Lack of keratinized tissue may be associated with a higher risk of peri-implantitis suggests a new study published in the Scientific Reports
Dental implants are the preferred choice to replace missing teeth and restore the function and aesthetics of the edentulous site. Although implants placed in the maxilla and mandible have demonstrated high survival rates throughout the years clinicians, as well as patients, should be aware of the possible technical and biological complications that may take place during the postoperative period. Among the most important complications to consider are peri-implant mucositis and peri-implantitis, which necessitate critical care. Peri-implant mucositis is defined as an inflammation limited in the soft tissue surrounding dental implants, characterized by bleeding on gentle probing with no detectable bone loss. On the other hand, peri-implantitis is accompanied by progressive bone loss, beyond the initial bone remodeling stage that occurs following implant placement, along with signs of inflammation in the peri-implant mucosa (i.e., bleeding on probing, suppuration). Peri-implantitis, in particular, can impact the health of the peri-implant tissue irreversibly and compromise the long-term survival of dental implants, even when treated. Consequently, prevention and early risk assessment remain the best strategy in the case of peri-implant inflammations.

This study aimed to investigate the effect of the lack of keratinized mucosa on the risk of peri-implantitis, while also accounting for possible confounding factors. A literature search was conducted in PubMed and Scopus, including human studies that assessed the presence and width of keratinized mucosa in relation to the occurrence of peri-implantitis. Twenty-two articles were included, and 16 cross-sectional studies we meta-analyzed.
The prevalence of peri-implantitis was 6.68–62.3% on patient-level and 4.5–58.1% on implant-level. The overall analysis indicated that the lack of keratinized mucosa was associated with a higher prevalence of peri-implantitis
Similar results were shown when subgroup analyses were performed, including studies with a similar case definition of peri-implantitis fixed prostheses only, patients under regular implant maintenance, and studies adjusting for other variables
Thus, the lack of keratinized mucosa is a risk factor that increases the prevalence of peri-implantitis and should be accounted for when placing dental implants.
Reference:
Mahardawi, B., Jiaranuchart, S., Damrongsirirat, N. et al. The lack of keratinized mucosa as a risk factor for peri-implantitis: a systematic review and meta-analysis. Sci Rep 13, 3778 (2023). https://doi.org/10.1038/s41598-023-30890-8