Activation of gelatinases in permanent human teeth after different experimental radiotherapy protocols

Abstract The objective of this study was to compare the activation of gelatinases in dentin-enamel junction (DEJ) and underlying dentin of permanent teeth after experimental radiotherapy in conventional and hypofractionated modalities. Newly extracted third molars (n = 15) were divided into three experimental radiotherapy groups: control, conventional (CR), and hypofractionated (HR) (n = 5 per group). After in vitro exposure to ionizing radiation, following standardized protocols for each modality, a gelatinous substrate was incubated on the tooth slices (n = 10 per group). Activation of gelatinases was measured by in situ zymography, expressed in arbitrary fluorescence units (mm2) from three tooth regions: cervical, cuspal, and pit. Fluorescence intensity was compared among radiotherapy protocols and tooth regions in each protocol, considering a significance level of 5%. Considering all tooth regions, the fluorescence intensity of the CR group was higher than the HR and control groups, both in DEJ and underlying dentin (p <0.001). In addition, the fluorescence intensity was higher in underlying dentin when compared to DEJ in all groups (p <0.001). Considering each tooth region, a statistically significant difference between CR and HR was only observed in the pit region of underlying dentin (p <0.001). Significant and positive correlations between fluorescence intensities in DEJ and underlying dentin were also observed (p <0.001). Experimental radiotherapy influenced the activation of gelatinases, as well as exposure to the conventional protocol can trigger a higher activation of gelatinases when compared to hypofractionated, both in DEJ and underlying dentin.

Resumo O objetivo deste estudo foi comparar a ativação de gelatinases na junção dentina-esmalte (DEJ) e na dentina subjacente de dentes permanentes após a radioterapia experimental nas modalidades convencional e hipofracionada. Os terceiros molares recém-extraídos (n = 15) foram divididos em três grupos de radioterapia experimental: controle, convencional (CR) e hipofracionada (HR) (n = 5 por grupo). Após a exposição in vitro à radiação ionizante, seguindo protocolos padronizados para cada modalidade, um substrato gelatinoso foi incubado nas fatias de dente (n = 10 por grupo). A ativação das gelatinases foi medida por zimografia in situ, expressa em unidades arbitrárias de fluorescência (mm2) de três regiões do dente: cervical, cúspide e fossa. A intensidade da fluorescência foi comparada entre os protocolos de radioterapia e as regiões do dente em cada protocolo, considerando um nível de significância de 5%. Considerando todas as regiões do dente, a intensidade de fluorescência do grupo CR foi maior do que a dos grupos HR e controle, tanto no DEJ quanto na dentina subjacente (p <0,001). Além disso, a intensidade da fluorescência foi maior na dentina subjacente quando comparada à DEJ em todos os grupos (p <0,001). Considerando cada região do dente, uma diferença estatisticamente significativa entre CR e HR foi observada apenas na região da fossa da dentina subjacente (p <0,001). Também foram observadas correlações significativas e positivas entre as intensidades de fluorescência no DEJ e na dentina subjacente (p <0,001). A radioterapia experimental influenciou a ativação das gelatinases, assim como a exposição ao protocolo convencional pode desencadear uma maior ativação das gelatinases quando comparada ao hipofracionamento, tanto no DEJ quanto na dentina subjacente.

Preemptive analgesia with ibuprofen increases anesthetic efficacy in children with severe molar hypomineralization: a triple-blind randomized clinical trial

Abstract Molar incisor hypomineralization (MIH) is often accompanied by dental hypersensitivity and difficulty in achieving effective analgesia. Objective: This study evaluated the effectiveness of preemptive analgesia in children with severe MIH, post-eruptive enamel breakdown, and hypersensitivity. Methodology: Ibuprofen (10 mg/kg child weight) or placebo was administered, followed by infiltrative anesthesia and restoration with resin composite. Hypersensitivity was evaluated in five moments. The data were analyzed using the chi-square test, Fisher's exact test, and t-test. Results: Preemptive analgesia provided benefits for the treatment of severe cases of MIH, with an increase in the effectiveness of infiltrative anesthesia and improved patient comfort during the restorative procedure. Conclusion: Preemptive analgesia has shown efficacy in reducing hypersensitivity during restorative dental procedures, evidencing the significance of this study for patients with MIH and hypersensitivity.

Effects of chlorhexidine varnish on caries during orthodontic treatment: a systematic review and meta-analysis

Abstract This study aimed to perform a systematic review and meta-analysis to evaluate the effectiveness of chlorhexidine varnish on the reduction of caries incidence during fixed orthodontic treatment. The literature searches involved The Cochrane Library, Medline, Scopus, OpenSigle databases and manual searches. The search on OpenSigle did not produce any additional articles. Clinical studies conducted in patients with orthodontic fixed appliances that used professional application of chlorhexidine varnish were included. The effect-size was calculated and a meta-analysis was performed. From 182 abstracts, a total of six articles fulfilled the inclusion criteria. After reading the full articles, one was excluded because of lack of a control group. Three articles were used for continuous data analysis, and two articles were used for the dichotomous data analysis. The pooled meta-analysis with continuous data demonstrated chlorhexidine varnish effectiveness on caries reduction (p = 0.003), with a mean difference and confidence interval of −1.49 [−2.47, −0.51]. On the basis of the pooled meta-analysis of continuous data, we were able to conclude that professional application of chlorhexidine varnish is effective in caries incidence reduction during fixed orthodontic treatment.

Mucocele and Fibroma: Treatment and Clinical Features for Differential Diagnosis

Mucocele is a benign lesion occurring in the buccal mucosa as a result of the rupture of a salivary gland duct and consequent outpouring of mucin into soft tissue. It is usually caused by a local trauma, although in many cases the etiology is uncertain. Mucocele is more commonly found in children and young adults, and the most frequent site is the lower inner portion of the lips. Fibroma, on the other hand, is a benign tumor of fibrous connective tissue that can be considered a reactionary connective tissue hyperplasia in response to trauma and irritation. They usually present hard consistency, are nodular and asymptomatic, with a similar color to the mucosa, sessile base, smooth surface, located in the buccal mucosa along the line of occlusion, tongue and lip mucosa. Conventional treatment for both lesions is conservative surgical excision. Recurrence rate is low for fibroma and high for oral mucoceles. This report presents a series of cases of mucocele and fibroma treated by surgical excision or enucleation and the respective follow-up routine in the dental clinic and discusses the features to be considered in order to distinguish these lesions from each other.

Mucocele é uma lesão comum na mucosa bucal, que resulta da ruptura de um ducto de glândula salivar e consequente derramamento de mucina para o interior dos tecidos moles circunjacentes. Frequentemente este derrame resulta de trauma local, embora em muitos casos a etiologia seja indefinida. É uma lesão não infecciosa benigna, que frequentemente afeta a cavidade bucal de crianças e adultos jovens, localizando-se geralmente na porção interna dos lábios inferiores. Por outro lado, o fibroma é um tipo de tumor benigno do tecido conjuntivo fibroso que pode ser considerado uma hiperplasia reacional do tecido conjuntivo em resposta a traumas e irritação. Geralmente são nodulares, com consistência firme, assintomáticos, coloração semelhante à da mucosa, base séssil, superfície lisa, localizados na mucosa jugal ao longo da linha de oclusão, língua e mucosa labial. O tratamento convencional para ambas as lesões é a excisão cirúrgica conservadora, sendo que sua recorrência é rara para fibromas e alta para as mucoceles. Este trabalho relata casos clínicos de mucocele e fibroma, tratados pela técnica de excisão cirúrgica ou enucleação, bem como descreve a proservação no consultório odontológico. As características importantes para o diagnóstico diferencial dessas lesões são discutidas.

Aspectos clínicos e moleculares da agenesia dentária congênita / Molecular and clinical aspects of congenital dental agenesis

A agenesia dentária consiste em uma anomalia comum de desenvolvimento, que resulta na alteração do número de dentes preentes na cavidade bucal e afeta aproximadamente 20% da população. Sua etiologia está associada a fatores ambientais, como infecções, traumas, quimioterapia, radioterapia e causas genéticas. Atualmente a etiologia mais aceita para explicar a ocorrência das anomalias dentárias é a alteração na expressão de genes específicos. Com base no conhecimento dos genes e fatores de transcrição envolvidos na odontogênese, presume-se que diferentes formas fenotípicas de agenesia dentária são causadas por mutações em diferentes genes. Os genes envolvidos na agenesia dentária em humanos incluem os fatores de transcrição (MSX1 e PAX9) que desempenham um papel crítico durante o desenvolvimento craniofacial e o gene que codifica uma proteína envolvida na via de sinalização canônica Wnt (AXIN2). Dessa maneira, a proposta do presente estudo é discorrer sobre os principais genes que têm sido relatados como reguladores da formação dental e a ocorrência de mutações nestes genes que poderiam resultar em agenesias dentárias

Dental agenesis is a common developmental anomaly which affects approximately 20% of the population and results in a reduction of number of teeth present in the oral cavity. The etiology is associated with environmental factors, such as infections, trauma, chemotherapy, radiotherapy, and genetic causes. Currently the widely accepted theory to explain the occurrence of dental agenesis is the change in the expression of specific genes. Different phenotypic patterns of dental agenesis are caused by mutations in genes and transcription factors involved in odontogenesis. In humans those genes include transcription factors (MSX1 and PAX9) that play a critical role during development and the gene coding for a protein involved in the canonical Wnt signaling (AXIN2). Therefore, the purpose of this study is to discuss about dental agenesis and the key genes that have been reported as regulators of dental formation and how the occurrence of mutations in these genes could result in dental agenesis

Changes in the profile of dental procedures performed in a pediatric clinic between 1980 and 2004

The goal of this research was to assess whether there was a change in the profile of dental procedures performed in the Pediatric Dental Clinic at the School of Dentistry of Ribeirão Preto at University of São Paulo during the period between the years 1980 to 2004. Using the dental records of 3,484 pediatric patients attended at the Pediatric Dental Clinic, we conducted a survey of clinical procedures performed by undergraduate students in the years 1980, 1984, 1988, 1992, 1996, 2000 and 2004. The following procedures, performed in deciduous and permanent teeth in children from 1 to 12 years, were: topicalapplications of fluoride, pit and fissure sealant applications, silver amalgam and composite resin fillings, pulpotomy and tooth extraction. The numeric values obtained for each procedure were converted into percentages, and data were analyzed using Fisher Exact or qui-square tests (α = 0.05). The results revealed the occurrence of a significant increase (p < 0.01) in percentage of topical fluoride applications (increase of 18.9%) and sealants applications (increase of 11.2%). On the other hand, the percentage of performance of silver amalgam and composite resin fillings, pulpotomies and tooth extraction showed a significant decline of 16.0, 6.0 and 16.1%, respectively (p < 0.05). It can be concluded that there was a decline of restorative, surgical and conservative endodontic procedures, with a concomitant increase of preventive procedures.

Efficacy of antimicrobial sprays for disinfection of children's toothbrushes: a randomized clinical trial

The objective of this study was to evaluate the efficacy of three spray antimicrobial solutions for the disinfection of childrenÆs toothbrushes. A 4-stage changeover system was used. The solutions studied were: BrushtoxTM (Spray 1), CosmocilTM + basic formula (Spray 2), basic formula (Spray 3), and control û sterile water (Spray 4). Forty children used the solutions in all stages. In each stage, the children received a new toothbrush and performed a single 1-min brushing. Thereafter, the solutions were sprayed six times at different positions on the toothbrush bristles. After four hours, microbiologic culture of the toothbrushes was performed. BrushtoxTM, CosmocilTM + basic formula, and basic formula presented a similar effect on prevention of cariogenic biofilm formation which was better than basic formula alone or sterile water. BrushtoxTM showed the best antimicrobial efficacy.