Abrasion of resin infiltrated enamel by tooth brushing / 대한구강보건학회지

OBJECTIVES: The purpose of this study was to evaluate abrasion of Icon(R) infiltrated, sound bovine enamel by using confocal laser scanning microscopy (CLSM) after toothbrush abrasion tests. METHODS: Sound bovine enamel specimens whose Vickers Hardness Number ranged from 280 to 320 were prepared. To measure abrasion, specimens were allocated to groups on the basis of tooth brushing stroke frequencies. Tooth brushing stroke frequencies were categorized into 5 groups: 1,800, 5,400, 10,800, 21,600 and 43,200 strokes. Both infiltration depth of Icon(R) and the abrasion depth were measured by CLSM. RESULTS: Mean infiltration depth of Icon(R) for sound bovine enamel was 98.6 microm. There was no statistically significant difference in enamel abrasion depth between groups with 5,400 strokes and 10,800 strokes, but the abrasion depth increased with further increase in tooth brushing stroke frequencies (P<0.001). The mean abrasion depth of resin infiltrated bovine enamel after 43,200 tooth brushing strokes was 17.45 microm. CONCLUSIONS: The magnitude of abrasion after 43,200 tooth brushing strokes, which corresponds to brushing 3 times a day for 4 years, was less than 20 microm. This result suggests that abrasion by tooth brushing would not be a clinical problem for resin infiltrated enamel.

Evaluation on the abrasion resistance of a surface sealant / 대한치과보존학회지

The purpose of this study was to evaluate the abrasion resistance of surface penetrating sealant which was applied on a composite resin restoration and to provide proper time to reapply sealant on composite resin surface. Two hundred rectangular specimens, sized 8 x 3 x 2 mm, were made of Micronew (Bisco, Inc., Schaumburg, IL, U.S.A) and divided into two groups; F group (n = 10) was finished with coarse and medium grit of Sof-Lex discs and BisCoverwas applied B group (n = 190) after finishing with discs. B group was again subdivided into nineteen subgroups. From B-1 group to B-18 group were subjected to toothbrush abrasion test using a distilled water-dentifrice slurry and toothbrush heads. B-IM group was not subjected to toothbrush abrasion test. Average surface roughness (Ra) of each group was calculated using a surface roughness tester (Surfcorder MSE-1700: Kosaka Laboratory Ltd., Tokyo, Japan). A representative specimen of each group was examined by FE-SEM (S-4700: Hitachi High Technologies Co., Tokyo, Japan). The data were analysed using cluster analysis, paired t-test, and repeated measure ANOVA. The results of this study were as follows; 1. Ra of F group was 0.898 +/- 0.145 microm and B-IM group was 0.289 +/- 0.142 microm. Ra became higher from B-1 group (0.299 +/- 0.48 microm) to B-18 group (0.642 +/- 0.313 microm). 2. Final cluster center of Ra was 0.361 microm in cluster 1 (B-IM ~ B-7), 0.511 microm in cluster 2 (B-8 ~ B-14) and 0.624 microm in cluster 3 (B-15 ~ B-18). There were significant difference among Ra of three clusters. 3. Ra of B-IM group was decreased 210.72% than Ra of F group. Ra of B-8 group and B-15 group was increased 35.49% and 51.35% respectively than Ra of B-IM group. 4. On FE-SEM, B-IM group showed the smoothest resin surface. B-8 group and B-15 group showed vertically shallow scratches, and wide and irregular vertical scratches on composite resin surface respectively. Within a limitation of this study, finished resin surface will be again smooth and glazy if BisCover would be reapplied within 8 to 14 months after applying to resin surface.

Evaluation on the abrasion resistance of a surface sealant / 대한치과보존학회지

The purpose of this study was to evaluate the abrasion resistance of surface penetrating sealant which was applied on a composite resin restoration and to provide proper time to reapply sealant on composite resin surface. Two hundred rectangular specimens, sized 8 x 3 x 2 mm, were made of Micronew (Bisco, Inc., Schaumburg, IL, U.S.A) and divided into two groups; F group (n = 10) was finished with coarse and medium grit of Sof-Lex discs and BisCoverwas applied B group (n = 190) after finishing with discs. B group was again subdivided into nineteen subgroups. From B-1 group to B-18 group were subjected to toothbrush abrasion test using a distilled water-dentifrice slurry and toothbrush heads. B-IM group was not subjected to toothbrush abrasion test. Average surface roughness (Ra) of each group was calculated using a surface roughness tester (Surfcorder MSE-1700: Kosaka Laboratory Ltd., Tokyo, Japan). A representative specimen of each group was examined by FE-SEM (S-4700: Hitachi High Technologies Co., Tokyo, Japan). The data were analysed using cluster analysis, paired t-test, and repeated measure ANOVA. The results of this study were as follows; 1. Ra of F group was 0.898 +/- 0.145 microm and B-IM group was 0.289 +/- 0.142 microm. Ra became higher from B-1 group (0.299 +/- 0.48 microm) to B-18 group (0.642 +/- 0.313 microm). 2. Final cluster center of Ra was 0.361 microm in cluster 1 (B-IM ~ B-7), 0.511 microm in cluster 2 (B-8 ~ B-14) and 0.624 microm in cluster 3 (B-15 ~ B-18). There were significant difference among Ra of three clusters. 3. Ra of B-IM group was decreased 210.72% than Ra of F group. Ra of B-8 group and B-15 group was increased 35.49% and 51.35% respectively than Ra of B-IM group. 4. On FE-SEM, B-IM group showed the smoothest resin surface. B-8 group and B-15 group showed vertically shallow scratches, and wide and irregular vertical scratches on composite resin surface respectively. Within a limitation of this study, finished resin surface will be again smooth and glazy if BisCover would be reapplied within 8 to 14 months after applying to resin surface.

Surface roughness and microleakage of class V composite restorations : Effect of surface sealing / 대한치과보존학회지

The purpose of this study was to compare the effect of surface sealing materials on microleakage and surface roughness in Class V composite restorations. Twenty five standardized Class V cavity preparations were made on the facial surface of human premolars and were randomly assigned to 5 groups. The teeth were restored with Z-250 after applying Single Bond. Following 7 days storage in distilled water at 37degrees C, the restorations were sealed as following systems : No sealing ; Single Bond Adhesive ; Biscover ; Fortify ; Optiguard. Then, toothbrush abrasion test was conducted using a wear testing machine. Surface roughness was measured by means of profilometer before and after toothbrushing and the results were statistically analysed by using a paired t-test and ANOVA. The bonded interfaces and the changes of surface roughness were examined by SEM. For microleakage test, specimens were stained in a 2% methylene blue solution, then longitudinally sectioned and analyzed for leakage at occlusal and cervical interfaces using stereomicroscope. The results were statistically analysed by using a Kruskal-Wallis and Mann-Whitney U test. Surface roughness was increasing in all groups after toothbrushing, but no statistically significant differences. In SEM observation, surface sealant was partially retained and partially detached in bonded interfaces. Especially, microgap was identified in cervical margins. In microleakage test, there was better seal in the enamel region and a significant difference between groups at occlusal margin. Control group and Single Bond group had significantly better marginal seal at enamel margin than cervical margin.