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

Dental Caries Clinical Trial

— Nobio  

Official title:

Nobio In Situ Clinical Study - Pilot Study

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT04059250
• Other study ID #: P0535966
• Status: Completed
• Phase: N/A
• Start date: May 28, 2019
• Est. completion date: March 10, 2020

Study information

• Verified date: March 2021
• Source: University of California, San Francisco
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

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.

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 25
• Est. completion date: March 10, 2020
• Est. primary completion date: March 10, 2020
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 80 Years

Eligibility

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

Related Conditions & MeSH terms

• Dental Caries
• Denture, Partial, Removable

Intervention

Device:
• Nobio composite
Nobio has developed a bactericidal composite, which does not leak out the bactericidal nano fillers
• traditional composite
traditional composite which has no bactericidal activities

Locations

Country	Name	City	State
United States	UCSF School of Dentistry, Preventive and Restorative Dental Sciences	San Francisco	California

Sponsors (2)

Lead Sponsor	Collaborator
University of California, San Francisco	Nobio Ltd.

Country where clinical trial is conducted

United States, 

References & Publications (14)

Benelli EM, Serra MC, Rodrigues AL Jr, Cury JA. In situ anticariogenic potential of glass ionomer cement. Caries Res. 1993;27(4):280-4. — View Citation

Beyth N, Houri-Haddad Y, Baraness-Hadar L, Yudovin-Farber I, Domb AJ, Weiss EI. Surface antimicrobial activity and biocompatibility of incorporated polyethylenimine nanoparticles. Biomaterials. 2008 Nov;29(31):4157-63. doi: 10.1016/j.biomaterials.2008.07.003. Epub 2008 Aug 3. — View Citation

Beyth N, Yudovin-Farber I, Bahir R, Domb AJ, Weiss EI. Antibacterial activity of dental composites containing quaternary ammonium polyethylenimine nanoparticles against Streptococcus mutans. Biomaterials. 2006 Jul;27(21):3995-4002. Epub 2006 Mar 27. — View Citation

Beyth N, Yudovin-Fearber I, Domb AJ, Weiss EI. Long-term antibacterial surface properties of composite resin incorporating polyethyleneimine nanoparticles. Quintessence Int. 2010 Nov-Dec;41(10):827-35. — View Citation

Chatzistavrou X, Velamakanni S, DiRenzo K, Lefkelidou A, Fenno JC, Kasuga T, Boccaccini AR, Papagerakis P. Designing dental composites with bioactive and bactericidal properties. Mater Sci Eng C Mater Biol Appl. 2015;52:267-72. doi: 10.1016/j.msec.2015.03.062. Epub 2015 Mar 28. — View Citation

Clasen AB, Ogaard B. Experimental intra-oral caries models in fluoride research. Acta Odontol Scand. 1999 Dec;57(6):334-41. Review. — View Citation

Dijkman GE, Arends J. Secondary caries in situ around fluoride-releasing light-curing composites: a quantitative model investigation on four materials with a fluoride content between 0 and 26 vol%. Caries Res. 1992;26(5):351-7. — View Citation

Gorton J, Featherstone JD. In vivo inhibition of demineralization around orthodontic brackets. Am J Orthod Dentofacial Orthop. 2003 Jan;123(1):10-4. — View Citation

Hals E, Nernaes A. Histopathology of in vitro caries developing around silver amalgam fillings. Caries Res. 1971;5(1):58-77. — View Citation

Hollanders ACC, Kuper NK, Maske TT, Huysmans MDNJM. Secondary Caries in situ Models: A Systematic Review. Caries Res. 2018;52(6):454-462. doi: 10.1159/000487200. Epub 2018 Apr 5. — View Citation

Kidd EA. Diagnosis of secondary caries. J Dent Educ. 2001 Oct;65(10):997-1000. — View Citation

Kuper NK, Montagner AF, van de Sande FH, Bronkhorst EM, Opdam NJ, Huysmans MC. Secondary Caries Development in in situ Gaps next to Composite and Amalgam. Caries Res. 2015;49(5):557-63. doi: 10.1159/000438728. Epub 2015 Sep 26. — View Citation

Maupomé G, Sheiham A. Criteria for restoration replacement and restoration life-span estimates in an educational environment. J Oral Rehabil. 1998 Dec;25(12):896-901. — View Citation

Zero DT. In situ caries models. Adv Dent Res. 1995 Nov;9(3):214-30; discussion 231-4. Review. — View Citation

* Note: There are 14 references in all — Click here to view all references

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Mineral Loss ?Z	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, ?Z, 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 ?Z (µm * vol % mineral) is calculated using Simpson's integration rule.	mineral loss ?Z is determined after the 4 week wearing period