Comparison of crestal bone levels, peri-implant indices, mucosal margin position, and pink esthetic score of posterior implant crowns fabricated with immediate vs delayed impressions: A 5-year retrospective cross- sectional study.

This 5-year cross-sectional study aimed to determine whether immediate and delayed impression workflows result in differences in crestal bone levels (CBLs), peri-implant indices, mucosal margin position, and pink esthetic score (PES). Patients who had received a single posterior implant crown in the premolar and molar regions for ≥5 years were identified. Outcome measurements for peri-implant indices, including modified plaque index (mPI), modified sulcus bleeding index (mSBI), presence or absence of bleeding on probing (BoP), and probing pocket depths (PPDs), were measured at six sites per implant. The peri-implant mucosal margin position was measured relative to an adjacent or contralateral tooth. CBLs were assessed radiographically using standardized vertical bitewing radiographs with the paralleling technique. PES was calculated with a total possible score of 14. The Shapiro-Wilk test was employed to assess the normality of the data distribution. For variables following a normal distribution, a two-sample t-test was used to compare the mean values between the two groups. Conversely, for non-normally distributed data, the Mann-Whitney U test was utilized to determine whether significant differences existed between the group distributions. The significance level was set at 0.05. Mean mesial CBL for the immediately- and delayed-impressed groups were -0.30 ± 1.01 mm and 0.07 ± 1.18 mm, respectively. Mean distal CBL for the same groups were -0.14 ± 0.56 mm and -0.30 ± 0.79 mm, respectively. Mean mesio-buccal, mid-buccal, and disto-buccal PPDs were 3.18 ± 1.08 mm, 1.36 ± 0.76 mm, and 2.73 ± 1.10 mm for the immediate impression group and 3.14 ± 1.35 mm, 1.93 ± 1.14 mm, and 3.07 ± 1.07 mm for the delayed impression group. Mean mesio-lingual, mid-lingual, and disto-lingual PPDs were 2.55 ± 0.69 mm, 1.45 ± 0.69 mm, and 3.09 ± 0.94 mm for the immediate impression group and 3.29 ± 0.83 mm, 2 ± 1.24 mm, and 3.50 ± 1.45 mm for the delayed impression group. Mean PES was 12.64 ± 1.03 and 12 ± 2 for the immediately- and delayed-impressed groups. There were no statistically significant differences between immediate and delayed impression groups for PES, peri-implant indices, mucosal marginal position, or CBLs. At 5 years, there was no significant difference in PES, CBL, peri-implant indices, or mucosal margin position between implants restored with immediate impressions and those restored with delayed impressions made after osseointegration and soft tissue healing.