Surface hardness evaluation of different composite resin materials: influence of sports and energy drinks immersion after a short-term period

OBJECTIVES: This study evaluated the effect of sports and energy drinks on the surface hardness of different composite resin restorative materials over a 1-month period. MATERIAL AND METHODS: A total of 168 specimens: Compoglass F, Filtek Z250, Filtek Supreme, and Premise were prepared using a customized cylindrical metal mould and they were divided into six groups (N=42; n=7 per group). For the control groups, the specimens were stored in distilled water for 24 hours at 37º C and the water was renewed daily. For the experimental groups, the specimens were immersed in 5 mL of one of the following test solutions: Powerade, Gatorade, X-IR, Burn, and Red Bull, for two minutes daily for up to a 1-month test period and all the solutions were refreshed daily. Surface hardness was measured using a Vickers hardness measuring instrument at baseline, after 1-week and 1-month. Data were statistically analyzed using Multivariate repeated measure ANOVA and Bonferroni's multiple comparison tests (α=0.05). RESULTS: Multivariate repeated measures ANOVA revealed that there were statistically significant differences in the hardness of the restorative materials in different immersion times (p<0.001) in different solutions (p<0.001). The effect of different solutions on the surface hardness values of the restorative materials was tested using Bonferroni's multiple comparison tests, and it was observed that specimens stored in distilled water demonstrated statistically significant lower mean surface hardness reductions when compared to the specimens immersed in sports and energy drinks after a 1-month evaluation period (p<0.001). The compomer was the most affected by an acidic environment, whereas the composite resin materials were the least affected materials. CONCLUSIONS: The effect of sports and energy drinks on the surface hardness of a restorative material depends on the duration of exposure time, and the composition of the material

Flexural strength of fluorapatite-leucite and fuorapatite porcelains exposed to erosive agents in cyclic immersion

OBJECTIVE: The aim of this study was to evaluate the fexural strength of two porcelain materials (IPS d.SIGN and IPS e.max Ceram) exposed to erosive agents. MATERIAL AND METHODS: One hundred and twenty bar-shaped specimens were made from each of fuorapatite-leucite porcelain (IPS d.SIGN) and fuorapatite porcelain (IPS e.max Ceram) and divided into 8 groups of 15 specimens each. Six groups were alternately immersed in the following storage agents for 30 min: deionized water (control), citrate buffer solution, pineapple juice, green mango juice, cola soft drink and 4% acetic acid. Then, they were immersed for 5 min in deionized water at 37ºC. Seven cycles were completed, totalizing 245 min. A 7th group was continuously immersed in 4% acetic acid at 80ºC for 16 h. The final, 8th, group was stored dry at 37ºC for 245 min. Three-point bending tests were performed in a universal testing machine. The data were analyzed statistically by 2-way ANOVA, Tukey's HSD test and t-test at signifcance level of 0.05. RESULTS: The fexural strengths of all groups of each porcelain after exposure to erosive agents in cyclic immersion did not differ signifcantly (p>0.05). For both types of porcelain, dry storage at 37ºC yielded the highest fexural strength, though without signifcant difference from the other groups (p>0.05). The fexural strengths of all groups of fuorapatite porcelains were signifcantly higher (p<0.05) than those of the fuorapatite-leucite porcelains. CONCLUSIONS: This study demonstrated that the erosive agents evaluated did not affect the fexural strength of the tested dental porcelains

Managing tooth surface loss

This chapter will emphasise the need to:Be aware that most patients diagnosed with tooth surface loss (TSL) do not need to be restored, at least in the short term, but need to be advised how best to control causative factors (e.g. extrinsic erosion, intrinsic erosion, and bruxism)Liaise with the patient's doctor to manage intrinsic erosion, e.g. gastro-oesophageal reflux disease (GORD) or bulimia. The patient must accept the risk of early failure if restorations are provided before the medical condition is controlledRecord baseline study models to monitor TSL longitudinallyImplement restorative treatment where there are major aesthetic concerns and uncontrolled dentine sensitivity or where further TSL would compromise restorabilityConsider restoring anterior teeth using composite. A large composite can later have its buccal surface covered with a ceramic veneer (sandwich technique)Be realistic about restoring posterior teeth and choose an appropriate material to cope with higher occlusal forces, particularly in bruxists. If teeth are to be crowned, patients need to be aware of the risk of pulp damage and its consequencesPlan reconstructions according to whether TSL is localised or generalised. Generalised wear is more difficult; space is created by increasing the occlusal vertical dimension

Influence of Chemical Degradation and Toothbrushing on Surface of Composites

Objective: The aim of this study was to evaluate the effect of chemical degradation media associated with brushing on surface roughness (Ra) and Knoop microhardness (KHN) analyses of different composites. Materials and methods: Eighty specimens were prepared for each composite: GrandioSO (Voco), Amaris (Voco), Filtek Supreme (3M ESPE), Filtek LS (3M ESPE). The specimens were divided into four groups according to the immersion in chemical degradation media for 7 days: artificial saliva (control), heptane, 0.02 M citric acid, 70% ethanol. The surface of specimens was submitted to 10950 brushing cycles (200 gm load) in an automatic toothbrushing machine with abrasive slurry. Surface roughness and microhardness measurements were obtained at baseline, after immersion in chemical degradation media and after brushing. Data were submitted to three-way repeated measures ANOVA and Tukey’s test (p < 0.05). Results: The KHN means for composites were: Grandio (153.5± 35.9)a, Filtek Supreme (87.0 ± 24.9)b, Amaris (64.5 ± 24.5)c, LS (69.0 ± 15.3)c; for storage media: artificial saliva (97.3 ± 46.7)a, ethanol (93.3 ± 49.9)a, citric acid (95.8 ± 42.1)a, heptane (87.6 ± 36.7)b; and after treatments: after chemical degradation (104.8 ± 49.7)a, baseline (93.8 ± 42.5)b, after brushing (81.9 ± 36.5)c. The Ra results for composites were: LS (0.15 ± 0.25)a, GrandioSO (0.19 ± 0.24)ab, Filtek Supreme (0.20 ± 0.22)ab, Amaris (0.23 ± 0.37)b; for storage media: artificial saliva (0.18 ± 0.31)a, heptane (0.18 ± 0.25)a, ethanol (0.20 ± 0.26)a, citric acid (0.21 ± 0.28)a, and after treatments: brushing (0.11 ± 0.14)a, after chemical degradation (0.23 ± 0.32)b, baseline (0.24 ± 0.32)b. Conclusion: Brushing after chemical degradation reduced surface roughness values. In general, chemical degradation did not affect composites roughness, but microhardness was significantly reduced. Heptane produced the biggest reduction in composites microhardness. Clinical relevance: The food-simulating solutions and brushing simulating alter the composites properties, and these alterations are material-dependent.Department of Restorative Dentistry Institute of Science and Technology Universidade Estadual PaulistaDepartment of Restorative Dentistry Institute of Science and Technology Universidade Estadual Paulist