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A Clinical Trial of an Acetal Resin Crown for Restoration of Primary Molars

This study has been completed.
Uri Zilberman
Information provided by (Responsible Party):
Ornit Cohen, Barzilai Medical Center Identifier:
First received: May 15, 2011
Last updated: July 2, 2013
Last verified: July 2013

Preformed stainless steel crowns have been used in Pediatric Dentistry to restore badly broken down primary teeth since 1950. They are generally considered more expedient to place than large multi-surface amalgam or composite restorations and have a longer life. They have been used successfully in clinical practice for many years and have presented little in the way of adverse events. The major drawback is the poor esthetics along with lingering concerns over potential health hazards associated with the nickel content. Several attempts have been made to improve upon the esthetics of stainless steel crowns such as veneering the buccal and occlusal surfaces and substituting composite resin for the entire crown, but to date none of these approaches have been very successful.

Acetal resin has been used in a number of applications in medicine and dentistry, and recently has met with early success when tested as a substitute for stainless steel crowns. It has a number of excellent physical and mechanical properties including a low coefficient of friction, good wear resistance, high fatigue resistance, good impact strength and resistance to creep.

The purpose of this trial is to compare the clinical performance of preformed acetal resin crowns and preformed stainless steel crowns.


The objective of this study is to compare the clinical performance of acetal resin crowns with preformed stainless steel crowns when used to restore primary molar teeth.

Condition Intervention Phase
Other Unsatisfactory Restoration of Tooth Procedure: Acetal crown, LD Caulk ltd, USA Phase 3

Study Type: Interventional
Study Design: Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Phase 3- Clinical Trial on Children. PROTOCOL 465-549

Further study details as provided by Ornit Cohen, Barzilai Medical Center:

Primary Outcome Measures:
  • Retention of acetal crowns for primary molars [ Time Frame: two years ]
    Number of patients with adverse events

Secondary Outcome Measures:
  • Color stability of acetal crown [ Time Frame: two years ]
    Change from baseline color of acetal crowns

Enrollment: 52
Study Start Date: April 2010
Study Completion Date: July 2013
Primary Completion Date: December 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Acetal crown
Clinical performance of acetal crowns for treatment of primary molars
Procedure: Acetal crown, LD Caulk ltd, USA
Experimental trial of preformed acetal crowns for primary molars
Other Name: Prefabricated crowns for primary molars

Detailed Description:


A minimum of 25 subjects contributing a minimum of 40 acetal crowns ( on primary molar teeth will be recruited from the patient pool of the pediatric dentistry clinic at Barzilai Medical Center, Ashkelon and enrolled into the study. A maximum of four crowns will be placed in any subject. It is estimated that it will take approximately 14 weeks to place all crowns and complete the baseline examination.


Ages Eligible for Study:   4 Years to 8 Years   (Child)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Patients of record at the pediatric dentistry clinic at Barzilai Medical Center, Ashkelon
  • Ages 3-8 (inclusive)
  • In need of at least one Stainless Steel Crown on either a first or second primary molar

Exclusion Criteria:

  • Medically compromising condition
  • Informed consent not given
  • Teeth with proximal space closures of sufficient magnitude to preclude placement of a test crown
  Contacts and Locations
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Please refer to this study by its identifier: NCT01359475

Pediatric Dental Clinic, BarzilaiMC
Ashkelon, Israel, 78278
Sponsors and Collaborators
Ornit Cohen
Uri Zilberman
Principal Investigator: Uri L Zilberman, DMD, PhD Barzilai Medical Center
  More Information

Responsible Party: Ornit Cohen, r&d unit, Barzilai Medical Center Identifier: NCT01359475     History of Changes
Other Study ID Numbers: BMC1505CTIL
PROTOCOL 465-549 ( Other Identifier: LD Caulk, Usa )
Study First Received: May 15, 2011
Last Updated: July 2, 2013

Keywords provided by Ornit Cohen, Barzilai Medical Center:
Acetal crowns
Primary molars
The retention of acetal crowns in primary dentition
Color changes of acetal crowns processed this record on August 17, 2017