Evaluation of the influence of preoperative plaque index on pain after surgical removal of impacted mandibular third molars

Considering the importance of pain as a main complication after mandibular third molar surgery, the effect of oral hygiene on the outcome of treatment and lack of sufficient information on the effect of preoperative plaque index on the severity of pain after mandibular third molar surgery, this study was undertaken to evaluate the influence of preoperative plaque index on pain after surgical removal of impacted mandibular third molars.
This study was designed as a cohort study. Plaque index of the patients admitted into the Islamic Azad University, School of Dentistry, Tehran in 2014, who required surgery for the removal of impacted wisdom teeth, was determined by the OLeary method. Thirty patients were selected; 15 subjects had a plaque index over 40% (case group) and 15 had a plaque index below 40% (control group). A 40% criterion was selected based on articles in the field of periodontology. The two groups were matched in relation to age, gender and the type of the impacted tooth. All the surgeries were carried out by one surgeon. The postoperative pain severity in both groups was recorded by VAS (visual analogue scale) on the first, third and seventh days after surgery and assessed by Man-Whitney U and Friedman tests at each time interval (α = 0.05).
The group with plaque indexes over 40% (the case group) reported higher postoperative pain levels than the control group with plaque indexes under 40% and this difference was statistically significant (p value = 0.01). However, in both groups, patients who had a longer duration of surgery reported more severe postoperative pain during the first week.
Poor preoperative oral hygiene correlated with more severe postoperative pain after surgical removal of impacted mandibular third molars.