Effects of antibiotics on the developing enamel in neonatal mice

The Prevalence of Developmental Enamel Defects in Israeli Children and Its Association with Perinatal Conditions: A Cross-Sectional Study

Molar incisor hypomineralization (MIH) and deciduous molar hypomineralization (DMH) affect the first permanent molars and second primary molars, respectively, causing a greater dental treatment burden and worse oral health quality of life among affected children. We assessed the prevalence and risk factors of MIH and DMH among 1209 children aged 3-13 years who attended a university dental clinic in Israel in 2019-2020. Clinical examinations were conducted to assess the presence of DMH and MIH. Potential etiological factors of MIH and DMH, including demographics, the mother's perinatal health, and the child's medical history during the first three years of life, were retrieved using a questionnaire. To examine the associations between the demographic and clinical variables and the prevalence of MIH and DMH, continuous variables were tested using the Kruskal-Wallis test with Bonferroni corrections. Categorical variables were analyzed by chi-squared test. Multivariate logistic regression was conducted to evaluate which of the significant variables found in the univariate analysis could predict a diagnosis of both MIH and DMH. The prevalence of MIH and DMH was 10.3% and 6.0%, respectively. Age ≥ 5 years, taking medications during pregnancy and severe lesions were associated with a greater risk for a diagnosis of DMH + MIH. Multivariate logistic regression with adjustment for age showed that the severity of hypomineralization was positively and significantly associated with a diagnosis of MIH + DMH with an odds ratio of 4.18 (95% confidence interval 1.26-17.16), p = 0.03. MIH should be diagnosed and monitored in young children to prevent further deterioration. Moreover, a preventive and restorative program for MIH should be established.

Enamel biomineralization under the effects of indomethacin and celecoxib non-steroidal anti-inflammatory drugs

The aim of this study was to explore the effects of nonsteroidal anti-inflammatory drugs on biomineralization of enamel. Sixty C57Bl6 male mice were used, which were assigned into three groups: celecoxib (n = 20) or indomethacin (n = 20) treatment for a period of 28 days or received no medication (control group, n = 20). Visual inspection and microcomputed tomography were used to analyze enamel morphology. Scanning electron microscopy–Energy dispersive X-ray and Knoop microhardness test were used to quantify chemical element content (Ca, P, C, O) and enamel microhardness, respectively. Tissues were collected to investigate the synthesis, activity or nuclear translocation of metalloproteinase-20, transcription factor Runx2, dentin sialoprotein and cyclooxygenase-2 enzyme by means of immunohistochemistry, in situ zymography and indirect immunofluorescence. Treatment with indomethacin and celecoxib reduced the Ca and P content, microhardness and mineral density in enamel. Treatment with nonsteroidal anti-inflammatory drugs caused an accumulation of metalloproteinase-20 and overall increased enzymatic activity in enamel matrix, while the synthesis of the transcription factor Runx2 was inhibited by these drugs. Interestingly, indomethacin inhibited Runx2 translocation to the nucleus whereas celecoxib did not. Those findings show that non-steroidal anti-inflammatory drugs impact the enamel biomineralization and could be involved in the etiology tooth enamel defects if used during the period of tooth formation and mineralization.