Study Results
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Basic Information
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ENROLLING_BY_INVITATION
NA
100 participants
INTERVENTIONAL
2020-09-15
2026-12-31
Brief Summary
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Detailed Description
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In dentistry, filling materials are needed repairing damage caused by dental caries as well as for occlusal rehabilitation. Composite restorations can be performed using direct or indirect technique. There are some shortcomings linked with direct technique, such as polymerization shrinkage, and also their manufacturing can be demanding due to circumstances in the oral cavity. Partly due to these, approximately 8 out 10 regular users of dental services need repetitive repair or replacement of old restorations within 5 years. One solution for manufacturing high-qualified and long-lasting restorations is chairside CAD/CAM (computer-aided design and computer-aided manufacturing) technology that includes both subtractive and additive manufacturing techniques. Additive techniques, also called 3D printing techniques, may provide novel possibilities to overcome the challenges linked with the durability of dental fillings. They might be used to fabricate more complex restorations compared to subtractive techniques with a reasonable cost. In 3D printing, successive layers of material are deposited under computer control to create an object layer by layer. The objects, having practically any shape or geometry, are produced from a model or design in an electronic form. The 3D printable models may be created with a CAD software package and in many cases utilize the imaging data by a dental scanner which have become widely available with high resolution. 3D printing may enable higher restoration accuracy compared to subtractive manufacturing techniques, where the accuracy is limited by the milling unit and machining tools. Another benefit is its low material loss. 3D printing process is fast and likely in future to be used chairside at the dental office. Only a few studies addressing the possibilities of 3D printing in dental filling manufacture exist in the current literature. Based on a previous in vitro study by the imvestigators, the accuracy of 3D printing technique is at least at the same level as milling technique in fabrication of dental inlay and onlay fillings, and thus might be a clinically acceptable alternative to the subtractive milling technique. Additional clinical investigations are needed to confirm these findings. The aim of the present study is to compare the success of dental fillings prepared using 3D printing technique to those manufactured with the direct composite technique.
Material and Methods
At total, 100 adult patients are selected from dental care patients of the Health Centre of Kaarina, Kaarina, Finland, as volunteers. Written informed consent forms are obtained from all patients at the beginning of the study. Participation in the study is voluntary and causes no additional costs for the patient.
Each patient requires two Class II, III or IV cavities to be restored in the dentition. The randomizations are performed by noting each tooth to be restored (Fédération Dentaire Internationale \[FDI\] two-digit code) on one form and the type of restorative system (direct technique vs. indirect technique utilizing 3D printing) on a second. First, a tooth number is drawn blindly. Subsequently, a restorative system is allocated to this tooth by blind drawing. The clinical procedures of cavity preparation and restoration placement are performed by two experienced dentists.
Clinical Evaluation Restorations are rated independently by blinded dentists at the Institute of Dentistry, University of Turku, Finland, who are not involved with the insertion of the indirect and the direct restorations and are unaware of the group status of the fillings. The two evaluators are calibrated against a reference standard. This clinical assessment method results in ordinally structured data for the outcome variables.
Statistical Analysis Power analysis was used to estimate the sample size. In the calculation, the distributions for clinically excellent or acceptable restorations (direct 87% vs. indirect 93%) based on a previous study. Based a previous in vitro study, it was estimated that restorations based on 3D printing technique have at least as high success rate as indirect ceramic restorations, 96%. When the statistical significance was set p \<0.05, alpha coefficients 0.05 and beta value 0.2, the sample size n=150 tooth restorations per group was calculated. The number of patients for the study is estimated between 75 (when 4 restorations are performed for each patient) and 150 (2 restorations performed for each patient).
Descriptive statistics are used to describe the frequency distributions of the evaluated criteria. To analyse the failure rate (distributions of Charlie scored versus non-Charlie-scored restorations) for direct vs. indirect restorations, 2x2 tables are created. Non-parametric statistical procedures are used due to ordinally structured data for the assessment of the restorations. Mann-Whitney U-test is used to explore significant differences at different time points between direct and indirect restorations. The same test is used to detect differences between baseline and follow-up registration. The standard value considered to demonstrate statistically significant differences was set at p \<0.05.
Ethical issues
Participation in the study is voluntary and requires an informed consent of the patient. The patient has a right to refuse or interrupt his/her participation in the study at any stage. The patients are treated according to the good clinical practices. Quality of the treatment is suspected to be at least at the same level as in normal treatment methods for restorative care. During the study, the patients will have additional check-ups as, which is compensated with economical or other benefits. Patient data are saved in patient registers at the care-providing instances. Research data are saved and analysed anonymously using SPSS 25 (IBM Statistic Viewer) program.
Conditions
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Study Design
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RANDOMIZED
CROSSOVER
TREATMENT
SINGLE
Study Groups
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Indirect restorations
For the indirect technique, the cavities are prepared according to the common principles for inlays/onlays. Digital impressions are taken of each tooth with a digital impression system (3Shape TRIOS® Intraoral Scanner).The dentist, utilizing the scanner's CAD SW, designs the 3D restoration. The design is imported from the scanner SW into the Rayo 3DToothFill SW to manufacture the mould and the restoration. After printing the mould, it is transferred to the Rayo robot which manufactures the restoration by casting filling material layers in the mould. The automated filling and curing procedures in the Rayo 3DToothFill robot are directed by Rayo 3DToothFill SW. After the manufacturing process is finished, the dentist cements the finished restoration into the cavity with a dual-cure resin cement (G-CEM LinkAce®).The indirect fillings are manufactured chair-side from the same composite material as in the direct technique.
Indirect restorations
see the Arm description
Direct restorations
The direct composite restorations are performed based on normal treatment practices. For both direct and indirect restorations, commercially available short-fibre reinforced composite material (everX Flow, GC) is used for core material (replacing dentin) and flowable composite material (G-ænial® Universal Injectable, GC) for surface (replacing enamel), according the manufacturer´s instructions. The occlusion and articulation are checked and adjusted, and the restoration is finished with polishing instruments.
Indirect restorations
see the Arm description
Interventions
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Indirect restorations
see the Arm description
Eligibility Criteria
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Inclusion Criteria
* first or second molars and permanent premolars needing restorations
* at least two class II restorations from the same tooth group (premolar/molar) should be performed in each patient
* the number of restorations of each technique should be equal in each patient
Exclusion Criteria
* spontaneous pain or sensitivity to percussion
18 Years
ALL
Yes
Sponsors
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University of Helsinki
OTHER
Oulu University Hospital
OTHER
University of Turku
OTHER
University of Eastern Finland
OTHER
University of Oulu
OTHER
Responsible Party
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Principal Investigators
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Kirsi Sipilä, Professor
Role: STUDY_DIRECTOR
University of Oulu, Finland
Locations
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Research Unit of Oral Health Sciences, University of Oulu
Oulu, , Finland
Countries
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References
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Alharbi N, Wismeijer D, Osman RB. Additive Manufacturing Techniques in Prosthodontics: Where Do We Currently Stand? A Critical Review. Int J Prosthodont. 2017 September/October;30(5):474-484. doi: 10.11607/ijp.5079. Epub 2017 Jul 27.
Ahlholm P, Sipila K, Vallittu P, Jakonen M, Kotiranta U. Digital Versus Conventional Impressions in Fixed Prosthodontics: A Review. J Prosthodont. 2018 Jan;27(1):35-41. doi: 10.1111/jopr.12527. Epub 2016 Aug 2.
Ahlholm P, Sipila K, Vallittu P, Kotiranta U, Lappalainen R. Accuracy of inlay and onlay restorations based on 3D printing or milling technique - a pilot study. Eur J Prosthodont Restor Dent. 2019 May 30;27(2):56-64. doi: 10.1922/EJPRD_01814Ahlholm09.
Astvaldsdottir A, Dagerhamn J, van Dijken JW, Naimi-Akbar A, Sandborgh-Englund G, Tranaeus S, Nilsson M. Longevity of posterior resin composite restorations in adults - A systematic review. J Dent. 2015 Aug;43(8):934-54. doi: 10.1016/j.jdent.2015.05.001. Epub 2015 May 21.
Beuer F, Schweiger J, Edelhoff D. Digital dentistry: an overview of recent developments for CAD/CAM generated restorations. Br Dent J. 2008 May 10;204(9):505-11. doi: 10.1038/sj.bdj.2008.350.
Chochlidakis KM, Papaspyridakos P, Geminiani A, Chen CJ, Feng IJ, Ercoli C. Digital versus conventional impressions for fixed prosthodontics: A systematic review and meta-analysis. J Prosthet Dent. 2016 Aug;116(2):184-190.e12. doi: 10.1016/j.prosdent.2015.12.017. Epub 2016 Mar 2.
Baratieri LN, Canabarro S, Lopes GC, Ritter AV. Effect of resin viscosity and enamel beveling on the clinical performance of Class V composite restorations: three-year results. Oper Dent. 2003 Sep-Oct;28(5):482-7.
Ebert J, Ozkol E, Zeichner A, Uibel K, Weiss O, Koops U, Telle R, Fischer H. Direct inkjet printing of dental prostheses made of zirconia. J Dent Res. 2009 Jul;88(7):673-6. doi: 10.1177/0022034509339988.
Eftekhar Ashtiani R, Nasiri Khanlar L, Mahshid M, Moshaverinia A. Comparison of dimensional accuracy of conventionally and digitally manufactured intracoronal restorations. J Prosthet Dent. 2018 Feb;119(2):233-238. doi: 10.1016/j.prosdent.2017.03.014. Epub 2017 Jun 2.
Garoushi S, Gargoum A, Vallittu PK, Lassila L. Short fiber-reinforced composite restorations: A review of the current literature. J Investig Clin Dent. 2018 Aug;9(3):e12330. doi: 10.1111/jicd.12330. Epub 2018 Feb 25.
Keshvad A, Hooshmand T, Asefzadeh F, Khalilinejad F, Alihemmati M, Van Noort R. Marginal gap, internal fit, and fracture load of leucite-reinforced ceramic inlays fabricated by CEREC inLab and hot-pressed techniques. J Prosthodont. 2011 Oct;20(7):535-40. doi: 10.1111/j.1532-849X.2011.00745.x. Epub 2011 Aug 1.
Lee KY, Cho JW, Chang NY, Chae JM, Kang KH, Kim SC, Cho JH. Accuracy of three-dimensional printing for manufacturing replica teeth. Korean J Orthod. 2015 Sep;45(5):217-25. doi: 10.4041/kjod.2015.45.5.217. Epub 2015 Sep 23.
Leinfelder KF. Evaluation of criteria used for assessing the clinical performance of composite resins in posterior teeth. Quintessence Int. 1987 Aug;18(8):531-6. No abstract available.
Mai HN, Lee KB, Lee DH. Fit of interim crowns fabricated using photopolymer-jetting 3D printing. J Prosthet Dent. 2017 Aug;118(2):208-215. doi: 10.1016/j.prosdent.2016.10.030. Epub 2017 Jan 12.
Mangani F, Marini S, Barabanti N, Preti A, Cerutti A. The success of indirect restorations in posterior teeth: a systematic review of the literature. Minerva Stomatol. 2015 Oct;64(5):231-40.
Nihtila A, Widstrom E, Elonheimo O. Adult heavy and low users of dental services: treatment provided. Swed Dent J. 2016;40(1):21-32.
Opdam NJ, van de Sande FH, Bronkhorst E, Cenci MS, Bottenberg P, Pallesen U, Gaengler P, Lindberg A, Huysmans MC, van Dijken JW. Longevity of posterior composite restorations: a systematic review and meta-analysis. J Dent Res. 2014 Oct;93(10):943-9. doi: 10.1177/0022034514544217. Epub 2014 Jul 21.
Schiffman E, Ohrbach R, Truelove E, Look J, Anderson G, Goulet JP, List T, Svensson P, Gonzalez Y, Lobbezoo F, Michelotti A, Brooks SL, Ceusters W, Drangsholt M, Ettlin D, Gaul C, Goldberg LJ, Haythornthwaite JA, Hollender L, Jensen R, John MT, De Laat A, de Leeuw R, Maixner W, van der Meulen M, Murray GM, Nixdorf DR, Palla S, Petersson A, Pionchon P, Smith B, Visscher CM, Zakrzewska J, Dworkin SF; International RDC/TMD Consortium Network, International association for Dental Research; Orofacial Pain Special Interest Group, International Association for the Study of Pain. Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) for Clinical and Research Applications: recommendations of the International RDC/TMD Consortium Network* and Orofacial Pain Special Interest Groupdagger. J Oral Facial Pain Headache. 2014 Winter;28(1):6-27. doi: 10.11607/jop.1151.
Study Documents
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Document Type: Study Protocol
View DocumentOther Identifiers
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2924410-5
Identifier Type: -
Identifier Source: org_study_id