No abstract

The aim of this study was to compare the caries prevention effectiveness, retention rates and the level of fluoride of saliva of a glassionomer sealant (GIS) with that of a resin-based sealant (RS). Eighty GIS and 80RS were placed on the first permanent molars in 40 children aged 7-10 years. Children were re-examined at 6, 12, 24, 36 and 48 months after the procedure. Saliva samples were collected before the sealant was applied and again at each appointment, and fluoride levels were measured. After 48 months, occlusal caries were seen in 4 and 12 teeth in GIS and RS groups respectively. There was a statistically significant difference in the fluoride levels of saliva between baseline and up to 12th month in GIS group. GISs presented effective prevention of caries development, even though the failure rate is higher when compared to the RSs. An increased salivary fluoride level due to GISs might be an additive effect on the prevention of dental caries.

This study evaluated dental fluorosis of the incisors and immunoreactivity in the brain tissues of rats given chronic fluoride doses pre- and postnatally. Female rats were given drinking water with 0, 30 or 100 ppm fluoride ad libitum throughout gestation and the nursing period. In addition, 63 male offspring were treated with the same water regimens as the mothers after weaning and were followed for 1, 3 or 5 months. The upper and lower incisors were collected, and all teeth were examined under a stereomicroscope and scored by two blinded examiners using a modified rodent enamel fluorosis index. Cortical, hippocampal and cerebellar brain samples were evaluated morphologically and immunohistochemically. All fluoride-treated pups were born with low body weight (p = 0.001). All animals from the fluoride groups had enamel fluorosis with defects of various degrees. The increase in the dental fluorosis scores in the fluoride treatment groups was significant (p < 0.01). The catalase immunoreactivity in the 30- and 100-ppm fluoride groups was significantly higher than that in the controls after 1, 3 and 5 months (p < 0.001). In conclusion, this study showed that rats with dental fluorosis had catalase immunoreactivity in the brain tissues, which may reflect the neurobehavioral toxicity of fluoride.

This study was carried out to determine the fluoride levels in the drinking water of Ergene River Basin, which is known as the lifeblood of the Thrace Region and one of the most contaminated river basins in Turkey. Drinking water samples were collected from 30 stations including residential areas located in the Ergene River Basin in dry (summer) season of 2018. Fluoride levels of water samples were determined by using a spectrophotometer and Cluster Analysis (CA) was applied to detected fluoride data to classify the investigated residential areas according to fluoride contents. Geographic Information System (GIS) was also used to make a visual explanation by presenting a distribution map of fluoride accumulations and also the detected data were evaluated in terms of teeth health of local people, who constantly drinks this water. According to detected data, the fluoride accumulations in drinking water of Ergene River Basin were determined between 0.246 ppm (Velimeşe Village) -1.460 ppm (Bayramlı Village). According to the results of CA, 3 statistically significant clusters were formed as "High Fluoride Cluster", "Optimum Fluoride Cluster" and "Low Fluoride Cluster".

Yeditepe Üniversitesi Diş Hekimliği Fakültesi, İstanbul, Türkiye Molar incisor hypomineralization (MIH) is defined as the hypomineralization of one or more first permanent molars with or without the involvement of the maxillary and mandibular permanent incisors. Although the etiology of MIH remains unclear, several etiological factors, such as the genetic and environmental factors and systemic disturbance during pre-, peri-, and postnatal period, can cause enamel defects and their occurrence. The prevalence of MIH is reported to be between 2.4% and 25% in different communities. Teeth with MIH are extremely hypersensitive, prone to rapid caries development, and can be difficult to manage in young patients, and thus, dentists may have difficulties during diagnosis, treatment planning, and managing children with MIH during treatment. Early diagnosis is essential because rapid breakdown of tooth structure may occur, resulting in acute symptoms and complicated treatment. This study aimed to review the diagnosis and etiological factors involved in the occurrence of MIH and to evaluate treatment approaches in the management of MIH. Keywords: Molar incisor hypomineralization, children, incisor, molar GİRİŞ Tanımı ve Oluşum MekanizmasıBir veya birkaç sürekli birinci büyük azı dişi ile birlikte sürekli keser dişlerinde etkilenebildiği, etiyolojisi tam olarak bilinmeyen, amelogenezisin olgunlaşma safhasında gözlenen, sistemik kaynaklı klinik hipomineralizasyona büyük azı keser hipomineralizasyonu (BAKH) denir (1). Son yıllarda yapılan çalışmalarda BAKH'nin sadece daimi dişleri etkilediği düşünülürken, Elfrink ve ark. (2) süt dişlerinde de BAKH görüldüğünü bildirmişler ve süt dişlerinin etkilendiği bu hipomineralizasyonu "süt azı keser hipomineralizasyonu" olarak tanımlamışlardır (2, 3). Doku anomalileri dişlerin organik matriks yapımı ve mineralizasyonunun histogenez döneminde karşılaştığı etkenler sonucunda meydana gelmektedir. Amelogenezis 3 ana evreden oluşur (4). Salgılama Evresi: Ameloblastlar mine matriks proteini üretirler. Mine oluşumu öncelikle tüberkül tepelerinden başlar ve servikale doğru ilerler. Hidroksiapatit kristalleri uzayarak büyümeye başlar ve bu sayede mine tabakası kalınlaşır. Bu evrede minenin %20'si mineralden oluşurken geri kalan kısmı ise su ve mine matriks proteininden oluşmaktadır (4).Geçiş Evresi: Mine matriks salgılanması sonucunda mine tam kalınlığına ulaşır. Ameloblastlar olgunlaşma evresindeki ameloblastlara dönüşür (4).Olgunlaşma Evresi: Olgun ameloblastlar mineralizasyonu düzenlerler ve mine tabakası sertleşir, kalınlaşır, kristaller büyür, mineralizasyonun %95'i tamamlanmış olur. Doğumda sekonder mineralizasyon tüberkül tepelerinden itibaren başlar ve mineralizasyon doğumdan sonraki 1 yıl boyunca devam eder (4).