Clinical trial NCT02609178: Basic Study of Fabricating Biomorphic Crowns
Official title: Comparative Evaluation of Different Occlusal Surface Designs of Artificial Crown
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Dental Crown
Prosthesis
Keywords: artificial crown
biomorphic
functional generated path
muscle-action theory
anatomic theory
Lead sponsor: Air Force Military Medical University, China
Sponsor class: OTHER
First posted: 2015-11-20
Enrollment: 12
Sex: ALL
Minimum age (years): 18
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: TREATMENT

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.

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.

Eligibility 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

Primary outcomes:
measure: △OT Value
timeFrame: 2 weeks(plus or minus 7 days) after tooth preparation
measure: △DT Value
timeFrame: 2 weeks(plus or minus 7 days) after tooth preparation
Secondary outcomes:
measure: Occlusal Adjusting Time for Crowns
timeFrame: 2 weeks(plus or minus 7 days) after tooth preparation
measure: Likert's Scale
timeFrame: 2 weeks(plus or minus 7 days) after tooth preparation
Other outcomes:
Locations:
city: Xi'an
country: China
facility: Stomatological Hospital of Fourth Military Medical University
state: Shanxi
Study officials:
affiliation: Stomatological Hospital of FMMU
name: Jihua Chen, PhD
role: STUDY_CHAIR
References:
citation: Mehl A. A new concept for the integration of dynamic occlusion in the digital construction process. Int J Comput Dent. 2012;15(2):109-23. English, German.
citation: Ikeda A, Miura H, Okada D, Tokuda A, Shinogaya T. The effect of occlusal contacts on adjacent tooth. J Med Dent Sci. 2005 Dec;52(4):195-202.
citation: Alhouri N, Watts DC, McCord JF, Smith PW. Mathematical analysis of tooth and restoration contour using image analysis. Dent Mater. 2004 Nov;20(9):893-9. doi: 10.1016/j.dental.2004.06.003.
citation: Vasconcelos FS, Neves AC, Silva-Concilio LR, Cunha LG, Rode Sde M. Influence of anatomic reference on the buccal contour of prosthetic crowns. Braz Oral Res. 2009 Jul-Sep;23(3):230-5. doi: 10.1590/s1806-83242009000300002.
citation: Kohal RJ, Gerds T, Strub JR. Effect of different crown contours on periodontal health in dogs. Clinical results. J Dent. 2003 Aug;31(6):407-13. doi: 10.1016/s0300-5712(03)00070-8.
citation: Takada J, Ono T, Miyamoto JJ, Yokota T, Moriyama K. Association between intraoral pressure and molar position and inclination in subjects with facial asymmetry. Eur J Orthod. 2011 Jun;33(3):243-9. doi: 10.1093/ejo/cjq060. Epub 2010 Sep 9.
citation: Olthoff L, Meijer I, de Ruiter W, Bosman F, van der Zel J. Effect of virtual articulator settings on occlusal morphology of CAD/CAM restorations. Int J Comput Dent. 2007 Apr;10(2):171-85. English, German.
citation: Memon S. A Comparative Evaluation of the Effect of Double Casting Technique Using Functionally Generated Path and Conventional Single Casting with Respect to Functional Articulation, Patient Satisfaction and Chair Side Time, in Single Unit Molar Teeth: An In Vivo Study. J Indian Prosthodont Soc. 2014 Dec;14(Suppl 1):119-25. doi: 10.1007/s13191-014-0379-6. Epub 2014 Jul 10.
citation: Curtis SR. Functionally generated paths for ceramometal restorations. J Prosthet Dent. 1999 Jan;81(1):33-6. doi: 10.1016/s0022-3913(99)70232-5.
citation: Wiklund L, Rossi F, Strata P, van der Want JJ. The rat olivocerebellar system visualized in detail with anterograde PHA-L tracing technique, and sprouting of climbing fibers demonstrated after subtotal olivary lesions. Eur J Morphol. 1990;28(2-4):256-67.
citation: Ender A, Mormann WH, Mehl A. Efficiency of a mathematical model in generating CAD/CAM-partial crowns with natural tooth morphology. Clin Oral Investig. 2011 Apr;15(2):283-9. doi: 10.1007/s00784-010-0384-z. Epub 2010 Feb 9.
citation: Becker CM, Kaldahl WB. Current theories of crown contour, margin placement, and pontic design. 1981. J Prosthet Dent. 2005 Feb;93(2):107-15. doi: 10.1016/j.prosdent.2004.11.005. No abstract available.
citation: Hazen SP, Osborne JW. Relationship of operative dentistry to periodontal health. Dent Clin North Am. 1967 Mar:245-54. No abstract available.
citation: Yuodelis RA, Weaver JD, Sapkos S. Facial and lingual contours of artificial complete crown restorations and their effects on the periodontium. J Prosthet Dent. 1973 Jan;29(1):61-6. doi: 10.1016/0022-3913(73)90140-6. No abstract available.
citation: Koidis PT, Burch JG, Melfi RC. Clinical crown contours: contemporary view. J Am Dent Assoc. 1987 Jun;114(6):792-5. doi: 10.14219/jada.archive.1987.0189.
citation: Parkinson CF. Excessive crown contours facilitate endemic plaque niches. J Prosthet Dent. 1976 Apr;35(4):424-9. doi: 10.1016/0022-3913(76)90010-x.
citation: Cho SH, Chang WG. Mirror-image anterior crown fabrication with computer-aided design and rapid prototyping technology: a clinical report. J Prosthet Dent. 2013 Feb;109(2):75-8. doi: 10.1016/S0022-3913(13)60018-9.