*3.3. Biologic Parameters*

On implant level only a statistically significant difference could be measured for the plaque score at 24 months (*p* = 0.042), with significantly less plaque for the equicrestally placed compared with subcrestally placed implants. However, at all other time points the plaque–and bleeding scores were not statistically significantly different, indicative of peri-implant health (Table 3).

**Table 3.** Mean plaque and bleeding on probing on implant level at 6, 12, 24 and 36 month for each study group and mean difference between respectively equicrestally versus subcrestally placed implants and implants with moderately rough versus minimally rough neck; *p* < 0.05 indicates a statistically significant difference (paired *t*-test).


For the probing pocket depth at implant level only at 24 months a statistically significant difference between equicrestally placed compared to subcrestally placed implants could be observed (Table 4). After three years all groups are comparable indicative of peri-implant health.

**Table 4.** Mean probing pocket depth on implant level at 6, 12, 24 and 36 months for each study group and the mean difference between respectively equicrestally versus subcrestally placed implants and implants with a moderately rough versus minimally rough neck; *p* < 0.05 indicates a statistically significant difference (paired *t*-test).

