Sulcus reproduction with elastomeric impression materials: a new in vitro testing method.

Accurate reproduction of periodontal sulci is essential for dental impressions but remains challenging for narrow depths. Prior research has shown that conventional methods struggle with sub-200 micrometer dimensions. No prior work had resolved how different mixing techniques affect sulcus depth capture. This gap motivated the development of a controlled in vitro model. The model simulates clinical conditions using a steel cone with a circumferential sulcus. Reversible hydrocolloid mimics periodontal tissue while steel represents root surfaces. The study focuses on how material type and mixing strategy influence depth accuracy. Four elastomers were tested: one vinyl polysiloxane, two polyethers, and one hybrid. The model allows precise 3D laser topography measurements. This approach offers a repeatable way to assess material performance under standardized conditions.

The aim was to evaluate how well elastomeric impression materials reproduce sulcus depth across varying widths. The study tested single- and double-mix techniques on a controlled model. Researchers wanted to determine if material type or mixing strategy affects depth accuracy. They focused on widths of 50, 100, and 200 micrometers. The model simulates clinical conditions with a steel cone and hydrocolloid. The goal was to identify which materials and techniques best reproduce narrow sulci. The study also aimed to compare single- and double-mix methods. The findings could inform material selection for periodontal impressions.

The study used a truncated steel cone with a 2 mm deep circumferential sulcus. Three widths were tested: 50, 100, and 200 micrometers. The root surface was steel, and periodontal tissue was reversible hydrocolloid. Four elastomers were tested: FLE, IMP, P2, and FUS. Single-mix impressions used light-body or monophase pastes. Double-mix involved light-body as syringe material with either monophase or heavy-body as tray material. Eight impressions were taken per group. Depth was measured using 3D laser topography at eight points spaced 45 degrees apart. Statistical analysis used ANOVA and multiple comparisons with p<0.05 significance. The model allowed controlled testing of material and technique effects.

At 200 microm width, FLE and IMP showed the best depth reproduction. FUS and P2 performed similarly but less effectively. For narrower sulci (50 and 100 microm), IMP outperformed all other materials. Double-mix techniques (L+H or L+M) reproduced sulci better than single-mix (M or L alone). No significant difference was found between L+H and L+M in double-mix. All materials reproduced 200 microm sulci close to nominal depth. IMP showed consistent superiority in narrower widths regardless of technique. Double-mix methods were more reliable for narrow sulci than single-mix approaches. These results suggest material and technique choices matter for depth accuracy.

The study found that material type and mixing technique significantly affect sulcus reproduction. IMP consistently showed superior penetration in narrow widths. Double-mix techniques outperformed single-mix in 50 and 100 microm sulci. All materials achieved near-nominal depth at 200 microm. The model proved useful for evaluating material performance. Authors suggest that double-mix methods are preferable for narrow sulci. Material selection should consider sulcus width requirements. The findings support the use of IMP for narrow sulcus impressions. These results align with the authors' hypothesis about technique and material effects.