Working…
COVID-19 is an emerging, rapidly evolving situation.
Get the latest public health information from CDC: https://www.coronavirus.gov.

Get the latest research information from NIH: https://www.nih.gov/coronavirus.
ClinicalTrials.gov
ClinicalTrials.gov Menu

Basic Study of Fabricating Biomorphic Crowns

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
 
ClinicalTrials.gov Identifier: NCT02609178
Recruitment Status : Completed
First Posted : November 20, 2015
Results First Posted : August 2, 2016
Last Update Posted : August 2, 2016
Sponsor:
Information provided by (Responsible Party):
Ji-hua Chen, Fourth Military Medical University

Brief Summary:
The purpose of this study is to compare among different designs of the occlusal surface of artificial crowns, trying to determine a guidance of fabricating artificial crowns with better mimesis of the original tooth crown in terms of morphology.

Condition or disease Intervention/treatment Phase
Dental Crown Prosthesis Procedure: FGP Procedure: AVR Not Applicable

Detailed Description:

For occlusal surface design, each subject would be given 3 crowns using different fabricating guidance -- the FGP technique(FGP),the average setting technique(AVR) and conventional technique(CON), separately. Upon baseline visit, general tooth preparation procedures would be performed, including impression taking before and after treatment and tooth preparation. Sometimes photo taking is needed. On try-in visit, subjects would be ask to fill in questionaires(Likert's scale) and the adjusting time for each crown would be recorded. Moreover, t-scan would be used to assess the occlusal equilibrium. All in all, including adjusting visit for FGP, the subjects have to visit the clinic for 3 times which would take them 3-week time.

The Institutional Board(IRB) of the Stomatological Hospital of Fourth Military Medical University(FMMU) would be in supervision of the whole study and is responsible for the quality assurance plan, data check and source data verification.

Subject recruitment would done within those patients visit the department of prosthodontics of the Stomatological Hospital of FMMU and have an interest towards this study. One clinician would be appointed to enroll the subjects according to the standards. To avoid errors, all the examinations done in the study shall be accomplished by the same clinician and the crowns fabricated in the study shall be designed by the same technician. The clinician and the technician participated would receive adequate training before the study to ensure their performance. Every subject in the study should assign informed consents at the beginning of the study and establish case report forms(CRFs). During the study, if adverse events(such as crown chipping, crown dropping or iatrogenic gingivitis, etc) happen, subjects are required to contact the investigator within 24 hours; and the investigator should then report to the IRB within 24 hours. Following treatment or compensation would be done according to the clauses stated in the informed consent signed by the subjects.

The whole study needs subjects in total. During the study, subjects have their own right to quit the study at any time if they have discussed with the investigator in advance. These subjects then are deemed as "unavailable". If subjects don't contact the investigator and quit the study(the investigators can't contact them within the follow-up period), their records then are deemed as "missing".

All the information collected in the study would be protected and only be used within this study. The statistical analysis of this study would be processed with the aid of the department of statistics of FMMU.

Layout table for study information
Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 12 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single (Participant)
Primary Purpose: Treatment
Official Title: Comparative Evaluation of Different Occlusal Surface Designs of Artificial Crown
Study Start Date : December 2015
Actual Primary Completion Date : March 2016
Actual Study Completion Date : March 2016

Resource links provided by the National Library of Medicine


Arm Intervention/treatment
Experimental: FGP design (FGP, AVR)
use functional generated path to execute different occlusal surface designs of the artificial crown and evaluate its efficacy
Procedure: FGP
To execute FGP technique, the occlusal surface of the interim should be back cut to leave at least 1mm occlusal space. Then apply the recording resin. Ask the subjects to close the mouth to maximum intercuspal position then perform right lateral, left lateral and protrusive movements in succession ending in maximum intercuspation position. Excessive resin then should be trimmed off and Bausch articulating paper would be used to mark the intercuspal contacts. Zinc oxide is then applied to check eccentric occlusion, trimmed off resin if there're interferences. Then the interim would be used as a copy to design the occlusal surface of the crown. (CAD/CAM)
Other Name: general

Procedure: AVR
the crowns in this group would be designed by setting virtual articulator to average mode (CAD/CAM)
Other Name: average value

No Intervention: conventional design (CON)
use conventional method to execute different occlusal surface designs of the artificial crown and evaluate its efficacy



Primary Outcome Measures :
  1. △OT Value [ Time Frame: 2 weeks(plus or minus 7 days) after tooth preparation ]

    Occlusion time (OT) is defined as the time from the first contact of occluding teeth to maximum intercuspation. OT is directly related with patients' occlusal contact pattern; and some have considered it as a capable description of occlusion.

    In the study, the OT value of each crown would be assessed before try-in (baseline) and immediately after try-in using T-scan (FGP, AVR, CON). Try-in procedure would be finished by the same clinician.

    △OT was calculated for minimizing individual difference among participants. The equation for △OT was:△OT(FGP/ AVR/ CON)= OT (FGP/ AVR/ CON)-OT(baseline)


  2. △DT Value [ Time Frame: 2 weeks(plus or minus 7 days) after tooth preparation ]

    Disocclusion time (DT) is defined as the time from maximum intercuspation to complete disocclusion during lateral movement. DT related tooth contacts with muscle activity. Abnormities in DT would result in change of muscle activity, thus facilitate the occurrence of temporomandibular joint disorders.

    In the study, the DT value of each crown would be assessed before try-in (baseline) and immediately after try-in using T-scan (FGP, AVR, CON). Try-in procedure would be finished by the same clinician.

    △DT was calculated for minimizing individual difference among participants. The equation for △DT was: △DT(FGP/ AVR/ CON)= DT (FGP/ AVR/ CON)-DT(baseline)



Secondary Outcome Measures :
  1. Occlusal Adjusting Time for Crowns [ Time Frame: 2 weeks(plus or minus 7 days) after tooth preparation ]
    Try-in procedure would be finished by the same clinician. The occlusal adjusting time would be counted using a timer and recorded.

  2. Likert's Scale [ Time Frame: 2 weeks(plus or minus 7 days) after tooth preparation ]

    The questionaire was designed to evaluate participants' feeling towards the occlusal interference. It would be given to the subject after immediately try-in the crowns. In the questionaire:

    Score 0 = No interference (feel comfortable while biting on the artificial crown) Score 1 = Moderate interference(could feel the artificial crown is higher when biting on the artificial crown, but when firmly clenched, the upper teeth could bite on the lower ones) Score 2 = High interference(the artificial teeth is higher that the upper teeth couldn't bite on all the lower teeth when firmly clenched)




Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.


Layout table for eligibility information
Ages Eligible for Study:   18 Years to 65 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • single crown restoration needed in posterior quadrants
  • the antagonist of the abutment tooth is purely natural or received minimum restorations that does not change its morphology too much
  • no orthodontic treatment history
  • stable occlusion
  • no parafunctional movements existed

Exclusion Criteria:

  • sequential crown restorations needed
  • the morphology of the antagonist of the abutment tooth has been largely changed by previous treatment
  • no contact exists between the abutment tooth and its antagonist
  • orthodontic treatment history
  • unstable occlusion
  • existed parafunctional movements
  • participated in other clinical studies

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02609178


Locations
Layout table for location information
China, Shanxi
Stomatological Hospital of Fourth Military Medical University
Xi'an, Shanxi, China, 710032
Sponsors and Collaborators
Fourth Military Medical University
Investigators
Layout table for investigator information
Study Chair: Jihua Chen, PhD Stomatological Hospital of FMMU

Publications:

Layout table for additonal information
Responsible Party: Ji-hua Chen, Dean, Professor, Fourth Military Medical University
ClinicalTrials.gov Identifier: NCT02609178    
Other Study ID Numbers: IRB-REV-2015039
First Posted: November 20, 2015    Key Record Dates
Results First Posted: August 2, 2016
Last Update Posted: August 2, 2016
Last Verified: June 2016
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Undecided
Keywords provided by Ji-hua Chen, Fourth Military Medical University:
artificial crown
biomorphic
functional generated path
muscle-action theory
anatomic theory
Additional relevant MeSH terms:
Layout table for MeSH terms
Salicylic Acid
Anti-Infective Agents
Antifungal Agents
Keratolytic Agents
Dermatologic Agents