Influence of the Gingival Condition on the Performance of Different Gingival Displacement Methods—A Randomized Clinical Study

Abstract

This randomized clinical study examined the influence of the gingival condition—healthy versus mild inflammation—on sulcus representation and possible gingival recession for two gingival displacement procedures prior to conventional impression making. The interventions double cord technique or a kaolin paste containing aluminum chloride were applied to 40 probands. The opposite quadrant served as intrapersonal reference (split-mouth design). Precision impressions were then made. Extraoral digitization of the plaster models resulting from the reference impression prior to gingival displacement, the intervention impression and control impressions were the basis for the computer-aided three-dimensional analysis. After six months, a mild artificial gingivitis was induced, and the contralateral quadrant (cross-over design) was examined for the intervention. The gingivitis deteriorated the sulcus representation for the double cord technique group but did not affect the paste technique group. The gingival condition had no influence on the marginal gingiva height changes. The minor extent of those changes, which were measured up to six months after intervention at the palatal study site, were not considered to be in the clinically relevant range for gingival recession. For healthy gingiva, the cord technique showed superior sulcus representation compared to the paste technique. This advantage was lost to a great extent under the conditions of mild gingivitis.

Gingival Displacement in the Vertical and Horizontal Dimension under the Condition of Mild Gingivitis—A Randomized Clinical Study

“…The inclusion and exclusion criteria were in close accordance with those already described for the previous study [6].…”

“…Few basic elements of the concept of a previous study [6], performed at the same study center, were used for this study design (Figure 1). For the intervention B, the paste (product in previous study: Expasyl, Pierre Rolland, Merignac, France) was replaced by the paste product 3M™ Astringent Retraction Paste (3M Oral Care, Seefeld, Germany).…”

“…For intervention A, the same procedure was performed as described in detail in the publication of the prior study [6]. Briefly summarized, a primary cord of size 1 (Retracto, impregnated, Roeko, Langenau, Germany) followed by a secondary cord of size 2 (Retracto, not impregnated, Roeko, Langenau, Germany) were applied on the premolars' palatal side from papilla to papilla.…”

“…Next to the cord technique, there is a variety of different cordless systems for gingival displacement, such as pastes, foams and gels [2]. The comparison of the currently well-known cordless techniques to the conventional cord technique generally showed superior gingival displacement performance for the cord technique under healthy gingival conditions [3][4][5][6][7][8]. However, it is necessary to differentiate between the different cordless systems.…”

“…In a comparative study of cord versus kaolin paste system (Expasyl) performance, in which mild gingivitis was induced on purpose, the gingival condition worsened the cord's performance but did not influenced the paste's condition [6]. This clinically highly relevant influencing factor was not investigated for further paste systems, especially not for the 3M™ Astringent Retraction Paste.…”