ABSTRACT
Statement of Problem: Because dental restorations are time consuming, dental material manufacturers make an attempt to discover new methods for rapidity and increasing the quality of restorations. With this objective in mind, plasma arc curing devices have been manufactured
Purpose: This study was done to compare the effect of plasma arc and halogen light curing on the microleakage of class V resin composite
Methods and Material: In this experimental study, on 80 extracted maxillary central teeth, standard class V cavities were prepared with incisal and gingival margins in the enamel and dentin. After etching and bonding, the teeth were randomly divided into two subgroups of 40 and restored with Amelogen composite. In the first group, halogen light curing for 40 seconds was used and in the second one plasma arc curing was used for four seconds. After thermocycling and sealing, the samples were immersed into the 0.5% fuchsine solution for 24 hours and then washed with water and cut. The microleakage was scored by stereomicroscope with 40X magnification. The data were analyzed using Mann-Whitney and Wilcoxon tests
Results: The mean of incisal wall microleakage in the plasma arc group was 1.42+/-0.98 and in the halogen group it was 0.67+/-0.02. The gingival margin in the plasma are group showed a mean of 1.75+/-1.48 and in the halogen group it was found to be 1.67+/-1.54. There were significant differences in the incisal wall [p =0.0001], but not in the gingival wall [p =0.744]. The average rate of microleakage in the gingival and incisal walls in the plasma arc group was 3.17+/-1.79 and in the halogen group it was 2.76+/-1.92; there were not any significant differences between the groups [p =0.32]
Conclusion: In the restorations with enamel margins halogen light curing and in all composite restorations plasma arc curing are preferred due to the short time of curing
ABSTRACT
Statement of Problem: The control of microleakage presents a challenge for posterior composite restorations. The technique for composite placement and treatment technique may cause some modifications in the microleakage. The results of different studies are varied
Purpose: This study aimed to evaluate the marginal microleakage in class II P60 resin composite restorations prepared with two restorative techniques and two polymerization systems
Materials and Method: Standard class II cavity preparations were performed on 56 carries- free extracted molars. Then, the teeth were randomly divided into four groups: 1] Bulk placement and conventional polymerization 2] Incremental placement and conventional polymerization 3] Bulk placement and soft start polymerization 4] Incremental placement and soft start polymerization. All the cavities were restored with single bond and P60 [3M/ESPE] resin composite. After thermo cycling, the specimens were immersed in 2% methylene blue solution for 24 hours and then washed. After sectioning, dye penetration was assessed by light stereomicroscopy at 40x magnification and then evaluated for microleakage by Kruskal-Wallis Test and Mann-Whitney tests
Results: Significant differences were found between the bulk with incremental technique and soft start with conventional polymerization. The highest and lowest rates of microleakage were in bulk conventional and incremental soft start group, respectively. A significant difference was found between groups
Conclusion: The use of incremental placement technique and soft start system results in less microleakage
ABSTRACT
The materials used for temporary filling of crown of teeth play an important role in sealing, prevention of underlying tissue contamination and prognosis of direct and indirect pulp capping. Similarly, they have an important role after endodontic treatment and before permanent restoration of the crown. Therefore, marginal microleakage of Zoliran [Iran made] and Zonalin [English made], two temporary restorative materials with a common base, Zinc-Oxide eugenol were studied and compared. In this study, 44 healthy extracted premolars were collected: and randomly divided into 4 groups; 2 groups each having 20 teeth for experimental study and two other groups each having 2 teeth as positive and negative control. In the two experimental groups and the positive group, standard access cavities similar to dimensions of pulp were formed and temporarily repaired with 4 mm of either Zoliran or Zonalin. After thermocyling, all of the groups were immersed in 1% methylene blue for 24 hours and marginal microleakages were measured using a 40x stereo microscope . The results of this study showed that marginal microleakage of Zoliran is higher than Zonalin and the t-test statistically showed a significant difference between microleakage of Zoliran and Zonalin [P=0.0001]. Conclusion: As the microleakage of Zonalin was lower than Zoliran in this study, it is advisable to use this material for temporary or intermediate sealing of cavities
ABSTRACT
Nowadays, the most commonly used dental materials are resin composites that have a capability of good reconstruction in the anterior part of the mouth. Therefore, the factories producing these materials endeavor to produce materials that in addition to esthetic properties have good adhering and lasting properties in order to prevent microleakages and recurrent caries. In this study, we compared the micro leakages of two types of resin composites; one Iran made and named Ideal Makoo and another Lichtenstein made and named Heliomolar. 50 healthy human upper premolars were extracted to perform the mentioned study. Then, class V standard cavities were prepared at the cervical area of facial surface such that the gingival portion was in cementum, while the occlusal portion was in enamel. The teeth were divided into two test groups of 25 teeth each. The first group cavities were filled with Ideal makoo resin composite and the second group restored by heliomolar resin composite, then finishing and polishing was done. The specimens were then placed in 370C temperature for 8 days and after that, the specimens were thermocyled and placed in 0.5% basic fuchsin solution for 48 hours. After washing, the specimens were sectioned in buccolingual direction and scanned by computer with Photoshop software to calculate microleakage separately in enamel and cementum. The results were analyzed by t, multivariate t, and t 2 Hotling tests. According to tests, the microleakage of enamel using Ideal Makoo resin composite was less than heliomolar resin composite [P=0.005]. Also. the microleakage of cementum in Heliomolar composite was significantly less than Ideal Makoo composite [P=0.014]. This investigation showed that neither Heliomolar nor Ideal-Makoo composites are able to completely eliminate microleakages in invitro conditions