Current Studies

All studies have been reviewed and approved by the University of Minnesota’s Institutional Review Board (IRB).

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In Vivo Assessment of the Tooth-Resin Composite Interface Using Optical Coherence Tomography

PI: Dr. Hooi Pin Chew

Sponsor: UMN SOD Veden Grant

The purpose of the study is to compare two ways to prepare your tooth for a filling. But, it is hard to see the microscopic changes to a filling clinically. We want to look at your filling with a special tool to see how the edges of a filling change over 18 months. This tool will help us to evaluate the edges of you filling.


Potential participants will be screened at the dental school by the study investigator to look at the tooth requiring a filling. Qualifying University of Minnesota (UMN) dental school patients will attend three (3) appointments at the UMN School of Dentistry over 18 months. First visit will include placement of the filling with two additional visits to monitor and record data about the filling. These visits will occur 6 and 18 months after the filling is placed.


A total of $160 will be paid in the form of Target gift cards; $10 at the screening appointment, $20 at procedure appointment, $50 at 6 month follow-up, and $80 at 18 month follow-up after the filling is placed. In addition, parking vouchers will be provided at the end of each appointment.

Inclusion Criteria:

Patient level

  • 18 years or older
  • Good general health
  • Fair oral hygiene
  • At least 20 teeth in occlusion
  • Available for the duration of the study

Tooth level

  • Occlusal caries in permanent posterior tooth; can be primary or secondary caries
  • Bucco-lingual caries not to exceed two-thirds of the occlusal table
  • Presence of caries confirmed via clinical and/or radiographic assessment
  • Selected tooth must be able to be isolated with either rubber dam or other isolation technique during procedure
  • Selected tooth must have opposing antagonist
  • Selected tooth should be periodontally healthy

Exclusion Criteria:

Patient level

  • Signs of bruxism

Tooth level

  • Wisdom tooth
  • Present with irreversible pulpitis
  • Periodontally compromised
  • Lesion requires cuspal coverage

How to get involved:


Kelli Trauger at [email protected].

Evaluating the performance of a new FDA-approved dental adhesive (bond) in tooth-colored fillings sponsored by 3M.

PI: Dr. Jorge Perdigao

Sponsor: 3M Company

The investigational device in this research study is Scotchbond™ Universal Plus (SBU+) Adhesive, which is manufactured by 3M. The intended purpose of SBU+ Adhesive is to be used as a bond-promoting substance between the tooth and dental restorations. It may also be used as a dentin sealant and as a bonding agent for repair of restorations. The comparator product (i.e., Control product) for the investigational device will be Scotchbond™ Universal (SBU) Adhesive, which is also manufactured by 3M.

The purpose of this research study is to compare SBU+ Adhesive with its predicate device (SBU Adhesive) in relation to functional aspects of the restorations. The follow-up period of 6, 12, and 24 months is based on previous 2-year studies of other composite resin adhesives showing differences in retention, fracture, and marginal adaptation scores.

Timeline: Patients will first be screened at the dental school by the study dentist to look at teeth requiring dental fillings. Qualifying patients will attend five (5) appointments at the University of Minnesota (UMN) School of Dentistry (SOD) over 24 months. First visit will include an in-person screening to make sure they meet eligibility requirements. Once screened, participants will be scheduled for an appointment to place two composite (tooth colored) fillings using the 3M dental adhesives with three (3) additional follow-up visits after the fillings are placed at 6, 12, and 24 months to record data on each tooth.

Compensation: A total of $300 will be paid in the form of a debit card; $50 after the filling appointment, $50 at 6-months, $100 at 12-months, and $100 at 24-months. In addition, up to $12 of parking will be  validated at the Washington Avenue Ramp on campus at the end of each appointment.

Inclusion Criteria:

  1. Between the ages of 18 and 70 years old at time of consent
  2. Needs at least two direct composite restorations for posterior Class I or Class II carious lesions in vital teeth that are asymptomatic and with minimal mobility (< 1 mm in the buccolingual direction) 
  3. Study teeth have a minimum buccolingual diameter of the occlusal surface that is at least 1/3 of the distance between the buccal and lingual cusps
  4. Teeth selected for Class II restorations need to have an adjacent tooth in a position that will allow for a contact relationship to be established
  5. Needs to read and understand the English language without assistance
  6. Available for all scheduled study visits for the duration of 24 months
  7. Good general health (i.e., meets ASA Level I or ASA Level II classification criteria)
  8. The selected teeth need to have occlusal contact with an antagonistic natural tooth
  9. Has existing radiographic images of the study teeth of current and acceptable diagnostic quality obtained within the previous 12 months (i.e., needs to be a patient of record at the UMN SOD)

Exclusion Criteria:
Preoperative exclusion criteria include the following:

  1. Has a history of adverse reaction to any materials used in this study
  2. Is pregnant or breast feeding at the time of screening
  3. Fewer than 20 teeth
  4. Is taking part in or planned to be enrolled in an evaluation of other restorative materials at any time during the study
  5. Advanced periodontal disease (i.e., Grace & Smales Mobility Index grade ≥ 2) that involve the study teeth
  6. Orthodontic appliance treatment within the previous 3 months
  7. Pronounced enamel wear facets, indicting severe, on-going bruxism
  8. Severe xerostomia
  9. The study tooth has a history of or existing, prolonged tooth hypersensitivity
  10. The study tooth is an abutment for fixed or removable prostheses
  11. The study tooth has a fracture or is visibly cracked such that it may impact the longevity of the tooth
  12. The carious lesion is stage RC5 or RC6 of the ICDAS radiographic scoring system
  13. Unable to understand study procedures or provide consent in English
  14. Is an employee or student of the study investigator(s)

Intraoperative exclusion criteria include the following:

  1. Pulp exposure of either study tooth during restoration procedure

Do you have a patient who qualifies? Contact Kelli Trauger at [email protected]

The Impact of Maxillofacial Prosthetic Rehabilitation on Oral Health-Related Quality of Life for Patients with Oral Cancer

PI: Dr. Heather Conrad

Funding: Delta Dental Grant 

Healthcare outcomes are prioritizing the functional health and well-being of the patient.
The objective of this study is to evaluate the effect of prosthetic rehabilitation of intra-oral defects in the oral cancer patient on their quality of life. 

Timeline: Potential participants will be consented and screened at the University of Minnesota (UMN) School of Dentistry (SOD) Faculty Dental Clinic (FDC) by the research team. Qualifying UMN SOD patients will attend two (2) research visits to respond to surveys at the beginning of treatment and at the end after delivery of the definitive maxillofacial prosthesis. 

Compensation: A total of $50 for completing two surveys will be paid using a Pre-Paid Debit Card; $25 for completing the baseline surveys, and $25 for completing the final surveys after the delivery of the definitive prosthesis. 

Inclusion Criteria: 

  • Adults aged 18 to 85 years old.
  • Any oral cancer diagnosis (benign or malignant). 
  • Patient of record at the UMN SOD or FDC. 
  • Any defect from tumor resection in need of intra-oral maxillofacial prosthetics as determined by the provider. The patient’s prosthesis should have potential for anchorage or retention either through the remaining teeth or soft tissue in the arch.
  • Written informed consent obtained from participant and ability for participant to comply with the requirements of the study.
  • Stated willingness to comply with all study procedures and availability for the duration of the study.

Exclusion Criteria:

  • Patients requiring extra-oral prosthetics or intra-oral defects with no potential for anchorage or retention. 
  • Individuals unable to read or speak English, and are unable to provide informed consent.  

How to get involved: Contact the study manager, Kelli Trauger, at [email protected]

Brain Mechanisms Underlying Endogenous Pain Modulation in Chronic TMD

PI: Estephan Moana-Filho DDS, MS, PhD

Sponsor: NIH/NIDCR

The overall goal of this study is to determine brain mechanisms in chronic TMD pain patients and pain-free controls using brain imaging and sensory testing.

Timeline: After screening to identify potential individuals, qualifying participants will complete three in-person study visits, two at the School of Dentistry and one at the MRI center (CMRR). The visits include a comprehensive clinical examination, filling out questionnaires, sensory testing, and a brain MRI scan session.

Major Inclusion Criteria:

  • Female participants only (biological sex)
  • Age between 18-65 tears.
  • Pain-free participants OR Chronic jaw pain (> three months)

Major Exclusion Criteria:

  • Certain medical conditions (examples: heart disease, diabetes, autism, trigeminal neuralgia).
  • Any MRI contraindications (examples: metal implants, claustrophobia)
  • Being left-handed only

Compensation: $250.00 plus parking validation if needed ($50 for completion of first visit, $100 for completion of second visit, $100 for completion of third visit)..

How to get involved?

Contact: [email protected], 612-625-8926