Using Valacyclovir to Manage Pain from Acute Apical Abscesses

Role of Herpesviruses as a Causative Factor in Acute Apical Abscess

PHASE2 · University of California, San Francisco · NCT05266040

This study tests if adding valacyclovir to antibiotics can help reduce pain for people with acute apical abscesses.

Quick facts

PhasePHASE2
Study typeInterventional
Enrollment60 (estimated)
Ages18 Years to 80 Years
SexAll
SponsorUniversity of California, San Francisco (other)
Locations1 site (San Francisco, California)
Trial IDNCT05266040 on ClinicalTrials.gov

What this trial studies

This clinical trial aims to evaluate the effectiveness of a treatment regimen combining valacyclovir and antibiotics for managing pain associated with acute apical abscesses. It will involve 250 participants who will be randomly assigned to receive either the combination treatment or antibiotics alone. Preoperative and postoperative imaging will be conducted using cone beam computed tomography (CBCT) to assess pain levels and healing outcomes. The study seeks to address the viral component of endodontic infections to improve patient outcomes.

Who should consider this trial

Good fit: Ideal candidates are adults aged 18 and older who are systemically healthy and exhibit signs of pulp necrosis with moderate to severe pain.

Not a fit: Patients with certain dental conditions, smokers, or those with allergies to the study medications may not benefit from this trial.

Why it matters

Potential benefit: If successful, this treatment could significantly reduce pain and accelerate healing for patients suffering from acute apical abscesses.

How similar studies have performed: While this approach is innovative, it builds on preliminary findings from a pilot study, indicating potential for success but is not yet widely tested.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Patient must be ≥ 18-year-old
* Patient must be systemically healthy; American Society of Anesthesiologists (ASA) Class I or II
* Patient must exhibit clinical evidence of pulp necrosis and acute apical abscess
* Patient must present with radiographic
* signs of apical disease either by
* periapical radiography or cone-beam
* computed tomography
* Patient consented to receive conventional pulpal debridement, incision and drainage at the end of the study
* Persistent pain of moderate or higher level (\>4) was the main inclusion criterion. Pain assessed as follows: 0 defined as no pain, 1-3 as mild pain, 4-6 as moderate pain, and 7-10 as severe pain

Exclusion Criteria:

* Smokers (more than 10 cigarettes per day)
* External or internal tooth resorption
* Marginal periodontitis
* Pregnant or nursing mothers (hormonal factors may influence the periapical condition)
* Documented allergic or adverse reactions to amoxicillin or valacyclovir
* Teeth with unusual anatomy or inaccurate clinical diagnosis on the day of treatment (i.e., partially necrotic pulp)
* Patients currently taking antibiotics or antiviral medications

Where this trial is running

San Francisco, California

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Acute Apical Abscess, Pain, Acute

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.