Page 151 - Peri-implant health: the effect of implant design and surgical procedure on bone and soft tissue stability

THE LONG-TERM EFFECT OF ADAPTING THE VERTICAL POSITION OF IMPLANTS ON PERI-IMPLANT HEALTH
Figure 3: X-ray representing one and the same patients with the bone level directly after placement (A) and after 6 (B), 12 (C), 24 (D), 36 (E), 48 (F), and 60 (G) months for the equicrestally (Group 1) and subcrestally placed implants (Group 2).
In the first six months, bone remodeling was 0.7 mm for the equicrestally placed implants and 0.0 mm in the subcrestally placed implants. Six months is the time period considered appropriate for initial bone remodeling, following biologic width establishment. Figure 2 shows the mean bone loss between 6 and 60 months for both groups. For the equicrestally placed implants, this was −0.09 mm (SD 0.47) with a maximum additional bone loss of 0.92 mm. The negative number of the mean is indicative for a small but statistically and clinically irrelevant bone gain (p = 0.335). For the subcrestally placed implants, this change was 0.08 mm (SD 0.16) with a maximum loss of 0.48 mm after initial bone remodeling. Although this change was statistically significant (p=0.021), it can be considered clinically irrelevant. When both treatment protocols are compared, the difference in bone loss between 6 and 60 months was not statistically significant (p = 0.077). Figure 3 is illustrative for the bone remodeling over time in both placement protocol, with the visible implant surface exposure in the equicrestally placed implant.
Peri-Implant Health
After 60 months, the overall mean plaque score based on all implants was 0.39 (SD 0.35 range 0.00–1.00), with a mean plaque score of 0.39 for the equicrestally placed implants (SD 0.34, range 0.00–1.00) and 0.39 for the subcrestally placed implants (SD 0.37, range 0.00–1.00). At 60 months, the mean plaque score of equicrestally and subcrestally placed implants was not statistically significantly different (p = 1.00). The overall mean bleeding on probing off all implants was 0.18 (SD 0.24, range 0.00–1.00), with a mean bleeding on probing of 0.20 (SD
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