Adhesion of three types of fissure sealant in saliva-contaminated and noncontaminated conditions: an in vitro study.

PURPOSE: To evaluate the proportion of microleakage (PM), shear bond strength (SBS), and the fissure sealant (FS) interface by scanning electron microscopy (SEM) in three kinds of FS when the enamel surfaces were contaminated with saliva. METHODS: 198 sound third molar teeth were randomly divided into three pretreatment condition groups (n = 66): dry, saliva contamination removed by cotton pellet, or saliva removed by air-drying. A resin-based FS (Clinpro™), amorphous calcium phosphate-containing FS (Aegis®), or glass ionomer-based FS (Fuji Triage®) was applied on the treated enamel, and PM and SBS were assessed. Two specimens from each group were observed with SEM. p values < 0.05 was considered statistically significant. RESULTS: Glass ionomer-based FS showed the highest PM in all three surface conditions (p values < 0.05 were considered statistically significant). No significant difference in PM was observed between resin-based FS and amorphous calcium phosphate-containing FS (p > 0.05). Resin-based FS showed significantly greater SBS in all three surface conditions compared to glass ionomer-based FS. SEM observations showed that saliva contamination led to gaps at the enamel-sealant interface. CONCLUSION: Neither cotton pellet-drying nor air-drying effectively removed saliva from the contaminated enamel surface. Glass ionomer-based FS showed the highest PM and the lowest SBS in contaminated and noncontaminated conditions. The highest SBS was obtained with resin-based FS.

Bond strength and adhesive interfacial micromorphology of self-adhesive resin cements: Effect of reduced times of pre-etching.

BACKGROUND: Although acid-etching could increase enamel bond strength of self-adhesive (SA) cements, it may lead to negative effect on dentin. The aim of this study was to assess the effect of shortening of phosphoric acid pre-etching duration on enamel/ dentin shear bond strength (SBS) and interfacial microstructure of Panavia SA Luting Plus (PASA) and Bifix SE (BXSE). MATERIAL AND METHODS: For both enamel and dentin, effect of pre-etching time was significant (p<0.001); however, effect of cement brand and the interaction of two factors was significant only for dentin (p≤0.008). Three pre-etching times increased SBS of both cements to enamel and BXSE to dentin. In case of dentin SBS of PASA, this improvement was significant only for 5 and 10 seconds (p<0.001). Adding acid-etching in the three times to both cements similarly improved interfacial adaptation, particularly for enamel. RESULTS: The evaluations of the biofilm elimination showed results that indicate that the 4% sodium hypochlorite group with positive pressure irrigation presented significant differences with the group that had irrigation with sodium hypochlorite activated with XP-endo Finisher and the chlorhexidine groups to 2% (P<0.05). CONCLUSIONS: Interfacial bond strength and adaptation of SA cements used in this study were improved following addition of enamel/dentin etching step for a short time. This was not exceeded for longer times than 5-second. Key words:Dentin bond strength, enamel bond strength, pre-etching time, self-adhesive cement.

Comparison of the Mean DMF Index in Type I Diabetic and Healthy Children.

STATEMENT OF THE PROBLEM: It is expected that the prevalence of caries would be more in diabetics than in non-diabetic individuals due to the complications subsequent to metabolic changes such as xerostomia and increased glucose level in saliva. On the other hand, the restriction of glucose consumption in the diabetics' diet would be a reason to justify decreasing dental caries in them. PURPOSE: The aim of this study was to compare the mean DMF (decayed, missed due to decay, and filled teeth) index in type I diabetic and healthy children. MATERIALS AND METHOD: The DMF index was assessed in 100 type I diabetic children (9-14 years-old, mean= 12±1.23) and compared with the DMF index in 100 age- and sex-matched metabolically healthy controls. Data were collected through a questionnaire and clinical examinations and analyzed statistically by t-test and one-way ANOVA. RESULTS: The results showed that there were no significant differences between the mean DMF index of diabetic children and healthy children. The mean DMF was significantly lower in those who regularly used a toothbrush and dental floss than in those who did not use in both groups (p< 0.05). CONCLUSION: Diabetes did not affect dental condition by itself but adequate oral hygiene had an important role in controlling caries and promoting oral status.