Single Nucleotide Polymorphisms and Dental Fluorosis: A Systematic Review.

Genetic factors contribute to susceptibility and resistance to fluoride exposure. The aim of this systematic review was to identify alleles/genotypes of single nucleotide polymorphisms (SNPs) associated with dental fluorosis (DF) and to identify them as protective or risk factors. PubMed, ScienceDirect, Cochrane Library, Scopus and Web of Science were searched for articles; the last search was performed in August 2022. Human studies that analyzed the relationship between SNPs and DF published in English were included; systematic reviews and meta-analyses were excluded. Methodological quality was graded using the Joanna Briggs Institute checklist and risk of bias was assessed using the Cochrane Collaboration's tool. Eighteen articles were included, 44% of which showed high methodological quality and data from 5,625 participants aged 6 to 75 years were analyzed. The SNPs COL1A2, ESR2, DLX1, DLX2, AMBN, TUFT1, TFIP11, miRNA17, and SOD2 were considered risk factors, and ESR1, MMP20, and ENAM were considered protective factors. In conclusion, there are alleles and genotypes of different single nucleotide polymorphisms involved in increasing or decreasing the risk of developing dental fluorosis.

Nano-structured hydroxyapatite and titanium dioxide enriching PENTA /UDMA adhesive as aesthetic coating for tooth enamel.

OBJECTIVES: The aim of this study was to investigate the effect of the nanostructured hydroxyapatite (NHAp) and titanium dioxide nanoparticles (NTiO2) on dispersion in an adhesive containing monomers of Dipenta erythritol penta-acrylate monophosphate (PENTA) and Urethane dimethacrylate (UDMA), as well as evaluating the structural, optical and mechanical behavior of the composite material for dental aesthetic application. METHODS: The NHAp powders were synthesized through the wet chemical methods of hydrothermal and ultrasound-assisted precipitation. The microstructure, morphology and composition analysis of the powder of NHAp and NTiO2 were performed by scanning and transmission electron microscopy. The optical microscopic identification of the different colors was obtained due to varying the amounts of NHAp and NTiO2 in the adhesive. On the other hand, the diffuse reflectance spectra of the coatings were evaluated every 2nm with the wavelength from 400 to 800nm for combined specular and diffuse reflectance. The nanomechanical properties of the aesthetic coating such as (H), elastic modulus (E) and nanoscratching were evaluated by nanoindentation. The roughness of the composite coatings were evaluated by AFM. RESULTS: From different powders combinations, NHAP 75%Wt-NTiO2 %25Wt, at (10Wt %) into a dental adhesive, the resulting mixture manifested the optimum aesthetic white appearance. The scanning and transmission electron microscopy images confirmed that the HAp nanorods and TiO2 nanoparticles sized were 55nm and 20nm respectively prepared by the high-energy ball mixed process. The values of nanomechanical properties of the optimum aesthetic coating were hardness, H=3.2±0.3GPa, elastic modulus, E=78±3GPa, Yield point, Y=107MPa±2 and scratching, maximum wear track deformation 3.7±0.12 µm2. The percentage of reflectance to optimum aesthetic white appearance was of 46.83% at 423nm of wavelength. CONCLUSIONS: The nanocomposite PENTA/UDMA with mixtures of Nanohydroxyapatite and titanium dioxide may be considerate as a mechanical toughened, also an option to modify shade qualities for dental aesthetic applications.

Effectiveness of a microabrasion technique using 16% HCL with manual application on fluorotic teeth: A series of studies.

BACKGROUND: Dental fluorosis is caused by excessive fluoride ingestion during tooth formation. As a consequence, there is a higher porosity on the enamel surface, which causes an opaque look. AIM: The aim of this study was to identify a dental intervention to improve the smile in patients with tooth fluorosis. Additional aims were to relate the stain size on fluorotic teeth with the effectiveness of stain removal, enamel loss and procedure time using a manual microabrasion technique with 16% hydrochloric acid (HCL). METHODS: An experimental study was carried out on 84 fluorotic teeth in 57 adolescent patients, 33 females and 24 males, with moderate to severe fluorosis. The means, standard deviations and percentages were analyzed using nonparametric statistics and ArchiCAD 15 software was used for the variables including stain size and effectiveness of stain removal. RESULTS: The average enamel loss was 234 µm and was significantly related to the procedure time categorized as 1-4 min and 4.01-6 min, resulting in a P > 0.000. The microabrasion technique using 16% HCL was effective in 90.6% of patients and was applied manually on superficial stains in moderate and severe fluorosis. Procedure time was less than 6 min and enamel loss was within the acceptable range. CONCLUSION: Microabrasion is a first-line treatment; however, the clinician should measure the average enamel loss to ensure that it is within the approximate range of 250 µm in order to avoid restorative treatment.

Impact of Dental Fluorosis, Socioeconomic Status and Self-Perception in Adolescents Exposed to a High Level of Fluoride in Water.

Objective: To identify adolescents' self-perception of dental fluorosis from two areas with different socioeconomic levels. Methods: A cross-sectional, descriptive study was conducted with 15-year-old youths by applying a questionnaire designed and validated to assess self-perceptions of dental fluorosis in two areas with different socioeconomic statuses (SESs). Fluorosis was clinically evaluated by applying the Thylstrup and Fejerkov (TF) index on the upper front teeth. Results: A total of 308 adolescents were included in the study. The medium-SES population, which was exposed to 2.5 ppm of fluoride in water, and the low-SES population, which was exposed to 5.1 ppm, presented the following levels of dental fluorosis: TF 2-3 (50%), TF 4-5 (45.6%) and TF 6-7 (4.4%) for medium SES and TF 2-3 (12.3%), TF 4-5 (67.1%) and TF 67 (20.6%) for low SES. A significant association was found between self-perception and dental fluorosis in those with medium and low SESs (p < 0.05). The multiple regression model found differences between TF levels and self-perception, with a 6-7 TF level for concerns about color (OR = 1.6), smile (OR = 1.2) and appearance (OR = 3.36). Conclusions: Self-perceptions of dental fluorosis affect adolescents such that adolescents with a medium SES have more negative perceptions than those with a low SES. Such perceptions increase as the TF index increases.

Aspectos descriptivos del odontoma: revisión de la literatura / Descriptive aspects of odontoma: literature review

Resumen: Los odontomas corresponden a los tumores odontogénicos más comunes (35-76%). Es un tumor benigno originado a partir de una alteración de células odontogénicas epiteliales y mesenquimatosas diferenciadas con capacidad de formar esmalte, dentina y cemento. Se clasifican en compuestos y complejos en una relación de 2:1, siendo la diferencia entre ambos la organización del tejido dentario. La etiología es desconocida pero se ha explorado la ocasión a infecciones, anomalías hereditarias, hiperactividad odontoblástica y traumatismos. El 75% de los casos se diagnostican antes de la segunda década de vida debido a un retraso en la erupción dental permanente, ya que son asintomáticos. El tratamiento es la enucleación tratando de conservar el diente permanente, siendo las recidivas poco frecuentes.

Abstract: Odontoma is the most commonly found odontogenic tumor (3576%). Odontoma is a benign tumor originating from an alteration of differentiated mesenchymal and epithelial odontogenic cells; it has the capacity of forming enamel, dentin and cement. They are classifi ed into compound and complex, in a 2:1 relationship, the difference between both being dental tissue organization. Etiology is still unknown but relation to infections, hereditary anomalies, odontoblastic hyperactivity and trauma has been explored. Since these tumors are asymptomatic, 75% of all cases are diagnosed before the second decade of life, due to a delay in eruption of permanent teeth. Treatment of choice for these tumors is enucleation, attempting to preserve the tooth; relapse is very uncommon.

Synthesis, biocompatibility and mechanical properties of ZrO2-Al2O3 ceramics composites.

This study evaluated cell viability, microhardness and flexural strength of two ceramic composites systems (ZA and AZ), pure alumina and zirconia. There were prepared homogeneous mixtures of 78wt%Al2O3+20wt%3Y-TZP+2wt%Al2O3w (AZ) and 80wt%3YTZP+18wt%Al2O3+2wt%Al2O3w (ZA), as well as 3Y-TZP (Z), pure Al2O3 (A) and commercial monolithic 3Y-TZP (Zc). Also mouse fibroblast cells 3T3-L1 and a MTT test was carried out at 24, 48 and 72 h. The surfaces were observed with SEM and the microhardness and three-point flexural strength values were estimated. The absolute microhardness values were: A>AZ>Z>Zc>ZA. Flexural strength of Zc, Z, and ZA were around double than AZ and A. All groups showed high biocompatibility trough cell viability values at 24, 48 and 72 h. Factors like grain shape, grain size and homogeneous or heterogeneous grain distributions may play an important role in physical, mechanical and biological properties of the ceramic composites.

Prevalencia del VPH en el proceso de malignización de lesiones de vías aérodigestivas superiores / HPV prevalence on malignant lesion process of the upper aerodigestive tract

Los papilovirus o virus del papiloma son considerados el grupo más prevalente de virus causantes de tumores de cabeza y cuello asociados a la infección con virus del papiloma humano (VPH). Según revisiones sistemáticas en México y Colombia, la prevalencia de VPH en el proceso de malignización de lesiones de vías aerodigestivas superiores (VADS) se presenta con una incidencia en orofarìnge de 35,6 por ciento, en cavidad oral 23,5 por ciento y en laringe 24,0 por ciento. En ésta revisión también destacan los genotipos de VPH de bajo riesgo (VPH 31, 45, 6 y 11), los cuales inducen la aparición de algunas lesiones precancerosas. La falta de un diagnostico oportuno del VPH y de las lesiones que deriven de este virus, puede complicar el tratamiento del mismo. En cuanto a los métodos de su diagnóstico, se demuestra la efectividad del método PCR-RFLP como el punto de partida del monitoreo de la infección y su progresión a cáncer. Estos métodos pueden permitir comprender la virulencia del mismo y contribuir a la disminución de las tasas de incidencia a causa de las imprecisiones de diagnostico clínico por metodologías convencionales ya que dificultan la detección precoz del cáncer de las vías aerodigestivas superiores.

Papilovirus or papillomaviruses are considered the most prevalent group of viruses that cause tumors of head and neck associated with infection with human papilloma virus (HPV). According to systematic reviews in Mexico and Colombia, the prevalence of HPV in the process of malignant lesions of the upper aerodigestive tract, can be shown with a clinical prevalence of 35,6 percent in oropharynx, 23.5 percent in oral cavity and 24.0 percent in larynx. This review highlights the genotypes of low-risk HPV (HPV 31, 45, 6 and 11), which induce the appearance of precancerous lesions. It demonstrates the effectiveness of PCR-RFLP method as a starting point for the monitoring of infection and progression to cancer this method can facilitate understanding of its virulence activity and contribute to reduced incidence rates because of the inaccuracies of clinical diagnosis by conventional methods that hinder the early detection of cancer of upper aerodigestive tract.

Microdureza profunda en una resina compuesta fotopolimerizada por diferentes fuentes de luz / Microhardness at depth of a dental composite resin fotocured troughthdiferents light sources

Introducción y Objetivo: Las lámparas fotopolimerizadoras son utilizadas actualmente en la práctica odontológica para estimular el endurecimiento de diferentes materiales de reconstruccióndental a base de resina compuesta, también llamada composite dental. El objetivo fue comparar la profundidad de polimerización provocada en una resina compuesta de uso dental, por dos sistemas convencionales de fotocurado y un láser Innova 300 adaptado experimentalmente a una longitud deonda de 488nm.

Introduction and Objective: The depth of polymerization caused in a dental composite resin through the fotoactivation with two conventional light sources and Innova 300 laser light adapted experimentally to 488nm length of wave were compared. Materials and Methods: 12 compositesamples were fotocured using 3 different sources of light in 2 different thickness dimensions,according to ISO 4049:2000 regulations. After 60 days of polymerization, micro hardness analyseswere carried out.

Tratamiento para manchas por fluorosis dental por medio de micro abrasión sin instrumentos rotatorios / Treatment for dental fluorosis spots by micro abrasion without rotary instruments

El diagnóstico juega un papel importante para elegir el tratamiento en los dientes con cambios de coloración provocados por caries o tinciones dentarias, dicho tratamiento debe ser apropiado para llenar las expectativas estéticas del paciente.

Diagnosis plays a major role when choosing a treatment for Fluor-stained teeth; such treatment must be appropriate to meet the patient’s expectations.