Research in Focus
Update on PEARL Network Studies

PEARL Executive Management Team
Jonathan A. Ship, DMD; Ronald G. Craig, DMD, PhD; Frederick A. Curro, DMD, PhD; Van P. Thompson, DDS, PhD

In 2005, NYUCD received a $26.7 million award from the National Institute of Dental and Craniofacial Research, part of NIH, to establish a regional practice-based research network (PBRN), the PEARL (Practitioners Engaged in Applied Research and Learning) Network. The PEARL Network links dental offices in research projects in order to bring greater scientific rigor to “everyday” issues in the practice and delivery of oral health care. It’s notable that only one year into the process of enrolling patients in clinical studies, the PEARL Network’s enrollment rate is much higher than the enrollment rate one typically finds in medical PBRNs. Below is an update on current PEARL studies.

Postoperative Hypersensitivity
Study overview: Postoperative hypersensitivity has been associated with the placement of resin-bonded composite restorations, but little has been published on the incidence and severity of postoperative hyper-sensitivity after placement of this common restoration. This study aims to determine (1) the incidence and severity of postoperative hypersensitivity in patients who receive class I resin-bonded composite restorations; (2) the relationship among restoration depth/width, dentin caries activity, lining and bonding materials, and techniques on postoperative hypersensitivity; and (3) the subject’s perceived quality of life after placement of a resin-bonded composite restoration.
Study enrollment: As of November 1, 2007, 334 teeth out of a targeted 500 have been enrolled. This is 67 percent of the enrollment goal.
Findings to date: It appears that postoperative hypersensitivity to resin-bonded composite is more prevalent than the profession had believed. The enrollment of additional subjects is essential to determine whether this trend continues.

Complete Versus Partial Removal of Deep Caries:
A Comparison of Treatment Outcomes

Study overview: During the excavation of deep caries, a common question arises as to whether it is preferable to remove all carious dentin and risk pulpal exposure or to leave carious dentin in close proximity to the pulp and seal the lesion using a dentin-bonded restoration. In the PEARL Deep Caries Survey, 80 percent of PEARL practitioners responded that they routinely remove all carious dentin while 20 percent responded that they partially remove deep caries. This study is designed to (1) compare pulp vitality one year after complete versus partial caries removal in deep class I carious lesions, (2) determine the effect of the two deep caries treatments on postoperative hyper- sensitivity and quality of life, and (3) evaluate lining and bonding techniques for non-vital outcomes.
Study enrollment: As of November 1, 2007, nine teeth in nine subjects have been enrolled, of a target enrollment of 560 teeth.

Endodontic Outcomes in General Practice
Study overview: The majority of non-vital teeth are treated endodontically in general practices, but the majority of studies on success rates of endodontic therapy have been conducted in specialty practices or in academic centers. In view of the increasingly common clinical question of whether the 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, non-vital teeth in general dental practices.
Study enrollment: As of November 1, 2007, 349 subjects have been enrolled. Target enrollment is 2,500.

Osteonecrosis of the Jaw
Study overview: Osteonecrosis of the jaw (ONJ) is a recently described condition characterized by prolonged exposure of bone in the mandible or maxilla usually in association with the administration of bisphosphonates used in the treatment of osteoporosis, hypercalcemia of malignancy, and several diseases of bone, including Paget’s disease. This study will recruit patients with ONJ and matched controls using the three NIDCR-supported Practice Based Research Networks to determine the risk factors for development of ONJ. The targeted enrollment is 60 cases.

For more information on the PEARL Network, or if you are a practicing dentist and interested in joining PEARL, please visit