口腔材料检测的项目与顺序

结论：项目由材料类别和接触方式决定，试样制备是数据可信的前提

口腔材料涵盖的范围很宽——充填材料、粘接材料、印模材料、义齿基托、根管材料、预防材料。不同类别的材料，考察项目差别很大。

但有一点是共同的：试样制备的规范性直接决定数据是否可信。

口腔材料多数需要现场调拌或固化，试样的制备方式（配比、混合时间、固化条件、试样尺寸）对结果的影响很大。制备不规范，测出来的数据既不能反映材料的真实性能，也无法与其他数据比较。

分类与项目的对应

各类材料还有共同的项目：生物相容性、溶解与吸水、颜色稳定性、以及包装与有效期。

试样制备的要求

配比准确。 按说明书规定的比例，双组分材料的配比偏差影响性能。

混合方式与时间。 手工调拌还是机械混合、混合多长时间。

固化条件。 光固化的光源、光强、照射时间、距离；化学固化的温度和时间。

试样尺寸。 按方法规定，尺寸偏差影响结果。

试样数量。 足够反映分散性。

试样的储存。 制备后到测试前的条件，多数需要在特定介质中保存特定时间。

「光固化的实际光强」是容易出问题的环节。 光固化灯的输出会随使用衰减，如果不核实实际光强，试样的固化程度可能不足，测出的强度偏低。建议在制备前测量光源的实际输出。

通用项目的考察

溶解与吸水。 材料在水或模拟唾液中的溶解量和吸水量。溶解量大意味着成分释放多，与生物相容性相关；吸水多意味着尺寸和性能可能变化。

颜色与颜色稳定性。 初始颜色与色号的匹配，以及在光照、着色剂作用下的颜色变化。

残留单体。 聚合类材料的未反应单体，与刺激性相关。

pH 值。 某些材料的酸碱性影响周围组织。

显影性。 需要在影像上可见的材料。

「颜色稳定性」对前牙修复材料尤其重要，因为变色会导致修复体与天然牙不协调，影响美观和使用者满意度。

力学性能的考察

压缩强度。 充填材料承受咀嚼力。

弯曲强度与模量。 反映材料的抗弯能力和刚度。

断裂韧性。 抵抗裂纹扩展的能力，对脆性材料重要。

表面硬度。 与耐磨相关。

耐磨性。 长期咀嚼下的磨损。

粘接强度。 与牙体组织或其他材料的结合。

疲劳。 反复咀嚼载荷下的表现。

「粘接强度的测试条件」影响结果很大 ——基材的处理方式、粘接面积、加载速度、以及测试前的储存条件（是否经过冷热循环）。这些条件都要规定并记录。

老化与耐久的考察

口腔环境对材料是严苛的：温度变化、湿度、pH 变化、咀嚼载荷、以及各种食物和饮料的化学作用。

冷热循环。 模拟进食冷热食物带来的温度变化，对粘接界面的考验尤其明显。

咀嚼模拟。 模拟咀嚼的循环载荷。

化学浸泡。 在不同 pH 或含着色剂的介质中浸泡。

光老化。 对颜色稳定性的考察。

「冷热循环后的粘接强度」是粘接材料的关键数据，因为粘接界面的失效多数是疲劳和热应力累积的结果，而不是一次性的过载。

测试顺序上的考虑

先做试样制备的确认。 确认制备条件符合要求，光固化的光强、固化程度。

再做非破坏的观察。 外观、颜色、尺寸。

然后做老化处理。 需要老化的项目先处理。

最后做破坏性的力学测试。

「固化程度的确认」值得作为第一步。 如果试样没有充分固化，后续所有的力学和化学数据都不可信。可以通过硬度、转化率等方式确认。

送检准备的建议

提供完整的使用说明。 配比、混合、固化条件。

提供配套器材。 调拌器具、光固化灯（如果有特定要求）。

提供足够的材料量。 试样制备和重复测试消耗量不小。

说明有效期与储存条件。 材料的状态影响性能。

提供配套材料。 比如粘接系统的处理剂、底涂剂。

说明适用的临床情形。 影响测试条件的设定。

生物相容性的考虑

口腔材料与口腔组织接触，生物相容性的评价要注意：

接触的组织。 牙体硬组织、牙髓、牙龈、黏膜、骨组织，各自的要求不同。

接触时间。 印模材料是短时，充填材料是长期。

试样的状态。 应当是按临床方式固化完成的材料，而不是未固化的原料。

浸提条件。 模拟口腔环境的介质和温度。

残留单体的考虑。 未固化的单体是主要的刺激源。

「试样必须充分固化」是这类材料评价的前提。 固化不完全的试样残留单体多，测出的刺激性偏高，不代表临床实际。

批次与稳定性

批次一致性。 不同批次的固化特性和性能一致性。

有效期内的稳定性。 接近有效期的材料性能是否仍达标。

储存条件的影响。 温度对材料性能的影响，某些材料需冷藏。

开封后的稳定性。 多次使用的包装，开封后的性能变化。

「开封后的稳定性」对多次使用的包装很重要，因为材料暴露于空气和水分后可能变化。

我们的做法

做口腔材料测试时，我们会严格按说明书规定的条件制备试样，并在制备前确认光固化光源的实际输出 ——这一步做不到位，后续数据都会偏差。

对于粘接类材料，我们建议做冷热循环后的强度复测，因为初始粘接强度容易做得好看，而临床失效多数发生在循环老化之后。

如果你有口腔材料需要安排检测，想先理清项目和试样制备的要求，可以把产品资料和使用说明发过来一起讨论，或者直接联系：132 4819 8029。能力范围见服务介绍，送检要求见送检要求，流程见检测流程。

English version

Conclusion. Dental materials span a wide range, covering restoratives, adhesives, impression materials, denture base materials, endodontic materials and preventive materials, and test items differ considerably between categories. One thing is common to all: the rigour of specimen preparation determines directly whether the data are credible. Most dental materials require mixing or curing at the point of use, and how specimens are prepared, in proportioning, mixing time, curing conditions and dimensions, strongly affects results. Prepared irregularly, the data neither reflect the material's true performance nor compare with anything else.

Items by category. Restoratives require strength, cure, shrinkage, wear resistance and colour. Adhesives require bond strength, durability and marginal seal. Impression materials require dimensional stability, elastic recovery and detail reproduction. Denture base materials require strength, water sorption, solubility and residual monomer. Endodontic materials require flow, setting, sealing and radiopacity. Preventive materials require release performance and retention. And ceramics require strength, fracture toughness and chemical resistance. Common items across categories cover biocompatibility, solubility and water sorption, colour stability, and packaging and shelf life.

Specimen preparation requirements. Proportioning must be accurate, since deviation in two-component materials affects properties. Mixing method and time must follow the instructions, whether by hand or machine. Curing conditions must follow specification, covering light source, irradiance, exposure time and distance for light-cured materials, and temperature and time for chemically cured ones. Specimen dimensions must follow the method, since deviation affects results. Specimen numbers must suffice to reflect variation. And storage between preparation and testing must follow specification, most requiring a defined period in a defined medium. Actual irradiance of the curing light is where problems arise: light output declines with use, and without verifying it specimens may be inadequately cured and measured strength comes out low. Measure the actual output before preparing specimens.

Common items. Solubility and water sorption cover how much material dissolves into and absorbs from water or simulated saliva; high solubility means greater release, which relates to biocompatibility, while high sorption means dimensions and properties may change. Colour and colour stability cover the match to the shade designation and the change under light and staining agents. Residual monomer covers unreacted monomer in polymerising materials, which relates to irritation. The pH of certain materials affects surrounding tissue. And radiopacity applies to materials that must be visible on images. Colour stability matters particularly for anterior restoratives, since discolouration leaves the restoration mismatched with natural teeth and affects appearance and satisfaction.

Mechanical items. Compressive strength applies to restoratives bearing masticatory load. Flexural strength and modulus reflect bending resistance and stiffness. Fracture toughness covers resistance to crack propagation, important for brittle materials. Surface hardness relates to wear. Wear resistance covers loss under prolonged mastication. Bond strength covers adhesion to tooth structure or other materials. And fatigue covers behaviour under repeated masticatory loading. Test conditions strongly affect bond strength results, including substrate preparation, bonded area, loading rate and storage before testing, particularly whether thermal cycling was applied. All of these must be specified and recorded.

Ageing and durability. The oral environment is demanding: temperature change, humidity, pH variation, masticatory loading and the chemical action of foods and drinks. Thermal cycling simulates temperature change from hot and cold foods and challenges the adhesive interface particularly. Chewing simulation applies cyclic masticatory load. Chemical immersion uses media of varying pH or containing staining agents. And light ageing addresses colour stability. Bond strength after thermal cycling is the key figure for adhesives, since interfacial failure clinically results from accumulated fatigue and thermal stress rather than a single overload.

Sequencing. Confirm specimen preparation first, verifying that conditions meet requirements including irradiance and degree of cure. Then perform non-destructive observation of appearance, colour and dimensions. Then apply ageing to items requiring it. And finally perform destructive mechanical testing. Confirming degree of cure deserves to come first: if specimens are inadequately cured, every subsequent mechanical and chemical result is unreliable. It can be confirmed through hardness or conversion measurements.

Preparing for submission. Provide complete instructions covering proportioning, mixing and curing. Provide the associated equipment, including mixing devices and curing lights where specific requirements apply. Provide sufficient material, since specimen preparation and repeated testing consume a considerable quantity. State shelf life and storage conditions, since material condition affects performance. Provide associated materials such as conditioners and primers within an adhesive system. And describe the clinical situations of use, which inform the test conditions.

How we handle it. For dental material testing we prepare specimens strictly according to the instructions and verify the actual output of the curing light beforehand; without that step, all subsequent data are skewed. For adhesive materials we suggest re-measuring strength after thermal cycling, since initial bond strength is easy to make look good while clinical failure mostly occurs after cyclic ageing.

Send us the product documentation and instructions and we will work through the items and specimen preparation. Phone or WeChat: +86 132 4819 8029.