Keratinized Gingiva Dimensions around Dental Implants Affect Gingival Health

Objectives: The aim of this prospective clinical trial was to investigate the association between the width of keratinized gingiva (KG) and gingival thickness with clinical and immunological parameters around dental implants. Methods: 39 dental implants (3I osseotite) that were rehabilitated by a single crown or fixed partial denture, and were in function for ≥1year , were examined. Clinical examinations include plaque index (PI), probing depth (PD), bleeding on probing (BOP), KG width, gingival thickness and buccal gingival recession. Gingival crevicular fluid (GCF) samples were collected for PgE2 assay. Results: PI and GI means were relatively low (0.42±.48 and 0.73±.53 respectively). PD ranged between 1-6mm (mean 3.04±.78), which is within the normal limits. Likewise, gingival recession ranged between 0-3mm (mean 0.6±.93). KG width ranged from 0-7mm (mean 2.154±1.98), while gingival thickness ranged from 0.47-2.46 mm (mean 1.19±.426). Statistically significant negative correlation was found between gingival thickness and gingival recession (r = .322, p = .0457) and similar trend was found between KG width and gingival recession (r = .272, p = .093). A negative correlation was also found between KG width and PgE2 level (r = .37, p = .0205). When data was dichotomized by KG width, it was found that wider gingival band (≥1mm) was associated with less gingival recession compared to narrow (<1mm) band (0.407±.14 and 1.04±.33, respectively, p= 0.0487). Likewise, low levels of GCF PgE2 were found in wide KG band (75.22±6.7pgr/s and 121.5±26.26 respectively, p= 0.0265). Similarly, thick gingiva (>1mm) were associated with less recession compared to thin (≤1mm) gingiva (0.31±.12 and 1.07±.31 respectively, p= 0.0487). Conclusions: The quality of KG around dental implants affects both clinical and immunological parameters at these sites. These findings are of special importance in the esthetic zone, where poor gingival quality may lead to greater gingival recession.