Amoxicillin Plus Metronidazole in Periodontal Maintenance

Long-term Effects of Sub Gingival Debridement Associated With Antibiotics in Individual Undergoing Maintenance Periodontal Therapy

Gum disease require a lifetime supportive periodontal care aiming at preventing additional inflammation and bone resorption. During this phase it is also relevant to keep germs under acceptable levels through proper daily hygiene although patient's cooperation tends to decrease over time.

There are conflicting opinions regarding combination of dental scaling with antibiotics. This is why the present study was designed to evaluate the clinical and microbiological effects of combined therapy 1 year following supportive periodontal care. Fifty patients who voluntarily decide to participate will receive dental scaling associated with two different antibiotics or placebo capsules. Paper points will be used to collect dental plaque samples and levels of bacteria will be determined. Dental specialists will also perform clinical examinations. Patients would be available for 4 dental appointments: prior to and 3, 6 and 12 months after dental scaling.

Study Overview

• Status: Completed
• Conditions: Periodontitis; Periodontal Pocket
• Intervention / Treatment: Other: placebo; Drug: Amoxicillin 500 milligrams capsules plus metronidazole 400 milligrams

Detailed Description

The benefits of amoxicillin (AMX) plus metronidazole (MTZ) adjunctive to scaling and root planing (SRP) require further investigation, particularly in individuals with a high occurrence of recurrent periodontal pockets under periodontal maintenance therapy (PMT). The aim of the study was to evaluate the clinical and microbiological outcomes of systemic AMX+MTZ adjunctive to SRP in patients with recurring sites [probing depth (PD) ≥5 mm) under PMT, after 1 year of follow-up, compared to SRP alone.

Methods: A randomized controlled clinical trial will be conducted with 50 individuals in a PMT program, which will be randomly allocate in two groups: control group (SRP and placebo; n=24) and test group (SRP and systemic MTZ+AMX; n=23). Participants of the present study will be selected from an open cohort study comprising individuals under a PMT program, who were monitored over 12 years of consecutive recall visits (from August 2009 to April 2023). Periodontal clinical parameters and subgingival biofilm samples will be collected by trained and calibrated examiners at baseline (T1), 3 (T2), 6 (T3) and 12 (T4) months after treatment. Microbiological analyses will be performed at T1, T2 and T4 by real-time quantitative polymerase chain reaction.

The percentage of residual pockets will be listed. Additionally, an overall mean PD value will be calculated for the treated sites initially measuring ≥ 5mm and clinical attachment loss (CAL) ≥ 3mm. Statistical testing for normality with respect to the distribution of study outcomes (clinical parameters) will be performed using the Kolmogorov-Smirnov test. Parametric and non-parametric tests (Chi-squared, Wilcoxon and Friedman tests) will be performed when appropriate. Spearman's correlation (r) will be used to evaluate the relationship between bacterial counts and periodontal condition between groups and evaluation times. All analyses will be performed using statistical software Statistical Package for the Social Sciences (SPSS) (p < 0.05).

• Study Type: Interventional
• Enrollment (Actual): 50
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Brazil
  • Minas Gerais
    • Belo Horizonte, Minas Gerais, Brazil, 31270-901
      • Federal University of Minas Gerais, Dental School

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• individuals under a PMT program
• monitored over ~13 years of consecutive recall visits (from August 2009 to May 2023).
• individuals reclassified as stage III and IV periodontitis
• not having presented the following clinical endpoint in two consecutive PMT visits - presence of ≤4 sites with PD ≥5 mm
• non-diabetics
• non-smokers
• no antibiotic use for any purpose within 3 months prior to entering the study

Exclusion Criteria:

• pregnant or lactating women
• smokers
• presence of systemic diseases that could affect the progression of periodontitis long-term administration of anti-inflammatory drugs,
• need for antibiotic premedication for routine dental therapy and
• allergy to metronidazole or amoxicillin

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: control; 1) scaling and root planing (SRP) plus systemic administration of placebo (n=25)	Other: placebo; supra and subgingival scaling and root planing (SRP) using manual and ultrasonic instruments in all residual pockets under anesthesia, performed within 2 consecutive days; systemic use of placebo containing corn starch capsules three times a day for 7 days after SRP
Experimental: antibiotics; 2) scaling and root planing (SRP) plus systemic administration of amoxicillin and metronidazole (n=25).	Drug: Amoxicillin 500 milligrams capsules plus metronidazole 400 milligrams; supra and subgingival scaling and root planing (SRP) using manual and ultrasonic instruments in all residual pockets under anesthesia, performed within 2 consecutive days; systemic use of amoxicillin (500 milligrams) + metronidazole (400 milligrams) three times a day for 7 days after SRP; Other Names: Amoxil; Amoxicillin Trihydrate

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
whole-mouth periodontal pocket depth improvement	mean pocket depth (PD) in millimeters	baseline and 12 months
changes in percentage of deep periodontal pocket	proportion of sites with PD ≥5 millimeters	baseline and 12 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
total bacterial load in sub gingival samples	mean total bacterial load	baseline and 3 months
levels of target species in sub gingival samples	mean levels of periodontal pathogens	baseline and 3 months

Collaborators and Investigators

• Sponsor: Federal University of Minas Gerais
• Collaborators: Conselho Nacional de Desenvolvimento Científico e Tecnológico
• Investigators: Principal Investigator: Fernando O Costa, PhD, Titular Professor in periodontics

Study record dates

Study Major Dates

• Study Start (Actual): July 1, 2023
• Primary Completion (Actual): September 1, 2024
• Study Completion (Actual): September 1, 2024

Study Registration Dates

• First Submitted: June 17, 2023
• First Submitted That Met QC Criteria: June 28, 2023
• First Posted (Actual): July 6, 2023

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: February 27, 2025
• Last Verified: February 1, 2025

More Information

Terms related to this study

• Keywords: periodontitis; metronidazole; amoxicillin; root planing; dental scaling; periodontal maintenance
• Additional Relevant MeSH Terms: Periodontal Diseases; Mouth Diseases; Stomatognathic Diseases; Periodontitis; Periodontal Pocket; Anti-Bacterial Agents; Anti-Infective Agents; Antiprotozoal Agents; Antiparasitic Agents; Metronidazole; Amoxicillin
• Other Study ID Numbers: 5.957.583

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No