Department of Biomedical and Neuromotor Sciences, DIBINEM, University of Bologna - Alma Mater Studiorum, Via San Vitale 59, Bologna 40125, Italy.
Oral Microbiology and Biomaterials Laboratory, Department of Biomedical, Surgical and Dental Sciences, via Pascal 36, Milan 20133, Italy.
J Dent. 2022 Jan;116:103893. doi: 10.1016/j.jdent.2021.103893. Epub 2021 Nov 16.
To evaluate the effects of microorganisms' contamination inside the dispensing syringes of different types of resin-based composites (RBCs).
This study encompassed two sections. First, an anonymous electronic survey was submitted via Google forms to Italian dentists to acquire information about composite handling during clinical procedures. Then, a bench test was performed on nanohybrid RBCs differing in matrix chemistry and fillers [FiltekTM Supreme XTE (3MTM); Venus Pearl (Kulzer GmbH); Admira Fusion x-tra (Voco)] to evaluate the microbial viability on their surfaces with/out photocuring. Uncured RBCs were exposed to standardized inocula of Streptococcus Mutans, Candida Albicans, Lactobacillus Rhamnosus, or mixt plaque in an in vitro model reproducing clinical restorative procedures. Half of the RBC specimens were cured after exposure. Microbial viability was assessed using an MTT-based test. Statistical analysis included three-way ANOVA and Tukey's tests (p<0.05).
Among 300 dentists completing the survey, the majority declared to use the spatula to carry the RBCs from the syringe to the dental cavity (50% same spatula; 35% two spatulas). However, 80% of respondents had personal feelings that using one spatula could be a source of cross-contamination. In vitro results using one spatula showed microbial contamination of all RBCs after one hour of storage. The contamination levels depended on the used strain and RBC type (p<0.0001), but photocuring did not reduce contamination (p = 0.2992).
Microbial species' viability on uncured RBCs and after photocuring shows the existence of a considerable risk of cross-infection. Clinical procedures in Restorative Dentistry need to acknowledge and to reduce such risk during RBCs handling.
Dentists must be aware of the possibility of cross-infection during restorative procedures, especially when the same spatula is repeatedly used for placing RBC in the cavity.
评估不同类型树脂基复合材料（RBC）的配药注射器内部微生物污染的影响。
本研究包括两个部分。首先，通过谷歌表单向意大利牙医提交了一份匿名电子调查，以获取有关临床操作中复合处理的信息。然后，对纳米杂化 RBC 进行了台架测试，这些 RBC 在基质化学和填料上有所不同[FiltekTM Supreme XTE（3MTM）；Venus Pearl（Kulzer GmbH）；Admira Fusion x-tra（Voco）]，以评估在未光固化和光固化条件下其表面的微生物活力。将未固化的 RBC 暴露于变形链球菌、白色念珠菌、鼠李糖乳杆菌或菌斑混合物的标准化接种物中，在体外模型中模拟临床修复程序。暴露后，将一半的 RBC 样本进行光固化。使用 MTT 基于测试评估微生物活力。统计分析包括三因素方差分析和 Tukey 检验（p<0.05）。
在完成调查的 300 名牙医中，大多数人表示使用刮刀将 RBC 从注射器转移到牙科腔中（50%使用同一刮刀；35%使用两把刮刀）。然而，80%的受访者个人认为使用一把刮刀可能是交叉污染的来源。使用一把刮刀进行的体外结果显示，所有 RBC 在储存一小时后都受到微生物污染。污染水平取决于所用菌株和 RBC 类型（p<0.0001），但光固化不能降低污染（p=0.2992）。
未固化 RBC 和光固化后微生物物种的活力表明存在相当大的交叉感染风险。在牙髓治疗过程中，临床程序需要认识到并降低 RBC 处理过程中的这种风险。
牙医在进行修复程序时必须意识到交叉感染的可能性，尤其是当同一刮刀反复用于将 RBC 放入腔中时。
