Department of Oral Rehabilitation, Faculty of Dentistry, University of Otago, Dunedin, New Zealand.
Pro Vice Chancellor Health Sciences, University of Otago, Dunedin, New Zealand.
J Esthet Restor Dent. 2020 Jun;32(4):410-415. doi: 10.1111/jerd.12581. Epub 2020 May 22.
This clinical study measured the change in opening and height of the displaced gingiva using paste and cord retraction materials for definitive impression making of natural teeth and assessed if they were comparable and clinically acceptable.
Impressions of 4 maxilla premolars from 10 participants were taken using a split-mouth protocol. All participants were free of periodontal disease, had a thick biotype, a minimal of 3 mm height of keratinized gingival tissue and gingival sulci depths of 2 mm. The bleeding index (BI), gingival index (GI) plaque index (PI), sulcular depth, level of attachment and tooth sensitivity were recorded at baseline, just after retraction, at 24 hours and at 2 weeks. Impressions were poured in stone and then after initial analysis were cross-sectioned to allow measurements of the gingival height change and gap size to be recorded.
The paste produced a slightly smaller gap compared to the cord (0.041 mm less, P = .014) whilst the mean displacement for the cord was 0.282 mm and paste was 0.241 mm respectively. Gingival height with the paste was 0.047 mm lower than that achieved by the cord (P = .208).
Cord and paste retraction produced comparable clinically acceptable gingival gaps, with the cord producing statistically larger gap size.
The cord and paste retraction materials produced comparable clinically acceptable gingival retraction.
本临床研究通过糊剂和缝线两种收缩材料对天然牙进行最终印模制取，测量移位牙龈的开口度和高度的变化，并评估其是否具有可比性和临床可接受性。
采用分口方案对 10 名参与者的 4 颗上颌前磨牙进行了印模制取。所有参与者均无牙周病，具有厚的生物型，角化龈组织高度至少为 3mm，牙龈沟深度为 2mm。在基线、收缩后即刻、24 小时和 2 周时记录出血指数（BI）、牙龈指数（GI）、菌斑指数（PI）、龈沟深度、附着水平和牙齿敏感度。制取印模后用石腊灌注，然后进行初步分析，再将其横截，以记录牙龈高度变化和间隙大小。
糊剂产生的间隙比缝线略小（小 0.041mm，P =.014），而缝线的平均移位量为 0.282mm，糊剂为 0.241mm。使用糊剂时的牙龈高度比使用缝线时低 0.047mm（P =.208）。
缝线和糊剂收缩均可产生临床可接受的、具有可比性的牙龈间隙，缝线在统计学上产生的间隙更大。
缝线和糊剂收缩材料均可产生临床可接受的、具有可比性的牙龈收缩效果。
