Optimizing the gingival phenotype: the contribution of combined i-PRF and microneedling therapy

The clinical management of thin gingival phenotype constitutes a daily challenge for the periodontologist. These tissues, characterized by low gingival thickness (GT), present increased structural vulnerability to tissue recession and inflammatory aggression. The emergence of minimally invasive protocols, such as the use of injectable platelet-rich fibrin (i-PRF) and microneedling (MN), now offers a promising alternative to strengthen these tissues without systematically resorting to more invasive autogenous grafts.

This systematic review with meta-analysis aims to precisely evaluate the efficacy of the combination of i-PRF and microneedling compared to these approaches used as monotherapy. The authors seek to determine whether this combination significantly improves gingival thickness and keratinized tissue width (KTW). The hypothesis tested is based on biological synergy: i-PRF provides the growth factors necessary for regeneration, while microneedling stimulates the mechanical tissue response. This analysis also evaluates the impact of this combined protocol on overall periodontal health and patient aesthetic satisfaction, while highlighting a certainty of evidence currently qualified as low by the researchers.

Methodology of the systematic review

The authors of this review screened five international databases, without language restrictions, to isolate the most relevant clinical evidence. The final selected corpus includes four prospective randomized clinical trials, all conducted using a split-mouth design, totaling 116 participants with a thin gingival phenotype.

The rigor of the analysis is based on a strict extraction protocol: two independent reviewers collected the data individually. To ensure the reliability of the results, the team assessed the risk of bias using the Cochrane RoB 2 tool and performed the meta-analysis using RevMan software version 5.1.

The experiment compared the effectiveness of the combination of i-PRF (injectable platelet-rich fibrin) and Microneedling (MN) versus monotherapies (i-PRF alone or MN alone). The primary and secondary endpoints included:

• Gingival thickness (GT) and keratinized tissue width (KTW).
• Clinical attachment level (CAL) and probing depth (PD).
• The plaque index (PI), as well as patient-reported comfort and aesthetic satisfaction.

In the practice, this methodology allows for evaluating whether the synergy of these two minimally invasive techniques surpasses the conventional approach during the first three months of healing.

Results: i-PRF + Microneedling synergy superior to monotherapy

The data synthesis highlights a synergistic effect between i-PRF and microneedling (MN) for the management of thin gingival phenotypes. The increase in gingival thickness (GT) constitutes the most significant result of this meta-analysis, particularly during the initial healing phase.

The authors report that the combined use of i-PRF and microneedling outperforms i-PRF alone for GT augmentation during the first trimester of follow-up. In contrast, the impact on keratinized tissue width (KTW) remains clinically and statistically inconclusive, regardless of the protocol used.

From a periodontal clinical perspective, significant improvements were observed for the following parameters:

• Clinical Attachment Level (CAL);
• Probing depth (PD);
• The Plaque Index (PI).

Beyond biometric measurements, the combined approach appears to promote a better patient experience, with higher comfort and aesthetic satisfaction scores compared to isolated treatments. However, it is imperative to note that the certainty of the evidence is rated as low. Analysis via the Cochrane RoB 2 tool reveals a high risk of bias among the included studies, which necessitates a cautious interpretation of these clinical gains.

Clinical analysis: A promising synergy for the thin phenotype

The results of this systematic review suggest that the combination of i-PRF with microneedling (MN) offers a tangible clinical advantage for increasing gingival thickness (GT). This synergy appears particularly effective during the first three months of treatment, surpassing the results of i-PRF monotherapy. For the practitioner, this means that mechanical stimulation through micro-perforations potentialises the action of autologous growth factors, promoting a more robust tissue response in cases of thin periodontal phenotypes.

However, a distinction must be made: while the thickness (GT) improves, the keratinized tissue width (KTW) does not seem to be significantly modified by this approach. In the dental practice, this technique should therefore be considered to reinforce the quality of existing tissue rather than to aim for a vertical gain of attached gingiva. The improvement in patient comfort and aesthetic satisfaction reported by the authors reinforces the interest of this minimally invasive approach compared to more extensive surgeries.

Limits and interpretative caution

The overall level of evidence remains modest. The review authors highlight a high risk of bias and a certainty of evidence rated as "low" according to Cochrane criteria. Although secondary periodontal parameters (probing depth, attachment level) show improvement, the small size of the compiled sample limits the statistical scope of the conclusions. Consequently, while the trend is positive, the integration of this protocol must be accompanied by rigorous monitoring, as long-term effects remain to be consolidated by more robust clinical data.

Summary of results

This meta-analysis, including 4 clinical trials and 116 participants, demonstrates that the combination of i-PRF with microneedling (MN) significantly increases gingival thickness compared to i-PRF alone, particularly during the first three months. While clinical parameters (probing depth, attachment level) and aesthetic comfort improve, the impact on keratinized tissue width (KTW) remains statistically insignificant.

In concrete terms, for the practitioner:

• Optimize the thin phenotype: Prioritize the synergy of i-PRF and microneedling to increase tissue thickness, an interesting minimally invasive option before orthodontic or implant treatment.
• Distinguish between thickness and width: Do not replace autologous grafting techniques with this protocol if your objective is specifically to increase the keratinized tissue width (KTW).
• Manage predictability: Although promising, these results are based on low-certainty evidence; maintain rigorous monitoring of tissue stability beyond the first trimester.

Technical lexicon of the study

i-PRF (Injectable Platelet-Rich Fibrin): Injectable platelet-rich fibrin concentrate, obtained by centrifugation of autologous blood without anticoagulant, used for its sustained release of growth factors.

Microneedling (MN): Minimally invasive technique consisting of creating controlled micro-perforations in the gingival mucosa to stimulate the healing cascade and induce neocollagenesis.

Gingival Thickness (GT): Gingival thickness measured quantitatively, a key parameter in defining periodontal phenotypes and an indicator of tissue resistance to mechanical stress.

Width of Keratinised Tissue (KTW): Width of the keratinised tissue, corresponding to the apico-coronal distance between the gingival margin and the mucogingival line.

Thin gingival phenotype: Periodontal morphology characterized by a low soft tissue thickness, associated with a greater susceptibility to gingival recessions and inflammation.

Clinical Attachment Level (CAL): Clinical attachment level representing the distance between the cemento-enamel junction and the bottom of the sulcus, used to assess the stability or destruction of periodontal supporting tissues.

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