Gingival biotype revisited—novel classification and assessment tool

Abstract

Objectives

To evaluate the relationship between gingival biotypes and gingival thickness based on probe transparency through the gingival margin and to assess the sensitivity of a novel classification method.

Material and methods

Sixty adult Caucasian subjects were stratified by their gingival biotype (GB) as defined by the transparency of a prototype double-ended periodontal probe through the buccal gingival margin into “thin” (30 subjects), “moderate” (15 subjects), and “thick” (15 subjects) GB. Three additional parameters were also assessed: gingival thickness (GT), probing depth (PD), and gingival width (GW).

Results

Median GT was 0.43 mm (P _25% 0.32; P _75% 0.58) for thin, 0.74 mm (P _25% 0.58; P _75% 0.81) for moderate, and 0.83 mm (P _25% 0.74; P _75% 0.95) for thick GB, respectively. GT was statistically significant different for thin versus moderate and thin versus thick, respectively (Kruskal-Wallis test, p < 0.05; Dunn’s test, thin versus moderate: p = 0.002; thin versus thick: p < 0.001; moderate versus thick: p = 0.089). GW was directly correlated with GT (Spearman correlation p < 0.01). The sensitivity of the new classification tool for diagnosing a thin GB was 91.3%. No adverse events or complications were reported.

Conclusion

GT differs significantly between the presented GB groups, hence, an alternative classification especially focusing on thin biotypes based on a modified periodontal probe might be advantageous. In addition, the presence of a thick gingiva is associated with a wide band of keratinized tissue.

Clinical relevance

This clinical setting might to be useful to identify high-risk patients with a very thin biotype and, consequently, higher risk for gingival recession after dental treatments.