{"title":"过氧化氢结构对自固化牙科复合材料反应性和机械性能的影响。","authors":"","doi":"10.1016/j.dental.2024.06.008","DOIUrl":null,"url":null,"abstract":"<div><h3>Objectives</h3><p>Hydroperoxides are key constituents of two-component dental materials. The objective of this study was to evaluate the influence of the hydroperoxide structure on the reactivity and on the mechanical properties of self-cure composites.</p></div><div><h3>Methods</h3><p>Hydroperoxides <strong>HP1–3</strong> were synthesized by selective catalytic oxidation of the corresponding <em>para</em>-substituted cumene precursors and isolated in high purity. They were characterized by <sup>1</sup>H NMR and <sup>13</sup>C NMR spectroscopy. 16 self-cure composites, based on the redox initiator system hydroperoxide (Cumene hydroperoxide (CHP), <strong>HP1–3</strong> or <em>tert</em>.-Amyl hydroperoxide (TAH))/polymerizable thiourea <strong>ATU1</strong>/copper(II) acetylacetonate, were formulated in Sulzer Mixpac two-component syringes. An equimolar hydroperoxide/<strong>ATU1</strong> ratio was selected for each self-cure composite. The reactivity and the final double-bond conversions obtained with these two-component materials was assessed using RT-FTIR spectroscopy. The flexural strength and modulus were measured using a three-point bending setup, after storage of the specimens for 45 min at 37 °C (dry) and for 24 h in water at 37 °C. The working time of each self-cure composite was measured using an oscillating rheometer.</p></div><div><h3>Results</h3><p>CHP derivatives bearing an electron withdrawing group (<strong>HP2</strong>: ester or <strong>HP3</strong>: nitrile) in the <em>para</em> position were found to be more reactive than CHP, whereas the compound bearing an electron donating group (<em>tert</em>-butyl, <strong>HP1</strong>) was less reactive; molecular modelling data were reported for a better understanding of this structure/reactivity/efficiency relationship. All CHP derivatives were more reactive than the aliphatic hydroperoxide TAH. Excellent mechanical properties were obtained with self-cure composites containing either CHP or a <em>para</em>-functionalized CHP derivative. By carefully selecting the amounts of oxidizing/reducing agents and metal catalyst, suitable working times can be obtained with all evaluated hydroperoxides. <strong>HP3</strong>, thanks to its high reactivity, is nonetheless the most promising compound.</p></div><div><h3>Significance</h3><p>The curing rate of self-cure composites can be adapted by modifying the structure of the hydroperoxide. In agreement with molecular modelling data, the incorporation of CHP derivatives bearing an electron withdrawing group in the <em>para</em> position is particularly attractive. Indeed, due to a significant reactivity enhancement, the desired properties (working time, flexural strength/modulus) can be obtained by incorporating moderate amounts of hydroperoxide/acylthiourea as well as particularly low contents of metal catalyst to the two-component dental materials.</p></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":null,"pages":null},"PeriodicalIF":4.6000,"publicationDate":"2024-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Influence of the hydroperoxide structure on the reactivity and mechanical properties of self-cure dental composites\",\"authors\":\"\",\"doi\":\"10.1016/j.dental.2024.06.008\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><h3>Objectives</h3><p>Hydroperoxides are key constituents of two-component dental materials. The objective of this study was to evaluate the influence of the hydroperoxide structure on the reactivity and on the mechanical properties of self-cure composites.</p></div><div><h3>Methods</h3><p>Hydroperoxides <strong>HP1–3</strong> were synthesized by selective catalytic oxidation of the corresponding <em>para</em>-substituted cumene precursors and isolated in high purity. They were characterized by <sup>1</sup>H NMR and <sup>13</sup>C NMR spectroscopy. 16 self-cure composites, based on the redox initiator system hydroperoxide (Cumene hydroperoxide (CHP), <strong>HP1–3</strong> or <em>tert</em>.-Amyl hydroperoxide (TAH))/polymerizable thiourea <strong>ATU1</strong>/copper(II) acetylacetonate, were formulated in Sulzer Mixpac two-component syringes. An equimolar hydroperoxide/<strong>ATU1</strong> ratio was selected for each self-cure composite. The reactivity and the final double-bond conversions obtained with these two-component materials was assessed using RT-FTIR spectroscopy. The flexural strength and modulus were measured using a three-point bending setup, after storage of the specimens for 45 min at 37 °C (dry) and for 24 h in water at 37 °C. The working time of each self-cure composite was measured using an oscillating rheometer.</p></div><div><h3>Results</h3><p>CHP derivatives bearing an electron withdrawing group (<strong>HP2</strong>: ester or <strong>HP3</strong>: nitrile) in the <em>para</em> position were found to be more reactive than CHP, whereas the compound bearing an electron donating group (<em>tert</em>-butyl, <strong>HP1</strong>) was less reactive; molecular modelling data were reported for a better understanding of this structure/reactivity/efficiency relationship. All CHP derivatives were more reactive than the aliphatic hydroperoxide TAH. Excellent mechanical properties were obtained with self-cure composites containing either CHP or a <em>para</em>-functionalized CHP derivative. By carefully selecting the amounts of oxidizing/reducing agents and metal catalyst, suitable working times can be obtained with all evaluated hydroperoxides. <strong>HP3</strong>, thanks to its high reactivity, is nonetheless the most promising compound.</p></div><div><h3>Significance</h3><p>The curing rate of self-cure composites can be adapted by modifying the structure of the hydroperoxide. In agreement with molecular modelling data, the incorporation of CHP derivatives bearing an electron withdrawing group in the <em>para</em> position is particularly attractive. Indeed, due to a significant reactivity enhancement, the desired properties (working time, flexural strength/modulus) can be obtained by incorporating moderate amounts of hydroperoxide/acylthiourea as well as particularly low contents of metal catalyst to the two-component dental materials.</p></div>\",\"PeriodicalId\":298,\"journal\":{\"name\":\"Dental Materials\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":4.6000,\"publicationDate\":\"2024-06-08\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Dental Materials\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0109564124001386\",\"RegionNum\":1,\"RegionCategory\":\"医学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"DENTISTRY, ORAL SURGERY & MEDICINE\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Dental Materials","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0109564124001386","RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"DENTISTRY, ORAL SURGERY & MEDICINE","Score":null,"Total":0}
Influence of the hydroperoxide structure on the reactivity and mechanical properties of self-cure dental composites
Objectives
Hydroperoxides are key constituents of two-component dental materials. The objective of this study was to evaluate the influence of the hydroperoxide structure on the reactivity and on the mechanical properties of self-cure composites.
Methods
Hydroperoxides HP1–3 were synthesized by selective catalytic oxidation of the corresponding para-substituted cumene precursors and isolated in high purity. They were characterized by 1H NMR and 13C NMR spectroscopy. 16 self-cure composites, based on the redox initiator system hydroperoxide (Cumene hydroperoxide (CHP), HP1–3 or tert.-Amyl hydroperoxide (TAH))/polymerizable thiourea ATU1/copper(II) acetylacetonate, were formulated in Sulzer Mixpac two-component syringes. An equimolar hydroperoxide/ATU1 ratio was selected for each self-cure composite. The reactivity and the final double-bond conversions obtained with these two-component materials was assessed using RT-FTIR spectroscopy. The flexural strength and modulus were measured using a three-point bending setup, after storage of the specimens for 45 min at 37 °C (dry) and for 24 h in water at 37 °C. The working time of each self-cure composite was measured using an oscillating rheometer.
Results
CHP derivatives bearing an electron withdrawing group (HP2: ester or HP3: nitrile) in the para position were found to be more reactive than CHP, whereas the compound bearing an electron donating group (tert-butyl, HP1) was less reactive; molecular modelling data were reported for a better understanding of this structure/reactivity/efficiency relationship. All CHP derivatives were more reactive than the aliphatic hydroperoxide TAH. Excellent mechanical properties were obtained with self-cure composites containing either CHP or a para-functionalized CHP derivative. By carefully selecting the amounts of oxidizing/reducing agents and metal catalyst, suitable working times can be obtained with all evaluated hydroperoxides. HP3, thanks to its high reactivity, is nonetheless the most promising compound.
Significance
The curing rate of self-cure composites can be adapted by modifying the structure of the hydroperoxide. In agreement with molecular modelling data, the incorporation of CHP derivatives bearing an electron withdrawing group in the para position is particularly attractive. Indeed, due to a significant reactivity enhancement, the desired properties (working time, flexural strength/modulus) can be obtained by incorporating moderate amounts of hydroperoxide/acylthiourea as well as particularly low contents of metal catalyst to the two-component dental materials.
期刊介绍:
Dental Materials publishes original research, review articles, and short communications.
Academy of Dental Materials members click here to register for free access to Dental Materials online.
The principal aim of Dental Materials is to promote rapid communication of scientific information between academia, industry, and the dental practitioner. Original Manuscripts on clinical and laboratory research of basic and applied character which focus on the properties or performance of dental materials or the reaction of host tissues to materials are given priority publication. Other acceptable topics include application technology in clinical dentistry and dental laboratory technology.
Comprehensive reviews and editorial commentaries on pertinent subjects will be considered.