RESUMO
BACKGROUND: The removal of the lower third molar is a routine procedure in oral surgery, yet it often leads to postoperative side effects, particularly inflammation. Despite various interventions explored in prior studies, there is still a need for effective strategies, such as anti-inflammatory substances, to address postoperative side effects. PURPOSE: The purpose of this study is to answer the following clinical question: Does the local injection of 0.9 M mannitol reduce postoperative pain, trismus, and swelling in patients undergoing bilateral symmetrically impacted mandibular third molar extraction? STUDY DESIGN, SETTING, SAMPLE: This prospective, single-blind, split-mouth study at Hamadan Dental School involved 30 patients with bilateral symmetrically impacted mandibular third molars. Inclusion criteria were: no current medication, no anesthesia allergies, bilateral symmetrically impacted mandibular third molars, non-smokers, and the absence of systemic diseases. Exclusion criteria were: poor oral hygiene, alcohol/cigarette use, drug consumption, diabetes, systemic/gastrointestinal disorders, infection at the surgical site, lack of patient cooperation, and mannitol/anesthetic allergy. PREDICTOR/EXPOSURE/INDEPENDENT VARIABLE: The predictor variable was therapeutic injection, and it was grouped into two categories, 0.9 M mannitol solution or distilled water. MAIN OUTCOME VARIABLE: The primary outcome variable was pain. Secondary outcomes are trismus, swelling, patient satisfaction, and analgesic consumption. COVARIATES: Covariates included demographic information and operative details. ANALYSES: Statistical analyses included repeated measures and paired t-tests with a significance level set at P < .05. RESULTS: The study comprised 30 participants (mean age: 22.6 ± 3.59 years; 6 men, 24 women). In the test group, pain intensity significantly decreased from 5.30 on surgery day to 0.00, with subsequent values of 2.97, 1.30, 0.40, 0.17, and 0.03. The control group also decreased from 7.68 to 0.00, with values of 4.73, 2.67, 0.97, 0.23, and 0.07. The difference was statistically significant (P < .001). No significant swelling differences at T1, T3, T5, and T7 (P > .05). The intervention group had improved maximum mouth opening at T1, T3, T5, and T7 (P = .011) compared to the control group. CONCLUSION AND RELEVANCE: Mannitol infiltration significantly reduces postoperative pain and trismus in impacted third molar surgery. This finding underscores the potential for improved patient comfort and recovery in this context.