Associate Professor, Prosthodontics, Faculty of Dentistry, Beirut Arab University, Beirut, Lebanon.
Professor, Fixed Prosthodontics, Faculty of Dentistry, Cairo University; Future University, New Cairo, Egypt.
J Prosthet Dent. 2019 Feb;121(2):265-270. doi: 10.1016/j.prosdent.2018.05.010. Epub 2018 Oct 26.
Although the conventional chemicomechanical cord technique is widely used, packing the cord into the sulcus may cause pain and bleeding. Cordless displacement techniques have been introduced, but a comparison of these systems is lacking.
The purpose of this clinical study was to evaluate the efficiency and gingival response of 4 cordless gingival displacement systems.
One hundred twenty teeth in 30 participants were allocated to 4 groups according to the material used: Tr (Traxodent; Premier Dental Products Co), Es (Expasyl; Acteon UK), Ez (Expazen; Acteon UK), and Mr (3M Retraction; 3M ESPE). Baseline measurements of periodontal indices and a digital scan were acquired. The cordless displacement pastes were applied according to the manufacturer's instructions. After removal, a second scan was acquired. Participants were recalled on the 2nd and 14th day to measure periodontal indices and for scans. Screenshots were superimposed to measure changes in the gingiva. Statistical differences among the different materials in achieving lingual and buccal vertical gingival displacement were tested using the related-samples Friedman 2-way ANOVA test by ranks at 3 time points such as immediate, at 2 days, and at 14 days (α=.05).
Immediate gingival displacement varied with the system used. For horizontal displacement, median values ranged between 150 μm (Tr) and 725 μm (Ez) for buccal displacement and between 93 μm (Tr) and 550 μm (Ez) for lingual displacement. Minimum and maximum displacements also varied and followed a similar trend, with Traxodent providing the lowest displacement. The plaque index and attachment level did not statistically differ before and after the treatment. The periodontal parameters were not statistically significant among the groups at all time intervals, except for the gingival index that increased for all the groups after 2 days.
Significant differences were found among the 4 tested systems in both vertical and horizontal gingival displacement. Expasyl, Expazen, and 3M Retraction exceeded the 200-μm requirements for horizontal displacement. Traxodent provided the least displacement in both vertical and horizontal dimensions.
尽管传统的化学机械根管技术被广泛应用，但将根管填充到根管内可能会引起疼痛和出血。已经引入了无绳根管移位技术，但缺乏这些系统的比较。
本临床研究的目的是评估 4 种无绳牙龈移位系统的效率和牙龈反应。
将 30 名参与者的 120 颗牙齿根据使用的材料分为 4 组：Tr（Traxodent；Premier Dental Products Co）、Es（Expasyl；Acteon UK）、Ez（Expazen；Acteon UK）和 Mr（3M Retraction；3M ESPE）。采集牙周指数和数字扫描的基线测量值。根据制造商的说明应用无绳移位糊剂。去除后，采集第二次扫描。在第 2 天和第 14 天，参与者被召回以测量牙周指数和进行扫描。叠加屏幕截图以测量牙龈的变化。使用相关样本 Friedman 2 路方差分析检验不同材料在实现舌侧和颊侧垂直牙龈移位方面的差异，在 3 个时间点（即时、第 2 天和第 14 天）进行等级相关检验（α=.05）。
即时牙龈移位因系统的不同而不同。对于水平移位，颊侧的中位数范围在 150 μm（Tr）至 725 μm（Ez）之间，舌侧的中位数范围在 93 μm（Tr）至 550 μm（Ez）之间。最小和最大位移也有所不同，呈相似趋势，Traxodent 提供的位移最小。治疗前后菌斑指数和附着水平无统计学差异。除第 2 天所有组的牙龈指数增加外，所有组在所有时间间隔的牙周参数均无统计学差异。
在垂直和水平牙龈移位方面，4 种测试系统之间存在显著差异。Expasyl、Expazen 和 3M Retraction 超过了水平位移 200 μm 的要求。Traxodent 在垂直和水平方向上提供的位移最小。
