Effect of Valaciclovir on Inter-Appointment Pain in Endodontic Treatment of Necrotic Teeth

Aim: To investigate the effect of oral valacyclovir on inter-appointment endodontic pain in single-rooted necrotic teeth diagnosed with symptomatic apical periodontitis (SAP).

Materials and Methods: This study was a randomized, triple-blind, placebo-controlled clinical trial conducted on 38 teeth. Participants were assigned to intervention or control groups using stratified randomization based on gender and baseline pain severity. Both groups received similar root canal treatment; the only difference was the administration of valacyclovir in the intervention group and placebo in the control group. Patients' pain levels were monitored and recorded at 6, 24, and 48 hours post-treatment using a Visual Analog Scale (VAS), along with their consumption of analgesic (ibuprofen).

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Key information

Conditions

Symptomatic Apical Periodontitis Neurologic Manifestations Pain Pathological Conditions, Signs and Symptoms Signs and Symptoms

Age range

18 year–60 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Tehran University of Medical Sciences, School of Dentistry

Tehran, 1439955991, Iran

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Patients between 18 and 60 years of age
Require primary root canal treatment (RCT) in single-rooted maxillary or mandibular teeth (anterior or posterior)
Diagnosed with symptomatic apical periodontitis (SAP) with confirmed pulp necrosis

Exclusion criteria

Teeth with unrestorable crowns
Presence of endodontic-periodontal or pure endodontic lesions
Complex root canal anatomies as defined by the AAE Endodontic Case Difficulty Assessment Form
Internal or external root resorption
Calcified canals
Root canal configuration other than Vertucci's Type I
Pain originating from more than one tooth
Marginal periodontitis
Parafunctional habits
Systemic diseases classified as ASA class II or higher
Diagnosed migraine or other headache disorders mimicking orofacial pain
Intellectual or cognitive impairments
Pregnancy or breastfeeding
Use of medications affecting pain perception
Current use of antibiotics or antiviral agents
Known allergies to study medications

Treatment and study plan

Valacyclovir

Drug

valacyclovir group received 2 g (two 1 g tablets) one hour prior to treatment, followed by 2 g 12 hours later, and 1 g at both 24 and 36 hours post-treatment

Placebo

Drug

The control group received a placebo identical in appearance and administration schedule

Primary outcomes

Pain intensity measured by Visual Analog Scale (VAS)

Time frame: 6, 24, and 48 hours post-treatment

The Visual Analog Scale (VAS) is a commonly used tool for assessing pain intensity in patients. In this method, the patient is asked to indicate the perceived level of pain on a 10-centimeter horizontal line, where 0 represents "no pain" and 10 denotes "the worst pain imaginable." Based on the scores provided by patients, pain intensity is categorized into three levels: scores from 0 to 3 indicate mild pain, 4 to 7 indicate moderate pain, and 8 to 10 indicate severe pain.

Secondary outcomes

Proportion of participants requiring ibuprofen as rescue analgesic

Time frame: Within 48 hours post-treatment

Sponsors and collaborators

Lead sponsor

Tehran University of Medical Sciences

Other

Registry information

Official study title

Effect of Oral Valaciclovir on Inter- Appointment Endodontic Pain in Single-Rooted Necrotic Teeth With Symptomatic Apical Periodontitis: A Randomized Clinical Trial

Important dates

Study start: 2024
Primary completion: 2025
Study completion: 2025
First posted: Jun 11, 2025
Registry last updated: Jun 11, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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