Influence of Keratinized Mucosal Width, Supracrestal Tissue Height, and Implant Diameter on Peri-Implant Marginal Bone Loss

A new study published in the Clinical Implant Dentistry and Related Research suggests that keratinized mucosal width, supracrestal tissue height, and implant diameter may influence peri-implant marginal bone loss.

There is evidence that the apico-coronal implant position and the mucosal phenotype can affect the extent of peri-implant bone loss. This clinical trial analyzes the bone remodeling and marginal bone loss that occur around conical-connection implants placed equicrestally and subcrestally, assessing the effect of the peri-implant soft-tissue phenotype.

Fifty-one patients received 56 implants of distinct diameters:

• 3.5 mm Ø (n = 6)
• 4.3 mm Ø (n = 41)
• 5 mm Ø (n = 9)

The implants were placed equicrestally, 1 mm subcrestally, and >1 mm subcrestally, depending on the initial supracrestal tissue height (STH). After 3 months of non-submerged healing, single metal-ceramic screw-retained implant-supported crowns were placed. Longitudinal measurements of STH, mucosal thickness, and keratinized mucosa width (KMW) were made at the time of implant placement (T0), crown placement (T1), and after 3 (T2) and 6 months (T3) of prosthetic loading. At each of these points, a radiographic evaluation of bone remodeling and marginal bone loss was also performed.

Results

STH was significantly greater for implants placed >1 mm subcrestally than for those placed 1 mm subcrestally. After 12 months of follow-up, a very significant (p < 0.001) loss of KMW was observed, in addition to a marginal bone loss of:

• 0.08 ± 0.1 mm in the group placed equicrestally
• 0.15 ± 0.2 mm in the group placed 1 mm subcrestally
• 0.14 ± 0.2 mm in the group placed >1 mm subcrestally

After the multiple linear regression, marginal bone loss was found to depend primarily on KMW (β = −0.43), while also being affected by STH (β = 0.32) and implant diameter (β = −0.28). Marginal bone loss may be influenced by the position with respect to the bone crest, as well as the KMW, STH, and implant diameter. However, more well-controlled studies are needed to verify these above-mentioned findings with different implant designs and connections.

Reference

Quispe-López N, Gómez-Polo C, Zubizarreta-Macho Á, Montero J. How do the dimensions of peri-implant mucosa affect marginal bone loss in equicrestal and subcrestal position of implants? A 1-year clinical trial. Clin Implant Dent Relat Res. 2024; 1-15. doi:10.1111/cid.13306

Keywords

• Keratinized mucosal width
• Supracrestal tissue height
• Implant diameter
• Peri-implant
• Marginal bone loss
• Quispe-López N
• Gómez-Polo C
• Zubizarreta-Macho Á
• Montero J