Nobio Clinical Study - Demineralization Prevention With a New Antibacterial Restorative Composite (Nobio)

March 11, 2021 updated by: University of California, San Francisco

Nobio In Situ Clinical Study - Pilot Study

Nobio has developed dental restorative materials with long term antibacterial properties in order to fight recurrent decay/caries around restorations. These composites with incorporated non-leaching antibacterial agents might overcome the vicious circle of newly developed cavities around freshly placed fillings.

The investigators will ask lower partial denture wearers to allow them to place a "gap model" with the Nobio-composite and enamel slab in one denture flange. In the other denture flange a gap model with a standard composite will be placed as control. In the laboratory the investigators will test with established methods for demineralization/caries prevention in the test and control enamel slabs, respectively.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

As a major issue in dentistry, it has been stated that two-thirds of all restorative dentistry involves the replacement of failed restorations. Secondary caries indicates a lesion developing at the margins of an existing restoration and is the major reason for replacement of amalgam and composite resin restorations in operative dentistry.

In research the use of experimental intra-oral caries models dealing with caries prevention has increased. The most realistic experimental model is the in vivo model that uses living teeth, followed by the in situ model using specimens with natural surfaces held in the mouth during the experimental period. In situ models have the potential to study both fundamental aspects of the caries process as well as more applied research problems in caries prevention in human subjects without actually causing caries in the natural dentition.

To simulate a failed interface between a tooth and a restoration, a gap can be formed between an enamel slab and the restoration prior to a cariogenic challenge. The "gap-model" will be inserted for instance into the denture flanges, and the cariogenic challenge occurs inside the mouth during the wear period..

Nobio has developed dental restorative materials with long term antibacterial properties in order to fight recurrent decay around restorations. These composites with incorporated non-leaching antibacterial agents might overcome the vicious circle of newly developed cavities around freshly placed fillings. The ongoing caries activity due to bacteria around the filling may be interrupted by quaternary ammonium silica dioxide (QASi) particles incorporated in the test composite at 1.2% (by weight). These particles are members of the Nobio Antimicrobial Particle (NAP) family (Nobio, Israel). QASi are synthesized to form a high concentration of antimicrobial groups that are covalently-bound onto a carrier core, such as silica. The resulting micro or nano-sized QASi particles are mixed with other fillers of the dental composite material, during manufacturing. Following in situ placement and light-initiated polymerization, QASi particles are permanently retained in the final dental restoration. Laboratory studies have shown that the quaternary ammonium silica particles are potent antibacterial agents, do not leach out in contrast to other antimicrobials or caries preventive active substances, inhibit the breakdown of the composite, and maintain antibacterial activity over time.

The study is an in situ study. Subjects, wearing lower partial dentures with acrylic flanges on both sides of the mouth will be recruited. On each side of the denture an enamel slab will be placed next to a composite, separated by a tiny gap. On one side of the denture the composite will be Nobio's antibacterial composite, on the other side a regular composite (a Nobio composite w/o particles or another commercial composite will serve as control material. Enamel slab and composite will be recessed into the flange, allowing microbial plaque to accumulate on top of it and especially in the gap.

After wearing the dentures for four weeks with the slabs, decalcification - ΔZ mineral loss - in the enamel slabs adjacent to the gap will be determined by cross-section microhardness testing in the laboratory. Average ΔZ mineral loss will be calculated for the Nobio group and the control group, and difference will be tested for statistical significance.

Study Type

Interventional

Enrollment (Actual)

25

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

  • United States
    • California
      • San Francisco, California, United States, 94143
        • UCSF School of Dentistry, Preventive and Restorative Dental Sciences

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

16 years to 78 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • aged between 18 and 80 years,
  • have at least six natural teeth remaining and have a recent history of dental caries
  • wearing lower partial denture (with replaced teeth on both sides of the mouth)
  • willing to wear their denture during the night
  • are in good health, of either gender
  • are in good current oral health with no active caries or periodontal disease (but with a history of caries)
  • have an understanding of the study
  • have saliva flow within the normal range (stimulated saliva flow rate of greater than 0.7 ml/minute)
  • no antibiotics for the last three months
  • willing to comply with all study procedures and protocols,
  • residing in San Francisco or other nearby locales with community water fluoridation (to eliminate water fluoridation as a potential confounding variable)
  • able to give written consent themselves
  • must be able to read and understand English
  • willing to sign the "Authorization for Release of Personal Health Information and Use of Personally Unidentified Study Data for Research" form; data will only be used for research

Exclusion Criteria:

  • subjects who have less than 6 natural teeth remaining
  • subjects who have used a 5,000 ppm fluoride toothpaste in the last 6 months
  • subjects who have used Chlorhexidine or any other antimicrobials (cetylpyridinium etc.) in the last 6 months
  • show evidence of extremely poor oral hygiene
  • subjects suffering from systemic diseases, significant past or medical history with conditions that may affect oral health or oral flora (i.e. diabetes, HIV, heart conditions that require antibiotic prophylaxis)
  • taking medications that may affect the oral flora or salivary flow (e.g. antibiotic use in the past three months, drugs associated with dry mouth / xerostomia)
  • other conditions that may decrease the likelihood of adhering to study protocol
  • in-office fluoride treatment within the last three months
  • subjects who will leave the area and are unable to complete the study

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: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Nobio flange
On the Nobio flange side of the lower partial denture the gap model will include a double sterilized piece of human enamel, a small gap, and next to it the Nobio composite.
Device: Nobio composite
Nobio has developed a bactericidal composite, which does not leak out the bactericidal nano fillers
Placebo Comparator: Traditional composite flange
On the traditional composite flange side of the lower partial denture the gap model will include a double sterilized piece of human enamel, a small gap, and next to it a traditional composite.
Device: traditional composite
traditional composite which has no bactericidal activities

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Mineral Loss ΔZ
Time Frame: mineral loss ΔZ is determined after the 4 week wearing period

The mineral loss is determined in the laboratory using cross-sectional microhardness testings of the enamel after the 4-weeks wearing period of the gap-model.

The overall relative mineral loss, ΔZ, for each sample is calculated by creating a hardness profile curve by plotting normalized volume percent mineral against distance from the outer enamel surface. The area under the curve that represents ΔZ (µm * vol % mineral) is calculated using Simpson's integration rule.
mineral loss ΔZ is determined after the 4 week wearing period

Collaborators and Investigators

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

Sponsor

University of California, San Francisco

Collaborators

Nobio Ltd.

Investigators

  • Principal Investigator: Peter Rechmann, UCSF - School of Dentistry - Preventive and Restorative Dental Sciences

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)

May 28, 2019

Primary Completion (Actual)

March 10, 2020

Study Completion (Actual)

March 10, 2020

Study Registration Dates

First Submitted

August 14, 2019

First Submitted That Met QC Criteria

August 14, 2019

First Posted (Actual)

August 16, 2019

Study Record Updates

Last Update Posted (Actual)

March 12, 2021

Last Update Submitted That Met QC Criteria

March 11, 2021

Last Verified

March 1, 2021

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • P0535966

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

Yes

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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