Fluorescence-aided identification technique using a low-cost violet flashlight and rotatory instruments for dental trauma splint removal.

BACKGROUND/AIM: Removing resin composites used for bonding dental trauma splints may result in irreversible damage to the enamel. This in vitro study evaluated the influence of additional violet illumination and different bur types on damage caused to tooth enamel. MATERIALS AND METHODS: Fifteen maxillary models with four bovine incisor teeth were prepared. All models were scanned using a laboratory scanning system (s600 ARTI; Zirkonzahn). Six experimental groups (n = 10) were generated by two study factors: lighting type (three levels), (1) low-cost (5-7 US$) violet LED flashlight (LUATEK, LT 408); (2) VALO Cordless light curing unit (Ultradent) with black lens; or (3) without additional illumination; and rotatory instrument (two levels), (1) diamond bur or (2) multifluted tungsten-carbide bur. New scanning was performed after splint removal, and the generated files were superimposed on the initial scans using Cumulus software. The light emitted by both violet light sources was characterized by using integrating sphere and beam profile. A qualitative and quantitative analysis of enamel damage and two-way ANOVA followed by Tukey's post hoc was used at an α = 0.05. RESULTS: The use of low-cost violet flashlight that emitted the violet peak light at 385 nm and VALO Cordless with black lens at 396 nm resulted in significantly lower damage to the enamel surface than those in the groups without additional violet light (p < .001). An interaction between rotatory instruments and lighting was found. When no additional violet lighting was used, the diamond bur presented higher mean and maximum depth values. CONCLUSIONS: Fluorescence lighting facilitated the removal of remnant resin composite dental trauma splints, leading to less invasive treatment. The diamond bur resulted in higher enamel damage than that affected by the multifluted bur when no violet lighting was used. A low-cost violet flashlight is a useful fluorescence-aided identification technique for removing resin composite dental trauma splints.

Dimensions of Occlusoproximal Cavitated Carious Lesions as a Cut-Off Point for Restorative Decision in Primary Teeth

ABSTRACT Objective: To investigate whether the dimensions of cavitated dentin carious lesions on the occlusoproximal surfaces of primary teeth could predict the location of cement-enamel junction (CEJ). Material and Methods: Two hundred extracted primary molars were selected and digital images were obtained. The teeth were set in arch models for clinical measurement. The cervical-occlusal (CO) and buccal-lingual/palatal (BL/P) cavities' dimensions were obtained by digital (Image J) and clinical (periodontal millimeter probe) assessments. The cervical margin location was also determined. The thresholds (cut-off points) were determined by sensitivity, specificity and the areas under the receiver operating characteristics curves (Az) for the two methods. Pearson's correlation coefficient was used to investigate the correlation between clinical and digital measurements. Logistic regression analysis was performed to evaluate the association between the dimensions and cervical margin location. Results: There was a strong correlation between methods for all measurements (CO: r=0.90, VL/P: r=0.95). Cavities with BL/P distance higher than 4.5 mm and CO dimension higher than 3.5 mm had a lower chance of presenting the cervical limit above the CEJ, irrespective of the measurement method. Conclusion: CO and VL/P dimensions could be used to predict the CEJ location and, ultimately, as a clinical parameter for restorative decision-making.

Three-dimensional non-destructive visualization of teeth enamel microcracks using X-ray micro-computed tomography.

Although the topic of tooth fractures has been extensively analyzed in the dental literature, there is still insufficient information about the potential effect of enamel microcracks (EMCs) on the underlying tooth structures. For a precise examination of the extent of the damage to the tooth structure in the area of EMCs, it is necessary to carry out their volumetric [(three-dimensional (3D)] evaluation. The aim of this study was to validate an X-ray micro-computed tomography ([Formula: see text]CT) as a technique suitable for 3D non-destructive visualization and qualitative analysis of teeth EMCs of different severity. Extracted human maxillary premolars were examined using a [Formula: see text]CT instrument ZEISS Xradia 520 Versa. In order to separate crack, dentin, and enamel volumes a Deep Learning (DL) algorithm, part of the Dragonfly's segmentation toolkit, was utilized. For segmentation needs we implemented Dragonfly's pre-built UNet neural network. The scanning technique which was used made it possible to recognize and detect not only EMCs that are visible on the outer surface but also those that are buried deep inside the tooth. The 3D visualization, combined with DL assisted segmentation, enabled the evaluation of the dynamics of an EMC and precise examination of its position with respect to the dentin-enamel junction.

Enamel Surface Damage following Debonding of Ceramic Brackets: A Hospital-Based Study.

METHODS: The current study includes 80 extracted premolars of human from the patient visiting for orthodontic treatment of Coorg Institute of Dental Sciences, Karnataka, India. The brackets were debonded using four different methods. The enamel surface damage after the procedure was assessed with the Enamel Surface Index (ESI); similarly, the Adhesive Remnant Index (ARI) score was used to determine the adhesive residual deposit. Scanning electron microscopy (SEM) was used to visualize better microporosities and micromechanical retention of adhesive remnants on the enamel surface. The normality of the data was tested using the Kolmogorov-Smirnov test. Depending upon the normality test result, the one-way ANOVA test or Kruskal-Wallis test was used to test the mean ESI and mean ARI differences among different debonding methods along with the appropriate post hoc tests. The necessary ethical clearance was obtained from the Ethics Committee of the institute. RESULTS: The ultrasonic scaler (US) technique led to more significant enamel surface damage, with 13 (65%) samples in the ESI scores III and IV against the satisfactory surface in 2 (10%) samples with the ligature cutter (LC) technique (ESI-I) reflecting LC as a better technique. The ESI scores (III and IV) for debonding plier (DP) and thermal method (TM) reflected a higher value in 12 (60%) and 10 (50%) samples and caused more damage to the enamel surface as compared to the LC technique. The ARI score was highest (ARI-1 = 40%) with the LC technique, followed by the US (ARI-1 = 20%), TM (ARI-1 = 15%), and DP (ARI-1 = 5%) methods. We have observed a significant association (p value <0.05) of the ARI score among four different debonding ways in terms of each tooth's residual adhesive after the bracket removal. CONCLUSION: The result establishes the LC technique as a more acceptable one as it causes minimal harm to the debonded surface. The adhesive left on the debonded area is also minimum as compared to the other three methods tested. Therefore, it can be suggested as an ideal method.

Prevalence and Etiological Factors of Dental Trauma among 12- and 15-Year-Old Schoolchildren of Lebanon: A National Study.

BACKGROUND: Traumatic dental injuries represent nearly 5% of children and adolescents' injuries leading to serious medical and psychological issues. This current study aims to evaluate the prevalence of dental trauma and its potential association with different predisposing factors among 12-and 15-year-old schoolchildren in Lebanon. MATERIALS AND METHODS: 7902 schoolchildren, 3806 male and 4096 female aged 12 years (n = 3985) and 15 years (n = 3917), were recruited by a stratified multistaged randomized cluster sampling method from public and private schools and were clinically examined in a national cross-sectional study. WHO criteria were used to assess anterior permanent teeth; the nature of trauma, the tooth involved, the size of the incisal overjet, and the type of the lip coverage were furthermore assessed. Data regarding age, sex, and causes of TDI were recorded through a structured questionnaire. RESULTS: The prevalence of dental trauma to anterior teeth was 10.9%. Maxillary central incisors (83.7%) were commonly affected. The most common type of injury was enamel fracture (68.3%), falls being the main reason (52.5%). Increased overjet (OR = 2.32, p = 0.034), deficient lip coverage (OR = 5.73, p = 0.019), and gender (OR = 5.36, p ≤ 0.001) were significant predisposing factors for dental trauma. CONCLUSION: This research highlighted many predisposing factors for dental trauma that affect commonly the anterior teeth. Based on these results, the implementation of strategic preventive measurements targeting especially the identified risk groups remains crucial.

Síntese e caracterização de ciclotrifosfato de sódio contendo cálcio e seu efeito na prevenção da erosão do esmalte in vitro / Synthesis and characterization of calcium-containing sodium cyclotriphosphate and its effect on preventing enamel erosion in vitro

O objetivo do presente estudo foi sintetizar e caracterizar ciclotrifosfato de sódio (NaTMP) contendo cálcio, e verificar seu efeito utilizando modelo de lesões iniciais de erosão do esmalte. Os ciclotrifosfatos contendo cálcio (CaNaTMP) foram sintetizados utilizando coluna para cromatografia e adição de sobrenadante de solução contendo hidróxido de cálcio e analisados por meio de microscopia eletrônica de varredura e espectroscopia de raios-X por dispersão de energia. Para determinar o efeito sobre lesões erosivas iniciais, blocos de esmalte bovino sadios (n=96) foram selecionados por dureza de superfície inicial e divididos em 8 grupos experimentais (12 blocos/grupo): controle (água deionizada), 0,24% NaF (1100 ppm F), 0,25%, 0,5% e 1% de NaTMP e CaNaTMP nas mesmas concentrações. Os blocos de esmalte foram imersos em 4 mL das soluções experimentais durante 2 minutos, seguidos por 4 desafios erosivos (ácido cítrico, 0,75%, pH 3,5, por 1 minuto, sob agitação). A porcentagem de perda da dureza de superfície (%SH) foi calculada após cada desafio ácido. Os dados foram submetidos à análise de variância de medidas repetidas a dois critérios, seguida pelo teste de Tukey (p< 0,05). O processo de síntese levou a substituição de átomos de Na por átomos de Ca e as partículas apresentaram tamanhos homogêneos. As soluções contendo 0,25%, 0,5% e 1% CaNaTMP apresentaram menor %SH quando comparadas as suas contrapartes sem cálcio (p< 0,001), após os quatro desafios erosivos. Quando comparado a solução contendo 1100 ppm F, as soluções 0,5% e 1% CaNaTMP promoveram redução na perda de dureza (p< 0,001). Concluiu-se que soluções contendo CaNaTMP promoveram efeitos protetores superiores em comparação ao grupo 1100 ppm F sobre lesões iniciais do esmalte(AU)

The objective of the present study was to synthesize and characterize sodium cyclotriphosphate (NaTMP) containing calcium and verify its effect using an initial enamel erosion model. Cyclotriphosphate containing calcium (CaNaTMP) was synthesized using column chromatography, and addition of a solution with calcio hydroxide supernatant and analyzed by scanning electron microscopy and energydispersive X-ray spectroscopy. To determine the effect on enamel initial erosion, sound bovine enamel blocks (n=96) were selected by initial surface hardness and divided into to 8 experimental groups (12 blocks/group): control (deionized water), 0.24% NaF (1100 ppm F), 0.25%, 0.5% and 1% NaTMP and CaNaTMP at the same concentrations. The enamel blocks were immersed in 4 mL of the experimental solutions for 2 minutes followed by 4 erosive challenges (citric acid, 0.75%, pH 3.5, for 1 minute, under stirring). The percentage of surface hardness variation (%SH) was calculated after each acid challenge. Data were subjected to two-way repeated measures analysis of variance, followed by Tukey's test (p< 0.05). The synthesis process led to the replacement atoms of Na by atoms of Ca with particles having, homogeneous sizes. The solutions containing 0.25%, 0.5% and 1% CaNaTMP promoted lower %SH when compared to their counterparts without calcium (p< 0.001), after the four erosive challenges. When compared to the solution containing 1100 ppm F, the 0.5% and 1% CaNaTMP solutions were superior in reducing hardness loss (p< 0.001). It was concluded that solutions containing CaNaTMP led to superior protective effects compared to the 1100 ppm F group on initial enamel erosion(AU)

Effect of different debonding techniques on shear bond strength and enamel cracks in simulated clinical set-ups.

OBJECTIVE: The aim of this study was to evaluate the relationship between debonding forces and enamel cracks length change between different debonding techniques. METHODS: 80 extracted premolar teeth with intact buccal enamel were divided into five groups. In each group, enamel cracks were evaluated by stereomicroscope before and after debonding. All teeth were bonded with metal brackets by self-cure adhesive (3M, USA) and then debonded by bracket debonding plier, fixed on the UTM machine, through five methods based on location of plier on brackets: OGwing (occlusogingival), MDwing (mesiodistal), Oblique, OGbase (occlusogingival) and Cusp-base. RESULTS: Based on non-parametric distribution of data, there was no significant difference between groups in ARI and enamel cracks length change. The highest shear bond strength for debonding presented in OG base method (25.25 ± 8.4) and the difference was statistically significant (P-value = 0.029). There was no linear relationship between shear bond strength and cracks length change and also between ARI and cracks length change. CONCLUSION: Despite the lower cracks length change in Cusp-base method than other groups, there wasn't significant difference between debonding methods. Also the amount of debonding forces and ARI do not affect the changes of cracks length.

Lesiones dentales no cariosas: etiología y diagnóstico clínico. Revisión de literatura / Non-carious dental lesions: etiology and clinical diagnosis. Literatura reviews

Las lesiones dentales no cariosas comprenden un conjunto de procesos que se caracterizan por la pérdida o el desgaste patológico de los tejidos duros del diente, como ser el esmalte y la dentina. En la etapa inicial es difícil el diagnóstico, cuando la lesión va en aumento y si no es tratada a tiempo ni se modifican los factores de riesgo pueden llegar afectar de manera progresiva la pulpa dental. Estas lesiones han aumentado en los últimos años, debido al mayor tiempo de dientes en boca, acompañado de hábitos parafuncionales y dietas altamente acidas, a esto se le agrega el estrés que también provoca perdida de estructura dental. Por lo que no toda perdida de tejido mineralizado de los diente es provocada por una carga bacteriana. Estas lesionesno cariosas difieren en su etiología, se debe ser muy minucioso en su evaluación clínica y descripción, ya que muchas características clínicas pueden generar un diagnóstico erróneo y por ende un tratamiento no predecible, se debe tomar en consideración la existencia de combinaciones entre lesiones. Objetivo: Conocer la etiología y características clínicas propias de cada lesión, para poder realizar un diagnóstico oportuno y seguro. La revisión se realizó por medio de una búsqueda en internet en los buscadores de Hinari, Science Direct, Google académico, revisando artículos originales y revisiones bibliográficas entre los años de 2014-2019. Conclusiones: Las lesiones dentales no cariosas tienen etiologías multi factoriales, características clínicas diferenciales y puede haber una combinación de varias patologías...(AU)

The effect of enamel fractures on oral health-related quality of life in adolescents.

BACKGROUND/AIM: Enamel fractures are the most common type of traumatic dental injury (TDI) in children and adolescents. Recognizing the impact of these fractures on oral health-related quality of life (OHRQoL) could contribute to the establishment of treatment protocols. The aim of this study was to assess and quantify the impact of enamel fractures on overall OHRQoL and domain scores in adolescents. MATERIALS AND METHODS: A cross-sectional study was conducted with 775 adolescents aged 11 to 14 years in the city of Santo Ângelo in southern Brazil. Sociodemographic variables were collected from parents/caregivers using a structured questionnaire. The adolescents answered the Child Perceptions Questionnaire (CPQ11-14 ). Physical examinations were performed by an examiner who had undergone training and calibration exercises for the investigation of TDI (Andreasen criteria), dental caries (WHO criteria), and malocclusion (Dental Aesthetic Index). Data analysis involved Poisson regression with robust variance. RESULTS: The prevalence of TDI was 11.9% and enamel fractures accounted for 79.3% of all injuries. In the multivariate analysis, adolescents with enamel fractures had 29% higher CPQ11-14 scores (worse OHRQoL) than those without TDI, even after adjustment for sociodemographic and clinical variables (mean ratio = 1.29; 95% CI: 1.09-1.53; P = .003). Enamel fractures exerted a negative impact on the functional limitation, emotional well-being, and social well-being domains. CONCLUSIONS: Enamel fractures exert a negative impact on the OHRQoL of adolescents, suggesting that subjective measures should be incorporated in the evaluation of patients with this traumatic injury.

Characterization of Enamel After the Use of Oral Hygiene Auxiliaries with Whiteners / Caracterización del esmalte después del uso de auxiliares de higiene bucal con blanqueadores

ABSTRACT The purpose of this study was to evaluate the effect of the use of the combined auxiliaries of oral hygiene with whitening agents on the micro-hardness and micro-morphology of dental enamel. Materials and Methods. 40 human incisors were used and sectioned to obtain 4x4mm samples and divided into four study groups. Group 1: Electric brushing with Toothpaste (BTP); Group 2: Electric brushing with Toothpaste+mouthwash (BTP+MW); Group 3: Electric brushing with Toothpaste+whitening pen (BTP+WP); Group 4: Electric brushing with Toothpaste+mouth wash+whitening pen (BTP+MW+WP). Samples were submitted toVickers micro-hardness test and visualized using scanning electron microscopy (SEM). Results. All groups, with the exception of group 1, showed a decrease in micro- hardness values after applying the treatments (p<0.05). Likewise, when comparing the values after the treatments between the groups, significant statistical differences were found in all of comparisons except for those of groups 2 and 4. SEM images showed changes in the morphology in all the study groups with the exception of group 1. Conclusion. Significant changes such as decrease in micro-hardness as well as in the topography of the enamel surface such as elevations, craters, porosities and etching patterns were founded after the use of the combination of auxiliaries of oral hygiene with whitening agents.

RESUMEN El propósito de este estudio fue evaluar el efecto del uso de los auxiliares de higiene oral combinados con agentes blanqueadores sobre la microdureza y la micro-morfología del esmalte dental. Materiales y métodos. Se utilizaron 40 incisivos humanos y se seccionaron para obtener muestras de 4x4 mm los cuales se dividieron en cuatro grupos de estudio. Grupo 1: cepillado eléctrico con pasta de dientes (BTP); Grupo 2: cepillado eléctrico con pasta dental+enjuague bucal (BTP+MW); Grupo 3: cepillado eléctrico con pasta dental+pluma blanqueadora (BTP+WP); Grupo 4: cepillado eléctrico con pasta dental+enjuague bucal+pluma blanqueadora (BTP+MW+WP). Las muestras fueron analizadas por medio de microdurezaVickers y microscopía electronica de barrido (SEM). Resultados. Todos los grupos, con la excepción del grupo 1, mostraron una disminución en los valores de microdureza después de aplicar los tratamientos (p<0.05). Del mismo modo, al comparar los valores después de los tratamientos entre los grupos, se encontraron diferencias estadísticamente significativas en todas las comparaciones, excepto en las de los grupos 2 y 4. Las imágenes de SEM nos muestran cambios en la morfología en todos los grupos de estudio con la excepción del grupo 1 Conclusión. Cambios significativos como la disminución de la microdureza y los cambios en la topografía de la superficie del esmalte, como elevaciones, cráteres, porosidades y patrones de grabado, se encontraron después del uso de la combinación de auxiliares de la higiene oral con agentes blanqueadores.

Odontología deportiva y prevención de trauma dentoalveolar / Sports dentistry and prevention of dentoalveolar traumas

La odontología deportiva es la rama de la medicina deportiva que se ocupa de la prevención y el tratamiento de las lesiones bucodentales y las enfermedades orales asociadas al deporte y el ejercicio. Por lo que se hace necesario la intervención de profesionales de la salud bucodental para hacer evaluaciones del deportista y el deporte que practica para ver los riesgos que puede tener de desarrollar y sufrir lesiones bucodentales como traumas dentoalveolares y lesiones no cariosas. Y de este modo realizar las recomendaciones a cada paciente que practica deporte, de los elementos que deben usar como equipamiento bucodental para evitar o reducir el daño dentoalveolar (AU)

Sports dentistry is the branch of sports medicine that deals with the prevention and treatment of oral injuries and oral diseases associated with sports and exercise. Therefore it is necessary the intervention of oral health professionals to make evaluations of the athlete and the sport he practices to see the risks that may have to develop and suffer oral injuries such as dentoalveolar trauma and non-carious lesions. And in this way make the recommendations to each patient who practices sports, of the elements that should be used as oral equipment to avoid or reduce dentoalveolar damage (AU)

Comportamiento del traumatismo dentario en el sector anterior en pacientes de ocho a 18 años / Behaivior of the dental traumatism in the previous sector in patients from eight to 18 years old

Fundamento: entre todas las enfermedades que afectan el complejo bucal se encuentran los traumas dentarios que son alteraciones causadas por factores extrínsecos e intrínsecos que dificultan el funcionamiento normal del mismo. Objetivo: evaluar el comportamiento del traumatismo en el sector anterior en pacientes de ocho a 18 años de edad. Métodos: se realizó un estudio descriptivo de serie de casos en 15 pacientes atendidos en el servicio de la clínica estomatológica de Gibara Holguín, que cumplieron con los criterios de inclusión, en el período desde enero de 2015 hasta enero de 2016. Los datos se procesaron en Excel, se calcularon porcentajes. Para mayor comprensión la información se mostró en tablas. Resultados: el grupo de edad más afectado resultó el de ocho a 11 años de edad con un discreto predominio del sexo masculino. En el comportamiento del traumatismo dentario anterior según la severidad de la lesión predominó la infractura del esmalte, con nueve pacientes. Conclusiones: el diente más afectado fue el incisivo central superior al predominar la infractura del esmalte de acuerdo con la severidad de la lesión (AU)

Background: among all the illnesses affecting the buccal complex we can find the dental traumas, they are alterations caused by extrinsic and intrinsic factors that make difficult the normal functioning of it. Objective: to evaluate the behavior of the traumatism in the anterior sector in patient from eight to 18 years of age. Methods: a descriptive study of series of cases was carried out in 15 patients assisted in the service of the Gibara dentistry clinic from January of the 2015 until January of the 2016. Data was processed in Excel, and percentage was calculated. To a better understanding, the information was shown in charts. Results: the most affected age group was the one from eight to 11 years of age, with a discreet prevalence of the masculine sex. In the behavior of the dental anterior traumatism according to the severity of the lesion the in-fracture of the enamel prevailed with nine patients. Conclusions: the most affected tooth was the superior central incisive prevailing the in-fracture of the enamel according to the severity of the lesion (AU)

Prevalence of traumatic dental injury to the anterior teeth in children attending paramilitary and nonparamilitary schools in Nigeria.

Objective: The objective of this study was to determine the prevalence of traumatic dental injuries (TDIs) in the anterior teeth among children attending paramilitary and nonparamilitary schools in Benin City, Nigeria. Materials and Methods: A multistage sampling technique was used to select children aged 8-12 years with a previous history of trauma to the orofacial region. A self-administered questionnaire was then applied, and each participant was examined clinically. Data collected included demographic characteristics, etiology and place of injury, affected teeth, type of dental injury, lip competence, and overjet values. Analysis of data was done with the SPSS version 21.0 software. Pearson's Chi-squared test was used to determine the association between variables and odds ratio. Statistical significance was determined at P < 0.05. Results: A total number of 1352 children (mean age: 9.89 ± 1.4 years) were examined and 154 (11.4%) had a previous history of TDI. The prevalence among respondents in the paramilitary schools was 84 (6.2%) and those in nonparamilitary schools 70 (5.2%). Falls and play was the most common cause of TDI and was higher in children in paramilitary schools. Ellis Class I was the most prevalent type of injury in 91 (59.1%), tooth number 21 was the most traumatized, and the school environment was the most common place. Of the total number of respondents with TDI, the relationship between etiology with age, lip competence, and overjet was statistically significant (P < 0.05). Conclusion: The prevalence of TDI among the study participants was 11.4% and more in the paramilitary schools than the nonparamilitary.

RésuméObjectif: L'objectif de cette étude était de déterminer la prévalence des traumatismes dentaires traumatiques (TDI) dans les dents antérieures chez les enfants. fréquentant des écoles paramilitaires et non paramilitaires à Benin City, au Nigeria. Matériels et méthodes: Une technique d'échantillonnage en plusieurs étapes a été utilisée. utilisé pour sélectionner les enfants âgés de 8 à 12 ans ayant des antécédents de traumatisme dans la région orofaciale. Un questionnaire auto-administré a ensuite été appliqué, et chaque participant a été examiné cliniquement. Les données collectées comprenaient les caractéristiques démographiques, l'étiologie et le lieu de la blessure, dents affectées, type de lésion dentaire, compétence labiale et valeurs overjet. L'analyse des données a été réalisée avec le logiciel SPSS version 21.0. Le test du chi carré de Pearson a été utilisé pour déterminer l'association entre variables et odds ratio. La signification statistique a été déterminée à p <0,05. Résultats: Un nombre total de 1352 enfants (âge moyen: 9,89 ± 1,4 ans) ont été examinés et 154 (11,4%) avaient des antécédents de TDI. La prévalence parmi les répondants des écoles paramilitaires était de 84 (6,2%) et ceux des écoles non paramilitaires de 70 (5,2%). Des chutes et le jeu était la cause la plus fréquente de TDI et était plus élevé chez les enfants dans les écoles paramilitaires. Ellis Classe I était le type le plus répandu de blessures chez 91 personnes (59,1%), la dent numéro 21 était la plus traumatisée et le milieu scolaire le plus fréquent. Du nombre total des répondants avec TDI, la relation entre l'étiologie, l'âge, la compétence labiale et l'overjet était statistiquement significative (p <0,05). Conclusion: La prévalence du TDI chez les participants à l'étude était de 11,4% et plus dans les écoles paramilitaires que dans les écoles non paramilitaires.

Método químico simplificado de desmineralización del esmalte dental humano / Simplified chemical method of demineralization in human dental enamel

Introducción: Se requieren métodos experimentales abreviados para simular las lesiones de desmineralización temprana de forma controlada y reproducible. Objetivo: Realizar una evaluación in vitro de un método simple de desmineralización incipiente del esmalte. Métodos: Estudio experimental aleatorizado con doble diseño factorial de réplicas. Se seleccionaron 12 terceros molares de sujetos humanos saludables para su desmineralización en solución de ácido láctico racémico. Las muestras se distribuyeron aleatoriamente: Grupo 1 (G1) (n= 6) ácido láctico a pH 2,4 y Grupo 2 (G2) (n= 6) ácido láctico a pH 5,4. A continuación, cada grupo se subdividió (n = 2) para evaluar el efecto de las soluciones a tres tiempos de exposición (7, 15 y 30 días) a 37 °C. La evaluación se llevó a cabo con estereomicroscopios, equipo de radiografía digital con un software de análisis digital de imágenes y microscopía de polarización. Se formuló una integración de los índices de respuesta y se realizó un ANOVA. Resultados: Los hallazgos visuales, radiográficos e histológicos mostraron que en el G1 en los tiempos 1 a 3, la desmineralización se caracterizó por una gran pérdida de la integridad del esmalte (80 por ciento a 100 por ciento). Visualmente, el G2 a los 7 días mostró opacidad y pérdida de brillo (16 por ciento) con preservación de la estructura superficial del esmalte. Conclusiones: Se demuestra que el empleo de ácido láctico durante 7 días a pH 5,4 produce una lesión clínica, radiográfica e histológica similar a una lesión temprana del esmalte(AU)

Introduction: Abridged experimental methods are required to simulate early demineralizing lesions in a controlled and reproducible way. Objective: Perform an in vitro evaluation of a simple method of incipient enamel demineralization. Methods: Randomized experimental study with a double factorial replication design. Twelve third molars from healthy human subjects were selected for demineralization in a racemic lactic acid solution. Samples were then distributed randomly: Group 1 (G1) (n= 6) lactic acid at pH 2.4 and Group 2 (G2) (n= 6) lactic acid at pH 5.4. Each group was then subdivided (n = 2) to evaluate the effect of the solutions at three exposure times (7, 15 and 30 days) at 37°C. The evaluation used stereomicroscopes, a digital x-rays apparatus with software for the digital analysis of images, and polarization microscopy. An integration of the response indices was formulated and ANOVA was performed. Results: Visual, radiographic and histological findings showed that G1 at time 1 through 3 displayed demineralization characterized by extensive loss (80 percent to 100 percent) of enamel integrity. Visually, G2 at 7 days exhibited opacity and loss of brightness (16 percent), with preservation of the surface structure of the enamel. Conclusions: It was shown that employing lactic acid for 7 days at pH 5.4 develops a clinical, radiographic and histological injury similar to an early enamel lesion(AU)

Método químico simplificado de desmineralización del esmalte dental humano / Simplified chemical method of demineralization in human dental enamel

Introducción: Se requieren métodos experimentales abreviados para simular las lesiones de desmineralización temprana de forma controlada y reproducible. Objetivo: Realizar una evaluación in vitro de un método simple de desmineralización incipiente del esmalte. Métodos: Estudio experimental aleatorizado con doble diseño factorial de réplicas. Se seleccionaron 12 terceros molares de sujetos humanos saludables para su desmineralización en solución de ácido láctico racémico. Las muestras se distribuyeron aleatoriamente: Grupo 1 (G1) (n= 6) ácido láctico a pH 2,4 y Grupo 2 (G2) (n= 6) ácido láctico a pH 5,4. A continuación, cada grupo se subdividió (n = 2) para evaluar el efecto de las soluciones a tres tiempos de exposición (7, 15 y 30 días) a 37 °C. La evaluación se llevó a cabo con estereomicroscopios, equipo de radiografía digital con un software de análisis digital de imágenes y microscopía de polarización. Se formuló una integración de los índices de respuesta y se realizó un ANOVA. Resultados: Los hallazgos visuales, radiográficos e histológicos mostraron que en el G1 en los tiempos 1 a 3, la desmineralización se caracterizó por una gran pérdida de la integridad del esmalte (80 por ciento a 100 por ciento). Visualmente, el G2 a los 7 días mostró opacidad y pérdida de brillo (16 por ciento) con preservación de la estructura superficial del esmalte. Conclusiones: Se demuestra que el empleo de ácido láctico durante 7 días a pH 5,4 produce una lesión clínica, radiográfica e histológica similar a una lesión temprana del esmalte(AU)

Introduction: Abridged experimental methods are required to simulate early demineralizing lesions in a controlled and reproducible way. Objective: Perform an in vitro evaluation of a simple method of incipient enamel demineralization. Methods: Randomized experimental study with a double factorial replication design. Twelve third molars from healthy human subjects were selected for demineralization in a racemic lactic acid solution. Samples were then distributed randomly: Group 1 (G1) (n= 6) lactic acid at pH 2.4 and Group 2 (G2) (n= 6) lactic acid at pH 5.4. Each group was then subdivided (n = 2) to evaluate the effect of the solutions at three exposure times (7, 15 and 30 days) at 37°C. The evaluation used stereomicroscopes, a digital x-rays apparatus with software for the digital analysis of images, and polarization microscopy. An integration of the response indices was formulated and ANOVA was performed. Results: Visual, radiographic and histological findings showed that G1 at time 1 through 3 displayed demineralization characterized by extensive loss (80 percent to 100 percent) of enamel integrity. Visually, G2 at 7 days exhibited opacity and loss of brightness (16 percent), with preservation of the surface structure of the enamel. Conclusions: It was shown that employing lactic acid for 7 days at pH 5.4 develops a clinical, radiographic and histological injury similar to an early enamel lesion(AU)

Efeito anti-erosivo de soluções contendo diferentes polímeros / Anti-erosive effect of solutions containing different polymers

O desgaste erosivo tem sido reconhecido como uma condição frequente nos últimos anos, principalmente devido a mudanças nos hábitos alimentares e comportamentais das populações em geral. Considerando a natureza irreversível desta condição, o diagnóstico precoce e a adoção de medidas preventivas são muito importantes. Dentre elas, a adição de polímeros a produtos de higiene bucal associados ou não a fluoretos apresenta-se como uma alternativa promissora, já que alguns polímeros apresentam compatibilidade com as estruturas dentais e capacidade de formação de um filme protetor. Este estudo foi subdivido em três artigos que visaram, através de diferentes abordagens, investigar o efeito anti- erosivo de polímeros formadores de filme, bem como o efeito da associação destes com fluoretos. O primeiro artigo consistiu em uma revisão da literatura sobre aspectos relacionados ao potencial de utilização dos polímeros para a prevenção da erosão dental. O segundo artigo consistiu em um estudo de varredura para verificar a capacidade de redução da dissolução da hidroxiapatita promovida por soluções contendo quatro polímeros (polioxirano, hidroxipropilmetilcelulose, pectina e um copolímero do polimetacrilato) associadas ou não com fluoreto de sódio -F (225 ppm F- ) e fluoreto de sódio + cloreto de estanho (800 ppm Sn2+) - FS. A mensuração do potencial zeta da hidroxiapatita dispersa tratada com as soluções experimentais foi realizada a fim de complementar a análise. O terceiro artigo consistiu em um estudo de ciclagem erosiva/reendurecedora na presença de película adquirida que se propôs a investigar o potencial de remineralização, potencial de proteção, a perda superficial e a tensão superficial do esmalte após o tratamento com as soluções contendo o copolímero do polimetacrilato. Concluiu- se que a utilização de polímeros formadores de filme, associados ou não a fluoretos, constitui uma abordagem promissora para prevenção da erosão dental. Dentre os polímeros investigados, o copolímero do polimetacrilato é um promissor agente para ser adicionado à produtos de higiene bucal visando a prevenção dos desgastes erosivos(AU)

Erosive wear has been recognized as a frequent condition in recent years, mainly due to changes in the dietary and behavioral habits of the general population. Considering the irreversible nature of this condition, early diagnosis and the adoption of preventive measures are very important. Among them, the addition of polymers to oral care products associated or not with fluorides is a promising alternative, as some polymers have compatibility with dental structures and ability to form a protective film. This study was subdivided into three articles that aimed, through different approaches, to investigate the anti-erosive effect of film- forming polymers, as well as the effect of their association with fluorides. The first article consisted of a literature review about aspects related to the potential use of polymers to prevent dental erosion. The second article consisted of a scanning study to verify the ability to decrease the hydroxyapatite dissolution promoted by solutions containing four polymers (polyoxyrane, hydroxypropyl methylcellulose, pectin and a polymethacrylate copolymer) associated or not with sodium fluoride -F (225 ppm F- ) and sodium fluoride + tin chloride (800 ppm Sn2+ ) -FS. Measurement of the zeta potential of dispersed hydroxyapatite treated with experimental solutions was performed to complement the analysis. The third article consisted of an erosive/rehardening cycling study in the presence of acquired pellicle that aimed to investigate remineralization potential, protection potential, surface loss and surface tension of the enamel after treatment with solutions containing the polymethacrylate. It was concluded that the use of film- forming polymers, associated or not with fluorides, is a promising approach for the prevention of dental erosion. Among the polymers investigated, the polymethacrylate copolymer is a promising agent to be added to oral hygiene products to prevent erosive wear(AU)

Prevalence of and factors associated with enamel fracture and other traumas in Brazilian children 8-10 years old.

The aim of this study was to assess the prevalence and discriminate the associated factors between enamel fractures and other trauma/trauma sequelae in 8 to 10-year-old Brazilian schoolchildren. A representative sample of 1,201 children from public and private schools were enrolled in this cross-sectional study. Questionnaires about sociodemographic characteristics were answered by parents. The outcome variable (traumatic dental injury, TDI) was multi-categorized. Independent individual variables were sex, age, number of residents in household, parents/caregivers' level of education, family income, dental caries, and overjet. Type of school was considered an independent contextual variable. Multilevel analysis, bivariate, and multivariate multinomial logistic regression models were performed. The prevalence of TDI was 14.0% (2.8% with other trauma/trauma sequelae). The multilevel analysis revealed no significant difference between the type of school and TDI. The multinomial logistic regression showed that boys (OR = 2.3; 95%CI: 1.1-4.8), older children (OR = 1.8; 95%CI: 1.1-3.0) and individuals with an overjet > 3 mm (OR = 2.5; 95%CI: 1.0-6.2) were more likely to present other trauma/trauma sequelae. Enamel fracture was not significantly associated with any variables. The prevalence of TDI in 8 to 10-year-old schoolchildren was 14% but only 2.8% of other trauma/trauma sequelae. Differences regarding the associated factors of TDI involving enamel fracture or other trauma/trauma sequelae were detected, suggesting that the different TDI classification cannot be evaluated as a single category.

Factors associated with dental fractures in Brazilian individuals.

AIM: The aim of the present study was to assess the association of sex, age, group of teeth, and type of accident (exposure) with dental fractures (outcome: enamel-dentine fracture without [EDF] or with pulp exposure [EDPF] and root fracture RF]). METHODS: In total, 1046 patients were selected. Logistic binary regression was used. RESULTS: The findings showed that EDF has less change of affecting individuals ≤9 years of age than ≥40 years of age (odds ratio [OR]: 0.58, 95% confidence interval [CI]: 0.35-0.95). Violence (OR: 3.07, 95% CI: 1.77-5.31), traffic accidents (OR: 1.50, 95% CI: 1.05-2.13), and sporting accidents (OR: 1.70, 95% CI: 1.19-2.44)] were associated with EDF. Regarding EDPF, the mandibular lateral incisors had a 10 times higher chance of being injured than canines and posterior teeth (OR: 10.43, 95% CI: 1.74-62.4). Those aged ≤9 years (OR: 0.21, 95% CI: 0.07-0.58) and 10-19 years (OR: 0.38, 95% CI: 0.17-0.88) had a significantly lower chance of being affected by RF. CONCLUSION: EDF and RF are associated with individuals ≥40 years of age; violence and traffic and sporting accidents are also associated with EDF, and mandibular incisors have a greater chance of being affected by EDPF.

Molar cusp deformation evaluated by micro-CT and enamel crack formation to compare incremental and bulk-filling techniques.

OBJECTIVES: To describe a method of measuring the molar cusp deformation using micro-computed tomography (micro-CT), the propagation of enamel cracks using transillumination, and the effects of hygroscopic expansion after incremental and bulk-filling resin composite restorations. METHODS: Twenty human molars received standardized Class II mesio-occlusal-distal cavity preparations. They were restored with either a bulk-fill resin composite, X-tra fil (XTRA), or a conventional resin composite, Filtek Z100 (Z100). The resin composites were tested for post-gel shrinkage using a strain gauge method. Cusp deformation (CD) was evaluated using the images obtained using a micro-CT protocol and using a strain-gauge method. Enamel cracks were detected using transillumination. RESULTS: The post-gel shrinkage of Z100 was higher than XTRA (P < 0.001). The amount of cusp deformation produced using Z100 was higher compared to XTRA, irrespective of the measurement method used (P < 0.001). The thinner lingual cusp always had a higher CD than the buccal cusp, irrespective of the measurement method (P < 0.001). A positive correlation (r = 0.78) was found between cusp deformation measured by micro-CT or by the strain-gauge method. After hygroscopic expansion of the resin composite, the cusp displacement recovered around 85% (P < 0.001). After restoration, Z100 produced more cracks than XTRA (P = 0.012). CONCLUSIONS: Micro-CT was an effective method for evaluating the cusp deformation. Transillumination was effective for detecting enamel cracks. There were fewer negative effects of polymerization shrinkage in bulk-fill resin restorations using XTRA than for the conventional incremental filling technique using conventional composite resin Z100. CLINICAL SIGNIFICANCE: Shrinkage and cusp deformation are directly related to the formation of enamel cracks. Cusp deformation and crack propagation may increase the risk of tooth fracture.

Effects of ultrasonic instrumentation on enamel surfaces with various defects.

OBJECTIVE: The aim of this study was to analyse the enamel damage caused by ultrasonic scaling of teeth with various enamel conditions that are difficult to identify by visual inspection, such as enamel cracks, early caries and resin restorations. METHODS: In total, 120 tooth surfaces were divided into 4 experimental groups using a quantitative light-induced fluorescence-digital system: sound enamel group, enamel cracks group, early caries group and resin restoration group. A skilled dental hygienist performed ultrasonic scaling under a standardized set of conditions: a ≤ 15° angle between the scaler tip and tooth surface and 40-80 g of lateral pressure at the rate of 12 times/10 s. Following scaling, the depth of enamel damage was measured using a surface profilometer and observed using scanning electron microscopy (SEM). RESULTS: The damage depth was the greatest in the enamel cracks group (37.63 ± 34.42 µm), followed by the early caries group (26.81 ± 8.67 µm), resin restoration group (19.63 ± 6.73 µm) and the sound enamel group (17.00 ± 5.66 µm). The damage depth was significantly deeper in the enamel cracks and early caries groups than in the sound enamel group (P < .05). SEM clearly revealed enamel loss in the enamel cracks, early caries and resin restoration groups. CONCLUSIONS: The results of this study suggest that ultrasonic scaling can cause further damage to teeth with enamel cracks, early caries and resin restorations. Therefore, accurate identification of tooth conditions and calculus before the initiation of ultrasonic scaling is necessary to minimize damage.