Microbiome and Immunogenity of Saliva During Orthodontic Therapy

March 22, 2023 updated by: Michael Nemec, Medical University of Vienna

Changes of Oral Microbiome and Immunogenity of Saliva During Orthodontic Therapy With Aligners and Multibracket Therapy - a Pilot Study

There are two essential ways of treatment in the field of orthodontics. The fixed appliance treatment with self-ligating or conventional brackets and treatment with aligners. Fixed orthodontic treatment has been the optional therapy for decades. Due to an increasing demand of patients for a more aesthetic treatment, the number of aligner treatments multiplied over the last years. Within the last years, a crucial role of oral microbiome in the maintenance of oral health was largely appreciated. However, to date there is no data on the effect of different orthodontic treatments on the oral microbiome. The aim of the research project is the prospective comparison of the oral microbiome in saliva of adult patients treated with Invisalign® aligners or metal brackets. We plan to include a sample of twenty healthy individuals. Half of the participants will receive aligner treatment with Invisalign® and half metal brackets. Saliva will be collected before, 3 and 6 months after the beginning of the orthodontic therapy via a stimulated a saliva collection. The 16S rDNA genes will be amplified and sequenced with Illumina MiSeq® System. Probing depth, bleeding on probing and Plaque Index will be evaluated over time and correlated with changes of the oral microbiome.

Study Overview

Detailed Description

Adult patients (18 years and older) from the Clinical Division of Orthodontics at the University Clinic of Dentistry Vienna will be invited to participate in this pilot microbiologic study according to defined inclusion/exclusion criteria after giving their consent. This study is a pilot project and therefore no sample size calculation will be made. Twenty patients will be treated with Invisalign® aligners and twenty patients will receive multibracket therapy. A previous microbiological study showed that lingual orthodontic therapy has a short-term effect on oral microflora. Another microbial study on colonization on dental implants also reported bacterial shift upon implant therapy.

All patients will get instructions in oral hygiene on the day when clinical records are gathered. On the day when the treatment plan will be presented to the patient, the Plaque Index will be evaluated by a trained orthodontist. For the start of the treatment a Plaque Index of < 20% is required. On the day before the orthodontic treatment is started, T0 sample collection will be conducted and periodontal indices will be assessed. A clinical examination including periodontal probing depth, bleeding on probing, and Plaque Index (PI) will be performed before (T0), after 3 months (T1) and after 6 months of the beginning of either aligner or bracket therapy. Microbiological sampling will be performed by stimulated saliva collection according to our protocol. Saliva samples will be divided in aliquots in stored in cryo-tubes at -80°C. Molecular detection of microorganisms by sequencing of 16S rDNA genes, sequencing analysis and taxonomic assignment will be performed at the Department of Laboratory Medicine at the Medical University of Vienna.

By sequencing of 16s rDNA genes with sequencing analysis and taxonomic assignment of bacteria in saliva we expect to reveal possible shifts in microbial phyla/genera between various time points. Metagenomic studies are commonly performed by analysing the prokaryotic 16S ribosomal RNA gene (16S rRNA), which is approximately 1,500 base pairs long and contains nine variable regions interspersed between conserved regions. Variable regions of 16S rRNA are frequently used in phylogenetic classifications such as genus or species in diverse microbial populations.

DNA Extraction:

Due to better quantitative and qualitative results in comparison to commercial DNA extraction kits, DNA will be isolated with a modified CTAB SDS chloroform-based method. Mechanical analysis will be carried out using 1mm silica spheres under addition of proteinase K (Qiagen, Venlo, Netherlands) as well as the detergents SDS (sodium dodecyl sulfate) and CTAB (cetyltrimethylammonium bromide). After extraction, the DNA quantity will be determined with Qubit® 2.0 via the dsDNA HS kit (Life Technologies, Carlsbad, California) and NanoDrop 2000c spectrophotometer (Thermo Scientific, Waltham, Massachusetts). Additionally, the absorption ratios A260/280 and A260/230 will be used to estimate the purity of the DNA.

Metagenome Analysis:

The overall composition of the bacterial organisms in the samples will be evaluated by analysing microbiome. Therefore, we will use high throughput sequencing with the MiSeq® platform (Illumina, San Diego, California). We will analyse the variable V3 and V4 regions of the 16S rRNA gene. For the phylogenetic classification, the bacterial 16S rRNA will be amplified using primers 27F (5'-CCT ACG GGN GGC WGC AG-3') and 1391R (5'-GACTACHVGGGTATCTAATCC-3').

Bioinformatic analysis:

The quality of the Next Generation Sequencing run will be assessed using the software FASTQC 0.11.4. The removal of low-quality bases will be carried out with the Trimmomatic-0.35 software . For sequence analysis and clustering similar sequences into clusters (OTUs) the UPARSE pipeline will be utilized. For comparison and statistical analysis of the microbiome data we will use RStudio (Team 2016) as platform with R as language (R Development Core Team 2010) and different R-packages.

Study Type

Interventional

Enrollment (Anticipated)

40

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

      • Vienna, Austria, 1090
        • Medical University of Vienna

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Class I skeletal relationship
  • Normo-divergent Frankfort Mandibular-Plane Angle
  • Minimal mandibular crowding in range from 1 to 3 according to Little's Index (Little 1975)

Exclusion Criteria:

  • Smoking habit
  • Presence of extensive dental restorations in proximity to the gingival margin
  • Presence of fixed bridges/crowns or partial dentures
  • Previous periodontal nonsurgical treatment (such as full mouth disinfection, quadrant-by-quadrant therapy, full mouth debridement) within the past year
  • Medications such as antibiotics, steroids, or nonsteroidal anti-inflammatory drugs within the past 6 months.
  • Plaque Index > 20% before start of treatment Diabetes Pregnancy

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Diagnostic
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Invisalign treatment
Aligner patients will be treated with Invisalign® aligners to correct malocclusion
Malocclusion will be treated with orthodontic appliances (fixed or removable)
Active Comparator: selfligating bracket treatment
Multibracket patients will be treated with self ligating orthodontic brackets
Malocclusion will be treated with orthodontic appliances (fixed or removable)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
changes of oral microbiome
Time Frame: up to 6 months
bacteria of the oral microbiome including cariogenic bacteria via dna sequencing
up to 6 months
changes of periodontal parameters
Time Frame: up to 6 months
plaque index
up to 6 months
changes of periodontal parameters
Time Frame: up to 6 months
probing depth
up to 6 months
changes of periodontal parameters
Time Frame: up to 6 months
bleeding on probing
up to 6 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
immunogenity of saliva on oral cells in vitro
Time Frame: up to 2 weeks
changes in viability
up to 2 weeks
immunogenity of saliva on oral cells in vitro
Time Frame: up to 2 weeks
gene expression changes via PCR
up to 2 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

November 1, 2019

Primary Completion (Actual)

September 1, 2022

Study Completion (Anticipated)

October 1, 2024

Study Registration Dates

First Submitted

September 22, 2019

First Submitted That Met QC Criteria

October 23, 2019

First Posted (Actual)

October 25, 2019

Study Record Updates

Last Update Posted (Actual)

March 23, 2023

Last Update Submitted That Met QC Criteria

March 22, 2023

Last Verified

March 1, 2023

More Information

Terms related to this study

Other Study ID Numbers

  • 1288/2019

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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