Irrigation - does it affect post-operative pain?

A randomised control trial involving eighty patients who were blindly allocated into four different groups for different disinfection and irrigation methods on lower permanent molars. The patients were treated by one experienced endodontist across two visits. The four methods of irrigation used were: 1. Conventional irrigation 2. Sonic irrigation activation system 3. Irradiation with a 980 nm diode laser and conventional irrigation 4. Irradiation with a 980 nm diode laser and sonic irrigation activation system Pain levels were then assessed postoperatively at 8 h, 24 h, 48 h and 7 days following access and chemomechanical preparation at the first visit.

Eighty patients who visited the Endodontic Department at Biruni University were included in the study. Those who were included were healthy adults, experiencing moderate to severe pain (self-scored from 4 to 10, based on a 0 to 10 pain scale) at the start of treatment and those who were given a dental diagnosis of 'symptomatic apical periodontitis' with a negative cold test in a mandibular molar.

Qualitative data was analysed using a chi-square test, Fisher's exact chi-square test and Fisher-Freeman-Halton exact test. The Kruskal-Wallis test and Willcoxon test were used to assess inter-group and intra-group parameters.

The study found that patients in all groups experienced a statistically significant decrease in pain levels postoperatively. However, different irrigation methods resulted in no statistically significant differences in pain levels. There were also no statistically significant differences based on gender or age. Statistical significance was reached when p < 0.05.

The use of sonic irrigation activation and irradiation with a 980 nm diode laser did not significantly reduce post-operative pain in adult mandibular molars undergoing endodontic treatment when compared to conventional irrigation methods.