Evaluation of gingival displacement methods in terms of periodontal health at crown restorations produced by digital scan: 1-year clinical follow-up.

The purpose of this clinical study was to compare the effects of the gingival displacement techniques of retraction cord, cordless paste system, and Er,Cr:YSGG laser troughing on the periodontal tissues around the crown restoration produced using a digital scan. This was analyzed by recording the probing depth (PD), plaque index, gingival index (GI), mobility, sensitivity, and bleeding on probing (BOP) index. This study included 60 mandibular 1 molars from 52 participants (20 males and 32 females) requiring crown restoration. The margin lines of the crown preparations were placed 1 mm subgingivally. Based on the gingival displacement technique used, the patients were divided into three groups: retraction cord, cordless paste system, and Er,Cr:YSGG laser troughing. A digital scan of the prepared tooth was performed. Follow-up appointments were scheduled at five different times: 1 day, 1 month, 3 month, 6 month, and 1 year. Six periodontal indices were used to assess the periodontal health. The chi-square test was used to compare categorical variables depending on the groups. There was a significant difference in the PD, GI, and BOP index scores among the three techniques during the 1-year clinical monitoring (p < 0.001). The PD in the three zones of the buccal surface showed a significant increase with time in the retraction cord and cordless paste system groups (p < 0.001). The highest GI scores were observed in the retraction cord group on the 1 day. The Er,Cr:YSGG laser troughing procedure produced lower PD, GI, and BOP index scores as compared to the retraction cord and cordless paste system procedures in the 1-year period.