pero si la exposición continúa luego del blanqueamiento dental, el color de los dientes se verá afectado.

ABSTRACT: The result of tooth whitening treatment may be affected in patients who consume staining drinks during treatment. The aim of this work was to evaluate the in vitro effect of the exposure to purple corn extract (chicha morada) on human enamel color, during and after the treatment of teeth whitening with 35 % hydrogen peroxide. Forty-eight human teeth were used, divided into groups according to the drink to which it was exposed: Peruvian purple corn extract (MM), green tea (T) and distilled water (A); half of the specimens exposed to each drink were subjected to tooth whitening with 35 % hydrogen peroxide during the first days of exposure to pigmentation, resulting in the following groups: Group A: Without bleaching + purple corn, Group B: Without whitening + green tea, Group C: No whitening + distilled water, Group D: With whitening + purple corn, Group E: With whitening + green tea, Group F: With whitening + distilled water. The color changes were measured with a digital spectrophotometer (VITA Easyshade Advance 4.0, VITA, Germany) before bleaching, during whitening, after whitening and at the end of 36 days of exposure to pigments. According to the ∆E, the purple corn extract differs significantly with the distilled water (p <0.05). Regarding the degree of luminosity, the purple corn extract with whitening presented the lowest luminosity values (p <0.05). As for the chroma, there were no differences between the groups (p> 0.05). Exposure to purple corn extract pigments the teeth, during whitening the purple corn extract does not affect the treatment, but if the exposure continues after tooth whitening, the color of the teeth will be affected.

Furcal-perforation repair with mineral trioxide aggregate: Two years follow-up.

Furcal perforations are significant iatrogenic complications of endodontic treatment and could lead to endodontic failure. Mineral trioxide aggregate (MTA) has been regarded as an ideal material for perforation repair, retrograde filling, pulp capping, and apexification. This case report describes a furcal perforation in a maxillary first molar, which was repaired using MTA. The tooth was endodontically treated and coronally restored with resin composite. After 2 years, the absence of periradicular radiolucent lesions, pain, and swelling along with functional tooth stability indicated a successful outcome of sealing the perforation using MTA.

Blanqueamiento interno: Reporte de caso / Non-vital bleaching: Case report

La discromia de un diente es una alteración que varía en etiología, localización y severidad. Esta puede estar relacionada a causas extrínsecas, intrínsecas o una combinación de ambos. Una manera de tratar estas piezas no vitales, es el blanqueamiento interno, el cual se presenta como una alternativa conservadora frente a otros procedimientos como restauraciones con resina, carillas o coronas cerámicas, ya que preserva al máximo la estructura dentaria. El objetivo de este trabajo es presentar un reporte de caso de una paciente con discromia de la pieza 21 y cómo fue tratada con blanqueamiento interno, además hacer una revisión de la literatura actual presentando la etiología de las alteraciones de color en dientes no vitales, las alternativas de tratamiento, así como los agentes disponibles para este fin. Las técnicas para realizar el blanqueamiento de una pieza no vital son: la técnica en consultorio o In-office bleaching, las técnicas ambulatorias (Walking bleach e inside/outside bleaching) y por último la técnica mixta. Asimismo existen agentes blanqueadores disponibles en diferentes concentraciones para realizar dichas técnicas, cuya efectividad será revisada en este trabajo. Existen diversos factores que afectarán la eficacia del blanqueamiento interno, como la edad del paciente, tiempo de oscurecimiento, el grado y origen de la discromia, que podrían afectar el resultado final y la longevidad del tratamiento.

Tooth discoloration varies in etiology, location and severity. It may be extrinsic, intrinsic or a combination of both. A treatment option in such cases is non-vital bleaching, which presents itself as a conservative alternative to other procedures like composite restorations, veneers or ceramic crowns, as it preserves the most of tooth structure. The aim of this paper is to report a clinical case of a patient with non vital tooth discoloration and how it was successfully treated with internal bleaching procedures; also to review the current literature discussing the etiology of discoloration in non-vital teeth, treatment options and agents available. Non-vital bleaching techniques include: In-office bleaching, walking bleach, inside/outside bleaching and finally, the combined technique. Bleaching agents are available in different concentrations for these techniques, whose effectiveness is discussed in this paper. There are several factors that could affect the effectiveness of non-vital bleaching, such as patient age, time, degree and etiology of discoloration. All of these can influence the final result and treatment longevity.

Effectiveness of nano-calcium phosphate paste on sensitivity during and after bleaching: a randomized clinical trial

The study aimed to evaluate the effectiveness of in-office bleaching and associated tooth sensitivity on application of nano-calcium phosphate paste as desensitizing agent. Bleaching was performed with 35% hydrogen peroxide gel in 40 patients who were randomly divided into placebo and nano-calcium phosphate paste groups. Bleaching efficacy (BE) was evaluated using a value-oriented Vita shade guide. Tooth sensitivity was recorded using a numeric rating scale (0–4) during bleaching and up to 48 h after each session. The primary outcome of absolute risk of tooth sensitivity was compared using the Fisher’s exact test (α = 0.05). The intensity of tooth sensitivity and the efficacy of in-office bleaching were also statistically evaluated. No significant differences in absolute risk and intensity of tooth sensitivity were detected between the groups (p = 1.0 and p = 0.53, respectively). BE was also found to be similar between the groups (p = 0.67). Although the use of a nano-calcium phosphate paste associated with fluoride and potassium nitrate did not influence the whitening outcome, but it also did not reduce bleaching-induced tooth sensitivity.