This study compared the efficacy of nimesulide and meloxicam in the control of pain, swelling and trismus, following the extraction of impacted inferior third molars. Twenty patients with two impacted inferior third molars, in similar positions, were selected. The patients were designated randomly to the meloxicam group (MEL: 7.5 mg twice a day for 5 days) or the nimesulide group (NIM: 100 mg for 5 days). Following the extractions, swelling was more pronounced in the MEL group than in the NIM group ( P ≤ 0.001). There were no significant differences in pain intensity between the treatment groups ( P > 0.05). At the 72-h evaluation, reduction was significantly larger in mouth opening in the MEL group compared with the NIM group ( P < 0.05). In conclusion, pain control was similar in both treatment groups. NIM was more effective than MEL in the control of swelling and trismus following the extraction of impacted lower third molars.
Inflammatory response is mediated by prostaglandins, the synthesis of which is initiated by the release of arachidonic acid from membrane phospholipids. The subsequent conversion of arachidonic acid to prostaglandin is catalyzed by cyclooxygenases (COX). There are two known isoforms of this enzyme, COX-1 and COX-2. Whilst COX-1 is expressed constitutively in most tissues for homeostatic functions, an array of stimuli, including inflammation, injury and mechanical stress, trigger the synthesis of COX-2, which, in consequence, induces the production of pro-inflammatory prostaglandins . Non-steroidal anti-inflammatory drugs (NSAIDs) inhibit the synthesis of prostaglandins, and are prescribed for pain relief and edema control following most oral surgery.
NSAIDs are categorized into four groups according to their efficacy as inhibitors of COX-1 and/or COX-2: selective COX-2 inhibitors (e.g. rofecoxib, NS-389); preferential COX-2 inhibitors (e.g. etodolac, meloxicam, nimesulide, celexoxib); NSAIDs with relatively poor selectivity (e.g. diclofenac, piroxicam); NSAIDs with weak inhibition of both COX-1 and COX-2 (e.g. many of the salicylates) .
It has been claimed that meloxican (MEL) and nimesulide (NIM) are preferential inhibitors of 3- to 12-fold selectivity for COX-2 over COX-1 in vitro . Recent studies have demonstrated the efficacy of MEL in controlling postoperative pain, swelling and trismus after the removal of impacted third molars . NIM has also been found to alleviate postoperative pain and swelling after maxillofacial surgery, such as that for the removal of third molars . In contrast to MEL, the effect of NIM on trismus control has not been evaluated.
The aim of the present study was to compare the efficacy of two NSAIDs, NIM and MEL, in controlling postoperative pain, swelling and trismus following the extraction of impacted lower third molars.
The protocol of the present study was approved by the Institutional Ethics Committee. The subjects were selected from a pool of patients admitted for regular dental treatment between January and September 2005. All participants, or their legal guardians, signed an informed consent form.
The study protocol involved a screening consultation followed by initial therapy to ensure gingival health and to establish the optimal biofilm control, surgical therapy and post-surgical examinations.
Twenty healthy, non-smoking patients (11 males and 9 females; mean age ± standard deviation: 20.3 ± 2.66 years) without contraindications to oral surgery and not taking any medication, who were to undergo surgical removal of bilateral and symmetrically placed impacted lower third molars were enrolled in the study. Orthopantomographic radiograms were taken to ensure the similarity of the tooth inclinations according to Winter’s classification (vertical, mesioangular and distoangular positions) . The impaction of the teeth was categorized as fully or partially bone-impacted.
A single examiner performed all clinical measurements prior to surgery (baseline) and 24, 48 and 72 h postoperatively ( Fig. 1 ). Swelling measurements were taken using a 2-0 nylon thread (Ethicon, Johnson & Johnson, São Paulo, SP, Brazil) and a millimeter ruler, and trismus measurements were made using a Willis caliper. To evaluate the swelling, markings with permanent marker were made prior to the surgery on the following facial regions: the angle of the mandible, the tragus, the labial commissure, the nasal border, laterally to the external corner of the eye, and on the soft pogonion. The following measurements were taken: Distance I; Distance II; Distance III; Distance IV; Distance V ( Fig. 1 ) . Trismus was evaluated by measuring the distance between the incisal edges of the upper and lower central incisors (Distance VI) . The sensation of pain was evaluated in the periods 8–12 h, 12–24 h and after 24 h postoperatively using a verbal rating scale , in which the patients indicated the intensity of pain according to six descriptive scores (1: no pain, 2: mild pain, 3: moderate pain, 4: severe pain, 5: very severe pain, 6: extreme pain). The amount of the analgesic, acetaminophen 750 mg (Tylenol ® , Cilag Farmacêutica Ltda, São Paulo, SP, Brazil) taken in the periods 8–12 h, 12–24 h and after 24 h postoperatively was also recorded. Gastrointestinal adverse events were registered on the patients’ charts.
According to the randomized, double-blind and crossed design of the study, bilateral molars were assigned randomly by the toss of a coin to either the MEL group (7.5 mg) or the NIM group (100 mg). Both drugs, kept in appropriate receptacles with a green or red label, were administered orally 1 hour before surgery, 12 h after the first dose, and thereafter once a day for 5 consecutive days.
Extra-oral antisepsis was performed with 2.0% chlorhexidine solution, and intraoral antisepsis with a 0.12% chlorhexidine rinse (Proderma Farmácia de Manipulação Ltda, Piracicaba, SP, Brazil). The nerve block of the inferior alveolar, lingual and buccal nerves was carried out using 2.0% lidocaine with 1:100,000 epinephrine (Lidocaína-Alphacaina, Adrenalina 1:100,000, DFL Ind. E Com. Ltda, Rio de Janeiro, RJ, Brazil). The surgery to remove the lower third molar followed the standardized technique. Briefly, an ‘L’ shaped incision was made, and a mucoperiosteal flap was elevated. When osteotomy and tooth section were performed on one side, the other side received the same treatment in order to standardize the surgical trauma. All procedures were performed under abundant irrigation with a sterilized 0.9% physiological solution.
During the first days after the surgery, the patients were authorized to take analgesics (acetaminophen 750 mg four times daily) (Tylenol ® , Cilag Farmacêutica Ltda, São Paulo, SP, Brazil) only in case of pain. They were instructed to eat only soft food, and to abstain from mouth washing during the first 24 h and from brushing and flossing around the surgical area until suture removal (14 days post-surgery). For plaque control, patients used a 0.12% chlorhexidine mouth rinse for 1 min twice a day for 2 weeks postoperatively.
The minimum interval between the removal of the first and the second impacted lower third molar was 15 days.
The Student–Newman–Keuls test or the Wilcoxon test was used to investigate potential differences within each treatment group and between the two groups. The χ 2 -test was used to assess the relationship between pain score and tooth impaction, and between pain score and tooth position. A one-way ANOVA, followed by a post hoc T -test or a Tukey-test, was used to compare the amount of analgesic used by the patients in relation to teeth impaction and the position, respectively.
The level for a significant difference was set at P ≤ 0.05. Calculations were performed using the SPSS statistical software package (SPSS Inc., Chicago, IL, USA).
All patients complied with the study protocol, tolerated the surgical procedures well, and completed the follow-up period. Neither gastrointestinal adverse events nor postoperative complications occurred during the study.
In both treatment groups, a significant increase in swelling was observed after surgery for all measurements taken ( P ≤ 0.001) ( Table 1 ). In general, the MEL group presented more pronounced swelling than the NIM group. The differences between both drugs were statistically significant after 24 h for Distance II, after 48 h for Distances II and V, and after 72 h for all distances measured ( P ≤ 0.03) ( Table 1 ).
|24 h||1.7 ± 1.3 a , b||1.8 ± 1.7 a , b||3.9 ± 2.0 a , b||3.1 ± 1.6 a , b , *||5.3 ± 4.1 a , b||3.9 ± 2.2 a , b||5.2 ± 4.1||4.9 ± 3.2 a||4.2 ± 3.4 a , b||3.1 ± 2.2 a , b|
|48 h||3.3 ± 2.2 c||2.6 ± 2.0 c||6.2 ± 2.3 c||4.5 ± 2.5 c , *||7.3 ± 3.5 c||6.1 ± 2.2 c||9.0 ± 5.2 c||7.4 ± 3.6 c||6.5 ± 3.4 c||4.9 ± 2.2 *|
|72 h||5.5 ± 3.9||3.3 ± 2.4 *||8.4 ± 3.2||5.7 ± 3.1 *||10.5 ± 3.5||7.3 ± 2.5 *||12.4 ± 5.5||9.4 ± 3.3 *||9.4 ± 4.0||6.5 ± 2.7 *|
In both groups, the pain intensity was significantly higher 8–12 h post-surgery than in the interval 12–24 h and after 24 h ( P ≤ 0.003) ( Fig. 2 ). No patients had pain or used analgesics after 24 h . The tendency for analgesic intake was higher in the first observation period than in the second ( P = 0.08). There was no significant difference in pain intensity between the MEL and NIM groups ( P > 0.05) and patients in both groups used a similar average amount of analgesics (8–12 h, MEL 2.55 ± 1.09 capsules, NIM 2.2 ± 0.83 capsules, P = 0.23; 12–24 h, MEL 1.70 ± 1.12 capsules, NIM 1.35 ± 0.49 capsules, P = 0.86) ( Table 2 ). Postoperative pain and analgesic intake did not differ between patients with partially or fully bone-impacted teeth, and were independent of the inclination of the third molars ( P > 0.05).