PEARL Studies

Current PEARL studies
Completed PEARL studies
PEARL publications
Turning an idea into a PEARL study


A typical PEARL study may last anywhere from one month to three years. Most are short-term observational studies that compare the effectiveness of diagnostic procedures, treatments, or materials; evaluate risk factors associated with particular treatments; or assess dentists' and/or patients' expectations of outcomes. All PEARL studies relate to the day-to-day clinical needs of private dentists and their patients by addressing a fundamental clinical question: Why we do what we do, and how can we do it better? All PEARL studies begin with an idea submitted by a PEARL Practitioner-Investigator: see Turning an idea into a PEARL study further down on this page. Once a study is completed, results are posted on a secure website where participating dentists can compare their outcomes with those of other Network members

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Current PEARL studies

The following PEARL studies are now under way and/or accruing practices:

Treatment of Deep Caries (PRL0604)
Dentists are frequently faced with the decision of whether to remove all carious dentin and risk pulpal exposure or to leave carious dentin in close proximity to the pulp and seal the lesion with a resin-bonded restoration during the excavation of a deep carious lesion.  To address this question, this study compares the effect of complete versus partial caries removal in class I and II deep carious lesions on (1) pulp vitality, (2) post-operative hypersensitivity and quality of life, and (3) the type of lining and bonding technique outcomes.

Implant Outcomes (PRL1012)
Periodontally compromised teeth or teeth with endodontic treatment failure are often replaced with an implant supported restoration.  Often the option of implant therapy is compared with the prognosis and cost of endodontic therapy.  Most recent survival studies on implants have reported success rates of greater than 95% for 5 to 10 years with almost all studies being conducted in University or specialist practices. However, few studies have been conducted concerning the relative success of implant treatment and restoration in general practice settings. The objective of the implant outcomes study is to evaluate the 3-5 year outcome of implant supported restorations and the factors associated with success or failure within general practice settings.  The implant study, together with endodontic treatment outcomes study, will provide practitioners with a basis with which to provide patients with a data based treatment outcome of implant versus endodontic treatment.

Post-Operative Hypersensitivity:  Randomized Comparative Effectiveness Research Trial (PRL1013)
Results of the PEARL study, “Post-operative hypersensitivity after placement of Class I bonded resin based composite restorations”, found that hypersensitivity was common after placement of this restoration but raised the questions as to whether placement of a liner was an effective means to decrease sensitivity.  This lead to our development of this two-armed, randomized clinical trial is to compare the effect on post-operative hypersensitivity of resin-bonded composite restorations using a dentin bonding agent, with and without placement of a resin modified glass ionomer liner.  The reduction in hypersensitivity between the 2 groups will be compared clinically using air and cold testing and by patient reported outcomes at three time points: prior to placement of the restoration and 1 and 4 week s post-operatively.  In addition, potential risk factors for post-operative hypersensitivity will be recorded including:  stage/extent of the carious lesion as measured by the proposed ADA Caries Classification System, lesion depth as measured on the preoperative radiograph, dentin caries ranked on opening the lesion, preparation depth, and patient sleep bruxism status.

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Completed PEARL studies

The following PEARL studies have been completed:

Deep Caries Treatment Survey (PRL0501)
A survey of the PEARL membership was conducted to determine preferred treatment approach for deep carious lesions and whether it was influenced by the practitioner’s expectations for pulpal exposure. Survey findings indicated that approximately 20% of PEARL Network dentists favored partial caries removal techniques. Given the various treatments employed, it was determined that a deep caries treatment outcome study was warranted, and thus this study’s results led directly to the PEARL study “Complete vs. Partial Removal of Deep Caries” (see above). The study's findings were published in the Journal of General Dentistry (see Oen et al., "Attitudes and Expectations...," 2007, below).

Postoperative Hypersensitivity in Occlusal Restorations (PRL0602)
This study was conducted to (1) determine the incidence and severity of POH as reported by patients who receive Class I RBC restorations; (2) measure the associations between POH and restoration width and depth, dentin caries activity, lining and bonding materials, and restorative materials and techniques; and (3) assess RBC restoration treatment and its impacts on oral health–related quality of life as reported by patients. Preliminary findings of this study were published in the July/August 2009 issue of Compendium of Continuing Education in Dentistry (see Berkowitz et al., “Postoperative hypersensitivity...,”2009, below).

Osteonecrosis of the Jaw (PRL0603)
Osteonecrosis of the jaw (ONJ) is a severe disease of bone that affects both the maxilla and mandible and is characterized by the intraoral exposure of bone and sequestrum formation.  Its cause is unknown but an increased incidence of ONJ has been associated with bisphosphonates, used in the treatment of osteoporosis, hypercalcemia of malignancy, and Paget’s disease.  The objective of this case control study is to determine the profile of factors, including bisphosphonate usage, that are predictive of ONJ.

Endodontic Treatment Outcomes (PRL0705)
The majority of endodontic therapy occurs in general practice settings; however, most studies on endodontic success rates have been conducted in specialty practices or in academic centers. Since the general dentist is frequently faced with the question of whether extraction and placement of a dental implant has a better long-term prognosis than conventional endodontic therapy, this study will determine the three- and five-year outcomes and risk factors associated with success and failure of endodontically-treated teeth in general dental practices.  This study defines failure from the patient’s perspective; i.e. any additional cost associated with the root canal and/or restorative procedure.

Analgesic use and effectiveness (PRL0706)
The dental profession has an ever-growing number of analgesics to prescribe or recommend for the management of pain. However, the most effective analgesic for a particular procedure or patient is often not clear. To address this issue, this study will determine (1) the degree of pain that a dentist perceives a procedure will produce and his /her prescription or recommendation to control the pain, and (2) the patient’s perception of how well the medication controlled the pain.

Treatment of Non-carious Cervical Lesions (PRL0707)
The treatment of hypersensitive non-carious cervical lesions (NCLs) remains controversial and few studies have compared the effectiveness of various treatments or their financial implications. The objective of this three-armed, randomized clinical trial is to compare treatment efficacy over a 6-month period, making this the longest study of its kind of three commonly used treatments for hypersensitive NCLs: (1) a chemoactive dentifrice, (2) a dentin bonding agent with sealant and, (3) a flowable resin-based composite restoration. The primary outcome objective is the reduction in hypersensitivity as measured by the patient. However, the study will also evaluate dentin tubule occlusion, retention of resin coatings, retention of restorations and lesion size by scanning electron microscopy examination of intraoral replicas of pre- and post-treatment NCL surfaces. Therefore, by study’s end, PEARL will be able to combine objective clinical assessments of the three NCL treatments with laboratory assessments of dentin tubule occlusion and lesion size.

Periodontal Diagnosis and Referral (PRL0808)
Completed in 2010, this study was designed to determine the criteria used to establish a periodontal diagnosis, the types of periodontal therapy provided, and who provides periodontal therapy in PEARL Network general dental practices.  A unique feature of the study was the “randomized clinical presentation” design, administered through the “Members Only” section of the PEARL website.  PEARL practitioner-investigators who maintain a general practice were randomly presented with 5 clinical scenarios that represent the range of periodontal health, gingivitis, and mild, moderate and severe periodontitis.  The practitioner-investigator was asked how she/he would examine, diagnose, and treat the patient described in the scenario in his/her own practice.  The study also sought to determine the criteria used to triage periodontal patients among the dentist, dental hygienist, and specialist and the use of adjuncts such as chemotherapeutics within the Network.

Survey to Assess the Impact of Dental Practice-Based Research Networks on Patient Care (PRL0809)
This trans-PBRN study will assess the impact of practice-based dental research on Network practices and on dentistry in general. A questionnaire is being administered to Practitioner-Investigators in the three NIDCR-funded Networks to determine whether and what changes have occurred in member practices. The questionnaire will be readministered annually as well as following the completion of studies and the publication of study results.

TMJD Pain (PRL0910)
Approximately 5-10% of the US population will seek care for painful temporomandibular muscle and joint disorders (TMJD) in their lifetime. General dentists are typically the first healthcare providers to see TMJD pain patients. However, there is no consensus regarding initial treatment for these problems. As a result, care varies from home-based self-care instruction with or without medications to use of mouth guards and other treatments. TMJD embraces a number of pains that involve the masticatory muscles, the temporomandibular joint, or both.  The objective of this survey is to learn more about the practitioner’s treatment habits with TMJD pain as well as to identify an interested group who would participate in a clinical study of TMJD.

Addictive Behavior Intervention (SBIRT)

The primary aim of this study is to assess the knowledge, attitudes, and beliefs of dentists regarding the provision of screening followed by treatment intervention and/or referral for 1) tobacco, 2) unhealthy alcohol use, and 3) illicit drug use.  The secondary aim is to identify practitioners who may be interested in participating in a future clinical trial of a dental practice-based substance use intervention. 

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PEARL publications

Peer Reviewed Publications

Ship JA, Curro FA, Caufield PW, Dasanayake A, Lindblad A, Thompson VP, Vena D, (2006) “Practicing dentistry using findings from clinical research. You are closer than you think”, Journal of the American Dental Association 137: 1488-1494.  PMID: 17082265

Veitz-Keenan A, Berkwoitz GS, Brandes I, Goldberg KL, Hamlin DA, Margolin R, (2007) “Practice-based research networks”, New York State Dental Journal 73(3): 14-15.  PMID: 17508672

Oen KT, Thompson VP, Vena D, Caufield PW, Curro FA, Dasanayake A, Ship JA, Lindblad A, (2007) “Attitudes and expectations of treating deep caries”, General Dentistry 55: 197-203.  PMID: 17511360

Thompson V, Craig  RG, Curro FA, Green WS, Ship JA, (2008) “Treatment of deep carious lesions by complete or partial removal: A critical review”, Journal of the American Dental Association, 139: 705-712.  PMID: 18519994

Curro FA, Craig RG, Thompson VP, (2009) “Practice-based research networks and their impact on dentistry: Creating a pathway for change in the profession”, Guest Editorial, Compendium of Continuing Education in Dentistry, 30(4): 184-187.  PMID: 19441734

Curro FA, Craig, RG, Vena D, Thompson VP, (2009) “The role of interim analysis as a quality assurance function in Practice Based Research Network (PBRN) clinical studies”, Compendium of Continuing Education in Dentistry, 30: 352-354.  PMID: 19715012

Berkowitz G, Horowitz A, Craig RG, Curro FA, Ship JA, Vena DA, Thompson VP, (2009) “Postoperative hypersensitivity in Class I resin-boned composite restorations in general practice: Interim results”, Compendium of Continuing Dental Education, 30: 356-363. PMID: 19715013 and

Barasch A, Cunha-Cruz J, Curro FA, Hujoel P, Sung AH, Vena D, Gilbert GH, Vionea-Griffin AE,  Safford MM. (2011)  “Dental risk factors for osteonecrosis of the jaw.”  J. Dental Res. 90 (2):  439-444.  PMID: 21317246

Curro FA, Grill A, Thompson VP, Craig RG, Vena D, Keenan AV, Naftolin F. (2011).  “Advantages of the Dental Practice-Based Research Network Initiative and its Role in Dental Education.”  Journal of Dental Education. 75 (8): 1053-1060.

Book chapter

DeNucci, D, & CONDOR Dental Practice-Based Research Networks.  (2010)  Chapter 14 Dental practice-based research networks, In Giannobile WV, Burt BA, Genco RJ, Burt B (Eds), Clinical Research in Oral Health. Singapore:  Wiley-Blackwell pp. 265-293.

Peer reviewed abstracts

Berkowitz G, Bernstein S, Horowitz AJ, Craig R, Curro RA, Ship J, Thompson VP, Vena D, Mosby K,  (2008) “Postoperative hypersensitivity in Class I RBC restorations: A PEARL study”,  J. Dental  Res. 87: 1086.

Bernstein S, Horowitz A, Craig RG, Curro FA, Ship J, Thompson V, Mosby K, Vena D, “Endodontic treatment and restoration outcomes in general practice”, J. Dental Res. 87:0212, 2008.

Veitz-Keenan A, Bernstein S, Craig R, Curro FA, Thompson VP, Ship JA, Vena D, Mosby K, Broder HL, “Endodontic treatment outcomes and OHRQOL outcomes in general practice”, J. Dental Res. 87: 2351, 2008.

Blanchard P, Fred S, Craig RG, Curro FA, Thompson VP, Wu J, Vena D, “Class I RBC preparation-related postoperative hypersensitivity: PEARL interim findings”, J. Dental Res. 88(A): 0171, 2009.

Wong YJ, Craig RG, Thompson VP, Wu J, Vena D, Curro FA, “Analgesic use and patient-reported effectiveness: PEARL interim results”, J. Dental Res. 88(A): 0278, 2009.

Man M, Pliszczak, J, Craig RG, Curro FA, Thompson VP, Wu J, Vena D, (2009) “General practice endodontic treatment and restorative findings”, J. Dental Res. 88: 0169.

Spielman H, Schaffer S, Craig RG, Curro FA, Thompson VP, Wu J, Vena D, (2009) “Hypersensitivity in Class I RBC restorations: PEARL interim findings”,  J. Dental Res.  88 (A): 170.

Craig RG, Johnson J. (2009) “An update from the PEARL Network and serving as a practice research coordinator for the PEARL Network”,  J. Dental Hygiene, 83: 87.

Lehmann M, Veitz_Keenan A, Craig R, Curro F, Thompson V, Wu J, Vena D, “Dentin caries activity in occlusal RBC restorations: PEARL Network findings”.  J. Dental Res.  89(A): 1507, 2010.

Spielman H, Schaffer S, Craig R, Thompson V, Vena D, “Single tooth endodontic and restorative treatment outcomes:  PEARL interim findings.”  J. Dental Res. 89(B):2084, 2010.

Oen K, Hirschfeld E, Craig R, Curro F, Thompson V, Wu J, Vena D “Partial vs. complete deep caries removal treatment: PEARL Network findings”,   J. Dental Res.  89 (B):  2086, 2010.

Keenan J, Wong Y, Craig R, Thompson V, Wu J, Vena D, “Practice-based research assessment of analgesic effectiveness: PEARL Interim findings. J. Dental Res. 89(B): 2085, 2010.

Botello-Harbaum, M., Matthews, A., Wu, J., Collie, D., Network, P.  “OHRQoL scores of patients participating in the PEARL Network”.  J Dental Res. 89 (B): 2447, 2010.

Hudson K, Bryan H, Thompson V, Vena D, Craig R, Wu J, Collie D, Curro F.  “Analgesics prescribed/recommended for coded dental procedures: PEARL practitioner profiles”.  J. Dental Res 90 (A):  2375, 2011.

Strober B, Dahlstrom F, Levatino W, Craig R, Curro F, Thompson V, Matthews A, Lomax T, Vena D.  (2011)  “Class I RBC restoration-related postoperative hypersensitivity:  PEARL Network findings J. Dental Res 90 (A):  148, 2011.

Kanorwalla Y, Hirschfeld E, Craig R, Curro F, Thompson V, Wu J, Collie D, Vena D.   “Complete vs. partial deep caries removal treatment:  PEARL baseline findings”.  J. Dental Res 90 (A):  427, 2011.

A.G Matthews, M. Botello-Harbaum, Vena D, Craig R, Curro R, Thompson V, Grill A, Broder H. “Hypersensitivity and oral health-related quality of life:  PEARL Network findings”.  J. Dental Res 90 (A):  106, 2011.

Horowitz A, Barna J, Craig R, Curro F, Thompson V, Wu J, Collie D, Vena D. “Outcomes of endodontic therapy in general practice:  PEARL Network findings”.  J. Dental Res 90 (A):  432, 2011.

Jetter C, Abboud-Niemczyk J, Craig R, Curro F, Thompson V, Wu J, Matthews AG, and Vena D.  “Pearl non-carious cervical lesion RCT baseline and sleep bruxism findings”.  J. Dental Res 90 (A):  149, 2011.

Rosen A, Martin J, DeStefano T, Craig R, Curro F, Thompson V, Matthews AG, Lomax T, Vena D.     “Periodontal diagnosis and treatment in general practice:  PEARL Network findings”.  J. Dental Res 90 (A):  429, 2011.

Botello-Harbaum M, Matthews A, Wu J, Collie D, Brodder H, Vena D, Thompson V, and The PEARL Network.  (2011) “OHIP-14 among patients participation in a practice-based research network: PEARL”.  J. Dental Res 90 (A):  1747, 2011.

McNeeley J, Wright S, Rotrosen J, Shelley D, Matthews AG, Buchholz M, Curro F, NYU School of Medicine, NYU School of Dentistry, VA NY Harbor Healthcare System, EMMES Corporation.  (2011). “Are dentists ready to offer screening, brief intervention and referral to treatment (SBIRT) for substance use?”  College for Problems of Drug Dependency (CPDD) 73rd Annual Meeting, Hollywood, Florida.

McNeely J, Wright S, Rotrosen J, Shelley D, Matthews AG, Buchholz M, Curro F, NYU School of Medicine, NYU College of Dentistry, VA NY Harbor Healthcare System, EMMES Corporation.  (2011). “Screening and interventions for substance use in dental clinics:  a survey of dentists on current clinical practices, policies and barriers.”  Clinical Translational Research and Education (ACRT/AFMR/SCTS Joint Annual Meeting) Washington, DC.

Alai S, Collie D, Vena D, and Lomax T. Incorporating the Curation of Metadata in a Dental Practice-Based Research Network. Accepted for 2011 Society for Clinical Trials Meeting.

Matthews AG and Vena D. Application of Excess Zero Methodology to Oral Health-Related Quality of Life: PEARL Network Findings. Accepted for 2011 Society for Clinical Trials Meeting.

Other Publications and Social Media

ADA News

ADA News

Dentistry IQ Newsletter

PEARL facebook page:

PEARL Newsletter:

PEARL Website:

PEARL Twitter page:

NYU Nexus PEARL Network Articles page 62 and page 98

“Dentists Vary Widely in Treating Periodontal Disease” Laird Harrison from Medscape Today

Hispanic Dental Association webpage:

National and International Presentations

Curro (2007). “Recruiting Dentists for Future Opportunities”, Greater New York Dental Meeting, New York City.

Craig (2007). “Status of the PEARL Network Studies”, Greater New York Dental Meeting, New York City.

Ship JA, L. A. (2008). “How to extend clinically relevant research into community through medical practices”, The Parkinson's Disease Foundation.

Ship (2008). “Dental Practice Based Research - Practitioner Driven Evidence Based Dentistry”, Chicago Mid-Winter Meeting, Chicago, Illinois.

Goldberg (2008). “Conducting Clinical Research in My Practice:  Lessons Learned”, Chicago Mid-Winter Meeting, Chicago, Illinois.

Chustckie (2008). “PEARL Membership:  Impact on My Practice”, Chicago Mid-Winter Meeting, Chicago, Illinois.         

Ship (2008). “Practice-Based Research:  The PEARL Experience”,   American Association for Dental Research Annual Meeting, Dallas, Texas.

urro (2008). “Multi-site IRB Approvals and Clinician Recruitment:  Challenges Faced by a Dental Practice-Based Research Network (PBRN)”, Agency for Healthcare Research and Quality (AHRQ), Bethesda, Maryland.

Thompson, France-Prouvoste (2008). “Recruitment of potential practitioner-investigators into the PEARL Network”, Nation's Capital Dental Meeting, Washington, DC.

Thompson, V. (2008). “US Practice-Based Research Networks:  One Model”, FDI Annual World Dental Congress, Stockholm, Sweden.

Wong (2009). “PEARL Network:  Current Activities”, PRECEDENT Annual Meeting, Portland, Oregon.

Curro (2009). “Pharmacology of drugs interaction with the mind and affecting society- The role of dentists and PBRNs”, Organization for Safety and Asepsis Procedures (OSAP), Plano, Texas.

Johnson J, Craig RG.  (2009). “An Update from the PEARL Network”, North American Dental Hygiene Research Conference, Bethesda, Maryland.

Curro (2009). “Research in community oral health centers:  strengths, challenges, feasibility, and data integrity”, National Network for Oral Health Access, National Primary Oral Health Conference, Nashville, Tennessee.

Curro (2009). “Sharing a vision for future community oral health center research:  Innovation built on experience”, National Network for Oral Health Access, National Primary Oral Health Conference, Nashville, Tennessee.

Wong, Curro (2009). “NIDCR funded practice-based research networks in dentistry:  who, what, where, and how”, Friends of the NIDCR, Bethesda, Maryland.

Curro (2009). “Determining the Infrastructure Support for Recruitment, Retention, and Conduct of PBRN Clinical Studies”, Agency for Healthcare Research and Quality (AHRQ), Bethesda, Maryland.

Curro (2010).  “Findings of the CONDOR Case-Control Study of ONJ.”   American Association of Dental Research (AADR), Washington, D.C.

Keenan, AV. (2010) “Tools for Effective Knowledge Transfer and Lifelong Learning:  The PEARL-NYU College of Dentistry Collaboration”,  ADEA:  295.

Curro FA.  (2010) “Data Integrity –Applying Clinical Close-Out Procedures to PBRN Studies”, AHRQ PBRN conference Bethesda, MD.  Abstract:  P-06.

Curro (2010). “Healthcare at the Crossroads:  Practice Based Research Networks and Their Impact on the Future of Patient Care”, Harvard University, Children's Hospital, Boston, Massachusetts.

Craig (2010). “Dental Practice Based Research Networks- A vehicle for change in the dental profession”, University of Connecticut, Farmington, Connecticut.

Curro, Cannon (2010).  “The PEARL Network”, Montefiore Hospital Dental Program, New York, NY.

Blanchard (2010).  “PEARL findings: Deep caries removal and postoperative hypersensitivity studies”, American Dental Association Annual Meeting, Orlando, Florida.

Thompson VT (2010).  “PEARL Overview”, American Dental Association Annual Meeting, Orlando, Florida.

Curro F, Lehmann M, Lozano-Pineda J, Balderas V, Botello-Harbaum M, (2010) “PEARL Network Review of Practitioner Conducted Clinical Studies”, Hispanic Dental Association, Chicago, IL.

Craig (2010).  “PEARL Periodontal Therapy and Endodontic Outcomes Studies”,  Greater New York Dental Meeting, New York, NY.

Curro (2010).  “PEARL PBRN Conducted Clinical Studies on Analgesic Use and the Findings from a Trans-PBRN Study on ONJ”, Greater New York Dental Meeting, New York, NY.

Thompson (2010).  “PEARL Postoperative Hypersensitivity and Deep Caries Studies”, Greater New York Dental Meeting, New York, NY

Curro FA (2010) “Healthcare Prescribers, Drug Safety, and the Safe Use Initiative”, Federal Drug Agency (FDA) Bethesda, MD.

Curro FA (2010)  “Oral Disease – Systemic Disease Associations”, Research Centers and Minority Institutions Nashville, TN.

Curro FA (2010)  “Data Integrity as the Bridge to Support the Translation of Comparative Effectiveness Research:  Results to the Point of Care” Falls Church, Virginia at the World Comparative Effectiveness Conference.

Curro FA (2011).  “Developing a Research Plan to Promote Drug Safety and Pharmacovigilance through the Practice-Based Research Network (PBRN) Initiative” NYU Department of obstetrics and gynecology research conference, New York, NY.

Ikeda J (2011).  “An Update from the PEARL Network” Northwest PRECEDENT Annual Meeting, Portland, OR.

Curro FA (2011).  “A Good Clinical Practice PBRN”, Agency for Healthcare Research and Quality (AHRQ), Bethesda, Maryland.

Curro FA (2011).  “Access – What exactly is the problem?  Are the problems in the states the same?”  Royal College of Surgeons of England presented May 31, 2011 in London, England.

Network Presentations

PEARL Network Annual Meeting (2006)

PEARL Network Annual Meeting (2007)

PEARL Network Annual Meeting (2008)

Craig (2009). “The PEARL Network May 2008-April 2009”, PBRN Monitoring Committee Report, Bethesda, Maryland

PEARL Network Annual Meeting (2009).

PEARL Network Annual Meeting (2010)

PEARL Network Annual Meeting (2011)

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Turning an idea into a PEARL study

All PEARL studies start with an idea submitted by a PEARL member. To submit a study idea, click here to access the “Suggest a New Research Protocol” form. Member-submitted ideas are evaluated by the PEARL Executive Management Team, and those judged both relevant and feasible are expanded into protocols that are in turn evaluated by the PEARL Executive Committee and NIH.

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