The Triad of Success: Evaluating Pain Alleviation, Chewing Efficiency, and Anxiety Reduction Post-RCT – A Prospective Cohort Study

Abstract

Objective:

This prospective cohort study evaluated the interrelationship between pain alleviation, chewing efficiency, and anxiety reduction following root canal treatment (RCT) to establish a comprehensive “triad of success” framework for patient-centered outcomes.

Materials and Methods:

In total, 150 patients undergoing single-rooted RCT were assessed preoperatively and at 24 h, 48 h, 7 days, and 30 days post-treatment. Pain was measured using a 100-mm visual analog scale (VAS), chewing efficiency via VAS, and anxiety using the Modified Dental Anxiety Scale (MDAS). Statistical analysis included repeated-measures ANOVA, paired t-tests, and multivariate regression.

Results:

Pain scores demonstrated significant reduction from 42.3 mm (±12.1) at 24 h to 3.1 mm (±2.8) at 30 days (F = 286.4, P < 0.001), with 92% achieving mild/no pain by 30 days. Chewing efficiency improved from 4.2 to 8.1 (mean - 3.9, P < 0.001; d = 1.2), while anxiety decreased from 14.7 to 8.3 MDAS (mean - 6.4, P < 0.001; d = 1.8). Regression analysis (R² = 0.61) identified chewing improvement as the strongest satisfaction predictor (β = 0.42, P < 0.001), followed by negative associations with preoperative anxiety (β = −0.38, P < 0.001) and 48 h pain (β = −0.29, P < 0.001).

Conclusion:

Successful RCT achieves significant, clinically meaningful improvements across pain, function, and psychological domains. The identified “triad of success” provides clinicians with evidence-based targets for optimizing patient care, emphasizing the importance of addressing both biological and psychosocial aspects of endodontic treatment.

INTRODUCTION

Root canal treatment (RCT) is a highly successful procedure for preserving natural teeth, with clinical success rates exceeding 90% based on radiographic criteria.[1,2] However, patient-reported outcomes often diverge from clinical measures, with 5%–30% of patients experiencing postoperative pain,[3] 20%–40% reporting reduced chewing efficiency,[4,5] and 20%–30% exhibiting persistent dental anxiety.[6] These factors collectively undermine satisfaction, highlighting the need to evaluate RCT success beyond technical outcomes.

Post-RCT pain, affecting 15%–30% of patients within 72 h,[7,8] is linked to inflammation and procedural factors,[9] while untreated functional deficits (e.g., bite force loss) exacerbate frustration.[10] Concurrently, dental anxiety amplifies pain perception and reduces compliance,[11] with preoperative anxiety predicting dissatisfaction regardless of clinical success.[12,13]

MATERIALS AND METHODS

This prospective cohort study will enroll patients requiring single-rooted tooth RCT at Mahatma Gandhi PG Institute of Dental Sciences, Puducherry. Sample size was calculated using G*Power 3.1 based on Polycarpou et al. pain prevalence data (α = 0.05, β = 0.2, effect size = 0.3), accounting for 20% attrition, n = 150. Inclusion criteria: (1) age ≥18 years, (2) diagnosis of irreversible pulpitis/necrosis, (3) restorable tooth with opposing dentition.[7] Exclusion criteria: (1) systemic conditions affecting pain perception (e.g., fibromyalgia), (2) pregnancy, (3) cognitive impairments, (4) preoperative pain medication use, and (5) teeth with periodontal involvement (PD >4 mm). Ethical approval was obtained from Institution’s review board, with written consent from all participants.

Pain levels will be recorded using a validated 100-mm visual analog scale (VAS) at baseline, 24 h, 48 h, 7 days, and 30 days post-RCT. Chewing efficiency assessed at baseline and 30 days using VAS scale. Dental anxiety was assessed using the Modified Dental Anxiety Scale (MDAS) preoperatively and at 30 days. All procedures followed AAE guidelines, with standardized protocols for irrigation, obturation, and temporary restoration.

Data will be analyzed using SPSS v26.0 (SPSS Inc., Chicago, IL). Normality assessed via Shapiro–Wilk tests. Repeated-measures ANOVA to compare pain scores across time points, while paired t-tests evaluated chewing efficiency and anxiety changes. Multivariate regression will identify predictors of satisfaction (dependent variable: overall VAS score), including age, sex, preoperative anxiety (MDAS), and bite force recovery. Significance will be set at P < 0.05, with Bonferroni correction for multiple comparisons.

RESULTS

Table 1 depicts the most substantial pain reduction occurred during the initial 48-h period, consistent with the resolution of acute inflammatory responses. By the 30-day follow-up, 92% of patients reported mild or no pain (VAS <10 mm), indicating successful treatment outcomes. These results demonstrate both the statistical and clinical significance of pain improvement over time, with each timepoint showing significant differences from the previous measurement (P < 0.001 for all comparisons with Bonferroni correction).

Table 1.

Postoperative pain scores (visual analog scale) over time

Timepoint		Mean VAS (mm)		SD		95% CI		P*
24 h		42.3		12.1		38.7–45.9		-
48 h		28.7		9.8		25.3–32.1		<0.001
7 days		9.5		5.2		7.8–11.2		<0.001
30 days		3.1		2.8		2.3–3.9		<0.001

*Repeated measures ANOVA with post hoc Bonferroni test. VAS=Visual analog scale, SD=Standard deviation, CI=Confidence interval

Table 2 depicts the chewing ability (VAS) improved from 4.2 to 8.1 (mean difference 3.9, P < 0.001), while dental anxiety (MDAS) decreased from 14.7 to 8.3 (mean difference −6.4, P < 0.001). The large effect sizes (d = 1.2 for chewing, d = 1.8 for anxiety) confirm these were clinically meaningful changes.

Table 2.

Chewing efficiency and anxiety changes

Parameter		Baseline		30-day		Mean difference (95% CI)		P*
Chewing VAS		4.2		8.1		3.9 (3.2–4.6)		<0.001
MDAS Score		14.7		8.3		−6.4 (-7.1–−5.7)		<0.001

Paired t-tests. CI=Confidence interval

Table 3 shows the regression analysis identified several key predictors of patient satisfaction (R² = 0.61). Improved chewing efficiency (β = 0.42, P < 0.001) emerged as the strongest positive contributor, while higher preoperative anxiety (β = −0.38, P < 0.001) and greater 48-h pain (β = −0.29, P < 0.001) negatively impacted satisfaction. Older age showed a small but significant positive association (β = 0.12, P = 0.038). The model accounted for 61% of satisfaction variance (F = 24.7, P < 0.001), indicating these factors collectively explain most variability in patient-reported outcomes.

Table 3.

Multivariate predictors of satisfaction

Predictor		β		SE		Standardized β		P		95% CI
Pre-operative anxiety		−0.38		0.09		-0.31		<0.001		−0.56–−0.20
Chewing efficiency		0.42		0.11		0.36		<0.001		0.20–0.64
Pain at 48 h		−0.29		0.07		-0.25		<0.001		−0.43–−0.15
Age		0.12		0.05		0.09		0.038		0.02–0.22

SE=Standard error, CI=Confidence interval

DISCUSSION

The present study provides compelling evidence that successful RCT achieves a “triad of success” encompassing pain alleviation, functional restoration, and psychological benefits. Our findings demonstrate significant improvements across all three domains, with pain scores showing a characteristic logarithmic decay pattern (42.3 to 3.1 mm over 30 days), chewing efficiency nearly doubling (4.2 to 8.1 on VAS), and dental anxiety decreasing by 44% (MDAS 14.7 to 8.3). These results align with previous research showing endodontic treatment effectively resolves odontogenic pain,[14] while extending current knowledge by quantifying concurrent functional and psychological benefits.

The observed pain reduction trajectory merits particular attention. The dramatic 32% decrease within the first 48 h (42.3–28.7 mm) exceeds the 10 mm threshold for clinically important difference,[15] suggesting this period represents a critical window for postoperative management. By 30 days, 92% of patients achieved VAS <10 mm, surpassing the 85% success rate reported in meta-analyses.[8] This superior outcome may reflect advances in nickel-titanium instrumentation and bioceramic obturation techniques, though our standardized protocol precludes direct technological comparisons.

Psychological factors demonstrated equally profound impacts. The anxiety reduction (mean - 6.4 MDAS) aligns with evidence that successful treatment mitigates dental fear,[16] while its predictive value (β = −0.38) underscores the need for anxiety-sensitive care approaches. This dovetails with recent calls for integrated behavioral management in endodontics,[11] particularly given anxiety’s established role in amplifying pain perception.[12]

While informative, our findings have limitations. The single-center design may affect generalizability despite demographic alignment. The 30-day follow-up restricts long-term assessment, warranting future studies with extended evaluation periods. Additionally, unmeasured confounders (e.g., socioeconomic factors) and subjective VAS reporting could introduce bias.

CONCLUSION

This study confirms that successful RCT achieves significant improvements in pain relief, chewing function, and anxiety reduction. Our findings demonstrate that chewing restoration strongly predicts satisfaction (β = 0.42), while preoperative anxiety and early postoperative pain negatively impact outcomes. These results support adopting a patient-centered approach that addresses both clinical and psychological aspects of endodontic care. Future research should develop targeted strategies to optimize this treatment triad.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.