Trimming Biting Surface May Reduce Pain in First 24 Hours After Root Canal Treatment

Published 22 September 2026
Reviewed by Dr. Advaitha Anand, BDS MDS (Conservative Dentistry & Endodontics)

Managing Pain After Root Canal Treatment

When a tooth develops deep decay, inflammation can reach the inner dental pulp, which contains nerves and blood vessels. This severe inflammation is known as irreversible pulpitis, a condition where the nerve tissue cannot heal itself and requires root canal therapy. Often, this inflammation extends to the tissues surrounding the tip of the root, causing a condition called symptomatic apical periodontitis. This combination typically results in severe tooth pain, particularly when biting or applying pressure.

While root canal treatment removes the inflamed tissue to resolve infection and long-term discomfort, patients can sometimes experience temporary soreness following their initial treatment appointment. Researchers have investigated clinical techniques to minimize this early post-treatment discomfort, including occlusal reduction—a procedure where the dentist slightly trims the biting surface of the tooth so it makes reduced contact with opposing teeth.

How the Study Was Designed

A randomized controlled trial evaluated the effect of occlusal reduction on pain intensity following root canal care. The study initially enrolled 200 participants aged between 18 and 44 years. All participants presented with decayed back teeth (molars) diagnosed with both irreversible pulpitis and symptomatic apical periodontitis.

Before treatment began, patients rated their baseline pain intensity using a visual analogue scale (VAS), a standardized measurement tool for self-reporting pain. Baseline pain levels were high and comparable between the study groups, showing a median initial pain score of 8 out of 10.

The participants were randomly assigned to two treatment groups:

Group A received occlusal reduction on the treated tooth.
Group B maintained intact biting surfaces without any reduction.

All root canal treatments were performed over two clinical visits by two experienced endodontists following standard root canal protocols. Ultimately, 180 participants completed the evaluation protocol and were analyzed.

Pain levels were recorded by participants at set time intervals:

First visit follow-ups: 6 hours (T1), 12 hours (T2), 24 hours (T3), 48 hours (T4), and 72 hours (T5).
Second visit follow-ups: 6 hours (T6), 24 hours (T7), and 48 hours (T8).

Data was evaluated using non-parametric statistical tests, specifically the Mann-Whitney U, Wilcoxon signed-rank, and Friedman tests.

What the Findings Showed

The trial found that occlusal reduction led to a statistically significant decrease in pain during the initial day following the first treatment appointment:

First 24 Hours: Patients in Group A experienced significantly lower pain scores compared to Group B at 6 hours (p = 0.021), 12 hours (p = 0.033), and 24 hours (p = 0.015) after the first visit.
Subsequent Time Points: From 48 hours after the first visit through the remaining follow-up periods (T4 to T8), pain scores showed no statistically significant differences between the two groups (p > 0.05).
Two-Day Relief: By 48 hours after the first visit (T4), the median pain score fell to zero in both groups and remained negligible across all remaining assessments.

The study concluded that reducing the biting surface provides significant immediate relief during the first 24 hours after initial root canal treatment in patients presenting with severe pre-operative pain.

Limitations of the Trial

When considering these results, several specific limitations noted in the study design should be kept in mind:

Sample Attrition: Out of 200 enrolled participants, 180 were included in the final analysis.
Demographics and Tooth Location: The study was restricted to adults aged 18 to 44 years and specifically examined molar teeth with decay. The findings may not apply to other age groups or different tooth types.
Subjective Reporting: Pain scores relied on self-reported measurements using the visual analogue scale.
Clinical Protocol: Procedures were conducted over two visits by two experienced specialist endodontists following specific standardized protocols.

What This Means for Patients

For patients requiring root canal treatment for severely inflamed molar teeth, early post-treatment discomfort can be a major concern. This study indicates that reducing contact on the biting surface of the affected tooth can help lessen pain during the first 24 hours after the initial appointment. The findings also highlight that for both groups, pain reduced to near-zero levels within 48 hours. Any decision to adjust biting surfaces during root canal therapy depends on individual clinical evaluations performed by the treating dentist.