Influence of vertical mucosal thickness and keratinized mucosal width on peri-implant health and marginal bone loss: a prospective study with a 2-year follow-up.

Background: Although it is known that the soft tissues around dental implants have an impact on its health and cause marginal bone loss, it is still uncertain exactly how. The aim of the study is to evaluate the effect of vertical mucosal thickness and keratinized mucosal width on marginal bone loss and periodontal clinical parameters in the 2-year follow-up of implants placed at the bone level.

Material and methods: 87 bone-level dental implants were placed in 31 patients. The initial vertical mucosal thickness (VMT) was recorded at implant placement. At the second year follow-up, gingival index (GI), plaque index (PI), probing depth (PD), bleeding on probe (BOP), radiographic marginal bone loss (MBL) and width of the keratinized mucosa (KMW) were all measured. MBL and periodontal clinical parameters were evaluated separately according to VMT and KMW. VMT was categorized into two groups, Group 1 (≤ 2mm) and Group 2 (> 2 mm). KMW was divided into two groups, Group A (< 2mm) and Group B (≥ 2 mm).

Results: Dental implants had a mean MBL of 0.39 ± 0.57 mm in the 2-year follow-up. MBL in Group 1 and 2 was 0.39 ± 0.42 mm and 0.38 ± 0.65 mm, respectively. MBL in Group A and B was 0.41 ± 0.68 mm and 0.37 ± 0.49 mm, respectively. No significant difference in MBL was found in the KMW and VMT groups (p>0.05). The group with the thicker vertical mucosa was shown to have statistically substantially higher PI and GI values (p=0.040 and p=0.014, respectively).

Conclusions: Within the limits of the present study, it was observed that the vertical mucosal thickness and the width of the keratinized mucosa did not affect the marginal bone loss. In addition, it was observed that the insufficiency of the width of the keratinized mucosa did not affect the periodontal clinical parameters, but the thicker vertical mucosa could increase the plaque index and gingival index.