Comparing the Effect of Topical Acidulated Phosphate Fluoride on Micro- Hardness of Two Fissure Sealants and One Flowable Composite

Objective: Probable effect of fluoride containing materials like APF on sealants is very important. The purpose of this study is to assess the effect of frequent application of APF (1.23%) on the surface microhardness of two fissure sealants and one flowable composite.Methods: In this experimental study, 81 specimens of two fissure sealants and one flowable composite were prepared, using special polymer mold in three groups of 27 including unfilled resin sealant (Fissurite F, Voco), filled resin sealant (Fissurit FX, Voco) and one flowable composite (Arabesk Flow, Voco). Then, these three groups were divided into three sub groups of 9 as follows: Group 1, 4, 7 (control): No treatment- Group 2, 8, 5: Single application using APF- Group 3, 6, 9: Six times application using APF. The APF was applied on the experimental specimens every time  for 4 minutes. Then, the samples were stored in the distilled water. Finally, the surface microhardness of the sealants was measured using Vickers test. The statistical analysis was performed by 2-way ANOVA & One-way ANOVA tests.Results: Type of materials (without filler, containing filler and flowable composite) was effective on the surface microhardness and the difference between three types of materials was statically significant (p<0.001).Unfilled fissure sealants, showed minimum surface microhardness and flow able composite showed maximum surface microhardness. Also, the frequency of gel use (once or many times), had no effect on the average surface microhardness of the materials under review (p>0.05).Conclusion: All three materials were resistant to the destructive effects of APF gel and it did not make a significant microhardness changes

Effect of Different Topical Agents on Remineralization of Early Enamel Lesion– an in vitro Study

Objective: This study aimed to compare the effect of using Casein phosphopeptide – amorphous calcium phosphate (CPP-ACP) paste, Remin-Pro and Fluoride Varnish on remineralization of  enamel lesions.Methods: In this experimental-in vitro study, 60 intact premolars and molars were used and flat enamel surfaces were prepared. The specimens were divided into 6 groups (N=10). After primary DIAGNOdent value measurement and a four-day immersion in demineralizing solution, the DIAGNOdent value were measured. Groups 1, 2 and 3 were treated by Fluoride varnish, CPP-ACP and Remin-Pro respectively, according to the manufacturer instruction and their DIAGNOdent value was read. Groups 4, 5, and 6 were treated by Fluoride varnish, CPP-ACP and Remin-Pro for 1  month (8 hours a day), respectively, and their DIAGNOdent value was measured. Then the specimens of these three groups were demineralized and pH cycled and their DIAGNOdent values were recorded. The data were analyzed by One-way analysis of variance (ANOVA) and repeated measures ANOVA.Results: After a one-month treatment, the DIAGNOdent value significantly decreased in groups 4, 5, and 6 in comparison to the manufacturer instruction (p<0.001). ANOVA test indicated that decrease mean value of DIAGNOdent value was significantly higher for Remin-Pro and CPP-ACP groups than Fluoride varnish group, from entrance time to the study to re-demineralization stage (p<0.001). Conclusion: All the three materials showed a statistically significant amount of remineralization after repeated application but the CPP-ACP and Remin pro were more resistant to  redemineralization and pH cycling

Comparison Study on Casein Phosphopeptide-Amorphous Calcium Phosphate Paste and Fluoride Gel on Remineralization of Demineralized Enamel Lesions

Objective: Tooth surface undergoes continuous remineralization and demineralization. The aim of this study was to compare the effect of Caseinphosphopeptide-amorphous calcium phosphate (CPP- ACP) paste and Fluoride gel on the microhardness of demineralized enamel lesions.Methods: Frothy eight specimens of premolar teeth were chosen and randomly divided to 4 groups of 12. After the initial measurement of micro-hardness the specimens were immersed in demineralizing solution for 4 day and then the measurements were recorded again. Two groups (GL and G3) were treated with CPP-ACP and Fluoride gel respectively according to manufacturer’s instruction. Two other groups (G2 and G4) were treated with CPP-ACP and fluoride gel every week for three months. After the treatments all specimens were taken into PH-cycling and the micro- hardness for each one were measured again. For data analysis, the Repeated Measures ANOVA test and the LSD tests were performed. In each group the percentage of micro-hardness recovery was measured.Results: Repeated Measures ANOVA and LED Test showed that the mean value of hardness was significantly decreased after demineralization in all groups (p=0.01). There was no significant difference in mean hardness value in groups (GL, G3) after treatment (p=0.1, p=0.12) In groups (G2, G4) the mean hardness value were significantly increased (p<0.0001, p=0.1). It is noticeable that the CPP-ACP was significantly more efficient than the fluoride gel.Conclusion: CPP-APC paste and fluoride gel both increase the micro-hardness of enamel when administrated for long time and repeated application

Effects of Treatment with Various Remineralizing Agents on the Microhardness of Demineralized Enamel Surface

Background and aims. Remineralization of incipient caries is one of the goals in dental health care. The present study aimed at comparing the effects of casein phosphopeptide-amorphous calcium phosphate complex (CPP-ACP), Remin Pro®, and 5% sodium fluoride varnish on remineralization of enamel lesions. Materials and methods. In this in vitro study, 60 enamel samples were randomly allocated to six groups of 10. After four days of immersion in demineralizing solution, microhardness of all samples was measured. Afterward, groups 1-3 under-went one-time treatment with fluoride varnish, CPP-ACP, and Remin Pro®, respectively. Microhardness of groups 4-6 was measured not only after one-month treatment with the above-mentioned materials (for eight hours a day), but also after re-exposing to the demineralizing solution. The results were analyzed by one-way analysis of variance (ANOVA), repeated measures ANOVA, and Fisher’s least significant difference (LSD) test. Results. None of the regimens could increase microhardness in groups 1-3. However, one-month treatment regimens in groups 4-6 caused a significant increase in microhardness. The greatest microhardness was detected in the group treated with CPP-ACP (P = 0.001). In addition, although microhardness reduced following re-demineralization in all three groups, the mean reduction was minimum in the CPP-ACP-treated group (P < 0.001). Conclusion. While long-term repeated application of all compounds improved microhardness, the remineralization potential of CPP-ACP was significantly higher than that of Remin Pro® and sodium fluoride varnish

Effect of Common Drinks on the Color Stability of Microhybrid and Nanohybrid Composites in Children

Introduction: In spite of numerous developments in resin composites products, their color stability is still a major problem particularly in pediatric dentistry, since frequent visits of children is of great importantance due to their behavior management, regardless of the problems pertaining to aesthetic and additional expenses. The purpose of this study was to evaluate the effect of common children drinks on the color stability of nanohybrid and microhybrid resin composites.Materials & Methods: In this experimental study, 80 disk samples (with diameter of 10 mm and depth of 2 mm) of microhybrid (point4 Kerr) and nanohybrid (Herculite XRV Ultra Kerr) resin composites were prepared. (categorized in 2 groups of 40).Then the samples of each group were divided into five subgroups of eight and were immersed in five different solutions (orange juice, red grape juice, fanta coke, chocolate milk) and distilled water as the control group for 4 hours daily for a period of 10 days. The color of samples was measured by a spectrophotometer at the beginning of the study and after staining using CIE lab system. The data were analysed by 2-Way ANOVA test.Results: 2-Way ANOVA showed that there was no significant statistical difference between the microhybrid (P4) and nanohybrid (HCU) resin composites with respect to the degree of staining in the mentioned solutions (P=0.29). Moreover 2-way ANOVA showed that type of the drink has a significant effect on the degree of staining of materials (P< 0.001).Conclusions: It doesn’t seem that the new nanocomposites have any considerable advantage to microhybrid resin composites regarding staining. Also regarding these results, colored drinks especially red grape juice and chocolate milk are not recommended in the first days after composite filling