Clinical comparition of using free gingival graft in patients presenting inadequate keratinized mucosa around dental implants in smokers and non-smokers: A controlled clinical study

Free gingival graft (FGG) is commonly used to increase keratinized tissue dimensions. The shrinkage of free gingival graft is a well-known clinical phenomenon. The aim of the present study is to investigate the effect of smoking on healing of FGG around dental implants and donor site. Twelve non-smoker and eight smoker patients presenting inadequate keratinized mucosa around dental implants in posterior area were included in the present study. Clinical parameters including probing depth, modified sulcus bleeding index and modified plaque index were determined. Individuals stents were prepared for all patients. All patients received FGG of same dimensions (5.0 mm x 10.0 mm). Vertical dimension of keratinized mucosa (KM) and vestibule sulcus depth were measured using individual stent. Tissue thickness of the FGG site and donor site were measured by ultrasonic device and transgingival probing. All measurements were performed at baseline, 30 and 90 and 180 days. Parametric and non-parametric statistical analyses were performed. There were no significant differences in demographics between smokers and non smokers (p> 0,05). Vertical dimension of keratinized mucosa and vestibule sulcus depth was significantly increased in both study groups at sixth month compared to baseline (p< 0,05). There was no significant difference between smokers and non-smokers in vertical dimension of mucosa and vestibule sulcus depth changes (p> 0,05). The thickness of keratinized mucosa in the recipient site significantly increased at first, third and sixth months compared to baseline (p< 0,05) in both groups. The total area of FGG significantly decreased at first, third and sixth months compared to baseline in both study groups (p< 0,05). The shrinkage of FGG significantly higher in smokers than non-smokers at sixth months (p< 0,05). Smoking does not seem to be an important factor for the changes in vertical dimension of keratinized mucosa and tissue thickness following FGG around dental implants with inadequate keratinized mucosa. However smoking might affect the total area of FGG.