<clinical_study>
  <!-- This xml conforms to an XML Schema at:
    https://clinicaltrials.gov/ct2/html/images/info/public.xsd -->
  <required_header>
    <download_date>ClinicalTrials.gov processed this data on September 20, 2023</download_date>
    <link_text>Link to the current ClinicalTrials.gov record.</link_text>
    <url>https://clinicaltrials.gov/ct2/show/NCT03777748</url>
  </required_header>
  <id_info>
    <org_study_id>UKA 373147</org_study_id>
    <nct_id>NCT03777748</nct_id>
  </id_info>
  <brief_title>Outcome of Implant-supported Overdentures</brief_title>
  <official_title>A Pilot Study to Clinically Evaluate Maxillary and Mandibular Overdentures Retained by Two Unsplinted Diameter-reduced Titanium-zirconium Implants</official_title>
  <sponsors>
    <lead_sponsor>
      <agency>RWTH Aachen University</agency>
      <agency_class>Other</agency_class>
    </lead_sponsor>
    <collaborator>
      <agency>Institut Straumann AG</agency>
      <agency_class>Industry</agency_class>
    </collaborator>
  </sponsors>
  <source>RWTH Aachen University</source>
  <oversight_info>
    <has_dmc>No</has_dmc>
    <is_fda_regulated_drug>No</is_fda_regulated_drug>
    <is_fda_regulated_device>No</is_fda_regulated_device>
  </oversight_info>
  <brief_summary>
    <textblock>
      The aim of this pilot study was to assess survival rates and peri-implant bone loss of two&#xD;
      narrow-diameter titanium-zirconium implants supporting maxillary and mandibular overdentures&#xD;
      during an observation time of 3 years. The masticatory performance, self-reported chewing&#xD;
      ability and change of oral health impact profile (OHIP) after rehabilitation were also&#xD;
      investigated.&#xD;
    </textblock>
  </brief_summary>
  <detailed_description>
    <textblock>
      According to the recent German Oral Health Study (DMS V), toothlessness is still frequently&#xD;
      represented in the German population. Thus in the group of 65 to 74 years old 12.4% were&#xD;
      edentulous. Whereas in the group of 75 to 100 years old 32.8% were toothless. Toothlessness&#xD;
      occurred more frequently in the upper jaw (19,8%) than in the lower jaw (13,7%).&#xD;
&#xD;
      Although maxillary complete dentures show less retention problems than mandibular complete&#xD;
      dentures, edentulous patients often wish prosthesis without a palatal coverage. Since the&#xD;
      palate is not covered by the prosthesis, the taste sense will not be affected. Zembic et al.&#xD;
      show a significantly higher patient satisfaction for esthetics (mean difference 8.8 mm ±&#xD;
      24.6) and taste (mean difference 28.4 mm ± 29.9) without palatal coverage. To prevent a&#xD;
      palatal coverage at least four implants in the upper jaw are recommended.&#xD;
&#xD;
      A systematic review concluded that implant loss rates for maxillary overdentures on two&#xD;
      implants were significantly higher than for four implants. The recommendation to place more&#xD;
      than two implants in the edentulous maxilla is also based on the results of a study by&#xD;
      Richter and Knapp. Richter et al. detected very low survival rates for two implants and&#xD;
      various anchoring elements in the edentulous upper jaw after mean observation time of five&#xD;
      years. The 15 patients received diameter-reduced (3.25 mm) implants in the canine area. The&#xD;
      implants were not parallel to each other due to anatomical limitations. The prostheses were&#xD;
      attached either with telescopes or locator attachments. The implant survival rate was 39% for&#xD;
      telescope attachments and 14% for locator attachments. The study resulted in high amount of&#xD;
      implant fractures. In contrast, a recent study of Zembic et al. concluded an implant survival&#xD;
      rate of 97.3% (1 year), for maxillary overdentures supported by 2 titanium-zirconium&#xD;
      implants.&#xD;
&#xD;
      However, the systematic review and meta-Analysis from Di Francesco et al. also verifies the&#xD;
      lack of evidence concerning the number of implants in the edentulous maxilla and the&#xD;
      relationship between overdenture survival and the patient's quality of life.&#xD;
&#xD;
      In the planned observation study, the investigators also used diameter-reduced (3.3 mm)&#xD;
      implants. Similarly in the study before the investigators selected a titanium-zirconium&#xD;
      (TiZr) implant called Roxolid® (Straumann) to prevent high rate of implant fracture.&#xD;
      According to several previous studies the TiZr small-diameter bone level implants provide at&#xD;
      least the same outcomes after 12 month as titanium Grade IV bone level implants. The implant&#xD;
      survival and success rates were 100% for TiZr implants.These promising results were first&#xD;
      indications for an improved mechanical property of TiZr implants which may extend implant&#xD;
      therapy to more challenging clinical situations, as discussed before for edentulous maxilla.&#xD;
&#xD;
      In addition, the investigators use a new anchoring system called CM LOC® and CM LOC Flex® to&#xD;
      compensate different implant angulation. CM LOC Flex® anchor system offers the special&#xD;
      advantage of a broad range of clinical applications due to its unique compensation function.&#xD;
      The abutment can be angled up to 60°, which significantly reduce the wear between female part&#xD;
      and titanium patrix. There is already an in vitro study by Passia et al., demonstrating&#xD;
      positive long-term retention behaviour for CM LOC® in comparison to Locator anchor.&#xD;
&#xD;
      In the actual study the investigators included ten maxillary and mandible edentulous patients&#xD;
      (58-79 years old) being dissatisfied with their complete dentures. In total, 40&#xD;
      diameter-reduced titanium-zirconium implants were placed in the canine region of the upper&#xD;
      and lower jaw. Following 3 to 5 months of healing, implant-supported overdentures were&#xD;
      inserted on two CM LOC® and CM LOC Flex® attachments depending on the indication. Implants&#xD;
      and overdentures were evaluated at 4 weeks (baseline) and 6, 12, 24, 36 months after&#xD;
      insertion of overdentures. Standardized radiographs were taken at implant loading and 12, 36&#xD;
      month after loading. Implant survival rates and bone loss were the primary outcomes.&#xD;
&#xD;
      The oral health related quality of life was assessed before and after treatment by means of&#xD;
      the questionnaires OHIP G14. Further, each patient completed an additional questionnaire to&#xD;
      evaluate chewing satisfaction for soft and hard foods. Questions were answered on a 100-mm&#xD;
      visual analogue scale (VAS). Additionally, the masticatory performance was assessed with a&#xD;
      standardized chewing test. The participants were instructed to chew standardised gums with&#xD;
      three degrees of hardness for 30 seconds, each on the right and left side as well as on both&#xD;
      sides. The chewed particles were then spread to a standardized detection sheet. Each sheet is&#xD;
      placed in a tripod, and photos were made. Chewing efficacy was obtained before treatment, at&#xD;
      baseline, 6, 12, 24, 36 month after implant loading.&#xD;
&#xD;
      Descriptive statistics were applied by calculating means, medians, standard deviations, and&#xD;
      interquartile ranges of bone loss and of the questionnaires. Bone loss and the questionnares&#xD;
      were statistically assessed using the Wilcoxon signed rank test. The level of significance&#xD;
      was set at 5%.&#xD;
&#xD;
      The evaluation of the standardized masticatory function test was performed automatically&#xD;
      through the use of a light sensor that measures the size and amounts of chewed particles.&#xD;
    </textblock>
  </detailed_description>
  <overall_status>Unknown status</overall_status>
  <last_known_status>Active, not recruiting</last_known_status>
  <start_date type="Actual">June 1, 2013</start_date>
  <completion_date type="Anticipated">December 30, 2022</completion_date>
  <primary_completion_date type="Actual">April 1, 2016</primary_completion_date>
  <phase>N/A</phase>
  <study_type>Interventional</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <allocation>N/A</allocation>
    <intervention_model>Single Group Assignment</intervention_model>
    <primary_purpose>Treatment</primary_purpose>
    <masking>None (Open Label)</masking>
  </study_design_info>
  <primary_outcome>
    <measure>Investigation of the success rates of the implants</measure>
    <time_frame>5 Years</time_frame>
    <description>Implant fracture, implant loss</description>
  </primary_outcome>
  <primary_outcome>
    <measure>Marginal bone loss</measure>
    <time_frame>5 years</time_frame>
    <description>Measurement of marginal bone loss on standardized radiographs [mm]</description>
  </primary_outcome>
  <secondary_outcome>
    <measure>Probing depth</measure>
    <time_frame>5 Years</time_frame>
    <description>Measurement of probing depth [mm]</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Gingival status</measure>
    <time_frame>5 Years</time_frame>
    <description>Assessment of gingival index</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Oral hygiene</measure>
    <time_frame>5 Years</time_frame>
    <description>Assessment of plaque index</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Oral Health Quality of Life</measure>
    <time_frame>5 years</time_frame>
    <description>Oral Health Impact Profile - G14 (OHIP-G14, short version of the OHIP with 14 questions, according to Slade). Responses are made on a scale of never (0), hardly (1), occasionally (2), fairly often (3) and very often (4), resulting in possible values from 0 to 56 points in total.</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Chewing satisfaction</measure>
    <time_frame>5 years</time_frame>
    <description>Assessment of the chewing satisfaction using a Visual Analogue Scale (VAS). The beginning of the scale is defined as &quot;completely dissatisfied&quot; and the end of the line as &quot;completely satisfied&quot;.</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Masticatory performance</measure>
    <time_frame>5 years</time_frame>
    <description>Assessment of the masticatory performance with a standardized chewing test. The participants are instructed to chew standardised gums with three degrees of hardness for 30 seconds each on the right and left sides as well as on both sides. The chewed particles were then spread to a standardized detection sheet. Each sheet is placed in a standardized stand support and are photographed.</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Survival rate of prosthetic restoration</measure>
    <time_frame>5 years</time_frame>
    <description>The prosthesis is examined for cracks, fractures, discolorations or other defects. Pass accuracy is examined. Visual and tactile control of the CM LOC® abutments and of the matrices (with retention inserts) are done.</description>
  </secondary_outcome>
  <number_of_arms>1</number_of_arms>
  <enrollment type="Actual">10</enrollment>
  <condition>Alveolar Bone Loss</condition>
  <condition>Bone Resorption</condition>
  <condition>Dental Implants</condition>
  <condition>Edentulous Maxilla</condition>
  <condition>Edentulous Patient</condition>
  <arm_group>
    <arm_group_label>Two dental implants in the edentulous maxilla and mandible</arm_group_label>
    <arm_group_type>Experimental</arm_group_type>
    <description>Edentulous maxilla und mandible are treated with two diameter-reduced tissue level implants (Straumann, Basel) and anchored with CM LOC® and CM LOC Flex® attachments (Cendres+Métaux SA, Bienne).</description>
  </arm_group>
  <intervention>
    <intervention_type>Device</intervention_type>
    <intervention_name>dental implants and stud attachments</intervention_name>
    <arm_group_label>Two dental implants in the edentulous maxilla and mandible</arm_group_label>
    <other_name>CM LOC® and CM LOC Flex® (Cendres+Métaux SA, Bienne)</other_name>
    <other_name>(sandblasted/acid-etched) SLActive® Roxolid® implants, Ø 3.3 mm (Straumann, Switzerland)</other_name>
  </intervention>
  <eligibility>
    <criteria>
      <textblock>
        Inclusion Criteria:&#xD;
&#xD;
          -  Female and male subjects older than 18 years.&#xD;
&#xD;
          -  Edentulous patients with a bone atrophy, which necessitates the use of&#xD;
             diameter-reduced implants and excessive augmentation procedures are denied by the&#xD;
             patient.&#xD;
&#xD;
          -  Sufficient bone supply with minimal risk of injury to neighboring structures when&#xD;
             using two 10 mm or longer implants per jaw.&#xD;
&#xD;
          -  Bone height above the N. alveolaris inferior of at least 11 mm and the precondition of&#xD;
             a one-stage implantation and augmentation.&#xD;
&#xD;
          -  Good health condition according to the Physical Status Classification System one or&#xD;
             two (American Society of Anesthesiologists, ASA 2010)&#xD;
&#xD;
          -  Good oral hygiene and an at most moderate tobacco consumption&#xD;
&#xD;
          -  Signed informed consent&#xD;
&#xD;
        Exclusion Criteria:&#xD;
&#xD;
          -  Indication for large augmentations of the jaw bone&#xD;
&#xD;
          -  Allergy to metallic implant components or prosthesis plastics&#xD;
&#xD;
          -  Bisphosphonate therapy&#xD;
&#xD;
          -  Chemo-, immuno-, or radiation therapy&#xD;
&#xD;
          -  Psychological disorder&#xD;
&#xD;
          -  Substance abuse&#xD;
&#xD;
          -  Pregnant woman&#xD;
&#xD;
          -  Persons who are placed in an institution on a judicial or administrative order&#xD;
&#xD;
          -  Any other circumstances that prevent the use of oral surgery&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>18 Years</minimum_age>
    <maximum_age>N/A</maximum_age>
    <healthy_volunteers>Accepts Healthy Volunteers</healthy_volunteers>
  </eligibility>
  <reference>
    <citation>Murphy WM. The effect of complete dentures upon taste perception. Br Dent J. 1971 Mar 2;130(5):201-5. doi: 10.1038/sj.bdj.4802647. No abstract available.</citation>
    <PMID>5278921</PMID>
  </reference>
  <reference>
    <citation>Zembic A, Wismeijer D. Patient-reported outcomes of maxillary implant-supported overdentures compared with conventional dentures. Clin Oral Implants Res. 2014 Apr;25(4):441-50. doi: 10.1111/clr.12169. Epub 2013 Apr 15.</citation>
    <PMID>23581398</PMID>
  </reference>
  <reference>
    <citation>Roccuzzo M, Bonino F, Gaudioso L, Zwahlen M, Meijer HJ. What is the optimal number of implants for removable reconstructions? A systematic review on implant-supported overdentures. Clin Oral Implants Res. 2012 Oct;23 Suppl 6:229-37. doi: 10.1111/j.1600-0501.2012.02544.x.</citation>
    <PMID>23062145</PMID>
  </reference>
  <reference>
    <citation>Kern JS, Kern T, Wolfart S, Heussen N. A systematic review and meta-analysis of removable and fixed implant-supported prostheses in edentulous jaws: post-loading implant loss. Clin Oral Implants Res. 2016 Feb;27(2):174-95. doi: 10.1111/clr.12531. Epub 2015 Feb 9.</citation>
    <PMID>25664612</PMID>
  </reference>
  <reference>
    <citation>Richter E, Knapp WJI. Auf zwei Eckzahnimplantaten abgestützte Oberkiefer-Coverdentureprothesen-Ergebnisse einer klinischen Studie. 2010;18:165-174.</citation>
  </reference>
  <reference>
    <citation>Zembic A, Tahmaseb A, Jung RE, Wismeijer D. One-year results of maxillary overdentures supported by 2 titanium-zirconium implants - implant survival rates and radiographic outcomes. Clin Oral Implants Res. 2017 Jul;28(7):e60-e67. doi: 10.1111/clr.12863. Epub 2016 May 6.</citation>
    <PMID>27150942</PMID>
  </reference>
  <reference>
    <citation>Al-Nawas B, Bragger U, Meijer HJ, Naert I, Persson R, Perucchi A, Quirynen M, Raghoebar GM, Reichert TE, Romeo E, Santing HJ, Schimmel M, Storelli S, ten Bruggenkate C, Vandekerckhove B, Wagner W, Wismeijer D, Muller F. A double-blind randomized controlled trial (RCT) of Titanium-13Zirconium versus Titanium Grade IV small-diameter bone level implants in edentulous mandibles--results from a 1-year observation period. Clin Implant Dent Relat Res. 2012 Dec;14(6):896-904. doi: 10.1111/j.1708-8208.2010.00324.x. Epub 2011 Mar 17.</citation>
    <PMID>21414131</PMID>
  </reference>
  <reference>
    <citation>Chiapasco M, Casentini P, Zaniboni M, Corsi E, Anello T. Titanium-zirconium alloy narrow-diameter implants (Straumann Roxolid((R))) for the rehabilitation of horizontally deficient edentulous ridges: prospective study on 18 consecutive patients. Clin Oral Implants Res. 2012 Oct;23(10):1136-41. doi: 10.1111/j.1600-0501.2011.02296.x. Epub 2011 Aug 18.</citation>
    <PMID>22092806</PMID>
  </reference>
  <reference>
    <citation>Passia N, Ghazal M, Kern M. Long-term retention behaviour of resin matrix attachment systems for overdentures. J Mech Behav Biomed Mater. 2016 Apr;57:88-94. doi: 10.1016/j.jmbbm.2015.11.038. Epub 2015 Dec 7.</citation>
    <PMID>26705935</PMID>
  </reference>
  <reference>
    <citation>Di Francesco F, De Marco G, Gironi Carnevale UA, Lanza M, Lanza A. The number of implants required to support a maxillary overdenture: a systematic review and meta-analysis. J Prosthodont Res. 2019 Jan;63(1):15-24. doi: 10.1016/j.jpor.2018.08.006. Epub 2018 Sep 28.</citation>
    <PMID>30269880</PMID>
  </reference>
  <reference>
    <citation>Jordan RA, Bodechtel C, Hertrampf K, Hoffmann T, Kocher T, Nitschke I, Schiffner U, Stark H, Zimmer S, Micheelis W; DMS V Surveillance Investigators' Group. The Fifth German Oral Health Study (Funfte Deutsche Mundgesundheitsstudie, DMS V) - rationale, design, and methods. BMC Oral Health. 2014 Dec 29;14:161. doi: 10.1186/1472-6831-14-161.</citation>
    <PMID>25547464</PMID>
  </reference>
  <verification_date>March 2020</verification_date>
  <study_first_submitted>December 6, 2018</study_first_submitted>
  <study_first_submitted_qc>December 13, 2018</study_first_submitted_qc>
  <study_first_posted type="Actual">December 17, 2018</study_first_posted>
  <last_update_submitted>March 10, 2020</last_update_submitted>
  <last_update_submitted_qc>March 10, 2020</last_update_submitted_qc>
  <last_update_posted type="Actual">March 12, 2020</last_update_posted>
  <responsible_party>
    <responsible_party_type>Sponsor</responsible_party_type>
  </responsible_party>
  <keyword>Oral Health Impact Factor</keyword>
  <keyword>Survival rate</keyword>
  <keyword>Maxillary overdenture</keyword>
  <keyword>Implant-Supported</keyword>
  <keyword>Bone Resorption</keyword>
  <keyword>Titanium-Zirconium</keyword>
  <keyword>Anchor System</keyword>
  <condition_browse>
    <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
    <mesh_term>Bone Resorption</mesh_term>
    <mesh_term>Alveolar Bone Loss</mesh_term>
    <mesh_term>Mouth, Edentulous</mesh_term>
  </condition_browse>
  <patient_data>
    <sharing_ipd>No</sharing_ipd>
  </patient_data>
  <!-- Results have not yet been posted for this study                                          -->
</clinical_study>


download date: ClinicalTrials.gov processed this data on September 20, 2023
link text: Link to the current ClinicalTrials.gov record.
url: https://clinicaltrials.gov/ct2/show/NCT03777748
org study id: UKA 373147
nct id: NCT03777748
lead sponsor: 
collaborator: 
has dmc: No
is fda regulated drug: No
is fda regulated device: No
The aim of this pilot study was to assess survival rates and peri-implant bone loss of two
      narrow-diameter titanium-zirconium implants supporting maxillary and mandibular overdentures
      during an observation time of 3 years. The masticatory performance, self-reported chewing
      ability and change of oral health impact profile (OHIP) after rehabilitation were also
      investigated.
According to the recent German Oral Health Study (DMS V), toothlessness is still frequently
      represented in the German population. Thus in the group of 65 to 74 years old 12.4% were
      edentulous. Whereas in the group of 75 to 100 years old 32.8% were toothless. Toothlessness
      occurred more frequently in the upper jaw (19,8%) than in the lower jaw (13,7%).

      Although maxillary complete dentures show less retention problems than mandibular complete
      dentures, edentulous patients often wish prosthesis without a palatal coverage. Since the
      palate is not covered by the prosthesis, the taste sense will not be affected. Zembic et al.
      show a significantly higher patient satisfaction for esthetics (mean difference 8.8 mm ±
      24.6) and taste (mean difference 28.4 mm ± 29.9) without palatal coverage. To prevent a
      palatal coverage at least four implants in the upper jaw are recommended.

      A systematic review concluded that implant loss rates for maxillary overdentures on two
      implants were significantly higher than for four implants. The recommendation to place more
      than two implants in the edentulous maxilla is also based on the results of a study by
      Richter and Knapp. Richter et al. detected very low survival rates for two implants and
      various anchoring elements in the edentulous upper jaw after mean observation time of five
      years. The 15 patients received diameter-reduced (3.25 mm) implants in the canine area. The
      implants were not parallel to each other due to anatomical limitations. The prostheses were
      attached either with telescopes or locator attachments. The implant survival rate was 39% for
      telescope attachments and 14% for locator attachments. The study resulted in high amount of
      implant fractures. In contrast, a recent study of Zembic et al. concluded an implant survival
      rate of 97.3% (1 year), for maxillary overdentures supported by 2 titanium-zirconium
      implants.

      However, the systematic review and meta-Analysis from Di Francesco et al. also verifies the
      lack of evidence concerning the number of implants in the edentulous maxilla and the
      relationship between overdenture survival and the patient's quality of life.

      In the planned observation study, the investigators also used diameter-reduced (3.3 mm)
      implants. Similarly in the study before the investigators selected a titanium-zirconium
      (TiZr) implant called Roxolid® (Straumann) to prevent high rate of implant fracture.
      According to several previous studies the TiZr small-diameter bone level implants provide at
      least the same outcomes after 12 month as titanium Grade IV bone level implants. The implant
      survival and success rates were 100% for TiZr implants.These promising results were first
      indications for an improved mechanical property of TiZr implants which may extend implant
      therapy to more challenging clinical situations, as discussed before for edentulous maxilla.

      In addition, the investigators use a new anchoring system called CM LOC® and CM LOC Flex® to
      compensate different implant angulation. CM LOC Flex® anchor system offers the special
      advantage of a broad range of clinical applications due to its unique compensation function.
      The abutment can be angled up to 60°, which significantly reduce the wear between female part
      and titanium patrix. There is already an in vitro study by Passia et al., demonstrating
      positive long-term retention behaviour for CM LOC® in comparison to Locator anchor.

      In the actual study the investigators included ten maxillary and mandible edentulous patients
      (58-79 years old) being dissatisfied with their complete dentures. In total, 40
      diameter-reduced titanium-zirconium implants were placed in the canine region of the upper
      and lower jaw. Following 3 to 5 months of healing, implant-supported overdentures were
      inserted on two CM LOC® and CM LOC Flex® attachments depending on the indication. Implants
      and overdentures were evaluated at 4 weeks (baseline) and 6, 12, 24, 36 months after
      insertion of overdentures. Standardized radiographs were taken at implant loading and 12, 36
      month after loading. Implant survival rates and bone loss were the primary outcomes.

      The oral health related quality of life was assessed before and after treatment by means of
      the questionnaires OHIP G14. Further, each patient completed an additional questionnaire to
      evaluate chewing satisfaction for soft and hard foods. Questions were answered on a 100-mm
      visual analogue scale (VAS). Additionally, the masticatory performance was assessed with a
      standardized chewing test. The participants were instructed to chew standardised gums with
      three degrees of hardness for 30 seconds, each on the right and left side as well as on both
      sides. The chewed particles were then spread to a standardized detection sheet. Each sheet is
      placed in a tripod, and photos were made. Chewing efficacy was obtained before treatment, at
      baseline, 6, 12, 24, 36 month after implant loading.

      Descriptive statistics were applied by calculating means, medians, standard deviations, and
      interquartile ranges of bone loss and of the questionnaires. Bone loss and the questionnares
      were statistically assessed using the Wilcoxon signed rank test. The level of significance
      was set at 5%.

      The evaluation of the standardized masticatory function test was performed automatically
      through the use of a light sensor that measures the size and amounts of chewed particles.
allocation: N/A
intervention model: Single Group Assignment
primary purpose: Treatment
masking: None (Open Label)
measure: Investigation of the success rates of the implants
time frame: 5 Years
description: Implant fracture, implant loss
measure: Marginal bone loss
time frame: 5 years
description: Measurement of marginal bone loss on standardized radiographs [mm]
measure: Probing depth
time frame: 5 Years
description: Measurement of probing depth [mm]
measure: Gingival status
time frame: 5 Years
description: Assessment of gingival index
measure: Oral hygiene
time frame: 5 Years
description: Assessment of plaque index
measure: Oral Health Quality of Life
time frame: 5 years
description: Oral Health Impact Profile - G14 (OHIP-G14, short version of the OHIP with 14 questions, according to Slade). Responses are made on a scale of never (0), hardly (1), occasionally (2), fairly often (3) and very often (4), resulting in possible values from 0 to 56 points in total.
measure: Chewing satisfaction
time frame: 5 years
description: Assessment of the chewing satisfaction using a Visual Analogue Scale (VAS). The beginning of the scale is defined as "completely dissatisfied" and the end of the line as "completely satisfied".
measure: Masticatory performance
time frame: 5 years
description: Assessment of the masticatory performance with a standardized chewing test. The participants are instructed to chew standardised gums with three degrees of hardness for 30 seconds each on the right and left sides as well as on both sides. The chewed particles were then spread to a standardized detection sheet. Each sheet is placed in a standardized stand support and are photographed.
measure: Survival rate of prosthetic restoration
time frame: 5 years
description: The prosthesis is examined for cracks, fractures, discolorations or other defects. Pass accuracy is examined. Visual and tactile control of the CM LOC® abutments and of the matrices (with retention inserts) are done.
arm group label: Two dental implants in the edentulous maxilla and mandible
arm group type: Experimental
description: Edentulous maxilla und mandible are treated with two diameter-reduced tissue level implants (Straumann, Basel) and anchored with CM LOC® and CM LOC Flex® attachments (Cendres+Métaux SA, Bienne).
intervention type: Device
intervention name: dental implants and stud attachments
arm group label: Two dental implants in the edentulous maxilla and mandible
other name: CM LOC® and CM LOC Flex® (Cendres+Métaux SA, Bienne)
other name: (sandblasted/acid-etched) SLActive® Roxolid® implants, Ø 3.3 mm (Straumann, Switzerland)
criteria: 
gender: All
minimum age: 18 Years
maximum age: N/A
healthy volunteers: Accepts Healthy Volunteers
citation: Murphy WM. The effect of complete dentures upon taste perception. Br Dent J. 1971 Mar 2;130(5):201-5. doi: 10.1038/sj.bdj.4802647. No abstract available.
PMID: 5278921
citation: Zembic A, Wismeijer D. Patient-reported outcomes of maxillary implant-supported overdentures compared with conventional dentures. Clin Oral Implants Res. 2014 Apr;25(4):441-50. doi: 10.1111/clr.12169. Epub 2013 Apr 15.
PMID: 23581398
citation: Roccuzzo M, Bonino F, Gaudioso L, Zwahlen M, Meijer HJ. What is the optimal number of implants for removable reconstructions? A systematic review on implant-supported overdentures. Clin Oral Implants Res. 2012 Oct;23 Suppl 6:229-37. doi: 10.1111/j.1600-0501.2012.02544.x.
PMID: 23062145
citation: Kern JS, Kern T, Wolfart S, Heussen N. A systematic review and meta-analysis of removable and fixed implant-supported prostheses in edentulous jaws: post-loading implant loss. Clin Oral Implants Res. 2016 Feb;27(2):174-95. doi: 10.1111/clr.12531. Epub 2015 Feb 9.
PMID: 25664612
citation: Richter E, Knapp WJI. Auf zwei Eckzahnimplantaten abgestützte Oberkiefer-Coverdentureprothesen-Ergebnisse einer klinischen Studie. 2010;18:165-174.
citation: Zembic A, Tahmaseb A, Jung RE, Wismeijer D. One-year results of maxillary overdentures supported by 2 titanium-zirconium implants - implant survival rates and radiographic outcomes. Clin Oral Implants Res. 2017 Jul;28(7):e60-e67. doi: 10.1111/clr.12863. Epub 2016 May 6.
PMID: 27150942
citation: Al-Nawas B, Bragger U, Meijer HJ, Naert I, Persson R, Perucchi A, Quirynen M, Raghoebar GM, Reichert TE, Romeo E, Santing HJ, Schimmel M, Storelli S, ten Bruggenkate C, Vandekerckhove B, Wagner W, Wismeijer D, Muller F. A double-blind randomized controlled trial (RCT) of Titanium-13Zirconium versus Titanium Grade IV small-diameter bone level implants in edentulous mandibles--results from a 1-year observation period. Clin Implant Dent Relat Res. 2012 Dec;14(6):896-904. doi: 10.1111/j.1708-8208.2010.00324.x. Epub 2011 Mar 17.
PMID: 21414131
citation: Chiapasco M, Casentini P, Zaniboni M, Corsi E, Anello T. Titanium-zirconium alloy narrow-diameter implants (Straumann Roxolid((R))) for the rehabilitation of horizontally deficient edentulous ridges: prospective study on 18 consecutive patients. Clin Oral Implants Res. 2012 Oct;23(10):1136-41. doi: 10.1111/j.1600-0501.2011.02296.x. Epub 2011 Aug 18.
PMID: 22092806
citation: Passia N, Ghazal M, Kern M. Long-term retention behaviour of resin matrix attachment systems for overdentures. J Mech Behav Biomed Mater. 2016 Apr;57:88-94. doi: 10.1016/j.jmbbm.2015.11.038. Epub 2015 Dec 7.
PMID: 26705935
citation: Di Francesco F, De Marco G, Gironi Carnevale UA, Lanza M, Lanza A. The number of implants required to support a maxillary overdenture: a systematic review and meta-analysis. J Prosthodont Res. 2019 Jan;63(1):15-24. doi: 10.1016/j.jpor.2018.08.006. Epub 2018 Sep 28.
PMID: 30269880
citation: Jordan RA, Bodechtel C, Hertrampf K, Hoffmann T, Kocher T, Nitschke I, Schiffner U, Stark H, Zimmer S, Micheelis W; DMS V Surveillance Investigators' Group. The Fifth German Oral Health Study (Funfte Deutsche Mundgesundheitsstudie, DMS V) - rationale, design, and methods. BMC Oral Health. 2014 Dec 29;14:161. doi: 10.1186/1472-6831-14-161.
PMID: 25547464
responsible party type: Sponsor
mesh term: Bone Resorption
mesh term: Alveolar Bone Loss
mesh term: Mouth, Edentulous
sharing ipd: No