Bleeding on probing

The estimated probability or observed proportion of BOP for implants was 0.31 (95% CI: 0.14–0.70) in the PRF group and 0.30 (95% CI: 0.12–0.77) in the control group. The ratio of the probability of observing BOP was 1.046 (95% CI: 0.91–1.20), indicating that the probability of observing BOP is 4.6% higher in the PRF group than in the control group. No statistical difference in BOP was observed between the groups (p = 0.51).

Plaque control record

The mean PCR in the control group was 8% (95% CI: − 2–19), whereas the mean PCR in the PRF group was 13% (95% CI: 4–22). The mean difference between the groups was 5% (95% CI: − 9–18%). There was no statistical difference in PCR between the groups (p = 0.51).

Keratinised peri-implant tissue

The width of the keratinised tissue around the implant was 3.15 mm (95% CI: 2.30–4.01) in the PRF group and 3.40 mm (95% CI: 2.43–4.37) in the control group. The difference between the groups was 0.25 mm (95% CI: − 1.54–1.05). No statistical difference in the width of the keratinised peri-implant tissue was observed between the groups (p = 0.70).

Recession of peri-implant soft tissue

The estimated probability or observed proportion of recession of > 0 mm buccal for implants was 0.15 (95% CI: 0.04–0.55) in the PRF group and 0.30 (95% CI: 0.12–0.77) in the control group. The ratio of the probability of observing recession of > 0 mm was 0.513 (95% CI: − 0.10–2.51), indicating that the probability of observing recession of > 0 mm was 4.87% lower in PRF group (1–0.513 = 0.487) than in the control group. No statistical difference in the recession of peri-implant tissue was observed between the groups (p = 0.41).