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Objective: To compare the incidence of microleakage associated with contemporary esthetic restorative-adhesive systems following cyclic wet and dry storage as a representation to the dry mouth condition. Methods: Standardized cervical cavities in both buccal and lingual surfaces of 100 extracted human premolars were restored in 10 groups (n=10 with 20 cavities) using 7 contemporary esthetic restoratives and 3 adhesive systems following their manufacturers’ instructions. Cavities in groups 1–3 were restored with self-adhesive restoratives; conventional glass-ionomer (GI) (Ketac Molar Aplicap), resin modified glass-ionomer (RMGI) (Vitremer) and self-adhesive flowable composite (SAFC) (Fusio Liquid Dentin). Conventional flowable (FC) (Filtek Z350 Flow), nano-hybrid (HC) (Filtek Z250 XT) and nano-filled (NC) (Filtek Z350 XT) methacrylate-based composites were used in conjunction with total-etch, 2-step adhesive (Adper Single Bond 2) to restore cavities in groups 4–6. The same restoratives were also used to restore cavities in groups 8–10 in the presence of self-etch, 1-step adhesive (Adper Easy One), while cavities in group 7 were restored with silorane-based composite (Filtek P90) together with its specific adhesive system. Five restored teeth from each group (10 cavities) were subjected to cyclic storage in wet and dry environment, each for 12h/day and for a total period of 30days, while the other 5 were tested with no cyclic storage to serve as control. Using dye penetration technique, the associated microleakage was then scored from 0 to 4 for all restorations according to the depth of dye penetration at both occlusal and gingival interfaces. The incidences of each score were recorded in percentages and the numerical microleakage data were statistically analyzed using Kruskal–Wallis and Mann–Whitney comparisons at α=0.05 to stand on the significance of differences detected between groups. Results: All restorative systems showed incidences of microleakage before and following cyclic storage in wet and dry environment with no specific manner declared for any. Statistical analysis of the scored data revealed no difference between different restorative systems under no storage condition, however HC, S and FC in groups 5, 7 and 8 showed higher rates of microleakage when subjected to cyclic wet-dry storage (Mann–Whitney, P0.05). For each restorative system, no significant difference (Kruskal–Wallis, P>0.05) was recorded between microleakage values recorded at occlusal and gingival interfaces. Conclusion: Occlusal and gingival sealing ability of flowable resin composite bonded with self-etch, 1-step adhesive is the most affected following cyclic wet-dry storage. Selection of such restorative option accordingly is not suggested for patients suffering from dry mouth.

Made available in DSpace on 2019-09-12T16:53:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2013 Objectives: This study measured the degree of conversion (DC), sorption, solubility and microhardness of methacrylate (Filtek Z250 and Filtek Z350XT) and silorane-based composites (Filtek P90). Methods: DC was measured using near infrared spectroscopy immediately and 24 h after the photoactivation. Sorption and solubility measurements were performed after 24 h, 4 weeks and 12 weeks of storage in water. Knoop microhardness was measured after 24 h and after thermal cycling. The data were statistically analyzed using ANOVA followed by Tukey's, Tamhane or paired t-tests (alpha = 0.05). Results: The DC for P90 (37.22 +/- 1.46) was significantly lower than the Z250 (71.44 +/- 1.66) and Z350 (71.76 +/- 2.84). Water sorption was highest in the Z250 and lowest in the P90. All the tested composites exhibited similar values after 24 h of immersion, and no significant differences were observed. No significant differences were observed between the solubilities of the P90 composite (12 weeks) and the Z250 or Z350 composites (4 weeks). KHN values were less elevated for the P90 composite and similar for the Z250 and Z350 composites. An effect of thermal cycling on KHN values was observed for all the composites (p < 0.001). Conclusions: Silorane produced the lowest DC and KHN values and exhibited lower water sorption and solubility compared to methacrylate- based composites. These differences suggest that silorane composites exhibit better hydrolytic stability after 3 months of water immersion compared to conventional methacrylate-based composites. Clinical significance: Silorane had higher hydrolytic stability after 3 months of water immersion than the methacrylate-based resins, despite the lower values of DC and KHN recorded. (c) 2013 Elsevier Ltd. All rights reserved. [Celerino de Moraes Porto, Isabel Cristina] Univ Fed Alagoas, Dept Restorat Dent, BR-57072970 Maceio, Alagoas, Brazil [Baggio de Aguiar, Flavio Henrique] Univ Estadual Campinas, Dept Restorat Dent, BR-13414903 Sao Paulo, Brazil [Brandt, William Cunha] Univ Santo Amaro, Dept Dent, BR-04829300 Sao Paulo, Brazil [Susy Liporoni, Priscila Christiane] Universidade de Taubaté (Unitau), Dept Restorat Dent, BR-12020340 Sao Paulo, Brazil

Objectives Verify if media and time of storage affect the translucency of a silorane-based composite (Filtek P90) compared to two methacrylate-based composites (Z350 and ROK), and compare two methods of translucency evaluation. Methods Specimens were divided into two groups ( n = 7) according to the storage media (deionized water or red wine). With a spectrophotometer (SP60) in reflectance mode, the CIE L * a * b * parameters and opacity percentage readings were conducted at baseline, 24 h, 30 days, and 180 days. Data were analyzed using two-way repeated measures ANOVA and Tukey ( p Results When stored in water, P90 showed an increase, whereas Z350 decreased in translucency. ROK did not exhibit any tendency over time. When stored in wine, the translucency of all materials decreased. A negative relationship was found between translucency parameter and opacity percentage. When stored in water, the a * values for P90 decreased, whereas Z350 and ROK showed values increasing over time. When stored in wine, the L * parameter tended to decrease over time, an effect that was less intense for P90. Moreover, the b * parameter for P90 decreased, whereas methacrylate-based composites increased over time. Conclusions P90 was more stable in red wine than the other materials and became more translucent in water whether metacrilate-based materials became more opaque. Both media as well as storage time affected the translucency of the materials tested. Translucency could be measured with both methods tested. Clinical significance Silorane-based composites seemed to be more stable than methacrylate-based composites in red wine and became more translucent over time in water, which was different than methacrylate-based composites. More studies are needed to clarify silorane-based composites performance.

Summary Objectives The objective of this manuscript is to outline the factors associated with hygroscopic and hydrolytic effects in dental polymer networks, and to review the literature generated over the past thirty years or more in this area. Methods Information was gathered from nearly 90 published articles or abstracts appearing in the dental and polymer literature. Studies were predominantly identified through a search of the PubMED database. Results Studies were included that provided direct evidence for the uptake of solvent by a polymer network and its subsequent physical or chemical effect, or the loss of molecular species into solvents. An attempt was made to select articles that spanned the timeframe from approximately 1970 to today to ensure that most of the classic literature as well as the latest information was included. Conclusions Dental polymer networks have been shown to be susceptible to hygroscopic and hydrolytic effects to varying extents dependent upon their chemistry and structure. The importance of these effects on the clinical performance of polymer restoratives is largely unknown, though numerous investigators have alluded to the potential for reduced service lives. Significance While the physical and mechanical properties of these materials may be significantly altered by the effects of solvent uptake and component elution, what may constitute the greatest concern is the short-term release of unreacted components and the long-term elution of degradation products in the oral cavity, both of which should be strongly considered during restorative material development.

Objectives: To evaluate the push-out bond strength of dimethacrylate (Clearfil SE Bond/Filtek Z250; and Adper SE Plus/Filtek Z250) and silorane-based (Filtek P90/Filtek P90) restorative systems following selective dentin pretreatment with a CPP-ACP-containing paste (MI Paste).