Allocation of participants

The schedule for gingival displacement and impression making followed Latin block design which is presented in tabular form.[8] On day 1, the baseline impression was made without gingival displacement. On day 2, day 22, and on day 42 impressions were made after gingival displacement on intact maxillary right central incisor with anyone of the three gingival displacement agents according to Latin block design [Table 1].

Latin block design used in the study

Impressions were made for all 10 participants with irreversible hydrocolloid impression material to fabricate custom trays and disinfected using 2% glutaraldehyde (Korsolex rapid, Daman, India) and poured using type III dental stone (Kalabhai, India). The custom trays (Tray material Asian acrylates, Mumbai, India) were fabricated by adapting two layers of softened baseplate wax (Deepti dental products, Ratnagiri, India) onto the diagnostic cast to act as a spacer for impression material.

Baseline impression was made using custom tray for each subject on day 1 for the control group (Group 1) in which no gingival displacement was done. Baseline impression was made using Polyether monophase impression material (3M ESPE, Impregum™, Germany) and disinfected using 2% glutaraldehyde and poured using type IV die stone (Ultrarock, kalabhai, India).

On day 2, day 22, and day 42, gingival retraction was done on intact maxillary right central incisor by any one of the three gingival retraction materials, i.e. stay-put (Group 2), expasyl (Group 3), and astringent gingival retraction paste (Group 4) as per the Latin block design. All three gingival retraction materials were used as per the manufacturer's instructions.