Effects of 3D Airway Geometry on the Airflow of Adults with Cleft Lip and Palate and Obstructive Sleep Apnea: A Functional Imaging Study.

Objective Individuals with cleft lip and palate (CLP) are at a high risk of developing obstructive sleep apnea (OSA). Hypothetically, the severity of OSA might be associated with the morphology of the upper airway (UAW) and the characteristics of the airflow. Thus, the present study aimed to assess and compare, in adults with CLP and skeletal class-III discrepancy, with or without OSA, simulations of airflow resistance and pressure according to the geometrical characteristics of the UAW and cephalometric parameters. Materials and Methods According to the results of type-I polysomnography tests, the sample ( n = 21) was allocated in 2 groups: 1) without OSA (N-OSA; n = 6); and 2) with OSA (OSA; n = 15). Cephalometric measurements were performed on the cone-beam computed tomography (CBCT) scans of the groups. After three-dimensional (3D) reconstructions, the volume (V) and minimal cross-sectional area (mCSA) of the UAW were generated. Computational fluid dynamics (CFD) simulations were used to assess key airflow characteristics. The results were presented at a significance level of 5%. Results The UAW pressure values and airway resistance did not differ between the groups, but there was a tendency for more negative pressures (26%) and greater resistance (19%) in the OSA group. Volume and mCSA showed a moderate negative correlation with resistance and pressure. The more inferior the hyoid bone, the more negative the pressures generated on the pharyngeal walls. Conclusion The position of the hyoid bone and the geometry of the UAW (V and mCSA) exerted effects on the airway-airflow resistance and pressure. However, key airflow characteristics did not differ among subjects with CLP, were they affected or not by OSA.

Diabetes mellitus and drug abuse during pregnancy and the risk for orofacial clefts and related abnormalities.

OBJECTIVE: to assessed the prevalence of diabetes mellitus (DM) and drug abuse in mothers of children with orofacial clefts (OFC). METHODS: 325 women who had children (0-3y) with clefts were interviewed. Data regarding type of diabetes, use of legal/illegal drugs during pregnancy, waist girth and fasting blood sugar at the first prenatal consult were collected. RESULTS: twenty seven percent of the women had DM, out of these, 89% had gestational DM, 5,5% type 1 DM and 5,5% type 2 DM. The prevalence of DM in mothers of children with OFC was 27%, it is significantly higher than the average Brazilian population which is 7.6% (p<0.01) (OR=4.5, 95%CI=3.5-5.8). Regarding drug abuse during pregnancy, 32% of the mothers used drugs and a significant positive correlation was observed between drug abuse and the occurrence of clefts and other craniofacial anomalies (p=0.028) (OR=2.87; 95%CI=1.1-7.4). CONCLUSIONS: DM and drug abuse during pregnancy increases the risk for OFC and related anomalies and early diagnosis of DM and prevention of drug abuse, especially in pregnant women, should be emphasized.

Diabetes mellitus and drug abuse during pregnancy and the risk for orofacial clefts and related abnormalities / La diabetes mellitus, el abuso de drogas durante el embarazo y el riesgo de malformaciones craneofaciales y anomalías relacionadas / Diabetes mellitus e uso de drogas durante a gravidez e o risco de fissuras orofaciais e anomalias relacionadas

Abstract Objective: to assessed the prevalence of diabetes mellitus (DM) and drug abuse in mothers of children with orofacial clefts (OFC). Methods: 325 women who had children (0-3y) with clefts were interviewed. Data regarding type of diabetes, use of legal/illegal drugs during pregnancy, waist girth and fasting blood sugar at the first prenatal consult were collected. Results: twenty seven percent of the women had DM, out of these, 89% had gestational DM, 5,5% type 1 DM and 5,5% type 2 DM. The prevalence of DM in mothers of children with OFC was 27%, it is significantly higher than the average Brazilian population which is 7.6% (p<0.01) (OR=4.5, 95%CI=3.5-5.8). Regarding drug abuse during pregnancy, 32% of the mothers used drugs and a significant positive correlation was observed between drug abuse and the occurrence of clefts and other craniofacial anomalies (p=0.028) (OR=2.87; 95%CI=1.1-7.4). Conclusions: DM and drug abuse during pregnancy increases the risk for OFC and related anomalies and early diagnosis of DM and prevention of drug abuse, especially in pregnant women, should be emphasized.

Resumen Objetivos: esta investigación estableció la prevalencia de diabetes mellitus (DM) y el abuso de drogas en madres de niños con malformaciones creaneofaciales (MCF). Métodos: 325 mujeres que tuvieron hijos (0-3 años) con malformaciones fueron entrevistadas. Se obtuvieron datos referentes a: tipo de diabetes; uso de drogas lícitas o ilícitas durante el embarazo; circunferencia de la cintura; y, glucemia en ayunas en la primera consulta prenatal. Resultados: el veintisiete por ciento de las mujeres tenían DM. Entre estas, el 89% tuvieron DM gestacional, el 5,5% DM tipo 1 y el 5,5% DM tipo 2. La prevalencia de DM en madres de hijos con MCF fue de 27%. Esto es significativamente más alto que el promedio de la población brasileña afectada por esa enfermedad, que es de 7,6% (p<0.01) (OR=4,5, 95%IC=3,5-5,8). Observando el abuso de drogas durante el embarazo, el 32% de las madres había utilizado drogas y una correlación positiva significativa fue observada entre el abuso de drogas y la ocurrencia de hendiduras y otras malformaciones craneofaciales (p=0,028) (OR=2,87; 95%IC=1,1-7,4). Conclusiones: la DM y el abuso de drogas durante el embarazo aumentan el riesgo de MCF y de anomalías relacionadas; se enfatiza la importancia del diagnóstico precoz de DM y la prevención del abuso de drogas, especialmente entre las mujeres embarazadas.

Resumo Objetivos: avaliar a prevalência de diabetes mellitus (DM) e o uso de drogas em mães de crianças com fissuras orofaciais (FOF). Método: 325 mulheres que tiveram filhos (0-3 anos) com fissuras foram entrevistadas. Os dados referentes tipo de diabetes, uso de drogas lícitas / ilícitas durante a gravidez, circunferência abdominal e glicemia em jejum na primeira consulta pré-natal foram coletados. Resultados: vinte e sete por cento das mulheres tinham DM. Destes, 89% tinham DM gestacional, 5,5% DM tipo 1 e 5,5% DM tipo 2. A prevalência de DM em mães de crianças com FOF foi de 27%, significativamente mais elevado que a média da população brasileira que é de 7,6% (p <0,01) (OR = 4,5, IC de 95% = 3,5-5,8). Com relação ao uso de drogas, 32% das mães eram usuárias drogas durante a gravidez e uma correlação positiva foi observada entre o uso de drogas e a ocorrência de FOF e anomalias relacionadas (p = 0,028) (OR = 2,87; IC95% = 1,1-7,4). Conclusões: DM e uso de drogas durante a gravidez aumentam o risco de FOF e anomalias relacionadas e o diagnóstico precoce de DM e a prevenção do uso de drogas, especialmente em mulheres grávidas, devem ser enfatizados.

Microtensile bond strength of etch-and-rinse and self-etch adhesives to artificially created carious dentin.

This article evaluates a pH-cycling model for simulation of caries-affected and caries-infected dentin (CAD and CID, respectively) surfaces, by comparing the bond strength of an etch-and-rinse and a self-etch adhesive system. For both adhesives, bonding to sound dentin (SD) showed that the microtensile bond strength (µTBS) values of SD, CAD, and CID were SD > CAD > CID (P < 0.05). Knoop microhardness number mean values followed the same trend. Adhesive systems were not able to totally penetrate into CAD and CID, forming more irregular resin-dentin interdiffusion zones and atypical resin tags than SD. The tested in vitro pH-cycling caries model allowed the evaluation of specific dentin substrate alterations in response to µTBS. The type of dentin and its histological structure played an important role in etch-and-rinse and self-etch bonding, as lower µTBS values were attained in CAD and CID.

Clinical evaluation of desensitizing treatments for cervical dentin hypersensitivity.

The aim of this study was to compare different treatments for dentin hypersensitivity in a 6-month follow-up. One hundred and one teeth exhibiting non carious cervical lesions were selected. The assessment method used to quantify sensitivity was the cold air syringe, recorded by the visual analogue scale (VAS), prior to treatment (baseline), immediately after topical treatment, after 1 week, 1, 3 and 6 months. Teeth were randomly assigned to five groups (n = 20): G1: Gluma Desensitizer (GD); G2: Seal& (SP); G3: Oxa-gel (OG); G4: Fluoride (F); G5: Low intensity laser-LILT (660 nm/3.8 J/cm(2)/15 mW). Analysis was based on the non-parametric Kruskal-Wallis test that demonstrated statistical differences immediately after the treatment (p = 0.0165). To observe the individual effects of each treatment, data was submitted to Friedman test. It was observed that GD and SP showed immediate effect after application. Reduction in the pain level throughout the six-month follow-up was also observed. In contrast, LILT presented a gradual reduction of hypersensitivity. OG and F showed effects as of the first and third month respectively. It can be concluded that, after the 6-month clinical evaluation, all therapies showed lower VAS sensitivity values compared with baseline, independently of their different modes of action.

Efeito da ciclagem térmica na microinfiltração e microtração de restaurações de resina composta / Effect of thermal cycling on microleakage and µTBS of resin-composite restorations

O objetivo deste estudo foi avaliar a microinfiltração e a resistência de união à dentina por meio do teste de microtração em restaurações classe III, usando dois sistemas adesivos - o autocondicionante Clearfil SE Bond®/ Kuraray (SE) e o sistema de condicionamento ácido total Single Bond®/3MEspe (SB) -, submetidas (C) ou não à ciclagem térmica (NC). Foram preparadas duzentas cavidades classe III em incisivos bovinos, divididas em quatro grupos: G1:SB/NC; G2:SB/C; G3:SE/NC; G4:SE/C. Após restaurados, os G1 e G3 foram imersos em solução corante e os dentes, levados à cortadora metalográfica, sendo as restaurações seccionadas no sentido V-L em fatias de 0,7 a 0,8 mm. Essas secções foram, primeiramente, avaliadas quanto à penetração de corante e, em seguida, submetidas ao teste de microtração (área adesiva: 1 mm2), confeccionando-se espécimes em forma de "hourglass". Para os G2 e G4 as amostras foram submetidas a 2000 ciclos térmicos (5-55 ºC) e, após, sofreram os mesmos procedimentos descritos para os G1 e G3. Quanto à microinfilitração, os resultados foram analisados pelo teste de Kruskal-Wallis (p < 0,05), não demonstrando diferença estatisticamente significativa entre os grupos. Os dados de microtração (MPa) foram submetidos ao teste Anova dois fatores e Tukey (p < 0,05): G1:18,80a; G2:19,78a; G3:13,29c; G4:6,23b. Independentemente da ciclagem térmica, os dois adesivos apresentaram a mesma permissibilidade de microinfiltração. O desafio térmico influenciou negativamente na força de adesão do autocondicionante SE, mas não interferiu nos valores do SB.

The aim of this study was to evaluate the microleakageand μTBS of class III composite resin restoration using two bonding systems – the self etching primer Clearfil SE Bond/Kuraray (SE) and the one-bottle Single Bond/3MEspe (SB) subjected (C) or not (NC) to thermal cycles. 200 box-type class III cavities were prepared on surfaces of bovine incisors and divided into 4 groups: G1:SB/NC; G2:SB/C; G3:SE/NC; G4:SE/C. After the restorative procedures, G1 and G3 were immersed in a dye solution and the restorations were sectioned perpendicular to the cervical margin interface into 0.7± 0.2 mm thick slabs. These sections were first evaluated according to dye penetration and then the slabs were further trimmed at the interface to produce samples with a hourglass shape (cross-sectional surfacearea of 1mm2) to μTBS test evaluation. The samples ofG2 and G4 were thermocycled (2.000 cycles, 5-55 oC) and then subjected to the same procedures described for G1 and G3. The microleakage results were analyzed by the de Kruskal-Wallis (p < 0.05) test, and no differences were observed among groups. The μTBS means were analyzed by the Anova 2 way and Tukey test:G1:18.80a; G2:19.78a; G3:13.29c; G4:6.23b. Regardless the thermal cycles, both adhesive systems present the same microleakage results. However, for SE thermal cycling had adversely affected the bond strength values,but for SB no differences were observed.

Influence of different exposure time required to stabilize hardness values of composite resin restorations.

AIM: The purpose of this study was to evaluate if Knoop hardness values (KHN) for top and bottom surfaces of resin composite materials can reach a plateau within a clinically acceptable photoactivation time. METHODS AND MATERIALS: Four light-curing units (LCUs) were evaluated in this study (n=5): QTH (Optilux501: 550 mW/cm2) and LEDs (FreeLight2: 1100 mW/cm2; UltraLume5: 900 mW/cm2; and Radii: 750 mW/cm2). Composite resin discs (4 mm x 2 mm) of Heliomolar (Ivoclar/Vivadent) and Herculite XRV (Kerr) were tested using five photoactivation times (20, 40, 60, 80, and 100 seconds). KHN were obtained for each test specimen and comparisons between LCUs, depths, and photoactivation times were analyzed using two-way analysis of variance (ANOVA) and polynomial regression analysis. RESULTS: Data for Heliomolar discs using linear regression found a relationship between the independent variables KHN and time with the Optilux501 at the top and bottom surfaces (r2=0.68/ r2=0.66). Radii presented a linear regression at the top surface (r2=0.75) and a quadratic regression at the bottom (r2=0.94). A quadratic regression was also detected for UltraLume5 and FreeLight2 at both top (r2=0.84/ r2=0.94) and bottom surfaces (r2=0.97/ r2=0.90), respectively, reaching a plateau at 80 seconds in all cases. For Herculite XRV, a quadratic regression was observed for all LCUs at the top and bottom surfaces and 80 seconds irradiation time was needed to reach a plateau in KHN. CONCLUSION: There is a specific, but not clinically acceptable, photoactivation time that KHN at both top and bottom surfaces can reach a plateau and is dependent on LCUs and the resin-composite tested. CLINICAL SIGNIFICANCE: The LCUs and the resin-composite formulation affected the exposure time required to stabilize hardness values. The overall performance of LED LCUs was better than the QTH LCU regardless of the material evaluated.

Clinical evaluation of desensitizing treatments for cervical dentin hypersensitivity

The aim of this study was to compare different treatments for dentin hypersensitivity in a 6-month follow-up. One hundred and one teeth exhibiting non carious cervical lesions were selected. The assessment method used to quantify sensitivity was the cold air syringe, recorded by the visual analogue scale (VAS), prior to treatment (baseline), immediately after topical treatment, after 1 week, 1, 3 and 6 months. Teeth were randomly assigned to five groups (n = 20): G1: Gluma Desensitizer (GD); G2: Seal&Protect (SP); G3: Oxa-gel (OG); G4: Fluoride (F); G5: Low intensity laser-LILT (660 nm/3.8 J/cm²/15 mW). Analysis was based on the non-parametric Kruskal-Wallis test that demonstrated statistical differences immediately after the treatment (p = 0.0165). To observe the individual effects of each treatment, data was submitted to Friedman test. It was observed that GD and SP showed immediate effect after application. Reduction in the pain level throughout the six-month follow-up was also observed. In contrast, LILT presented a gradual reduction of hypersensitivity. OG and F showed effects as of the first and third month respectively. It can be concluded that, after the 6-month clinical evaluation, all therapies showed lower VAS sensitivity values compared with baseline, independently of their different modes of action.

Variability of shear and microtensile bond strength tests to enamel and dentin / Variabilidade de testes de cisalhamento e microtração ao esmalte e à dentina

Purpose: This study aimed to provide guidelines about the coefficient of variation (CV) of shear (SBS) and microtensile (µTBS) bond strength to enamel and dentin. Methods: A search of the English language peer-reviewed literature was conducted using the PubMed database from 2000 to 2009. Only bond strength studies (SBS and µTBS) that have tested both enamel and dentin substrates were selected. The following information was gathered from the 103 papers selected: groups mean and standard deviation (SD), repetition number, and type of statistical analysis. The CV of each study was calculated by using its mean and SD values, the normality of shear and microtensile CV was analyzed using Shapiro-Wilk test, and a CV classification was established for each variable. Results: According to the CV classification proposed, values below 10.3% and 11.3% could be considered low for shear bond strength to enamel and dentin, respectively; and values below 15.4% to enamel and 16.4% to dentin could be considered low for the microtensile test. Values higher than 46.8% and 62.1% (shear bond strength to enamel and dentin) and 45.9% and 45.5% (microtensile bond strength to enamel and dentin) showed a very high variability. Conclusion: Such classification can be useful for future experiments on adhesive materials to estimate statistical power and data precision.

Objetivo: Este estudo se propôs a fornecer diretrizes sobre o coeficiente de variação (CV) de ensaios de resistência ao cisalhamento (SBS) e à microtração (µTBS) em esmalte e dentina.Metodologia: Uma busca de artigos publicados de 2000 a 2009 foi realizada na base de dados PubMed. Apenas estudos (SBS e µTBS) que testaram esmalte e dentina foram considerados elegíveis. As seguintes informações foram coletadas dos 103 artigos selecionados: média e desvio-padrão (DP) dos grupos, número de repetições e análise estatística. O CV de cada estudo foi calculado utilizando-se média e DP, a normalidade dos CV de cada teste foi analisada pelo teste de Shapiro-Wilk e classificações para os CV foram estabelecidas. Resultados: De acordo com a classificação proposta, valores menores que 10,3% e 11,3% são baixos para estudos de cisalhamento ao esmalte e dentina, respectivamente. Para estudos de microtração, baixa variabilidade é obtida com CV menores que 15,4% (esmalte) e 16,4% (dentina). Experimentos com CV maiores que 46,8% e 62,1% (cisalhamento no esmalte e dentina) e 45,9% e 45,5% (microtração no esmalte e na dentina) apresentam variabilidade muito alta. Conclusão: Esta classificação pode ser útil para futuros experimentos em Odontologia adesiva para estimar o poder estatístico dos testes e a precisão dos dados.

In vitro microTBS of one-bottle adhesive systems: sound versus artificially-created caries-affected dentin.

This in vitro study aimed to evaluate a pH-cycling model for simulation of caries-affected dentin (CAD) surfaces, by comparing the bond strength of etch-and-rinse adhesive systems on sound and artificially-created CAD. Dentin substrates with different mineral contents and morphological patterns were created by submitting buccal bovine dentin to the following treatments: (1) immersion in artificial saliva during the experimental period (sound dentin, SD), or (2) induction to a CAD condition by means of a dynamic pH-cycling model (8 cycles, demineralization for 3 h followed by mineralization for 45 h). The bond strength of Excite or Prime and Bond NT adhesive systems was assessed using the microtensile bond strength (microTBS) test. Dentin microhardness was determined by cross-sectional Knoop evaluations. Resin-dentin morphology after the treatments was examined by scanning electron microscopy. SD produced significantly higher microTBS than CAD for both adhesives evaluated, without differences between materials. CAD exhibited lower microhardness than SD. Morphological analysis showed marked distinctions between SD and CAD bonded interfaces. Under the conditions of this study, differences in morphological pattern and dentin mineral content may help to explain resin-dentin bond strengths. The proposed pH-cycling model may be a suitable method to simulate CAD surfaces for bonding evaluations.

Effect of light curing units on marginal adaptation and hardness of Class II composite resin restorations.

AIMS: The aim of this study was to test the influence of different curing protocols on dentin marginal adaptation and the hardness of two composites. METHODS AND MATERIALS: Three light-curing-units (LCUs): Quartz-Tungsten-Halogen (QTH: 541 mW/cm2), Argon-Ion-Laser (AL: 277 mW/cm2), and Plasma-Arc-Curing (PAC: 1818 mW/cm2) and two composites FiltekZ250 (F) and Tetric Ceram HB (TC) were tested. Sixty standardized "vertical-slot-Class II-cavities" were prepared at the mesial surface of bovine incisors and divided into six groups (n=10). Composites were placed using the Single Bond adhesive system and cured in 2 mm increments according to the manufacturers' instructions. After polishing, epoxy replicas were processed for scanning electron microscopy (SEM) marginal adaptation analysis at 500x magnification. The specimens were then sectioned transversally to the dental long axis, embedded in polyester resin, then polished and submitted to the Knoop hardness test at gingival and occlusal portions of the restoration. Data were analyzed using two-way analysis of variance (ANOVA) and Tukey's test (p=0.05). RESULTS: The gap margins ranged between 4.3 to 5.8 microm, and no statistically significant differences were revealed in marginal adaptation for LCUs or for composites (p>0.05). Location influenced hardness (p=0.01). The occlusal portion presented significantly higher KHN than the gingival portion for all composite-LCU combinations. Regardless of the LCU used, TC produced statistically significant lower hardness values (ranging between 82.8 to 110.7 KHN) than F (ranging between 105.9 to 117.3 KHN). CONCLUSIONS: Hardness and gap formation were not dependent on the LCUs tested in this study. Different resin composite was found to be a significant factor with regards to hardness but not gap formation.

Effect of photoactivation systems and resin composites on the microleakage of esthetic restorations.

AIM: The aim of this study was to evaluate the influence of four photoactivation systems [quartz tungsten halogen (QTH), light-emitting diode (LED), argon ion laser (AL), and plasma arc curing PAC)] on cementum/dentin and enamel microleakage of Class II restorations using a microhybrid [Z250-3M ESPE] and two packable composites [(SureFil-Dentsply and Tetric Ceram HB-Ivoclair/Vivadent]. METHODS AND MATERIALS: Three hundred sixty "vertical-slot Class II cavities" were prepared at the mesial surface of bovine incisors using a 245 carbide bur in a highspeed handpiece. Specimens were divided into twelve groups (composite-photoactivation systems). Half of the specimens had the gingival margin placed in enamel (n=15) and the other half in cementum/dentin (n=15). Composites were inserted and cured in 2 mm increments according to manufacturers' recommended exposure times. After polishing, the samples were immersed in 2% methylene blue solution, sectioned, and evaluated at the gingival margins. Data were submitted to statistical analysis using the Kruskal-Wallis and Mann-Whitney tests. RESULTS: No significant differences were found among the photoactivation systems and among resin composites (p>0.05). Microleakage was not significantly affected by location (enamel vs. cementum/dentin, p>0.05). These findings suggested neither the photoactivation systems nor the resin composite types might have an effect on the microleakage at gingival margins Class II cavities.

2-year Clinical evaluation of sodium hypochlorite treatment in the restoration of non-carious cervical lesions: a pilot study.

This pilot study evaluated the effect of removing acid-etch-exposed dentin collagen on the clinical performance of composite restorations of noncarious cervical lesions placed using 2 different adhesive systems. Fifty-six restorations were placed in 14 subjects, each subject receiving at least 4 restorations. No cavity preparation or mechanical retention form was used. The variables tested were: 1) dentin treatment prior to application of the adhesive (acid-etch only vs acid-etch and collagen removal) and 2) type of adhesive (acetone- vs ethanol-based). For the acid-etch only groups, enamel and dentin were etched with 37% phosphoric acid for 15 seconds, rinsed and blot dried. Prime & Bond 2.1 (Dentsply Caulk) or Single Bond (3M ESPE) was applied and light-cured according to the manufacturer's instructions. For the acid-etch and collagen removal groups, the enamel and dentin were etched and rinsed in the same manner and a 10% sodium hypochlorite (NaOCl) solution was applied for 60 seconds and rinsed before adhesive application. Filtek Z-250 (3M ESPE) was applied to all specimens and light-cured according to the manufacturer's instructions, and the restorations were finished and polished immediately. The restorations were evaluated for pre- and post-operative sensitivity, retention, marginal staining and secondary caries at baseline, 12 and 24 months after placement, using modified USPHS criteria. Data were analyzed using the Kruskal-Wallis and Wilcoxon statistical tests (p=0.05). At 24 months, the retention rates for Prime & Bond 2.1 with and without NaOCl pretreatment were 80% and 63%, respectively. The corresponding retention rates for Single Bond were 70% and 90%. Marginal staining was minimal. Statistical analyses revealed no significant differences at any time interval between groups for retention or marginal staining. No post-operative sensitivity or secondary caries was detected during the study.

Associação do clareamento de consultório ao caseiro: rápida mudança estética / Association of in-office and at-home bleaching: quick esthetic change

O clareamento dental oferece ao cirurgião-dentista uma forma conservativa, simples e econômica para obter estética através da mudança de cor nos dentes. As técnicas disponíveis atualmente incluem o clareamento realizado em consultório, o clareamento caseiro e a associação de ambas. Este trabalho descreve casos clínicos realizados com a associação destas técnicas e empregando diferentes concentrações de agentes clareadores para obter resultados rápidos e satisfatórios.

Dental bleaching offers a conservative, simplified and economical approach to change the color of teeth. Current bleaching techniques include a dentist-prescribed in-office technique, an at-home applied technique or a combination of both. This paper describes clinical cases performed with the association of these techniques with different bleaching agents to obtain faster and satisfactory and results.

Influence of thermal and mechanical load cycling on microtensile bond strengths of total and self-etching adhesive systems.

This study evaluated the influence of different thermal (TC) and mechanical (MC) cycling protocols on microtensile bond strength (muTBS) to cervical dentin margins of Class II restorations using two total-etch (TE) adhesives and one self-etching (SE) primer. Class II slot cavities were prepared on the mesial surfaces of 168 bovine incisors and were divided into three groups according to the bonding system used: Single Bond, OptiBond Solo Plus and Clearfil SE Bond. All cavities were restored with Filtek Z250 composite. Following restorative procedures, the restored teeth were allocated to seven subgroups (n = 8) according to the thermal/mechanical protocol performed: G1-control (no cycling), G2-100,000 MC, G3-200,000 MC, G4-500,000 MC, G5-100,000 MC+1,000 TC, G6-200,000 MC+1,000 TC, G7-500,000 MC+1,000 TC. TC was performed using 5 +/- 2 degrees C and 55 +/- 2 degrees C baths, with a dwell time of 60 seconds in each bath. MC was achieved with an axial force of 80 N at 2 cycles/second. The restorations were sectioned perpendicular to the cervical bonded interface into two 0.8-1-mm thick slabs. The slabs were trimmed at the interface to obtain a cross-sectional surface area of 0.8-1 mm2. All specimens were then subjected to muTBS (v = 0.5 mm/minute). Fracture mode analysis was performed using SEM. Bond strength mean values (MPa) were analyzed with ANOVA 3-way and Tukey's test (alpha = 5%). Dunnett's test was used to compare tested groups against Control groups of each adhesive system (alpha = 56%). SE primer presented lower mean bond strength values when compared to TE adhesives (p = 0.05). In addition, specimens restored with the SE primer did not resist to the 200,000 and 500,000 MC associated with TC. The application of 100,000 MC did not present a significant decrease in bond strength when compared to the control. Mixed failures were predominant for all groups. The higher the amount of thermal/mechanical cycles, the greater the number of mixed failures and the lower the percentage of adhesive failures.

Microtensile bond strengths of composite to dentin treated with desensitizer products.

PURPOSE: This study was designed to analyze the influence of desensitizing procedures on dentin bond strength. MATERIALS AND METHODS: Forty bovine incisors were used, divided into four groups (n = 10): G1: control; G2: Gluma Desensitizer (Heraeus Kulzer); G3: Oxa-Gel (Art-Dent); G4: low-intensity laser (MMOptics). The buccal surface was wet ground flat with 180-, 400- and 600-grit silicon carbide abrasive paper to expose midcoronal dentin and create a uniform surface. After the application of the desensitizing agents to the exposed dentin, the specimens were etched with 35% phosphoric acid for 30 s, and an adhesive (Single Bond) was applied and light cured. A 4-mm high crown of composite resin (Filtek Z250) was then built up. Specimens were trimmed to an hourglass shape with cross sections of 1 mm2. Each specimen was individually fractured by a microtensile testing machine at a crosshead speed of 0.5 mm/min. The data, recorded in MPa, were analyzed with one-way ANOVA and the Duncan test (p = 0.05). RESULTS: Specimens treated with dentin desensitizers (except Gluma) yielded significantly lower mean bond strengths than nontreated control specimens. The mean values in MPa (+/- SD) were: G1: 13.4 (6.2); G2: 13.2 (4.8); G3: 7.15 (4.3); G4: 7.21 (4.6). CONCLUSIONS: Among the desensitizing agents studied, only Gluma Desensitizer did not detrimentally influence the bond strength values. It is a useful material for dentin desensitization.

The effect of light-curing source and mode on microtensile bond strength to bovine dentin.

PURPOSE: The purpose of this study was to evaluate the effects of different light-curing techniques on the microtensile bond strength of hybrid and packable resin composite to dentin. The null hypotheses were that different light-curing techniques do not affect the adhesion of resin composites to tooth structure and that different resin composites do not have a similar bond to dentin. MATERIALS AND METHODS: One hundred four box-shaped buccal preparations were made and dentin/enamel adhesive was applied according to the manufacturer's instructions (Single Bond 3M ESPE). A hybrid resin composite (Filtek Z250, A2, 3M ESPE) or a packable resin composite (Solitaire 2, A2, Heraeus Kulzer) were inserted in bulk and polymerized using one of these techniques (n = 13): (a) Soft-start (SS) using a halogen lamp (QTH); (b) LED low intensity; (c) Plasma arc (PAC) curing for 6 s for packable resin composite and 3 s for the hybrid resin composite; (d) Conventional (C) QTH curing for 40 s. Afterwards, specimens were thermocycled 1,000 times between 5 degrees C and 55 degrees C in tap water, and were sectioned into beams with a rectangular cross-sectional area of approximately 1 mm2. Microtensile bond strength testing was performed using a universal testing machine at a crosshead speed of 0.5 mm/min. RESULTS: Bond strength means +/- (SD) in MPa were: Filtek Z250: SSQTH = 17.9 (5.4); LED = 17.9 (6.4); PAC = 16.8 (6.8); CQTH = 16.1 (4.6). Solitaire 2: SSQTH = 12.4 (6.4); LED = 15.5 (4.3); PAC = 16.2 (4.4); CQTH = 13.8 (5.7). The data were structured in a split-plot design and analyzed by a two-way ANOVA and Tukey's tests (alpha = 0.05). CONCLUSION: The light-curing method did not significantly affect bond strengths. However, the bond strengths of the packable resin composite were significantly lower than those of the hybrid resin composite for all polymerization techniques, suggesting that the restorative material itself might be a more critical factor in adhesion than the curing method.

Influence of different tests used to measure the bond strength to dentin of two adhesive systems.

PURPOSE: To investigate the behavior of two bonding systems: self-etching primer Clearfil Liner Bond 2V (CLB) and total-etch Single Bond (SB) when submitted to two bond strength tests: shear bond strength (SBS) and microtensile (MTBS). METHODS: Flat dentin surfaces were obtained at the facial surface of extracted bovine incisors. muTBS started with adhesive application and incremental resin composite insertion. Samples were then sliced into 1 mm slabs parallel to the long axis of the tooth. Half of the specimens from each group were trimmed in order to obtain dumbbell-shaped (D) specimens with a cross-sectional area of 1 mm2, and in the other half of the group, the slabs were cut into beams (B) with a cross section of 1 mm2 area. Specimens were individually fractured on a microtensile apparatus. For SBS, crown segments were embedded in polyester resin and a flat dentin surface was exposed for bonding. After adhesive and restorative procedures were accomplished, the specimens were kept in water for 24 hours prior to bond testing. The tests were performed in a universal testing machine. MPa values were analyzed by Tukey's test (P < 0.05), two-way ANOVA (muTBS) and Student's t-test (SBS). RESULTS: Mean values (SD) on muTBS were: SB/B: 42.6 (15.1), SB/D: 35.4 (6.8), CLB/B: 14.3 (10.3) and CLB/D: 27.0 (7.9). SBS values (SD) were: SB: 17.3 (5.6) and CLB 15.9 (7.2). Beam specimens bonded with CLB presented the lowest results. SBS did not show statistical differences between groups. The results showed that the shear bond test seemed to lack the sensitivity that is required to detect subtle differences between bonding agents or procedures.

Effect of whitening dentifrices on the superficial roughness of esthetic restorative materials.

PURPOSE: The purpose of this study was to investigate the surface roughness (Ra) of different esthetic restorative materials following simulated toothbrushing using different whitening dentifrices. MATERIALS AND METHODS: Cylinders of Esthet-X (Dentsply Caulk, Milford, DE, USA), Durafil VS (Heraeus Kulzer, Wehrheim, Germany), and Vitremer (3M ESPE, St. Paul, MN, USA) were made using molds (4 mm in diameter for 2 mm in height). The superficial roughness was evaluated using a profilometer (Ra) with a cutoff length of 0.25 mm and a speed of 0.1 mm/s. The specimens (N=13) were submitted to 7,500 brushing cycles using five different toothpastes: (1) Crest Regular (control; Procter & Gamble): silica abrasive (C); (2) Crest Extra Whitening (Procter & Gamble, Cincinnati, OH, USA): bicarbonate+calcium pyrophosphate (CE); (3) Dental Care A & H (Arm & Hammer, Camilla, GA, USA): bicarbonate (DC); (4) Rembrandt Plus Whitening (Oral B Laboratories, Belmont, CA, USA): carbamide peroxide+alumina/silica (RP); and (5) experimental: hydrogen peroxide+calcium carbonate (EX). RESULTS: The data were analyzed by analysis of variance and Tukey's test (alpha=.05) for each restorative material, and the results [difference between final and initial roughness: Ra(F)-Ra(I) in microm] were as follows: Esthet-X: EX=0.15+0.07a; RP=0.29+0.16a; CE=0.96+0.33b; C=1.03+0.29b; DC=1.48+0.37b; Durafil VS: RP=0.09+0.07a; EX=0.55+0.23abc; C=0.96+0.26bc; CE=1.03+0.33cd; DC=1.09+0.37d; and Vitremer: EX=0.10+0.08a; RP=0.26+0.19a; CE=0.94+0.27b; DC=1.13+0.46bc; C=1.50+0.32c (different letters mean differences among groups). CONCLUSION: It was verified that the dentifrices containing carbamide or hydrogen peroxide along with alumina+silica and calcium carbonate, respectively (groups 4 and 5), produced minor changes in Ra when compared with the control group and with those dentifrices containing bicarbonate (groups 2 and 3). CLINICAL significance The results of this study indicate that whitening dentifrices evaluated containing silica or calcium carbonate were less abrasive when used on the resin-based esthetic restorative materials than those that contain sodium bicarbonate.

Avaliação da resistencia de uniao de diferentes sistemas adesivos em dentina / Shear bond strengths evaluation of different adhesive systems to dentin

O objetivo deste estudo foi comparar a resistência de união em dentina de quatro sistemas adesivos de frasco único e dois autocondicionantes. Noventa fragmentos obtidos da porção coronária de dentes bovinos foram incluídos em resina de poliestireno e desgastados com lixas abrasivas até se obter uma superfície plana em dentina. Em seguida, os espécimes foram divididos aleatoriamente em seis grupos (n=15), de acordo com o sistema adesivo: [SB]Single Bond; [PB]Prime & Bond NT; [EX]Excite; [OCB]One Coat Bond; [CLF]Clearfil SE Bond e [OUB]One-Up Bond F. Sobre cada superfície dentinária foi aplicado o sistema adesivo e confeccionado um cilindro de resina composta Z250, utilizando-se uma matriz de teflon bipartida. Após 7 dias, o teste de cisalhamento foi realizado em uma máquina de ensaio universal (EMIC) com velocidade de O,5mm/min. Os dados obtidos em MPa foram submetidos à análise estatística (ANOV A e Tukey, p