复合树脂充填材料的研发策略和进展

复合树脂充填材料是牙体直接粘接修复的首选材料,其良好的性能可以满足临床牙体修复治疗的要求,恢复结构和功能并兼具微创和美观。为进一步提高临床疗效,改善复合树脂材料性能的局限性是根本的解决策略。本文总结目前的研究进展,重点阐述改良复合树脂材料的性能,研发新型复合树脂包括抗菌复合树脂、再矿化生物活性树脂和自修复复合树脂的进展,为新型复合树脂充填材料的研究趋势提供新思路。     

复合树脂收缩应力测量系统初探

目的 探讨复合树脂聚合收缩应力的测试方法及树脂基质对收缩应力的影响.方法 使用模拟临床条件下的聚合收缩应力测量系统,测量两种以新型单体为基质的复合树脂(P 90、维纳斯钻石)和传统基质复合树脂(Z350和卡瑞斯玛)光照开始后收缩力值变化情况,并测得复合树脂在光照后300 s时的聚合收缩应力值.结果 两种采用新型基质的复合树脂在光照后300 s时的收缩应力显著低于传统基质复合树脂,4种被测复合树脂收缩应力的大小依次为Z350[ (4.08 ±0.12)MPa]＞卡瑞斯玛[(1.92 ±0.10)MPa]＞维纳斯钻石[(1.16 ±0.03)MPa] ＞P90[(0.94±0.04)MPa] (P ＜0.05).且两种新型复合树脂的聚合收缩反应速率较缓慢.结论 本测量系统可实时有效监测复合树脂固化过程中收缩应力的变化过程;以新型单体代替传统树脂基质是开发低收缩复合树脂的有效途径.     

五种充填用流动性复合树脂的耐磨性能研究

目的比较5种充填用流动性复合树脂的耐磨性能,为临床选择适用于[牙合]力承担区直接充填治疗的流动性复合树脂提供参考。方法以可压实复合树脂(Majesty)为对照组,选用5种充填用流动性复合树脂(A组:Filtex 350 XT Flow;B组:Beautifil Flowable Plus;C组:Clearfil Majesty LV2;D组:Unifil LoFlo Plus;E组:Sonic Fill组)为研究对象,每组材料制备6个半球形试件。在微摩擦磨损实验机下,树脂试件垂直加载20 N,与牛牙釉质往复对磨1万次后测量球头磨斑直径并在扫描电镜下观察磨斑微观形貌。采用单因素方差分析比较各组磨斑直径差异。结果对照组、A、B组磨斑直径[分别为(1033±43)、(1068±48)、(1237±86)μm]差异无统计学意义(P>0.05),C、D、E组磨斑直径[分别为(1550±150)、(1384±222)、(1525±81)μm]均显著大于对照组和A组(P<0.05)。扫描电镜显示,对照组、A、B组填料粒度范围较大,磨耗面可见填料的碎裂和局部缺损;C、D、E组填料颗粒较小,并可见多处整块填料脱落的痕迹。结论填料粒度范围大的流动性复合树脂的耐磨性能与可压实复合树脂相当,有望用于[牙合]力承担区直接充填治疗。     

含聚合单体微胶囊的牙科新型自修复抗菌复合树脂合成初探

目的 合成含聚合单体微胶囊的牙科新型自修复抗菌复合树脂,并探讨相关性能,为其进一步临床应用提供参考.方法 制备含聚合单体三乙二醇二甲基丙烯酸酯的微胶囊,分别以0、2.5％、5.0％、7.5％及10.0％质量分数添加至含长链烷基季铵盐新型纳米二氧化硅抗菌填料的复合树脂中,生成含聚合单体微胶囊的牙科新型自修复抗菌复合树脂(新型树脂组),以纳米瓷化复合树脂(Tetric N-Ceram)为对照.三点弯曲实验检测各组树脂弯曲强度和弹性模量(每组样本量为6);单刃V形切口梁法测试各组树脂断裂韧性及自修复效率(每组样本量为6),同时进行扫描电镜观察.结果 引入7.5％聚合单体微胶囊时,新型树脂组弯曲强度和弹性模量分别为(96.4±14.3) MPa和(6.2±1.1) GPa,与对照组[分别为(99.1±1 1.9) MPa和(6.1±1.1)GPa]差异均无统计学意义(P＞0.05);当聚合单体微胶囊质量分数为7.5％和10.0％时,新型树脂的自修复效率分别为(66.8±7.0)％和(79.3±9.7)％;扫描电镜示愈合面有黑色不规则薄膜覆盖.结论 含聚合单体微胶囊的牙科新型自修复抗菌复合树脂具有较强的自修复功能,展示了良好的临床应用前景.     

Clearfil复合树脂修复牙体缺损的临床疗效观察

日本生产的Clearfil复合树脂的特点是:颜色与自然牙酷似、逼真、粘接力强,操作方便,广泛用于各类牙体缺损的修复及覆盂变色牙。我们于1987年10月开始使用该复合树脂,治疗后的牙齿外观、颜色、光泽度满意,现将我们的疗效和体会报告如下。     

牙科用玻璃纤维增强复合树脂的研究

目的：研究玻璃纤维增强丙烯酸树脂的力学性能。方法：将Ｅ玻璃纤维按６１．９７％、７２．６０％、７７．６８％（重量比）,与丙烯酸树脂制成单向玻璃纤维增强复合材料,并测试其弯曲强度、弯曲模量和面内剪切强度。结果：随着纤维比例的提高,复合材料的弯曲强度有显著性增加（Ｐ＜０．０５）,达（１３２９．４６±８５．１３）ＭＰａ。７２．６０％组和７７．６８％组与６１．９１％组相比,弯曲模量提高非常显著（Ｐ＜０．０１）,达（３４．０６±３．５８）ＧＰａ;面内剪切强度降低非常显著（Ｐ＜０．０１）,为（５３．５２±４．６２）ＭＰａ。结论：玻璃纤维对丙烯酸树脂的弯曲性能具有增强作用。     

五种充填用流动性复合树脂的耐磨性能研究

目的比较5种充填用流动性复合树脂的耐磨性能,为临床选择适用于力承担区直接充填治疗的流动性复合树脂提供参考。方法以可压实复合树脂(Majesty)为对照组,选用5种充填用流动性复合树脂(A组:Filtex 350 XT Flow;B组:Beautifil Flowable Plus;C组:Clearfil Majesty LV2;D组:Unifil LoFlo Plus;E组:Sonic Fill组)为研究对象,每组材料制备6个半球形试件。在微摩擦磨损实验机下,树脂试件垂直加载20 N,与牛牙釉质往复对磨1万次后测量球头磨斑直径并在扫描电镜下观察磨斑微观形貌。采用单因素方差分析比较各组磨斑直径差异。结果对照组、A、B组磨斑直径[分别为(1 033±43)、(1 068±48)、(1 237±86) μm]差异无统计学意义(P>0.05),C、D、E组磨斑直径[分别为(1 550±150)、(1 384±222)、(1 525±81) μm ]均显著大于对照组和A组(P<0.05)。扫描电镜显示,对照组、A、B组填料粒度范围较大,磨耗面可见填料的碎裂和局部缺损;C、D、E组填料...     

复合树脂嵌体修复磨牙缺损的临床疗效观察

目的观察复合树脂嵌体修复磨牙缺损的临床疗效。方法选择163例磨牙缺损患者的200颗患牙，将其分为2组，每组患牙100颗。分别采用直接法复合树脂嵌体和复合树脂直接充填修复患牙。于修复完成6个月和5年复诊。采用美国公共卫生署修复体临床评价标准对患者口内充填体进行疗效评价。结果修复后6个月，嵌体修复成功率为91．8％（90／98），树脂直接充填成功率为91．8％（89／97），经Х^2检验两者临床疗效差异无统计学意义（P〉0．05）。修复后5年，嵌体修复成功率为87．9％（80／91），树脂直接充填修复成功率为67．4％（60／89），Х^2检验显示嵌体的临床疗效优于树脂直接充填，差异有统计学意义（P〈0．05）。结论复合树脂嵌体修复磨牙缺损临床疗效良好，其长期临床疗效显著优于传统复合树脂直接充填。     

两种充填方式对不同光固化复合树脂充填体内孔隙的影响

目的 探讨光固化复合树脂的稠度及充填方式对充填体内孔隙的影响,以期为复合树脂的临床应用提供参考.方法 6位操作者将3种复合树脂(树脂A:Prodigy;树脂B:Tetric EvoCeram;树脂C:Tetric Ceram HB)以器械充填和注射充填的方式充填入模拟I类洞中,将充填体纵向片切成0.5 mm厚的切片,测定切片内孔隙数量;并测试未进行充填的复合树脂内的固有孔隙数量.结果 未充填的复合树脂内固有孔隙数量极少(≤5个);稠度居中的树脂B的孔隙数量[器械充填和注射充填分别为(1137.1±365.0)和(566.1±206.4)个]远多于稠度最大的树脂C[分别为(193.1±35.8)和(156.3±33.0)个]和稠度最小的树脂A[分别为(241.0±116.1)和(195.8±28.7)个,P<0.05).树脂B器械充填的孔隙数量明显多于注射充填(P<0.05),而树脂A和C两种充填方式的孔隙数量差异均无统计学意义(P>0.05).结论 复合树脂充填体内的孔隙基本是在充填过程中形成的,孔隙数量与复合树脂稠度无线性关系;并非所有复合树脂用注射充填均能显著减少充填体内孔隙数量.     

光固化复合树脂凝胶玻璃化后固化收缩量评价

目的 评价光固化复合树脂在凝胶点后特别是玻璃化后的固化收缩量,以期为深入研究光固化复合树脂的固化收缩特性提供新的评价方法.方法 利用本实验室自主研制开发的一种基于激光测距技术的固化收缩测量仪,获得5种光固化复合树脂自光照开始后300 s内的固化收缩量一时间曲线和固化收缩速率-时间曲线,并通过收缩速率-时间曲线计算凝胶点和转变点V以及凝胶点后及玻璃化后的固化收缩量.结果 5种光固化复合树脂的凝胶点为0.77 ～ 1.59 s,差异有统计学意义(P＜0.01);转变点V为1.99～6.33 s,差异有统计学意义(P＜0.01);凝胶点后收缩量为33.35～53.18 μm,差异有统计学意义(P＜0.01);玻璃化后收缩量为16.43～30.58 μm,差异有统计学意义(P＜0.01);总收缩量为39.25～64.84μm,差异有统计学意义(P＜0.01).5种光固化复合树脂凝胶点后收缩量及玻璃化后收缩量的顺序与总收缩量的顺序有所不同.结论 通过动态测量光固化复合树脂固化收缩量,可推测凝胶点和转变点V,从而获得更具有实用意义的复合树脂固化收缩特性评价参考值.     

十种纳米填料光固化复合树脂聚合收缩性能的比较与评价

目的 探讨10种纳米填料光固化复合树脂的聚合收缩情况,评价纳米填料在光固化复合树脂聚合收缩性能中的作用.方法 采用激光位移传感器进行非接触式测量,实时监测10种纳米填料光固化树脂(CM:Clearfil Majesty; CX:Ceram·X;F:Fulfil;E:Estelite α;PM:Premisa; TN:Tetric N-Ceram restorative;S:Spectrum TPH3;TB:Tetric Bulk Fill;Z:Z350XT;P:P90)的聚合收缩情况.测量光固化时的体积收缩率、收缩速率峰值以及到达峰值的时间.采用单因素方差分析10种材料的差异.结果 10种纳米填料光固化树脂的体积收缩率差异有统计学意义(P＜0.01).10种纳米填料光固化树脂的体积收缩率范围为1.20％ ～ 3.09％,P＜PM ＜Z≈E ＜TN≈CM≈TB ＜CX ＜S ＜F,其中Z与E、TN与CM间差异无统计学意义,体积收缩率较接近.收缩速率峰值范围为2.14～ 14.76 μm/s,到达峰值的时间范围为3.29～5.39 s.结论 10种纳米填料复合树脂的聚合收缩差异显著,填料含量和粒径对复合树脂聚合收缩有一定影响作用,增加填料含量,减小纳米填料的粒径,有助于降低聚合收缩率.     

义齿基托塑料电热聚合器的研制

介绍一种新的用于口腔修复专业的甲基丙烯酸甲脂热处理聚合设备。该设备可以将树脂的加压和热处理功能合为一体。有６８℃和１００℃两个温度档，并且具有相应符合树脂材料热聚合工艺规范要求的恒温时间。整个聚合过程无需人工管理。该产品操作简单、耐用、节电、无污染，实用性强。     

VOLUMETRIC POLYMERIZATION SHRINKAGE OF CONTEMPORARY COMPOSITE RESINS

The polymerization shrinkage of composite resins may affect negatively the clinical outcome of the restoration. Extensive research has been carried out to develop new formulations of composite resins in order to provide good handling characteristics and some dimensional stability during polymerization. The purpose of this study was to analyze, in vitro, the magnitude of the volumetric polymerization shrinkage of 7 contemporary composite resins (Definite, Suprafill, SureFil, Filtek Z250, Fill Magic, Alert, and Solitaire) to determine whether there are differences among these materials. The tests were conducted with precision of 0.1 mg. The volumetric shrinkage was measured by hydrostatic weighing before and after polymerization and calculated by known mathematical equations. One-way ANOVA (á=0.05) was used to determine statistically significant differences in volumetric shrinkage among the tested composite resins. Suprafill (1.87±0.01) and Definite (1.89±0.01) shrank significantly less than the other composite resins. SureFil (2.01±0.06), Filtek Z250 (1.99±0.03), and Fill Magic (2.02±0.02) presented intermediate levels of polymerization shrinkage. Alert and Solitaire presented the highest degree of polymerization shrinkage. Knowing the polymerization shrinkage rates of the commercially available composite resins, the dentist would be able to choose between using composite resins with lower polymerization shrinkage rates or adopting technical or operational procedures to minimize the adverse effects deriving from resin contraction during light-activation.     

Clinical strategies for esthetic excellence in anterior tooth restorations: understanding color and composite resin selection

Direct composite resin restorations have become a viable alternative for patients that require anterior restorative procedures to be integrated to the other teeth that compose the smile, especially for presenting satisfactory esthetic results and minimum wear of the dental structure. Technological evolution along with a better understanding of the behavior of dental tissues to light incidence has allowed the development of new composite resins with better mechanical and optical properties, making possible a more artistic approach for anterior restorations. The combination of the increasing demand of patients for esthetics and the capacity to preserve the dental structure resulted in the development of different incremental techniques for restoring fractured anterior teeth in a natural way. In order to achieve esthetic excellence, dentists should understand and apply artistic and scientific principles when choosing color of restorative materials, as well as during the insertion of the composite resin. The discussion of these strategies will be divided into two papers. In this paper, the criteria for color and material selection to obtain a natural reproduction of the lost dental structures and an imperceptible restoration will be addressed.     

Effect of different composite modulation protocols on the conversion and polymerization stress profile of bulk-filled resin restorations

ObjectiveThe aim of this in vitro study was to test the effect of different composite modulation protocols (pre-heating, light-curing time and oligomer addition) for bulk filling techniques on resin polymerization stress, intra-pulpal temperature change and degree of conversion.MethodsClass I cavities (4 mm depth × 5 mm diameter) were prepared in 48 extracted third molars and divided in 6 groups. Restorations were completed with a single increment, according to the following groups: (1) Filtek Z250XT (room temperature – activated for 20 s); (2) Filtek Z250XT (at room temperature – activated for 40 s); (3) Filtek Z250XT (pre-heated at 68 °C – activated for 20 s); (4) Filtek Z250XT (pre-heated at 68 °C – activated for 40 s); (5) Filtek BulkFill (at room temperature – activated for 20 s); (6) Filtek Z250XT (modified by the addition of a thio-urethane oligomer at room temperature – activated for 40 s). Acoustic emission test was used as a real-time polymerization stress (PS) assessment. The intra-pulpal temperature change was recorded with a thermocouple and bottom/top degree of conversion (DC) measured by Raman spectroscopy. Data were analyzed with one-way ANOVA/Tukey's test (α = 5%).ResultsPre-heating the resin composite did not influence the intra-pulpal temperature (p = 0.077). The thio-urethane-containing composite exhibited significantly less PS, due to a lower number of acoustic events. Groups with pre-heated composites did not result in significantly different PS. Filtek BulkFill and the thio-urethane experimental composite presented significantly higher DC.SignificanceResin composite pre-heating was not able to reduce polymerization stress in direct restorations. However, thio-urethane addition to a resin composite could reduce the polymerization stress while improving the DC.     

不同洞缘设计对树脂充填应力影响的三维有限元分析

目的　评价不同洞缘角对复合树脂充填体应力的影响。方法　在后牙面Ⅰ类洞设计不同洞缘角 ,进行复合树脂充填 ,并采用三维有限元法对承受垂直和侧向力所产生的应力计算分析。结果　在所设计的 90°、75°、6 0°、45°及弧型等 5种洞缘角中 ,90°时拉、切应力分别为 18 75 7MPa和2 2 30 9MPa;75°时应力明显减小为 10 5 80MPa和 14 2 6 5MPa ;6 0°时为 9 0 2 5MPa和 13 2 30MPa。受作用力后树脂表面产生的拉应力和切应力最大 ,分别为 18 75 7MPa和 2 2 30 9MPa ,第二层明显减小为 2 5 86MPa和 6 80 0MPa。结论　后牙树脂充填时 ,洞缘角应制备成 6 0°～ 75°的斜面有利于获得较好的充填效果。     

Thermal analysis of bulk filled composite resin polymerization using various light curing modes according to the curing depth and approximation to the cavity wall

Objective

The purpose of this study was to investigate the polymerization temperature of a bulk filled composite resin light-activated with various light curing modes using infrared thermography according to the curing depth and approximation to the cavity wall.

Material and Methods

Composite resin (AeliteFlo, Bisco, Schaumburg, IL, USA) was inserted into a Class II cavity prepared in the Teflon blocks and was cured with a LED light curing unit (Dr''s Light, GoodDoctors Co., Seoul, Korea) using various light curing modes for 20 s. Polymerization temperature was measured with an infrared thermographic camera (Thermovision 900 SW/TE, Agema Infra-red Systems AB, Danderyd, Sweden) for 40 s at measurement spots adjacent to the cavity wall and in the middle of the cavity from the surface to a 4 mm depth. Data were analyzed according to the light curing modes with one-way ANOVA, and according to curing depth and approximation to the cavity wall with two-way ANOVA.

Results

The peak polymerization temperature of the composite resin was not affected by the light curing modes. According to the curing depth, the peak polymerization temperature at the depth of 1 mm to 3 mm was significantly higher than that at the depth of 4 mm, and on the surface. The peak polymerization temperature of the spots in the middle of the cavity was higher than that measured in spots adjacent to the cavity wall.

Conclusion

In the photopolymerization of the composite resin, the temperature was higher in the middle of the cavity compared to the outer surface or at the internal walls of the prepared cavity.