Bond strength of self-adhesive resin cements to tooth structure

The aim of this study was to evaluate the strength of the bond between newly introduced self-adhesive resin cements and tooth structures [i.e., enamel and dentin]. Three self-adhesive cements [SmartCem2, RelyX Unicem, seT SDI] were tested. Cylindrical- shaped cement specimens [diameter, 3 mm; height, 3 mm] were bonded to enamel and dentin. Test specimens were incubated at 37°C for 24 h. The shear bond strength [SBS] was tested in a Zwick Roll testing machine. Results were analyzed by one-way ANOVA and t-test. Statistically significant differences were defined at the alpha= 0.05 level. Bond failures were categorized as adhesive, cohesive, or mixed. The SBS values ranged from 3.76 to 6.81 MPa for cements bonded to enamel and from 4.48 to 5.94 MPa for cements bonded to dentin [p >0.05 between surfaces]. There were no statistically significant differences between the SBS values to enamel versus dentin for any given cement type. All cements exhibited adhesive failure at the resin/tooth interface. Regardless of their clinical simplicity, the self-adhesive resin cements examined in this study exhibit limited bond performance to tooth structures; therefore, these cements must be used with caution

Effect of oral diseases on mothers giving birth to preterm infants

To determine the association between preterm birth [PTB] and maternal oral diseases during pregnancy. This prospective study was performed by the neonatal and dental departments at Jordan University Hospital. The study included 100 women who gave birth to preterm singleton infants [born less than 37 complete weeks from last menstrual period] between January and July 2009. The control group included an equal number of women who delivered singleton, full-term infants on the same day or the day after the women in the study. The mothers' demographic data were collected using a questionnaire, and an oral examination was conducted for each participant. Statistical analysis was performed using SPSS for Windows release 16.0 [SPSS Inc., Chicago, Ill., USA]. Factors related to PTB were studied in univariate and multivariate logistic regression analyses. Significantly higher DMFT [decayed, missing, filled teeth] index scores, Silness and Loe plaque index scores and Muhlemann tooth mobility index scores were associated with PTB. Mothers who did not have prepregnancy dental checkups had a significantly higher incidence of PTB. Fewer mothers in the PTB group visited dentists during their last pregnancy compared with controls. Oral health, especially healthy periodontium, is one reliable indicator for predicting a safe pregnancy outcome